Handbook of Pediatric Neurosurgery

related to systemic injury (such as hypovolemia,
dehydration, and renal dysfunction), which may
compound the situation.
Serum Na fluid balance should be monitored
judiciously in these patients, and attention must
be paid to hydration status and central venous
pressure. Hyponatremia must be avoided. Al-
though there is little evidence to support this, we
prefer to maintain serum sodium in the higher
range of normal if ICP is a problem.
1.4.2 Medical Therapies
Osmotherapy
Intravenous hyperosm olar agents to reduce ICP
have been in use for quite som e tim e. The
agents m ost comm only used are m annitol and
hypertonic saline (HTS). Mannitol works by two
m echanism s: it decreases the viscosity of blood,
inducing a reflex arteriolar vasoconstriction,
w hich results in decreased cerebral blood vol-
um e and ICP, while an osm otic m echanism
draws fluid from the interstitial space into the
cerebral vasculature. Mannitol requires an intact
blood–brain barrier to function adequately. HTS
exerts an e ect on ICP and improves CPP
through a number of m echanism s, including
improved blood rheology, creating an osm otic
gradient, stimulating vascular release of natriu-
retic peptide, improving cardiac output, and
reducing inflamm ation. Overzealous use of HTS
or mannitol is not without its adverse e ects,
and this should be borne in m ind whenever
using either of these two agents. Although level
II and III evidence exists for the use of HTS
in pediatric TBI with intracranial hypertension,
the recently published pediatric guidelines for
m anagem ent of severe TBI failed to find any
studies supporting the use of m annitol in this
setting.9,16,17 Recent trends have favored HTS
above m annitol.
Sedation and Muscle Paralysis
Little evidence exists for the use of muscle paraly-
sis in the treatment of intracranial hypertension.
Previous research has shown a benefit from the
use of thiopental and etomidate in treating raised
ICP, although the risks inherent in the use of these
medications should be considered. Both thiopen-
tone and etomidate have been shown to reduce
ICP, although correlation with outcome remains
unclear.18,19 Thiopentone is generally used as a
second tier therapy, along with craniectomy or
hypothermia, to control refractory increased ICP.
Table 1.3 Checklist of causes of raised ICP and suggested action
Potential cause of
raised ICP
Action
Cerebral venous
congestion
Head of bed up at 30 degrees
Head position neutral
Cervical collar and head and neck strapping loosened
Adequate patient sedation and analgesia
Ensure ventilatory pressures not raised
Sedate for procedures/maneuvers associated with increases in ICP (suctioning,
patient manipulation)
Hypercarbia and hypoxia

Ventilate to Pco2 of 30 to 37.5 mm Hg. If possible, titrate against some measure
of brain oxygenation change
Prevent systemic hypoxia. Keep Pao2 preferably above 80 to 100 mm Hg
Hyponatremia

Maintain serum Na+ 140 to 150 mmol/L
Cerebral swelling and edema

Osmotherapy with hypertonic saline (monitor serum Na+) or mannitol
Seizure

Continuous EEG monitoring
Administer antiepileptic medication if unable to monitor for seizures or if
clinical suspicion of seizure
Pyrexia

Keep normothermic using antipyretics and active cooling
Expanding intracranial hematoma/
hydrocephalus
Urgent CT scan and surgery as indicated
Abbreviations: CT, computed tomography; EEG, electroencephalogram; ICP, intracranial pressure.
Note: Prior to initiating any intervention to decrease ICP, confirm that the ICP monitoring device is calibrated and
functioning correctly.
General and Critical Care
8

Antiepileptic Medication
Subclinical seizures may occur in over 50% of crit-
ically ill children and are known to lead to
increased ICP and potential secondary injury.20,21,22
Where resources for continuous electroencephalo-
gram (cEEG) monitoring are not available in the
critical care setting, it may be reasonable to treat
children with antiepileptic medication empirically.
Hypothermia
Although previous studies had shown promise for
moderate hypothermia as a neuroprotective inter-
vention, enthusiasm for this modality has waned
in recent years in light of new research showing
no significant impact on outcome.23 At our center,
hypothermia is not part of the management proto-
col for severe TBI in children.
Corticosteroids
Previous studies have failed to show any benefit of
steroids in TBI, with the largest trial to date finding
an increased risk of mortality in the treatment
group.24 The study did, however, have very broad
selection criteria across a wide range of severity
and heterogeneity in pathology. It is possible that
there are some subgroups of TBI patients that may
benefit from corticosteroid therapy.
Barbiturate-induced Coma
Barbiturate-induced coma using thiopentone or
pentobarbital is sometimes used as a treatment of
intracranial hypertension refractory to both medical
and surgical treatments. This modality is limited by
its negative cardiorespiratory e ects, which necessi-
tate close cardiovascular monitoring and support.
No correlation with outcome has been proven.9
1.4.3 Surgical Options
Mass Lesion Evacuation
Surgical removal of any significant space-occupy-
ing lesion such as traumatic extradural, subdural,
and intracerebral hematoma is the first-line surgi-
cal treatment of raised ICP. Quite often, ICP and
other neurophysiological monitors are placed at
this time.
CSF Drainage
CSF drainage via EVD is a relatively simple strategy
in trauma to reduce ICP. As previously mentioned,
this intervention also allows for monitoring of ICP
via EVD transduction. However, EVD placement in
this setting is often di cult because of cerebral
swelling and small ventricular size, often requiring
image-guidance and potentially increasing risks
related to drain malposition and multiple attempts
at placement. The collapse of ventricles with CSF
drainage also limits this intervention. The clinician
should keep in mind the risks of increased hema-
toma on insertion, CSF infection, and failure to dia-
gnose ICP spikes when the EVD is on drainage as
opposed to monitoring.
1.4.4 Decompressive Craniectomy
DC for the treatment of raised ICP continues to
divide opinion on the management of raised ICP in
severe TBI. Although there is a clear potential ben-
efit in reducing ICP via craniectomy in cases where
both simple and medical measures have been
exhausted, evidence for overall benefit is conflict-
ing. This procedure carries a significant risk of
neurological morbidity, and commits the patient
to having a second operation at some point to
undergo a cranioplasty. Various surgical options
have been described, the most common being
bifrontal and a large hemicraniectomy on the side
of the more injured hemisphere. The bone is
placed either in a bone fridge (preferably minus
70 °C) or in an abdominal pocket.
The only randomized trial of DC on outcome in
children was a small pilot study by Taylor et al
in 2001.25 They found a significant improvement
in outcome in patients managed with DC and con-
ventional medical management as opposed to
standard medical management alone; however,
the procedure was atypical in comparison to
more widespread use—a bilateral small temporal
decompression without dural opening—and the
ICP reduction was modest.
The DECRA trial, a randomized multicenter trial
assessing the impact of early DC in severe TBI in
adult patients, showed a decrease in ICP with DC
but significantly worse outcome.26 The study was,
however, criticized for having a very low threshold
for instituting this surgical option (medically refrac-
tory ICP of more than 20 mm Hg for 15 minutes in a
1-hour period) and so most patients who had sur-
gery had modestly elevated ICP Also, ICP was
well controlled in the medical arm, the patients of
which still had the option of DC if ICP was refrac-
tory. The RESCUEicp trial showed reduced mortality
but increased disability, so the decision comes
down to what disability is acceptable.27 If a DC is to
ICP Management
9

be performed, it should be done in a controlled
manner; loss of control of brain swelling after
the dura is opened can lead to disastrous acute
herniation through the defect. Brain swelling must
be maximally controlled, even if temporarily, before
the dura is opened, by using a combination of eleva-
tion of the head, good anesthesia, mannitol/
HTS, avoidance of hypertension, and temporary
hyperventilation. Thereafter, the dura should be
grafted with pericranium or a dural substitute. The
bone removal should be as large as possible to max-
imize ICP reduction and minimize fungation of
brain across a narrow defect and consequent com-
pression of cortical veins. Postoperative hyperten-
sion should be avoided as this may increase edema
in the decompressed hemisphere. It is our practice
to replace the bone flap as soon as brain swelling
has subsided, preferably within 4 to 6 weeks, to
minimize delayed injury to the underlying brain
and hydrocephalus.
1.5 Summary
Management of ICP in the traumatic setting
requires a logical, stepwise approach, employing
simple strategies first and moving on to more
complex medical and surgical treatment modal-
ities as needed. A good understanding of the cause
of the raised ICP as well as the physiological e ects
and potential risks of the treatment modalities
employed leads to safe decision-making and e ec-
tive treatment in these patients.
1.6 Questions
1. Name the main volume-occupying constituents
of the intracranial compartment, and list some
of the pathological processes that may increase
the ICP in the injured brain.
2. Describe nonoperative methods of reducing
pathologically elevated ICP.
3. What are the implications of altered regulatory
mechanisms such as pressure autoregulation
and flow-metabolism coupling?
4. What are the physiological and clinical
consequences of increased ICP?
5. Discuss the surgical options to decrease ICP in
terms of indications and complications.
References
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intensive treatment targeting intracranial hypertension
improves outcome in severe bacterial meningitis: an
intervention-control study. PLoS One. 2014; 9(3):e91976
[2] Shafi S, Diaz-Arrastia R, Madden C, Gentilello L. Intracranial
pressure monitoring in brain-injured patients is associated
with worsening of survival. J Trauma. 2008; 64(2):335–340
[3] Farahvar A, Gerber LM, Chiu YL, Carney N, Härtl R, Ghajar J.
Increased mortality in patients with severe traumatic brain
injury treated without intracranial pressure monitoring. J
Neurosurg. 2012; 117(4):729–734
[4] Chesnut RM, Temkin N, Carney N, et al. Global Neurotrauma
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2481
[5] Chesnut RM. Intracranial pressure monitoring: headstone or
a new head start. The BEST TRIP trial in perspective.
Intensive Care Med. 2013; 39(4):771–774
[6] Figaji AA, Fieggen AG, Argent AC, Leroux PD, Peter JC. Does
adherence to treatment targets in children with severe
traumatic brain injury avoid brain hypoxia? A brain tissue
oxygenation study. Neurosurgery. 2008; 63(1):83–91,
discussion 91–92
[7] Rohlwink UK, Zwane E, Fieggen AG, Argent AC, le Roux PD,
Figaji AA. The relationship between intracranial pressure and
brain oxygenation in children with severe traumatic brain
injury. Neurosurgery. 2012; 70(5):1220–1230, discussion
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[8] Figaji AA, Zwane E, Fieggen AG, et al. Pressure autoregulation,
intracranial pressure, and brain tissue oxygenation in children
with severe traumatic brain injury. J Neurosurg Pediatr. 2009;
4(5):420–428
[9] Kochanek PM, Carney N, Adelson PD, et al. Guidelines for the
acute medical management of severe traumatic brain injury
in infants, children, and adolescents–second edition. Pediatr
Crit Care Med. 2012; 13 Suppl 1:S1–S82
[10] Padayachy LC, Figaji AA, Bullock MR. Intracranial pressure
monitoring for traumatic brain injury in the modern era.
Childs Nerv Syst. 2010; 26(4):441–452
[11] Exo J, Kochanek PM, Adelson PD, et al. Intracranial pressure-
monitoring systems in children with traumatic brain injury:
combining therapeutic and diagnostic tools. Pediatr Crit Care
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[12] Kouvarellis AJ, Rohlwink UK, Sood V, Van Breda D, Gowen MJ,
Figaji AA. The relationship between basal cisterns on CT and
tim e-linked intracranial pressure in paediatric head injury.
Childs Nerv Syst. 2011; 27(7):1139–1144
[13] Smielewski P, Czosnyka M, Steiner L, Belestri M, Piechnik S,
Pickard JD. ICM +: software for on-line analysis of bedside
monitoring data after severe head trauma. Acta Neurochir
Suppl (Wien). 2005; 95:43–49
[14] Lundberg N, Troupp H, Lorin H. Continuous recording of the
ventricular-fluid pressure in patients with severe acute
traumatic brain injury. A preliminary report. J Neurosurg.
1965; 22(6):581–590
[15] Lundberg N. Continuous recording and control of ventricular
fluid pressure in neurosurgical practice. Acta Psychiatr Scand
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[16] Peterson B, Khanna S, Fisher B, Marshall L. Prolonged
hypernatremia controls elevated intracranial pressure in
head-injured pediatric patients. Crit Care Med. 2000; 28(4):
1136–1143
[17] Fisher B, Thomas D, Peterson B. Hypertonic saline lowers
raised intracranial pressure in children after head trauma. J
Neurosurg Anesthesiol. 1992; 4(1):4–10
[18] Bramwell KJ, Haizlip J, Pribble C, VanDerHeyden TC, Witte
M. The e ect of etom idate on intracranial pressure and
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traum atic brain injury. Pediatr Em erg Care. 2006; 22(2):
90–93
General and Critical Care
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[19] de Bray JM, Granry JC, Monrigal JP, Leftheriotis G, Saumet JL.
E ects of thiopental on middle cerebral artery blood
velocities: a transcranial Doppler study in children. Childs
Nerv Syst. 1993; 9(4):220–223
[20] Abend NS, Gutierrez-Colina AM,Topjian AA, et al. Nonconvulsive
seizures are common in critically ill children. Neurology. 2011;
76(12):1071–1077
[21] Vespa PM, Miller C, McArthur D, et al. Nonconvulsive
electrographic seizures after traumatic brain injury result
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[22] Vespa PM, Nuwer MR, Nenov V, et al. Increased incidence and
impact of nonconvulsive and convulsive seizures after traumatic
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[23] Adelson PD, Wisniewski SR, Beca J, et al. Paediatric Traumatic
Brain Injury Consortium. Comparison of hypothermia and
normothermia after severe traumatic brain injury in children
(Cool Kids): a phase 3, randomised controlled trial. Lancet
Neurol. 2013; 12(6):546–553
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[25] Taylor A, Butt W, Rosenfeld J, et al. A randomized trial of very
early decompressive craniectomy in children with traumatic
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[26] Chi JH. Craniectomy for traumatic brain injury: results from
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[27] Hutchinson PJ, Kolias AG, Timofeev IS, et al. RESCUEicp Trial
Collaborators. Trial of decompressive craniectomy for trau-
matic intracranial hypertension. N Engl J Med 2016; 375(12):
1119–1130
ICP Management
11

2 Pain Management for Pediatric
Neurosurgical Patients
Joanne E. Shay
2.1 Introduction
Pain management in pediatric neurosurgical pa-
tients transcends the usual boundaries for pedia-
tric pain management imposed by developmental
pharmacokinetics, pharmacodynamics, and phar-
macogenomics. Because of the additional concern
for assessing neurological function, especially a
potentially deteriorating mental status examina-
tion, caution is the keyword. The goal is to provide
balanced analgesia that facilitates neurological
assessment without clouding neurologic evalua-
tion by providing symptom targeted therapy. There
is also evidence that inadequate analgesia may
impact future pain responses in children with evi-
dence of hyperalgesia and concerns for ine ective
coping behavior.1
Pediatric neurosurgical patients must be consid-
ered among the most vulnerable patient groups
requiring post-operative analgesia owing to their
surgical condition that required treatment and
their comorbidities often including neurologic dys-
function that produced or resulted from that con-
dition, such as spasticity and hypotonia. Pediatric
neurosurgical patients are also at risk for the gen-
eral comorbidities that a ect the population. In
light of these considerations, pediatric neurosurgi-
cal patients must be considered to be at greater
risk of complications from analgesic therapy. This
risk can be reduced by caring for patients in a
monitored setting with caregivers who are experi-
enced in assessing and treating pediatric pain and
the side e ects of that therapy. Once the patient is
transitioned from parenteral to enteral pain medi-
cations and is at baseline neurologic status, the
need for cardiorespiratory monitoring can be re-
evaluated and eliminated as indicated by the over-
all medical condition. A multimodal approach to
pharmacotherapy that includes narcotic and non-
narcotic drugs with a goal of creating synergy is
preferable. This strategy can reduce the side e ects
from larger doses seen with monomodal drug
therapy. Nonpharmacologic interventions such as
massage, guided imagery, hypnosis, relaxation
therapy, and acupressure can be useful as an adju-
vant to medical therapy in some pediatric patients.
The general approach to analgesic therapy is to
employ intravenous (IV) agents while the patient
is unable to tolerate a regular diet and then to
transition to oral analgesics once a regular diet is
tolerated, be that solid food or tube feedings. The
expectation is that after 5 to 7 days the child will
require less frequent dosing of oral narcotics, and
usually within 7 to 10 days postoperatively the
pain will be successfully managed with nonnar-
cotic and nonpharmacologic interventions.
Pediatric practice includes five distinct patient
age demographics, namely neonates (including
premature babies), infants and toddlers, pre-
schoolers, school-aged children, and adolescents.
Although each demographic includes special con-
siderations that can impact analgesic therapy from
the pain assessment perspective, the lion’s share of
pharmacologic maturation takes place in the first
year of life.
2.2 Pediatric Pain Assessment
Pain was defined by the International Association
for the Study of Pain in 1994 as “An unpleasant sen-
sory and emotional experience associated with
actual or potential tissue damage, or described in
terms of such damage.”2 As with any medical inter-
vention, the e cacy of pain management must be
considered and assessed in a systematic construct.
The anatomic structures necessary for the pain
experience, specifically the cortex with thalamic
projections and peripheral nerves with projections
to the spinal cord, are present as early as 26 weeks
of gestation, although in an immature form.3
The routine provokes, quality, radiates, severity,
time (PQRST) rubric used to characterize pain in
adults is sometimes inadequate in children because
of a lack of patient experience with the pain envi-
ronment or an inability to connect nociception with
an experience by the child. Additionally, distress
and situational factors may influence the reported
pain experience. Physiologic markers alone may
also be inadequate to assess the pain experience,
especially in the face of dehydration and fever. For
these reasons, and usually in the first 3 to 4 years
of life, caregiver observational measures for pain
assessment are used in addition to self-reporting.
Assessment of pain in children requires a multimo-
dal approach, utilizing the patient’s narrative,
12

family and caregiver observations, and the historical
experience of the nursing and medical sta .
2.2.1 Observational Pain
Assessment Tools
The FLACC scale, an observational assessment tool
which rates Face, Legs, Activity, Cry, and Consol-
ability on a 0 to 2 (0 = none/normal, 1 =some,
2 =frequent/constant) scale for a maximum score
of 10, is simple to use and reliable and is validated
for use in children ranging from 4 to 18 years of
age for assessing post-operative pain and pain
associated with painful procedures.4 A FLACC score
of 4 or more is indicative of pain. The FLACC rating
scale has also been validated for use in assessing
pain after immunization in 2- through 6-month-
old infants,5 and is commonly used for pain assess-
ment in all children.
2.2.2 Self-reported Pain
Assessment Tools
For children capable of self-reporting their pain
experience, a variety of evaluation tools to assess
the intensity of the pain exist. The Poker Chip Tool
Method can be used in children as young as 3 years
old and involves showing the child four red poker
chips and asking them to show how many pieces
of hurt they have. Although toddlers may not have
counting skills, they are capable of understanding
“more” and “less” and this tool has been validated
for this age group.6 The Wong-Baker Faces scale
has been validated to assess pain in school-
aged children.7 The visual analog scale (VAS) is a
100-mm horizontal line anchored at each end by
nonstandardized verbal descriptor anchors such as
“no pain” and “pain as bad as it could be.” The VAS
can be used for children as young as 5 years old,
and is sensitive to changes in pain associated with
analgesic therapy. The Numerical Rating Scale
(NRS), which is probably the most widely used in
verbal school-aged children, and is simply a query
for a score from 1 to 10, is validated in children
older than 8 years.8
Preverbal, nonverbal, developmentally delayed,
cognitively impaired, and demented patients are
all at risk for inadequate analgesia.9 Facial expres-
sion, while not a reliable pain assessment tool in
verbal patients, is of utility in assessing the pain
experience in nonverbal patients. The Non-
communicating Children’s Pain Checklist–Post-
operative Version (NCPC-PV) is a formal pain
assessment tool that has been used successfully
for nonverbal children in the hospital setting. This
tool allowed adult caregivers who were unfamiliar
with their pediatric patients to accurately assess
signs of postoperative pain.10 The NCPC-CV can be
used to supplement clinical judgment in nonverbal
children with special needs.
2.3 Pediatric Pharmacokinetics
2.3.1 General
The main body components that a ect drug distri-
bution are muscle mass, total body water content,
fat content, and plasma protein content. In the
neonatal period, there are less muscle mass, less
fat content, and greater total body water content
as compared to the adult. The plasma proteins
responsible for drug distribution and elimination
are diminished as well. All of these di erences are
exaggerated in preterm infants. Hepatic phase 1
oxidative reactions carried out by the cytochrome
P450 enzymes reach adult values generally within
the first year of life. Phase 2 conjugation reactions,
such as glucuronidation, generally reach adult lev-
els by 6 to 12 months of age. Renal clearance of
drugs for drugs predominantly cleared in the kid-
ney is decreased in the first month of life, and
reaches adult values after 6 months of age. Lipo-
philic drugs such as diazepam can be expected to
have a smaller volume of distribution, less plasma
protein binding, and lower hepatic clearance in
neonates. Hydrophilic drugs such as morphine will
have a greater volume of distribution; however,
clearance and elimination are decreased. Consider-
ing these di erences and the lack of predictability
during illness, it is imperative that infants and tod-
dlers receiving analgesic therapy are in a moni-
tored setting with caregivers who are skilled at
assessing and treating pain in children. Further-
more, physicians prescribing analgesics for chil-
dren must be aware of the complications and side
e ects of these medications and be prepared to
manage them.
2.4 Impact of Preexisting
Comorbidities on Analgesic
Management
Fortunately, most pediatric patients do not share
the acquired health problems of adults; however,
as more children survive previously life-threaten-
ing conditions, we do see pediatric patients with
chronic health problems from varying stages of
Pain Management for Pediatric Neurosurgical Patients
13

corrected or palliated congenital heart defects,
genetic metabolic errors, and malignancies. In
addition, the neurosurgical patient population has
a higher incidence of preexisting neurologic defi-
cits from congenital defects such as spina bifida
and myopathies. Pediatric patients who have sur-
vived traumatic brain and spinal cord injury (SCI)
also present challenges for analgesic management.
2.4.1 Childhood Obesity
It is estimated that one out of six children and ado-
lescents in the United States are either overweight
or obese.11 Obesity-related comorbidities that are
of particular importance in pain management are
obstructive sleep apnea and obesity hypoven-
tilation syndrome, suspicion of which (unless spe-
cifically ruled out by polysomnogram) requires
cardiorespiratory monitoring in the perioperative
period to guide safe administration of opioid anal-
gesics and other sedating adjuvants. In children,
tonsillectomy and adenoidectomy (T&A) surgery
is assumed to cure most airway obstructive symp-
toms; however, in obese children who have un-
dergone T&A, there may be persistent respiratory
rhythmogenic failure postoperatively.12
Nonalcoholic steatohepatitis is also a feature of
childhood obesity; however, its implication for
pain management other than following weekly
liver function enzyme testing in the face of pro-
longed acetaminophen dosing is unknown.
Therapeutic Modifications
In general, pharmacokinetic considerations for hy-
drophilic drugs such as morphine and hydromor-
phone suggest that bolus dosing be based on lean
body weight instead of total body weight.13 For lip-
ophilic drugs such as fentanyl, initial dosing based
on lean body mass may undertreat pain; however,
subsequent maintenance dosing based on lean body
weight is advisable.13 Strategies for administering
analgesics in children with obstructive sleep apnea
include consideration of nonopioid analgesics (acet-
aminophen, nonsteroidal anti-inflammatory drugs
[NSAIDs]), initiating opioid therapy with lower than
standard dosing and increasing if needed. If using
IV patient-controlled analgesia (PCA), the strategy
includes starting with lower than standard basal
rates and transitioning to oral/enteral medications
as quickly as possible. Wound infiltration with local
anesthetics during wound closure, if possible, is
advisable, as is using preemptive scalp blocks for
intracranial procedures.
2.4.2 Seizures
Pediatric neurosurgical patients have an increased
risk of seizures because of both preoperative
congenital and acquired comorbidities such as
neurofibromatosis, cerebral palsy, and brain
tumors. Drugs used to treat seizures exhibit vary-
ing degrees of protein binding and hepatic enzyme
induction that impact the pharmacokinetics of
analgesic and sedative drugs by causing a relative
resistance to their e ects.14 In addition, antiepilep-
tic drugs exhibit side e ects such as sedation,
hypotension, encephalopathy, and gastrointestinal
(GI) disturbances that may be mistakenly attrib-
uted to analgesics or their withdrawal. These con-
siderations highlight the need for conservative
dosing, careful patient monitoring, and considera-
tion of subjective and objective pain assessment
tools.
2.4.3 Myopathies, Myotonias, and
Spinal Muscular Atrophy
Myopathies present a heterogeneous group of dis-
orders sharing a common trait of mitochondrial
origin and lactic acidosis from an ine cient
metabolism of pyruvate with a resultant shift to
anaerobic metabolism. Children with myopathies
exhibit generalized weakness and are at risk for
respiratory insu ciency.
Myotonic dystrophy is a degenerative disease
of the skeletal muscles linked to the myotonin-
protein kinase gene and a resulting sodium and
chloride channel defect (“channelopathies”) pro-
ducing pathologic muscle membrane depolariza-
tion, which results in muscle wasting.
Spinal muscular atrophy, caused by degenera-
tion of spinal motor neurons, is one of the most
common inherited lethal diseases in childhood,
and results in floppy limbs and swallowing di -
culties.15
Although these disorders have di erent etiolo-
gies and varying severity of presentation, they
share comm on features of progressive functional
deterioration especially with stress. Patients with
these conditions are at increased risk for respira-
tory failure postoperatively, and may require
invasive or noninvasive respiratory support. As in
the other special needs populations, these consid-
erations highlight the need for conservative
dosing, use of nonsedating adjuvants and local
anesthetics, careful patient m onitoring, and im -
plementation of subjective and objective pain
assessm ent tools.
General and Critical Care
14

2.4.4 Chronic Pain and Preexisting
Painful Conditions
Postoperative pain management may be con-
founded by preoperative conditions incidental to
the surgical procedure, such as headaches with
Chiari I malformation and back pain from scoliosis.
Demographic factors such as female gender, adoles-
cence, and surgical approach may predispose
patients to more intense postoperative pain.16
Patients who have been maintained on an analgesic
regimen prior to surgical intervention should be
expected to require supplemental analgesics in
addition to resumption of the preoperative medica-
tions. The extent of supplementation is variable,
and is related to the dosing and schedule of admin-
istration. The additional duration of analgesic ther-
apy in this setting is variable as well, considering
that in many cases the impetus for surgery is the
elimination of chronic pain. This result may take
time to achieve, and may coincide with increased
analgesic requirements to treat acute postoperative
pain. Children who have been receiving opioid anal-
gesics for more than 2 weeks preoperatively may be
at risk for abstinence syndrome and may require
gradual medication tapering before complete dis-
continuation of the opioid. Abstinence syndrome is
manifest by symptoms including irritability, diar-
rhea, fever, tachypnea, anorexia, insomnia, sweating
tremors, hyperreflexia, and emesis. In addition,
children receiving long-term therapy with benzo-
diazepines and α-2 adrenergic agonists may require
dose tapering before discontinuation of these drugs
as well, in consideration of similar physical depend-
ence. Occasionally, patients will have been taking
medications preoperatively that are discontinued
abruptly postoperatively. This may result in rebound
hyperalgesia, and may require reinstating an exist-
ing medication or initiating a new drug class to
optimize analgesia.
2.5 Analgesic Considerations
for Specific Neurosurgical
Procedures
2.5.1 Intracranial Tumors
In the pediatric population, brain tumors are the
most common type of solid tumors and, along
with leukemia, account for more than half of all
new cases of cancer.17 Intracranial tumors in the
pediatric population may be broadly classified as
either supratentorial or infratentorial, based on
the anatomical location, in relation to the tento-
rium cerebelli. The importance of the site of the
craniotomy has been demonstrated in adult stud-
ies, where pain in infratentorial region, for exam-
ple, posterior fossa surgery, is significantly higher
in comparison to frontal craniotomy, i.e., supraten-
torial location.18 This may be explained by the
need for greater muscle and soft-tissue dissection
in infratentorial areas, particularly especially in the
region of the neck.
The perception that craniotomies are “pain-
less” m ay have originated from the fact that the
brain is considered to be insensate. Yet, pain
from other structures cannot be ignored as sig-
nificant sources of postoperative pain. Postcra-
niotomy pain is of somatic origin originating
from the scalp, pericranial m uscles, soft tissue,
and dura mater manipulation.19
Several studies have shown that contrary to his-
torical perception, the adult population does expe-
rience significant pain following craniotomies.20
Adult studies have reported 10 to 15% of patients
experience severe pain in the immediate postope-
rative period, with 15 to 50% of patients reporting
severe chronic postcraniotomy headaches. Postcra-
niotomy headaches may be debilitating and are
often closely correlated to inadequate analgesia in
the acute postcraniotomy period.
The literature is limited on postcraniotomy pain
specifically in the pediatric population. Yet, there
are studies that have demonstrated an inverse
relationship between age and incidence of postcra-
niotomy pain.21
The mainstay of postoperative analgesia after
craniotomy is intraoperative scalp block combined
with NSAIDs and opioids. Preoperative scalp block
using local anesthetic can decrease intraoperative
anesthetic requirements and can influence inten-
sity and duration of postoperative craniotomy
pain.22 The value of a nerve block performed prior
to incision is based on the theory of “preemptive
analgesia,” which blunts intense nociceptor stimu-
lation and thus prevents central sensitization. Cen-
tral sensitization is the process of dynamic range
adjustment by neurons of the central nervous sys-
tem so that subsequent noxious stimuli are experi-
enced with even greater intensity.
A scalp block alone will not provide prolonged
analgesia in a neurosurgical patient who has under-
gone an invasive surgery such as craniotomy.
Opioids are clearly the most e ective analgesic
agent, but are often withheld because of the side
e ects that may impact assessment and manage-
ment perioperatively. Aggressive pain management
Pain Management for Pediatric Neurosurgical Patients
15

may result in an overly sedated patient, which may
mask signs of neurological deterioration.
Additionally, the direct respiratory depressant
e ect of opioids may result in hypoventilation and
hypercarbia, which will directly result in increased
cerebral blood flow and increased intracranial
pressure. On the other hand, pain that is poorly
treated may result in hypertension and increased
intracranial pressure and cause unwanted neuro-
logical e ects. Thus, pain management with
opioids requires a delicate balance, and may be
safely undertaken especially if combined with non-
opioid analgesics in order to reduce the total
amount of opioid given to the patient.
2.5.2 Intracranial Cerebrovascular
Disease
Intracranial cerebrovascular disease, in respect of
the pediatric population, includes arteriovenous
(AV) malformations and moyamoya disease. Moya-
moya is a rare chronic cerebrovascular disease
which presents with variable clinical symptoms
that are progressive in nature. Clinically, the dis-
ease may present with: ischemic stroke, intracra-
nial hemorrhage, seizures, headache, and transient
ischemic attack.
Physiologically, it occurs due to progressive ste-
nosis/occlusion of terminal portions of the internal
carotid arteries and the proximal portion of the
anterior and middle cerebral arteries. The name of
the disease originates from Japan, where moyamoya
means a “pu of smoke,” in reference to the angio-
graphic demonstration of the collaterals that form
due to the stenosis, giving it such an appearance.
The most e ective treatment for this disease is
surgical, and optimal pain management postopera-
tively is a necessity. Pain in these children must be
avoided because of an increase in cerebral metabo-
lism that occurs with pain. Recurrence of symptoms
such as headache and transient ischemic attacks
may be triggered by pain and straining during cry-
ing or coughing. Inadequate analgesia may even
cause postoperative cerebral infarction.23
Despite the sedation and side e ect profile of
opioids, they are considered the mainstay of a pain
regimen to manage analgesia in a child with moya-
moya. E ective analgesia must be achieved while
preventing oversedation,since frequent neurological
checks will be required in a disease that can cause
neurological deterioration unexpectedly and rapidly.
Again, adopting the multimodal analgesic approach
is most beneficial, with the goal of avoiding the side
e ects of larger doses ofeach individual agent.
AV malformations are another cerebrovascular
condition which may be seen in children. These
occur when there is a connection between an intra-
cranial artery and vein, which bypasses the capillary
system. Clinically, these present if the malformation
expands or bleeds, causing seizure, focal neurologi-
cal deficit, or pain.24 AV malformations present
acutely; thus, it is important to once again provide
analgesia while avoiding oversedation as frequent
neurological checks will be necessary. Since extre-
mes of blood pressure may be detrimental, with
hypertension possibly causing bleeding and hypo-
tension preventing adequate brain perfusion, it is
essential to maintain analgesia and sedation, while
also maintaining hemodynamic stability.
2.5.3 Craniofacial Reconstruction/
Calvarial Bone Tumors
Craniofacial reconstruction for craniosynostosis is
a fairly high-risk, invasive surgery. Many children
will receive blood transfusions because of blood
loss which mainly occurs at the scalp and cranium.
Early repair will allow expansion of the intracra-
nial vault and prevent hydrocephalus from a rap-
idly growing brain within a confined space. The
postoperative pain is much less dramatic in com-
parison to the surgical repair that has been
performed. Most of these children will be kept
comfortable with opioids usually in the form of
intermittent IV dosing or PCA pump. In the pedia-
tric population, this pump is controlled either by
parent or nurse, depending on individual institu-
tional guidelines and experience.
Continuous infusion of opioids is sometimes
avoided in order to allow for early clinical recogni-
tion of neurological deficits.
2.5.4 Spinal Cord Disorders
Scoliosis in the pediatric age group is di erenti-
ated by etiology and includes congenital scoliosis,
idiopathic adolescent scoliosis, and neuromuscular
scoliosis. The complexity of the surgery is usually
dictated by the curvature of the spine that is to be
corrected. Because of extensive involvement of
muscles and bones of the spine, as well as place-
ment of hardware such as screws and rods, the
postoperative course may be challenging and often
requires trial and error to find a regimen that
manages pain while also minimizing side e ects.
These patients benefit from a true multimodal
regimen, including opioids, initially in the form of
an IV PCA. Because of extensive muscle resection,
General and Critical Care
16

the patients will be at high risk of muscle spasm;
thus, diazepam or a similar drug given around the
clock can help prevent severe muscle spasm pain.
Usually, because of concerns for bone growth heal-
ing, NSAIDs such as ibuprofen and ketorolac are
avoided. Acetaminophen is also beneficial and may
help decrease the opioid requirement. An e ective
analgesic plan for the postscoliosis repair patient
is essential to aid in physical therapy and mobiliza-
tion. Poor pain control often delays discharge from
the hospital, and as one of the most painful proce-
dures that a child may undergo, progress often
goes hand in hand with su cient analgesia.
2.5.5 Chiari Malformation
Chiari malformations are anatomic abnormalities
of the posterior fossa causing cephalad displace-
ment of the cerebellar vermis through the foramen
magnum. The malformations are categorized by
the severity of the disorder and by the parts of the
brain that protrude into the spinal canal. Symp-
toms vary depending on the type of malformation,
but may include such complaints as neck pain,
imbalance, muscle weakness, and paresthesias.
Treatment of the malformation is often depend-
ent on the symptoms. Extreme cases may require
neurosurgical intervention.25 Chiari type 1 malfor-
mation is of a milder variety; these patients are
often treated conservatively for chronic headache
and neck pain. Pain treatments may include tradi-
tional agents such as opioids, NSAIDs, muscle
relaxants, and antidepressants drugs. Patients may
also benefit from physical therapy.
2.5.6 Traumatic Brain Injury
Patients sustaining traumatic brain injury (TBI)
can present with neurological impairment along a
spectrum of incapacitation ranging from mild
headache and memory loss through coma. In this
setting, loss of cognitive and communicative func-
tion may necessitate implementation of pain
assessment tools used for nonverbal or cognitively
impaired children. Parental input is essential when
trying to assess pain levels and provide analgesic
therapy. A reasonable rule of thumb is to assume
that obvious tissue injury is painful (e.g., long bone
fracture), and will require analgesia. As in other
instances of neurological injury, overmedication
resulting in persistent sedation will prevent
assessment of the neurological examination and
must be avoided. Strategies for pain management
in this setting include lowering doses and using
nonnarcotic adjuvants to synergize the narcotic
e ects. In some situations, it may be possible to
include local anesthetics in the management of
musculoskeletal injuries, in the form of either field
blocks or peripheral nerve blocks.
Days or weeks after severe TBI (Glasgow Coma
Scale [GCS] <8) patients may develop sympathetic
storming, which manifests as episodic agitation,
fever, posturing, and diaphoresis. These episodes
place the patient at risk for secondary brain injury,
hypertension, and arrhythmias. This storming is
often observed concomitantly with weaning of
analgesics and sedatives in the intensive care unit
(ICU) setting. Therapeutic strategies include pro-
longing or foregoing the narcotic weaning process,
transitioning to longer-acting narcotics to avoid
the peak and trough e ect, and initiating adjuvant
therapies, such as clonidine, an α-2 receptor ago-
nist that reduces circulating levels of norepinephr-
ine and epinephrine.
2.5.7 Spinal Cord Injury
SCI patients may initially exhibit loss of sensation
both above and below the level of spinal injury, and
it is common to find that patients who have sus-
tained upper body injuries in addition to the spinal
injury will report these “new” pain symptoms days
after the initial trauma. In this setting, new pain
complaints must be evaluated for etiology in addi-
tion to treating pain symptoms. In addition, once
the initial spinal shock resolves, with spinal injuries
above the level of the splanchnic outflow (T6) auto-
nomic dysreflexia (AD) may occur. AD results from
the stimulation of intact peripheral sensory nerves
below the SCI and the interruption of the course of
the ascending sympathetic neurons combined with
the interruption of the descending inhibitory path-
ways which produce hypertension and vasodilation
above the SCI results in headache. Vasomotor brain-
stem reflexes attempt to lower the blood pressure
by increasing parasympathetic tone to the heart,
producing bradycardia, and parasympathetic signs
of sweating and flushing above the level of spinal
injury. A balanced analgesic approach may mitigate
signs of AD.
2.5.8 Hydrocephalus and
Interventricular Shunts
Whether the cause of hydrocephalus is obstruc-
tion to cerebrospinal fluid (CSF) outflow or CSF
overproduction, hydrocephalus causes headache.
The treatment of hydrocephalus is surgical;
Pain Management for Pediatric Neurosurgical Patients
17

indeed, administration of narcotics in the setting
of hydrocephalus can result in rapid and poten-
tially lethal decompensation. In addition to
post-op pain from the procedure, there may be a
component of superimposed chronic headache
pain. Furthermore, in the immediate post-operative
phase, pain management may be complicated by
chronic analgesic use, inappropriate coping skills,
and withering family dynamics. The overall analge-
sic strategies remain the same, and include careful
narcotic titration and use of nonnarcotic adjuvants
to diminish sedation and unwanted narcotic side
e ects. In addition, behavioral psychology and liai-
son psychiatry services may be required to manage
the longstanding issues associated with chronic
headaches and analgesic dependence.
2.5.9 Peripheral Nerve Injury/
Repair
Peripheral nerve injury and pain that arises from
repair of such injury usually result in neuropathic
pain. In addition to the pain, patients will also have
motor and sensory deficits from the nerve injury
itself. Mild pain may initially be treated with
NSAIDs. More moderate pain may respond to tricy-
clic antidepressants (TCAs), such as nortriptyline
or antiepileptics such as gabapentin. If these more
conservative approaches are unsuccessful, opioids
may be useful, although opioids have limited suc-
cess with neuropathic pain and oftentimes lead to
escalating doses and dependence. Neuropathic
pain may be also be amenable to more aggressive
treatment such as spinal cord stimulators.26
2.5.10 Implantable Devices
Post-operative analgesia for implantable devices
(vagal nerve stim ulators, baclofen pumps) in
children requires an appreciation for the preope-
rative status of the patient and any home medi-
cations that may impact post-operative analgesic
therapy such as antiepileptics that induce hep-
atic enzymes and may increase clearance of nar-
cotics and sedatives. (See the section Seizures
earlier.) In addition, patients may be receiving
medications such as valium at home that have
sedative e ects that may be synergized by resid-
ual anesthetic agents and perioperative analge-
sics. In this setting, it is advisable for patients to
be cared for in a monitored setting with care-
givers skilled in assessing and treating pain in
children. Special monitoring should be main-
tained until the child resum es their regular diet
and is able to tolerate enteral analgesics and is
neurologically at baseline.
2.6 Common Analgesics Used
in Children
2.6.1 Opioids
Opioids can be used safely in children. Table 2.1
and Table 2.2 list the most commonly used ente-
ral and parenteral narcotic medications and their
doses.27
Opioids can be prescribed in an “as
needed” schedule for patients with mild pain;
however, scheduled dosing is preferable in acute
painful conditions, especially the postoperative
setting. PCA has been shown to be safe and
Table 2.1 Oral agents
Drug

Parenteral/oral ratio Starting doses and intervals
<50 kg (mg/kg)

>50 kg and adult (mg flat dose)
Oxycodone

N/A

0.1 mg/kg every 3–4 h

5–10 mg every 3–4 h
Morphine
Immediate release

1:3

0.3 mg/kg every 3–4 h

15–20 mg every 3–4 h
Sustained release

1:5

Flat dose only!!
20–35 kg: 10–15 mg every 8–12 h
35–50 kg: 15–30 mg every 8–12 h
30–45 mg every 8–12 h
Hydromorphone

1:2–1:4

0.03–0.08 mg/kg every 3–4 h

1–2 mg every 3–4 h
Methadone

1:2

0.2 mg/kg every 4–8 h

10 mg every 4–8 h
Codeine

NRa
30–60 mg every 3–4 h
aBecause of the FDA Black Box warning against use of this drug in post-operative pediatric T&A patients, and evidence of
pharmacogenetic metabolic variation, the use of this drug is not recommended for pediatric neurosurgical patients.28
General and Critical Care
18

e ective in children; however, managing PCA for
children should not be undertaken by novices and
is outside the scope of this textbook.
Side E ects of Opioids
Common side e ects of opioids include sedation,
pruritus, and opioid-induced bowel dysfunction,
which is manifested by nausea or combined con-
stipation and nausea. Table 2.3 lists the common
drugs for treatment of narcotic side e ects most
patients receiving narcotics will develop some
degree of bowel dysfunction ranging from consti-
pation to nausea and vomiting. Itching is also a
common side e ect of narcotic therapy, usually
worse with parenteral administration of narcotics
and narcotic infusions. Low-dose naloxone infu-
sions have been shown to be e ective for treating
itching related to IV narcotic therapy; however,
this should only be undertaken by practitioners
who are expert in the management of pain in chil-
dren. Sedation is an e ect of narcotics, although
sometimes unwanted. Strategies to avoid sedation
include dose reduction and increasing interval of
dosing, although this can be di cult if the pain is
severe. Another alternative is to switch from one
drug to another, in equianalgesic doses.
2.6.2 Nonnarcotic Analgesics
NSAIDs
NSAIDs inhibit the enzymes COX-1 and COX-2,
thereby preventing production of central and
peripheral prostaglandins. This group of drugs
include: acetaminophen, aspirin, ibuprofen, nap-
roxen, and ketorolac. Inhibition of COX-1 is
responsible for GI complications such as ulceration
and bleeding. Certain NSAIDs (particularly ketoro-
lac) also have other undesirable actions such as
reversible antiplatelet adhesion and aggregation
e ects and negative e ect on bone grow th and
Table 2.2 Parenteral agents
Drug

Equianalgesic IV
dose (mg)
Starting doses and intervals
<50 kg (mg/kg)

>50 kg and adult (mg flat dose)
Fentanyl

0.1

0.5–1.0 µg/kg every 1–2 h

25–50 µg/kg every 1–2 h
Morphine

10

Bolus: 0.05–0.1 mg/kg every 1–2 h
Infusion: 0.025 mg/kg/h
Bolus: 2.5–5 mg every 0.5–2 h
Infusion: 1–2 mg/h
Hydromorphone

1.5–2

Bolus: 0.02 mg/kg every 1–2 h
Infusion: 0.03–0.04 mg/kg/h
Bolus: 1 mg every 1–2 h
Infusion: 0.2–0.3 mg/h
Methadone

10

0.1 mg/kg every 4–8 h

5–10 mg every 4–8 h
Meperidine

75–100

NRa
NR
aMeperidine is metabolized to normeperidine, which can cause seizures.
Table 2.3 Common drugs for treatment of narcotic side e ects
Side effect

Drug

Starting doses and intervals
<50 kg (mg/kg)

>50 kg and adult (mg flat dose)
Constipation

Senna (oral only)

10 mg/kg
Bedtime
187–364 mg
Bedtime
Constipation

Docusate (oral only)

10 mg/kg
Every 4 h
50–500 mg
In 1–4 doses
Not to exceed 500 mg per day
Nausea

Serotonin receptor antagonists
(IV only)
Zofran
0.15 mg/kg every 6 h
4 mg every 6 h
Dolasetron
0.35 mg/kg every 6 h
12.5 mg every 6 h
Nausea and
itching

Diphenhydramine (IV or oral)

0.5–1 mg/kg every 4–6 h
Can be sedating
25–50 mg every 4–6 h
Can be sedating
Abbreviation: IV, intravenous.
Pain Management for Pediatric Neurosurgical Patients
19

healing.29 Concerns about bleeding limit the use of
NSAIDs in the perioperative setting (Table 2.4).
Despite these side e ects, there remains an
e ective role for NSAIDs within the realm of pain
management. NSAIDs are considered “weaker”
analgesics and are combined with other pharma-
cological therapies in order to e ectively treat
postoperative pain from neurosurgical procedures.
The analgesic properties of NSAIDs make them
useful as adjuvant, opioid-sparing agents.
Acetaminophen
Acetaminophen primarily prevents central pro-
duction of prostaglandin, with minimal anti-
inflammatory action. It may also produce analgesia
Table 2.4 Nonopioid analgesics
Drug

Starting doses and intervals
<50 kg (mg/kg)

>50 kg and adult (mg flat dose)
Ketorolac

0.5 mg/kg IM/IV every 6 h, up to max-
imum of 72 h
30 mg every 6 h, not to exceed 120 mg/d
Ibuprofen

5–10 mg/kg orally; not to exceed 40 mg/
kg/d
300–800 mg orally every 6 h
Acetaminophen

Oral
Neonates
Dose: 10–15 mg/kg orally every 6–8 h.
Maximum: 60 mg/kg/d
Infants/children
Dose: 10–15 mg/kg orally every 4–6 h.
Maximum: 75 mg/kg/d up to 1 g/4 h and
4 g/d
>12 y
Dose: 325–650 mg orally every 4–6 h.
Maximum: 1 g/4 h and 4 g/d
Oral
325–650 mg orally every 4 h or 500 mg
orally every 8 h
IV
12.5 mg/kg IV every 4 h or 15 mg/kg IV
every 6 h
Not to exceed 750 mg/dose or 3.75 g/d
IV
650 mg IV every 4 h or 1,000 mg IV
every 6 h
Not to exceed 4 g/d
Clonidine

Oral and transdermal
1 µg/kg/dose every 4 h orally
Oral and transdermal
1 µg/kg/dose every 4 h orally
Diazepam

Oral
0.12–0.8 mg/kg/d every 6–8 h
Oral
2–10 mg/kg/d every 6–8 h
IV
0.05–0.1 mg/kg every 4–6 h
IV
2–10 mg IV/IM every 3–4 h
No more than 30 mg/8 h
Gabapentin

3–12 y
10–15 mg/kg/d divided every 8 h
300 mg orally at bedtime, then gradually
increase as tolerated to 300 mg every 8 h
>12 y
300 mg orally every 8 h, may increase up
to 600 mg orally every 8 h
Amitriptyline

Load:
0.1 mg/kg orally at bedtime; increase as
tolerated over 2–3 wk
Load:
75 mg/d orally
Maintenance
0.5–2 mg/kg orally at bedtime
Maintenance
150–300 mg/d orally in single or divided
doses
Abbreviations: IM, intramuscular; IV, intravenous.
General and Critical Care
20

by antagonizing substance P and the N-methyl-D-
aspartate (NMDA) receptor at the level of spinal
cord. It may be administered in a variety of routes:
oral, IV, or rectal. It is considered a weaker analge-
sic and must usually be combined with other anal-
gesics in order to e ectively treat postoperative
pain.
Acetaminophen has toxic potential, and is one of
the main causes of liver failure in the United
States; thus, dosages must be kept well within
daily limit (less than 4 gm/day, though Food and
Drug Administration (FDA) has proposed decreas-
ing this limit to 3.25 gm/day in adults).30 Acetami-
nophen has historically been combined with
opioids in such formulations as Vicodin, but these
formulations are becoming increasingly rare
because of the risk of acetaminophen toxicity. In
the pediatric age group, this is especially an area of
concern and acetaminophen/opioid combination
analgesics are not recommended.
Ibuprofen
Ibuprofen has analgesic, anti-inflammatory, and
antipyretic properties. It acts by nonselectively
inhibiting COX-1 and COX-2. Ibuprofen has a strong
association with gastric ulceration and bleeding,
and thus must be used with caution.
Ketorolac
Ketorolac acts by nonselectively inhibiting COX-1
and COX-2 and also has analgesic, anti-inflamma-
tory, and antipyretic activity. Ketorolac must be
used with caution perioperatively and postopera-
tively because of inhibition of platelet aggregation.
Because of known side e ects, its use is limited to
5 days or less, with most practitioners cautiously
discontinuing it after 3 days of use. Other adverse
e ects include gastric ulcers/bleeding and renal
dysfunction. It is most commonly administered
intravenously or intramuscularly; although oral
formulations are manufactured, they are not
widely available.
Acetylsalicylic Acid
Salicylate, one of the oldest nonopioid drugs avail-
able, suppresses production of prostaglandin and
thromboxane by irreversible inactivation of COX-1
and COX-2 enzymes. Aspirin has been widely
abandoned as adjuvant in postoperative pain ma-
nagement, secondary to platelet inhibition and its
known association with gastric ulcers and bleed-
ing. In the pediatric population, it has also been
long abandoned because of its possible implication
with Reye’s syndrome.29
Clonidine
Clonidine is a widely used drug with a variety of
indications and routes of administration. Though
primarily known as an antihypertensive, it is also
an e ective analgesic. Clonidine can be adminis-
tered by a variety of routes: IV, oral, transdermal,
epidural, and intrathecal. It provides sedation and
analgesia and is very e ective in the treatment of
withdrawal symptoms from opioids and benzodia-
zepines.
Clonidine is an α-2 agonist, which works presy-
naptically and causes a decrease in norepinephrine
release, at central as well as peripheral adrenergic
receptors. The pain pathway includes inhibition
of these signals at the dorsal horn of the spinal
cord and then continues to higher CNS centers.
Norepinephrine is released in the dorsal horn as
an inhibitory pain neurotransmitter, when there is
stimulation of the α-2 receptor. The modulation of
pain transmission produces analgesia and makes
clonidine an e ective nonopioid adjuvant. Cloni-
dine also produces analgesia by cholinergic activa-
tion in the dorsal horn of the spinal cord by
increasing acetylcholine levels in CSF when admin-
istered intrathecally.
Clonidine is used as an adjuvant analgesic, pri-
marily as an opioid-sparing agent, for the neuro-
surgical patient. With judicious use of clonidine, it
is possible to reduce the amount of opioid used
postoperatively. Clonidine may cause bradycardia,
hypotension, and excessive sedation. Dexmedeto-
midine is another α-2 agonist, which has more
selective action in comparison to clonidine and
produces potent sedation without respiratory
depression, thus explaining its popularity in post-
operative ICU sedation as well as for deep proce-
dural sedation.
Antidepressants
This group of medications includes TCAs, such as
amitriptyline, and newer drugs, such as duloxe-
tine. Antidepressants produce analgesia by inhibi-
tion of re-uptake of 5-HT and norepinephrine, and
also have other e ects such as NMDA antagonism,
decrease in sympathetic α-2 receptor activity and
sodium channel blockade.29
The older group of antidepressants, the TCAs,
has greater analgesic e ect compared to newer
Pain Management for Pediatric Neurosurgical Patients
21

agents and is beneficial for treating neuropathic.
The cleaner pharmacological profile of the newer
antidepressants seems to have decreased its utility
as an analgesic.
Antiepileptic Analgesics
This group of drugs is most beneficial in the treat-
ment of neuropathic pain. The original drug of this
group that was most studied is carbamazepine.
Carbamazepine has a long list of drug interactions,
which are not seen with the newer drugs, includ-
ing gabapentin and pregabalin, a group of weak
anticonvulsants which bind at voltage-gated cal-
cium channels. Despite their names, these drugs
do not have any involvement with gammaami-
nobutyric acid (GABA) receptors. They produce
analgesia by decreasing the presynaptic release of
neurotransmitters that are responsible for produc-
ing pain, such as glutamate, norepinephrine, and
substance P.
NMDA Receptor Antagonists
This group of drugs includes ketamine and metha-
done, both of which have been proven to be bene-
ficial in the treatment of chronic pain. Ketamine is
primarily used as a general anesthetic adjuvant
and is helpful in decreasing opioid usage perioper-
atively. Ketamine also acts by decreasing central
hypersensitivity. Its use is limited by its hallucino-
genic properties, which may be prevented by co-
administering a benzodiazepine, although this side
e ect limits its use outside of the perioperative
arena.
Methadone, another well-established drug for
pediatric pain management, has dual mechanism
of action, acting at both opioid receptors and NMDA
receptors. It is an excellent long-lasting analgesic
agent, especially beneficial in weaning protocols
for patients who have opioid dependence. Metha-
done does a ect the cardiac QT interval, and elec-
trocardiographic (ECG) monitoring is indicated
with initiation and long-term use of the drug.
Muscle Relaxants
Muscle relaxants are divided into two groups:
neuromuscular blockers and spasmolytic. In refer-
ence to pain management, the focus is on spasmo-
lytic, which is centrally acting and help to relieve
spasms and musculoskeletal pain. These medica-
tions also confer an element of sedation, which
may be beneficial in the immediate postoperative
period, but are undesirable once a patient seeks to
return to normal daily activities.
The commonly used muscle relaxants include
benzodiazepines, such as diazepam, baclofen, and
cyclobenzaprine. Muscle relaxants are beneficial in
postoperative analgesia and help to alleviate pain-
ful muscle spasms that are not relieved with
opioids. By adding spasmolytics to a pain regimen,
opioid consumption may be drastically reduced.
Local Anesthetics
Local anesthetic wound infiltration can provide
sensory analgesia and diminish the need for nar-
cotics in the postoperative setting. Local anes-
thetics can be used for most incision wounds,
including craniotomy and implantable device bat-
tery generator pockets. It is not advisable to per-
form peripheral nerve blocks in patients who have
undergone peripheral nerve procedures, since the
sensory and motor blockade seen with these
blocks will cloud the postoperative neural exam.
The most common local anesthetics used for
wound infiltration are lidocaine, which should not
exceed a dose of 5 mg/kg, and bupivacaine, which
should not exceed a dose of 2.5 mg/kg. Epinephr-
ine is often added to these local anesthetics to pro-
vide vasoconstriction, and the dose of epinephrine
is 0.5 to 1 µg/kg, unless contraindicated by a pre-
existing patient condition.
Local Anesthetic Toxicity
Direct intravascular local anesthetic injection must
be avoided, and aspiration before injection and
slow injection can prevent catastrophe. Local anes-
thetics have varying degrees of cardiotoxicity, and
can cause arrhythmias as well as complete heart
block. Local anesthetic overdose can also cause
seizures, and the lactic acidosis produced from the
seizure combined with the cardiotoxic e ects is
lethal.
Treatment of Local Anesthetic Toxicity
Supportive therapy of local anesthetic toxicity
includes seizure suppression, e ective cardiopul-
monary resuscitation (CPR) if needed, and airway
management. Treatment is with 20% lipid emul-
sion, 1.5 mL/kg bolus over 1 minute, repeated
every 5 minutes for persistent circulatory collapse
and an infusion of 0.25 mL/kg/min (can be doubled
to 0.5 mL/kg/min if hypotension persists) for a
minimum of 30 minutes.
General and Critical Care
22

2.6.3 Opioid and Sedative
Weaning
General
Weaning of opioid analgesics is necessary in the
setting of prolonged opioid therapy. In some chil-
dren this can be as short as 10 days, and is most
likely attributable to some currently unknown
pharmacogenomic expression. Certainly after tak-
ing narcotics for more than 3 weeks, a weaning
plan must be made. In the setting of oral narcotics
at usual doses, this weaning may entail nothing
more than scheduled spacing of the dose from
every 4 to 5 to 6 to 8 to 12 to 24 hours. More fre-
quent dosing, demands for higher doses, and usage
beyond the usual postoperative phase should be
concerning and the primary care physician or
pediatrician should be involved in addressing the
problem and may require consultation of an
expert in Pediatric Chronic Pain Management.
Calculating the Narcotic Drug
Weaning Schedule
Narcotic weaning in the setting of supraphysiologic
dosing and multiple drugs can be complicated, and
should be guided by experts in pediatric pain med-
icine. The general approach is to transition the total
calculated IV and oral narcotic drug dose to a
24-hour morphine equivalent, taking 60% of that
morphine equivalent and converting to a daily
methadone dose. The calculated methadone dose
(IV or oral) can be given every 6 hours in the first
day of transition, and should then be spaced to
three times a day (every 8 hours) thereafter. During
the transition to methadone, rescue doses of either
oral or IV opioid should be available, in a standard
dose, such as oxycodone 0.1 mg/kg every 4 hours.
During the transition phase and for the duration of
weaning, pain scores and withdrawal scores, such
as the Neonatal Abstinence Score, must be followed
with vigilance for signs and symptoms of with-
drawal, which include tachycardia, low-grade fever,
diaphoresis, emesis, and diarrhea. Each day the
methadone dose should be weaned from 5 to 20%
depending on the patient’s condition and duration
of therapy. Once the methadone is at a normal
0.1 mg/kg or less, the dose interval can be stretched
from 8 to 12 hours, and subsequently to a daily
dose for a few days and then discontinued. It is
suggested that an expert in pediatric pain manage-
ment be consulted for weaning of narcotics and
sedatives in chronically ill children.
Weaning Adjuvant Drugs
Dexmedetomidine and clonidine discontinuation
may cause abstinence syndrome and require grad-
ual weaning after as few as 5 days of therapy. The
total dose for each drug must be calculated, transi-
tioned to an enteral dose, and weaned systemati-
cally, as tolerated. Benzodiazepines may also cause
physical dependence, and should be weaned as
tolerated in a systematic fashion as well, guided by
sedation and abstinence scores. In the setting of
multiple drugs requiring weaning, it is recom-
mended that not more than one drug be weaned
each day. It is also advisable to have an expert in
pediatric pain medicine consult and devise a sys-
tematic weaning plan with options for break-
through medications available. The weaning proc-
ess may be lengthy, and it may be necessary to
slow down or retreat from weaning if signs and
symptoms of physical withdrawal develop.
2.7 Review Questions
(True or False)
1. Pediatric patients less than 1 year of age do not
have the neural mechanisms to feel pain, and so
it is not necessary to prescribe pain medications
for this age group after surgery.
2. Obese children who have had T&As in the past
are at no increased risk of respiratory
depression when treated with narcotics for
post-operative pain.
3. A 3-year-old child develops a low-grade fever,
diaphoresis, tremors, and diarrhea 10 days after
a tethered cord repair, and the mother reports
that she had given the child the oxycodone that
was prescribed every 3 to 4 hours since
discharge, but she stopped abruptly 2 days ago
when the medication ran out. Is it most likely
that this child has a wound infection?
4. The most e ective drug to treat local anesthetic
toxicity is Dilantin.
References
[1] Taddio A, Katz J, Ilersich AL, Koren G. E ect of neonatal
circumcision on pain response during subsequent routine
vaccination. Lancet. 1997; 349(9052):599–603
[2] Merskey H, Bogduk N, eds. Part III: Pain terms, a current list
with definitions and notes on usage. In: Classification of
Chronic Pain. 2nd ed. IASP Task Force on Taxonomy. Seattle,
WA: IASP Press; 1994:209–214
[3] Derbyshire SWG. Can fetuses feel pain? BMJ. 2006; 332
(7546):909–912
Pain Management for Pediatric Neurosurgical Patients
23

[4] Merkel SI, Voepel-Lewis T, Shayevitz JR, Malviya S. The
FLACC: a behavioral scale for scoring postoperative pain in
young children. Pediatr Nurs. 1997; 23(3):293–297
[5] Taddio A, Hogan ME, Moyer P, et al. Evaluation of the
reliability, validity and practicality of 3 measures of acute
pain in infants undergoing immunization injections. Vaccine.
2011; 29(7):1390–1394
[6] Huguet A, Stinson JN, McGrath PJ. Measurement of self-
reported pain intensity in children and adolescents. J
Psychosom Res. 2010; 68(4):329–336
[7] Garra G, Singer AJ, Domingo A, Thode HC, Jr. The Wong-Baker
pain FACES scale measures pain, not fear. Pediatr Emerg Care.
2013; 29(1):17–20
[8] von Baeyer CL, Spagrud LJ, McCormick JC, Choo E, Neville K,
Connelly MA. Three new datasets supporting use of the
Numerical Rating Scale (NRS-11) for children’s self-reports of
pain intensity. Pain. 2009; 143(3):223–227
[9] Herr K, Coyne PJ, Key T, et al. American Society for Pain
Management Nursing. Pain assessment in the nonverbal
patient: position statement with clinical practice
recommendations. Pain Manag Nurs. 2006; 7(2):44–52
[10] Breau LM, Finley GA, McGrath PJ, Camfield CS. Validation
of the non-communicating children’s pain checklist –
postoperative version. Anesthesiology. 2002; 96(3):528–535
[11] Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of
obesity and trends in body mass index among US children
and adolescents, 1999–2010. JAMA. 2012; 307(5):483–490
[12] O’Brien LM, Sitha S, Baur LA, Waters KA. Obesity increases the
risk for persisting obstructive sleep apnea after treatment in
children. Int J Pediatr Otorhinolaryngol. 2006; 70(9):1555–1560
[13] Cella M, Knibbe C, Danhof M, Della Pasqua O. What is the right
dose for children? Br J Clin Pharmacol. 2010; 70(4):597–603
[14] Kofke WA. Anesthetic management of the patient with
epilepsy or prior seizures. Curr Opin Anaesthesiol. 2010; 23
(3):391–399
[15] Sasano N,Fujita Y,So M,Sobue K,Sasano H,Katsuya H.Anesthetic
management of a patient with mitochondrial myopathy,
encephalopathy, lactic acidosis, and stroke-like episodes
(MELAS) during laparotomy.JAnesth.2007; 21(1):72–75
[16] Vetter TR. A clinical profile of a cohort of patients referred to
an anesthesiology-based pediatric chronic pain medicine
program. Anesth Analg. 2008; 106(3):786–794
[17] Ward E, DeSantis C, Robbins A, Kohler B, Jemal A. Childhood
and adolescent cancer statistics. CA: A Cancer Journal for
Clinicians. 2014; 64: 83103. doi:10.3322/caac.21219
[18] National Cancer Institute. Childhood cancers. Available at:

childhood. Updated January 10, 2008. Accessed November 1,
2013
[19] Thibault M, Girard F, Moumdjian R, Chouinard P, Boudreault
D, Ruel M. Craniotomy site influences postoperative pain
following neurosurgical procedures: a retrospective study.
Can J Anaesth. 2007; 54(7):544–548
[20] Saha P, Chattopadhyay S, Rudra A, Roy S. Pain after craniotomy:
a time for reappraisal? Indian J Pain. 2013; 27(1):7–11
[21] Morad AH, Winters BD, Yaster M, et al. E cacy of
intravenous patient-controlled analgesia after supratentorial
intracranial surgery: a prospective randomized controlled
trial. Clinical article. J Neurosurg. 2009; 111(2):343–350
[22] Mordhorst C, Latz B, Kerz T, et al. Prospective assessment of
postoperative pain after craniotomy. J Neurosurg Anesthesiol.
2010; 22(3):202–206
[23] Nguyen A, Girard F, Boudreault D, et al. Scalp nerve blocks
decrease the severity of pain after craniotomy. Anesth Analg.
2001; 93(5):1272–1276
[24] Parray T, Martin TW, Siddiqui S. Moyamoya disease: a review
of the disease and anesthetic management. J Neurosurg
Anesthesiol. 2011; 23(2):100–109
[25] Pubmed Health. Arteriovenous malformation-cerebral.
Available at:
PMH0001783/. Updated November 2, 2012. Accessed
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Chiari malformation fact sheet. Available at:
ncbi.nlm.nih.gov/pubmedhealth/PMH0001783/.

Updated
September 30, 2013. Accessed November 5, 2013
[27] Kuehn BM. FDA: No codeine after tonsillectomy for children.
JAMA. 2013; 309(11):1100
[28] Bunchorntavakul C, Reddy KR. Acetaminophen-related
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[29] eMedicine. Traumatic peripheral nerve lesions treatment &
management. Available at:
article/1172408-treatment. Updated August 1, 2013.
Accessed November 8, 2013
[30] Monitto CL, Kost-Byerly S, Yaster M. Pain management. In:
Davis PJ, Cladis FP, Motoyama EK, eds. Smith’s Anesthesia for
Infants and Children. 8th ed. Philadelphia, PA: Elsevier
Mosby; 2011:418–440
General and Critical Care
24

II
Section II
Neuroradiology
3 Conventional Radiography

26
4 Ultrasonography

28
5 Computed Tomography

32
6 Conventional Magnetic
Resonance Imaging

35
7 Advanced MRI Techniques

38

3 Conventional Radiography
Thierry A.G.M. Huisman
3.1 Introduction
Conventional radiography takes advantage of the
di erential absorption, penetration, and reflection
of roentgen rays (X-rays) by biological tissues.
Anatomical structures with a high density such as
the calvarial bone appear dense (white), while air-
filled paranasal sinuses or soft tissues of the neck
appear lucent (dark).
The use of plain radiography should be limited
as much as possible in children. Children are more
susceptible to the deleterious side e ects of ioniz-
ing radiation and their life expectancy is signifi-
cantly longer compared to adults. Each request for
a conventional radiography should be carefully
evaluated. The benefits should outweigh the
possible risks. Alternative nonionizing imaging
modalities such as ultrasonography or magnetic
resonance imaging (MRI) should be considered.
The number of images should be limited as much
as possible, and suboptimal images (e.g., due to
motion artifacts) should not be repeated if diag-
nostic. Furthermore, all imaging should follow the
as low as reasonably achievable (ALARA) principle
taking advantage of newest tube and detector
technologies, which allow lowering of the radia-
tion dose.
Conventional radiography remains a valuable,
fast, and widely available imaging tool for the
workup of many acute (e.g., trauma) and chronic
(e.g., remodeling of the skull in neurofibromatosis)
neurosurgical pathologies. The two-dimensional,
projectional technique allows one to study espe-
cially the osseous neuroanatomy in detail. The
large field of view may be of advantage to get a
quick oversight of, for example, the alignment of
the vertebral bodies in kyphoscoliosis. Finally,
pathological calcifications (e.g., craniopharyng-
ioma), foreign bodies (penetrating injuries), and
the location and integrity of various implant devi-
ces (e.g., ventriculoperitoneal shunts, vagus nerve
stimulator, position of deep electrodes, baclofen
pump, spinal rods) can be evaluated.
3.2 Skull Radiography
Typically, skull radiography is performed in two
planes, an anteroposterior (AP) and a lateral pro-
jection. Depending on the indication for the study,
additional focused views may be completed,
including dedicated views of the orbits, sella tur-
cica, paranasal sinuses, and programmable shunt
reservoirs.
Nowadays, skull radiography plays only a very
limited role in the acute workup of head trauma.
Similarly, skull radiography is nowadays rarely
used for the preoperative workup of isolated or
syndromal craniosynostosis, positional plagioce-
phaly, or skeletal dysplasias. Computed tomogra-
phy (CT) allows one to study both the bony
calvarium and the brain. In addition, multiplanar
two-dimensional as well as three-dimensional
image reconstructions render valuable additional
diagnostic information, replacing skull radiogra-
phy in nearly all cases.
Skull and orbital radiography may be performed
to rule out ferromagnetic foreign bodies prior to
MRI. In addition, skull radiography can be used to
follow the position, configuration, and packing of
intracranial aneurysm coils and intravascular
embolization material.
3.3 Sinus Radiography
Rarely, a preoperative sinus radiography is per-
formed to plan neurosurgical access, in particular
for transsphenoidal approaches of sellar patholo-
gies. Similar information can be extracted from a
low-dose bone CT study. Acute and chronic sinus-
itis is nowadays also evaluated by low-dose CT.
3.4 Stenvers and Schüller
Radiography
These dedicated focused views of the petrous bone
allow evaluation of the inner ear structures and
petrous apex in detail. These views have, however,
been replaced by low-dose temporal bone CT. On
rare occasions, for example, evaluation of the cor-
rect positioning of cochlear implants, these views
may be considered.
3.5 Shunt Survey
In children with suspected dysfunction of a ventri-
culoatrial, ventriculopleural, or ventriculoperito-
neal shunt, the entire course of the shunt should
26

be evaluated by conventional radiography. The
imaging protocol includes radiographies of the
skull in two planes (AP and lateral), and single AP
views of the neck, chest, and abdomen. Images are
evaluated for shunt disconnection, kinking, or
fixed positioning of the distal shunt on follow-up
imaging possibly within a pseudo-mass lesion,
which may indicate that the tip of the shunt is
caught within an encapsulated cerebrospinal fluid
collection.
3.6 Cervical Spine and
Craniocervical Junction
Conventional radiography remains an important
tool in the acute workup of craniocervical or cervi-
cal spine trauma. Typically, three images are
acquired, namely a true AP, lateral, and dedicated
transbuccal odontoid view. Imaging can be per-
formed with a neck collar in position. If an instable
fracture is ruled out and the child continues to
complain about cervical instability and/or pain,
functional lateral views in maximal flexion and ex-
tension may be added. The cervicothoracic region
is frequently obscured by the overlying shoulders.
A repeat lateral view with simultaneous down-
ward pulling of the arms may be performed. Alter-
natively, a “swimmer’s view” may o er a better,
nonobscured view of the cervicothoracic junction.
Oblique lateral views to study the neuroforamina
are rarely performed.
Familiarity with the normal developing skeleton
is essential to prevent misdiagnosis. Synchondrosis
may mimic fractures, the space between the ante-
rior contour of the dens and anterior arch of the
first cervical body is wider in children than in
adults, and a physiological subluxation between
the second and third cervical vertebral body is
usually seen. The soft tissues should be scrutinized
for soft-tissue swellings. A widening of the prever-
tebral space may suggest a prevertebral hema-
toma. Many reference lines have been published in
the literature to facilitate diagnosis and quantify
pathology. The best known lines include the Swi-
schuk line (spinolaminar line), McRae line, Cham-
berlain line, Wackenheim line, and many more.
Craniocervical images may also be used to dif-
ferentiate between a basilar impression, which is
often secondary to preexisting conditions, and
basilar invagination, which is usually congenital.
Frequently, a CT and/or MRI w ill follow con-
ventional radiography to rule out, identify, or
quantify spinal cord or discoligam entous injury
or compression.
3.7 Thoracic and Lumbosacral
Radiography
Similar to the cervical spine, AP and lateral views
of the thoracic and lumbosacral spinal column
may be acquired in trauma, infection, tumor, or
malformation. Additional oblique lateral views
may be helpful to identify pathologies of the neu-
roforamina, which may include a widening due to,
for example, schwannomas in neurofibromatosis
or narrowing related to developmental anomalies
such as spondylolysis (dog with neck collar).
3.8 Total Spine Radiography
In the diagnostic workup of multilevel segmenta-
tion or formation anomalies (e.g., in Vertebral, anal
anomalies, tracheo-esophageal fistula, renal anoma-
lies [VATER] association), in spinal dysraphias, and
in cases of idiopathic or acquired scoliosis with or
without hyperkyphosis or hyperlordosis, the entire
spinal column is examined in an AP and lateral pro-
jection. Whenever possible, this should be per-
formed in the upright standing position. The degree
of scoliosis is typically quantified by measuring the
Cobb angle (named after Dr. John R. Cobb), which
refers to the coronal plane deformity seen on an AP
view of the spinal column. The Cobb angle is defined
as the angle formed between lines perpendicular to
a line drawn parallel to the superior end plate and
to a line drawn parallel to the inferior end plate of
the most tilted superior and inferior vertebral
bodies, respectively. The degree of coexistent hyper-
kyphosis/lordosis is measured on a lateral projec-
tion in similar fashion.
Occasionally, an additional AP view of the pelvis
will be completed to determine the degree of
pelvic tilt.
Whenever possible, the gonads should be
shielded for the study.
Conventional Radiography
27

4 Ultrasonography
Thierry A.G.M. Huisman
4.1 Introduction
Ultrasonography (US) of the central nervous sys-
tem, orbits, head and neck region, and spine is a
safe imaging modality that does not require seda-
tion, can be performed at bedside, is widely avail-
able, and is well accepted by patients and their
parents.1 It can be repeated as often as necessary
because of the lack of ionizing radiation. Ultra-
sound can render multiplanar two- and three-
dimensional grayscale anatomical images of the
central nervous system in high resolution. In addi-
tion, color-coded duplex evaluation of the intra-
cranial vasculature with spectral sampling of the
arterial pulse waves gives important functional
hemodynamic data. US requires a well-trained
sonographer or physician familiar with the pedia-
tric pathologies who is able to perform an opti-
mized, personalized study and knows how to take
full advantage of technologically advanced, mod-
ern US units. Various transducers including vector,
curved array, and linear probes capable of scan-
ning at multiple megahertz (MHz) settings should
be available and able to attain at least 15 MHz.
Moreover, the imaging algorithms within the
machine should be optimized for the various age
groups (e.g., preterm vs. term neonate). This “tun-
ing” of the machine algorithms in cooperation
with the manufacturer’s technical representative
can dramatically improve resolution, contrast, and
conspicuity of pathology.
4.2 Anatomical
Ultrasonography of the Brain
Typically, the neonatal brain is sampled in the
sagittal and coronal plane through the anterior
fontanel. In addition, mastoid fontanel, posterior
fontanel, and suboccipital views through the fora-
men magnum should be included for a better
exploration of the contents of the posterior fossa
(brain stem and cerebellum). Depending on
the probe, three-dimensional data sets may be
acquired that allow secondary multiplanar recon-
structions, which match the more typical com-
puted tomography (CT) and magnetic resonance
imaging (MRI) planes. The used US probe should
have a footprint that matches the size of the acous-
tic window, should be positioned in the center of
the fontanel, and should maintain good contact
with the scalp through the use of appropriate
amounts of US gel. Depending on the pathology
encountered, more detailed assessment of lesions
located along the convexity of the cerebral hemi-
spheres may occasionally require additional scan-
ning with higher frequency probes.
Indications for brain US are diverse and depend
on the clinical and physical symptoms (e.g., acute
onset of seizures, unexplained acute drop in the
hematocrit), occurrence of perinatal complications
(e.g., perinatal asphyxia or depression), systemic
diseases (e.g., coagulation disorders, sepsis), pre-
natally diagnosed pathologies (e.g., isolated and
syndromal ventriculomegaly). In addition, serial
brain US studies may be performed as part of rou-
tine screening to monitor (e.g., hydrocephalus
after intraventricular hemorrhage) or to exclude
complications of treatment (e.g., hemorrhage in
children on extracorporeal membrane oxygena-
tion). Scanning is also advised before and after
major surgery.
With progressing closure of the fontanels, the
diagnostic sensitivity of brain ultrasound declines.
The time point of fontanel closure varies, but typi-
cally highly diagnostic studies are possible until
about 4 to 6 months of age. As a rule of thumb, if
the fontanel can be palpated, a diagnostic study is
possible.
Indications for brain ultrasound:
● Germinal matrix hemorrhage (GMH) grade I, II,
and III.
● Periventricular (hemorrhagic) venous infarction,
formerly known as grade IV GMH.
● Intraventricular and choroid plexus
hem orrhage.
● Parenchymal hemorrhage.
● Extra-axial hemorrhage (epidural, subdural, and
subarachnoid hemorrhage).
● Hypoxic ischemic injury (HII).
● Arterial ischemic stroke.
● Brain malformations:
– Dandy–Walker malformation.
– Arnold–Chiari II and III malformation.
– Corpus callosum agenesis/dysgenesis.
– Septo-optic dysplasia.
– Holoprosencephaly.
– Schizencephaly and migrational abnormalities.
– Vein of Galen aneurysmal malformation.
– Arachnoid cysts.
28

● Hydrocephalus:
– Congenital hydrocephalus (aqueductal
stenosis).
– Acquired (secondary to hemorrhage or
infection).
– Syndromal.
● Infections.
● Trauma.
● Congenital benign and malignant brain tumors
(teratoma, lipoma).
Images are evaluated for focal or di use imaging
findings similar to other cross-sectional imaging
modalities.
GMHs are dependent on their age or stage of
evolution identified as a focal hyper- or hypoecho-
genic lesion typically confined to the caudo-
thalamic groove (GMH grade I). In grade II GMH,
intraventricular extension of the hemorrhage is
noted without associated ventriculomegaly, while
in GMH grade III intraventricular extension is com-
plicated by ventriculomegaly.
Periventricular venous infarction is believed to
be a complication of a GMH at the caudothalamic
groove, which compresses the adjacent collector
vein that is draining the periventricular white
matter into the deep venous system. Consequently,
a venous stasis occurs, which may evolve into a
venous infarction. The ischemic white matter is
typically hyperechogenic in its acute phase and
may become progressively hypoechogenic because
of progressive tissue resolution. The hyperechoge-
nicity matches the distribution of the venous terri-
tory. The periventricular venous ischemia may be
complicated by a hemorrhagic transformation
resulting in a periventricular hemorrhagic venous
infarction. The hemorrhage is typically seen as a
focal hyperechogenic mass within the ischemic
white matter. These lesions were previously
known as grade IV GMH.
Intraventricular hemorrhage is typically recog-
nized by the direct identification of blood products
within the ventricles, often with sediment layering
in the posterior, dependent parts of the ventricles.
In addition, intraventricular blood products may
result in a chemical inflammation of the ependy-
mal lining with resultant hyperechogenicity. A
focal, hyperechogenic choroid plexus enlargement
is strongly suggestive of a choroid plexus hemor-
rhage.
The imaging characteristics of parenchymal
hemorrhages are dependent on their age and are
noted as a focal hyperechogenic (acute/subacute)
or hypoechogenic (chronic) mass lesion within the
brain. Compression of adjacent brain structures
may be present dependent on the size of the
hemorrhage.
Extra-axial hemorrhages may be challenging
because they are frequently obscured secondary to
the acoustic shadowing from the osseous bounda-
ries of the fontanels. An asymmetric size of the lat-
eral ventricles or a midline shift is suggestive of an
extra-axial hemorrhage. Dedicated imaging that
takes advantage of the additional fontanels may
enhance detection. Subarachnoid hemorrhages are
typically recognized by hyperechogenic material
within the hemispheric sulci.
Di use HII due to perinatal asphyxia or cardiac
arrest with di use brain swelling is recognized by
a di use hyperechogenicity of the hemispheric
white matter with resultant increased corticome-
dullary di erentiation, slitlike ventricles, e aced
basal cisterns, and a lowered resistive index (RI)
value.
Focal arterial ischemic injury may occur secon-
dary to multiple pathologies. In the acute phase, a
focal hyperechogenicity is noted, which may a ect
both the white matter and overlying cortical gray
matter typically within the territory of intracranial
arteries. On follow-up, the ischemic tissue will
progressively resolve and become hypoechogenic,
eventually resulting in a porencephalic cyst.
Brain malformations are recognized by identifi-
cation of the key anatomical features of the malfor-
mation. Subtle components may be overlooked by
US. Most classic malformations, however, can
easily be recognized.
Evaluation of the degree and possible etiology of
hydrocephalus typically relies on the subjective
analysis of the overall size and configuration of the
ventricles on anatomical US images. Recently,
more objective quantitative data are collected to
detect subtle changes in ventriculomegaly. The
ventricular index (VI=total width of the lateral
ventricle on coronal view/total biparietal width in
the same image) has become a popular, easy-to-
measure scalar for monitoring ventricular size.
4.3 Doppler Ultrasonography
of the Brain
Doppler sonography allows studying patency of
the major intracranial arteries (circle of Willis) and
veins (superficial and deep venous system) includ-
ing evaluation of the flow direction. Moreover,
spectral analysis of the arterial pulse waves
sampled within major branches of the circle of
Ultrasonography
29

Willis allows calculation of the RI values. The RI
value is calculated as the ratio between the maxi-
mal end-diastolic and end-systolic flow velocities
([peak systolic velocity–minimum diastolic veloc-
ity]/peak systolic velocity). The RI value may serve
as an objective scalar of the intracranial hemo-
dynamics. For full-term neonates, the normal RI
values range between 0.65 and 0.75, while preterm
infants have a slightly higher RI value (0.77–0.80).
Measurement of the RI values can give valuable,
functional information in addition to the anatomi-
cal US images.
Serial evaluation of the RI values is especially
helpful in the follow-up of hydrocephalus. An
increase in central arterial RI values may occur
because of decrease in diastolic flow secondary to
elevated intracranial pressure in cases of rapidly
progressive ventriculomegaly. In infants and chil-
dren, RI values exceeding 0.80 and 0.65, respec-
tively, is abnormal. Baseline measurements are
useful to distinguish between an overlap in normal
and abnormal values. Treated ventriculomegaly
may be assessed with serial follow-up of the RI val-
ues as needed.
Serial Doppler sonography may be used to eval-
uate arteriovenous malformations, including the
vein of Galen aneurysmal malformation. In partic-
ular, Doppler sonography allows evaluation of the
e ects of endovascular occlusion. In significant
arteriovenous shunting, the peak systolic and dia-
stolic flow velocities are elevated. Normalization of
these flow scalars indicates successful treatment.
In addition, the RI values will normalize.
RI values are lowered in cases of global brain
edema, for example, because of hypoxic brain
injury or in sepsis. Traumatic brain injury can alter
cerebral blood flow dynamics in several ways.
First, after subarachnoid hemorrhage, vasospasm
may cause elevated cerebral blood flow velocity.
Second, if severe injury leads to cerebral edema,
elevated RI values reflects increased intracranial
pressure. If the intracranial pressure exceeds mean
arterial pressure (RI>1.0), reversed diastolic flow
may be identified. Following a traumatic brain
injury, Doppler US can be applied to determine the
impact of therapy, including hyperventilation.
Finally, Doppler US can be used to confirm
brain death. Patterns on Doppler US most speci-
fic to brain death are near-total absence of ante-
grade flow or complete absence of flow, timed
average mean velocity of less than 10 cm/s over
30 minutes, and prominent bidirectional or “rever-
berant” flow (high peak systolic velocity and a con-
sistent retrograde diastolic component, away from
the brain). Doppler US for brain death diagnosis
should, however, be done cautiously in infants, as
reverberant flow may be indicative of circulatory
arrest alone.
4.4 Ultrasonography of
the Spine
US of the spinal canal and spinal cord can be per-
formed within the first months of life before the
progressive ossification of the dorsal elements of the
vertebral column obscures the acoustic window. The
spinal canal and its contents are typically evaluated
in the sagittal and axial plane. The width of the spi-
nal canal, size, configuration and location of the
spinal cord, central canal, and cauda equine are eval-
uated. In addition, cine-loop imaging allows evalua-
tion of the pulsatility and mobility of the spinal
cord. Imaging is typically performed with a high-
resolution, high-frequency linear transducer. The
vertebral bodies are counted either from the cervical
spine downward or from the coccyx upward.
Indications for spinal ultrasound:
● Spinal dysraphia:
– Skin dimple or tag.
– Cutaneous fistulous tract with or without
discharge.
– Tethered cord.
– Spectrum of myelomeningoceles and
diastematomyelia.
– Hydromyelia.
● Sacrococcygeal teratoma.
● Spondylitis with or without intraspinal abscess.
● To rule out spinal malformations in genetic
disorders.
4.5 Ultrasonography of
the Orbits
US of the orbits can give valuable information about
the preseptal soft tissues, the eye globe, the optic
nerve, and the immediate retrobulbar soft tissues
including the central retinal artery and superior
ophthalmic vein. Orbital ultrasound is performed
with a high-frequency linear transducer through
the closed eyelid. Measurement of the optic nerve
sheet diameter has been proposed as an additional
quantitative marker of increased intracranial pres-
sure, but is rarely used in clinical routine.
Orbital US is depending on the hospital settings
performed by ophthalmology or pediatric neuro-
radiology. Indications include orbital malformations,
Neuroradiology
30

orbital trauma, intraorbital hemorrhages, tumors
(retinoblastoma), retinal detachments, orbital in-
flammation, and arterial or venous thrombosis.
4.6 Ultrasonography of the
Head and Neck
US of the head and neck region are primarily
within the field of otorhinolaryngology. The most
frequent indications include evaluation of a com-
plicated lymphadenitis or tonsillitis, infected
branchial cleft cysts, vascular or lymphatic malfor-
mations, and focal mass lesions. Doppler sonogra-
phy of the major neck vessels may be considered
to rule out a spontaneous or posttraumatic arterial
dissection or a venous thrombosis (Lemierre’s dis-
ease).
Reference
[1] Orman G, Benson JE, Kweldam CF, et al. Neonatal head
ultrasonography today: a powerful imaging tool! J
Neuroimaging. 2015; 25(1):31–55
Ultrasonography
31

5 Computed Tomography
Thierry A.G.M. Huisman
5.1 Introduction
Computed tomography (CT) is an imaging techni-
que that uses an X-ray tube that rotates around
the object of interest. A simultaneously rotating
detector row opposite to the X-ray tube measures
the amount of X-rays that have penetrated the
body. The simultaneous rotation of X-ray tube and
detector row allows us to spatially localize the
degree of X-ray attenuation within the body,
which gives information about the consistency
and quality of examined tissues. The collected raw
data are subsequently postprocessed with genera-
tion of two-dimensional axial images. Based on
the applied reconstruction algorithm, dedicated
soft-tissue and bone images are calculated. Nowa-
days, scanners measure a three-dimensional iso-
tropic volume of data that can be reconstructed in
multiple planes (multiplanar reconstructions) typ-
ically in the axial, sagittal, and coronal plane. In
addition, three-dimensional images in various tex-
tures and qualities can be calculated.
5.2 Hounsfield Units
The basic image contrast of CT relies on the di er-
ing attenuation of the X-ray beam by the examined
tissues. The attenuation level is expressed in
Hounsfield units (HU), named after the inventor of
the CT, Sir Godfrey N. Hounsfield. By definition,
the radiodensity of water is calibrated to zero
Hounsfield units. The radiodensity and the num-
ber Hounsfield units of other substances and tis-
sues are related to the density of water in a linear
fashion ( Table 5.1). Typically, the white matter is
hypodense compared to the gray matter, resulting
in a well-defined corticomedullary di erentiation.
The density of the white matter is determined by
many factors, which include degree of water con-
tent, progressing myelination, and packing of
white matter tracts. Consequently, the density of
the white matter will gradually increase with pro-
gressing brain maturation. This variation in den-
sity should be carefully considered when studying
the brain of very young children. Intracranial hem-
atomas may also show a variation of CT density
over time. The imaging appearance of hematomas
varies depending on the hematomas’ age, size,
location, and hematocrit. Hyperacute (<12 hours)
hematomas may be isodense to the brain, rapidly
becoming hyperdense in the acute (12 hours to
2 days) and early subacute (2–7 days) phase, and
again progressively isodense and later hypodense
in the late subacute (8 days to 1 month) and
chronic (1 month to years) phase.1
5.3 Intravenous Contrast Media
The diagnostic yield of a CT study can be further
increased by the sim ultaneous intravenous injec-
tion of iodinated contrast agents. In pathologies
where an interrupted blood–brain barrier is
expected (e.g., neoplasm , infection), intravenous
contrast injection m ay increase diagnostic sensi-
tivity and specificity. Contrast-enhanced CT is,
however, lim ited in the evaluation of m eningitis
because the increased enhancem ent of the
m eninges m ay rem ain undetected because of the
obscuring hyperdensity of the adjacent skull.
5.4 CT Angiography, CT
Venography, and CT Perfusion
CT angiography (CTA) and CT venography (CTV)
take advantage of a rapid intravenous bolus injec-
tion of contrast agents, which allows studying the
intracranial vasculature in two- and three-dimen-
sional detail. CTA should be considered in the diag-
nostic workup of acute arterial or venous stroke,
congenital or acquired vasculopathies, vascular
malformations, aneurysms, and highly vascular-
ized neoplasms. CTV is helpful if a thrombosis of
the superficial or deep venous system is suspected.
Moreover, perfusion-weighted CT with calculation
of multiple hemodynamic maps (e.g., cerebral
blood flow and volume, mean transit time, time to
peak) may help identify areas of critical perfusion
in ischemic stroke.
Table 5.1 Hounsfield units of various tissues
HU
Air

–1,000
Fat

–100
Water

0
Cerebrospinal fluid

15
White matter

20–30
Gray matter

30–40
Bone

>600
32

5.5 Limitations of CT Contrast
Agents
It should be determined if the patient is allergic to
iodinated contrast agents before injection. If there
is a previous history of allergic reactions, the pa-
tient should receive a prophylactic preparation,
which typically includes a combination of predni-
sone, diphenhydramine, and possibly an additional
H2 antagonist, starting 24 hours prior to the study.
In addition, care should be taken to use only non-
ionic contrast agents. Finally, the best prevention
of contrast reactions is not to give contrast or to
choose another imaging modality that does not
require the use of iodinated contrast agents.
Furthermore, if there is a history of impaired
renal function, the use of intravenous contrast
agents should be carefully evaluated. If a contrast-
enhanced CTstudy is considered essential for diag-
nosis and decisions about treatment, the patients
should be well hydrated prior to the study, the
amount of contrast agent may be reduced, and
hemodialysis should be considered after the study.
5.6 Radiation Exposure
CT studies represent a major source of exposure to
ionizing radiation. The use of CT should always be
carefully considered in this vulnerably young pa-
tient group. If no radiation-free alternative imag-
ing is possible or available, care should be taken to
use high-end CTscanners which are equipped with
modern dose-reduction techniques. Depending on
the clinical question, the imaged region should be
limited as much as possible (e.g., avoid unneces-
sary radiation of the eye lenses), multiphase
contrast-enhanced studies should be avoided, and
follow-up studies should be tailored to the rele-
vant questions to be answered.2 The so-called
localizer at the beginning of each CT study should
also be studied in detail because it may harbor
important information (e.g., shunt disconnection),
which may be outside of the imaged CTvolume.3
Finally, when in doubt about the best study to
be done, it is worthwhile to seek advice from the
radiologist.
5.7 Indications
5.7.1 CTof the Brain
CT of the brain can be diagnostic in a multitude of
acute and chronic neurosurgical pathologies. CT
should be considered in children with an acute onset
of focal or generalized neurological symptoms,
unexplained mental deterioration, head trauma,
pre- and postoperative workup, follow-up of hydro-
cephalus, complications of meningitis, stroke, hem-
orrhage, etc. In most cases, a non-contrast-enhanced
CTis diagnostic. If a complex finding is noted, CTwill
frequently be followed by magnetic resonance imag-
ing (MRI) unless an emergent neurosurgical inter-
vention is necessary, MRI is contraindicated, or the
patient cannot be transported to MRI.
In traumatic brain injury, images should be
reconstructed using both soft-tissue and bone
algorithms. Two- and three-dimensional recon-
structions of the skull have proven to be helpful to
identify skull fractures that extend along the axial
plane. In addition, fracture extension into sutures
is easily depicted. Multiplanar coronal and sagittal
soft-tissue reconstructions enhance identification
of extra-axial hematomas.
Non-contrast-enhanced CT is frequently used
for the follow up of children with shunted hydro-
cephalus in order to rule out shunt malfunction.
Various dose-reduced protocols are available.
Because many of these children will receive multi-
ple studies over their lifetime, alternative nonio-
nizing imaging techniques should, however, be
considered. Nowadays, ultrafast MRI protocols
allow imaging the ventricles within minutes. Typi-
cally, a single-shot T2-weighted protocol is used in
which each slice is measured within 400 to
800 ms, which is in most cases fast enough for
even the very young children.
CT is typically limited in the diagnostic workup
of children with seizures related to developmental
disorders, neurometabolic diseases, or autoim-
mune inflammatory diseases including Rasmus-
sen’s encephalitis. CT may reveal only the tip of
the iceberg, while MRI allows studying the malfor-
mation in better detail.
Three-dimensional reconstruction of the skull
allows preoperative evaluation of skull remodeling
in isolated or syndromal craniosynostosis.
Contrast-enhanced CT should be performed if a
focal mass lesion is noted, unless an MRI will fol-
low. Similarly, contrast-enhanced CTA or CTV
should be considered if a vascular lesion (e.g.,
aneurysm, arteriovenous malformation) or an
arterial or venous thrombosis is suspected.
5.7.2 CTof the Petrous Bone and
Skull Base
High-resolution thin-sliced CT of the petrous bone
allows us to study the osseous anatomy of the
Computed Tomography
33

delicate inner ear (cochlea, vestibule, semicircular
canals) and middle ear (ossicles) structures.
Images are typically reconstructed in multiple
planes with separate magnification of both sides.
Temporal bone CT is usually performed for otolog-
ical indications (e.g., cholesteatoma, inner ear
deafness). More frequently temporal bone imaging
is carried out after traumatic brain injury with
fractures involving the skull base. The floor of the
middle cranial fossa including clivus, sphenoid
body, and sinus should be carefully scrutinized for
fractures. Contrast injection is rarely indicated
unless a concomitant vascular injury is suspected.
5.7.3 CTof the Orbits
Many pathologies may require a CTof the orbits. In
the pediatric age group, one of the most frequent
indications is an acutely swollen eye. Contrast-
enhanced CT is typically performed to di erentiate
between a preseptal inflammation and a retrobul-
bar process. Contrast injection is indicated to rule
out abscess formation and/or thrombosis of the
superior ophthalmic vein. The adjacent cavernous
sinus should also be studied for possible thrombus
extension.
The second most frequent indication for orbital
CT is a traumatic injury to the orbits. CT images
should be reconstructed in both soft-tissue and
bone algorithm. Direct injury to the globe, lens,
optic nerve, and orbital muscles should be
excluded, as well as osseous lesions, which may
include orbital wall fractures as well as fractures
extending into the optic canal. The adjacent ante-
rior skull base and frontal lobes should also be
evaluated for traumatic lesions.
Less frequently, orbital CT is performed because
of mass lesions, which may include benign lesions,
such as dermoids, venous angiomas, and optic
nerve gliomas, malignant lesions, such as rhabdo-
myosarcomas and retinoblastomas, or metastatic
lesions to the orbits such as in systemic neuroblas-
toma. For these indications, simultaneous contrast
injection should be considered if no MRI is sched-
uled/performed.
In general, CT of the orbits should be done cau-
tiously because of the high sensitivity of the pedia-
tric eye lens for radiation-induced cataract. In
addition, in children with retinoblastoma, an
increased risk for radiation-induced secondary
malignancies, such as osteosarcomas of the orbits,
has been reported.
5.7.4 CTof the Paranasal Sinuses
Indications for paranasal sinus CT include sinusitis,
trauma, and preoperative workup for transsphe-
noidal resection of sellar tumors (e.g., pituitary
adenoma). CT is typically done in a low-dose
approach without the injection of intravenous
contrast agents. Mucosal thickening and primary
or secondary bony changes are well depicted on
bone images. Intrasellar calcifications suggestive of
a craniopharyngioma are also easily noted.
5.7.5 CTof the Vertebral Column
Indications for vertebral column CT are multifold
and most frequently include trauma, infection,
tumor, or malformation. In children, soft-tissue
and bone images should be reconstructed in three
orthogonal planes and, whenever necessary, addi-
tional three-dimensional images may be obtained.
Sagittal soft-tissue reconstructions are espe-
cially helpful in children who sustained a trau-
matic head and neck injury. Because of the unique
biomechanical properties of the pediatric cranio-
cervical junction, there is an increased risk for
ligamentous injury at this level with possible dis-
ruption of the tectal membrane. Retroclival hemato-
mas may result in subsequent compression of the
lower brainstem and upper cervical spinal cord. Sag-
ittal soft-tissue images facilitate diagnosis.
Two- and three-dimensional image reconstruc-
tions of the spinal column should be considered in
complex spinal dysraphia. Preoperative planning
may benefit from an exact display of the mal-
formed anatomy.
Occasionally, CT is performed in addition to MRI
in children with vertebral infections (e.g., spondy-
litis, spondylodiscitis) or vertebral tumors (e.g.,
osteosarcoma, Ewing’s sarcoma) to get a better
insight into the osseous structure.
Finally, whole-spine CT may serve as baseline
study in children with scoliosis.
References
[1] Huisman TA. Intracranial hemorrhage: ultrasound, CT and
MRI findings. Eur Radiol. 2005; 15(3):434–440
[2] Pindrik J, Huisman TA, Mahesh M, Tekes A, Ahn ES. Analysis
of limited sequence head CT for children with shunted
hydrocephalus: potential to reduce diagnostic radiation
exposure. J Neurosurg Pediatr. 2013; 12(5):491–500
[3] Orman G, Bosemani T, Aylin T, Poretti A, Huisman TA. Scout
view in pediatric CT neuroradiological evaluation: do not
underestimate! Childs Nerv Syst. 2014; 30(2):307–311
Neuroradiology
34

6 Conventional Magnetic Resonance Imaging
Thierry A.G.M. Huisman
6.1 Introduction
Magnetic resonance imaging (MRI) generates
images of the central nervous system based on the
distribution and electromagnetic characteristics of
protons within the body while exposed to a strong
modulated external magnetic field. Depending on
the used pulse sequences, various image contrasts
can be generated. T1- and T2-weighted sequences
serve as the backbone of anatomical MRI. Multiple
additional, specialized MR sequences are nowa-
days available. Many of these sequences represent
variations on the T1- and T2-weighted sequences
but may o er additional specific contrasts, thereby
facilitating diagnosis.
6.2 T1- and T2-weighted
Sequences
For anatomical imaging, typically T1- and T2-
weighted sequences are being used. On T1-weighted
images, fluid (cerebrospinal fluid [CSF]) appears
hypointense, and on T2-weighted images, fluid
appears hyperintense. The signal intensity of the
gray and white matter is highly dependent on the
degree of brain maturation. In the first months of
life, the gray matter appears T1-hyperintense and
T2-hypointense compared to the white matter;
around 8 to 10 months of age, the gray and white
matter become isointense to each other, before a
reversal of contrast occurs in which the gray matter
becomes T1-hypointense and T2-hyperintense in
relation to the white matter. The time evolution of
the changes in signal intensities is somewhat di er-
ent for the T1- and T2-weighted imaging because
the T1 and T2 relaxation phenomena are deter-
mined by varying maturational processes. Progress-
ing white matter myelination and increasing fiber
packing follow a well-programmed pattern. The first
regions to mature include the sensory and motor
cortex, including the corticospinal and sensory
tracts extending through the corona radiate, inter-
nal capsule, and mesencephalon into the brainstem.
Almost simultaneously, the visual cortex and optic
radiation show an early myelination. These areas
appear particularly T1-hyperintense and T2-hypoin-
tense. Familiarity with the normal-progressing brain
maturation is essential to identify disease processes.
6.3 Contrast-enhanced
T1-weighted MRI
Similar to CT, injection of intravenous contrast
agents may facilitate diagnosis in pathologies that
injure the blood–brain barrier (e.g., neoplasms,
infection) or show an intrinsic increased vascular-
ity (e.g., vascular malformations). In MRI, gadoli-
nium-based contrast agents are used. The para-
magnetic e ects of gadolinium shorten the T1
relaxation times of the examined tissue. Lesions
with a leaky blood–brain barrier consequently
appear T1-hyperintense. In high concentrations,
the paramagnetic properties of gadolinium may
result in a focal signal loss or susceptibility artifact.
Within the brain, gadolinium does not reach a high
enough concentration to induce focal signal loss;
this may, however, be observed within the renal
pelvis and urinary bladder. Gadolinium-based con-
trast agents used in diagnostic dosage have no sig-
nificant impact on the T2 relaxation times; the T2
signal characteristics are not altered. Conse-
quently, T2-weighted sequences may be acquired
after gadolinium-based contrast agents have been
injected.
Less than 1/1,000 patients may show minor
allergic reactions to gadolinium-based contrast
agents. Side e ects include facial swelling, head-
ache, nausea, and a rash or hives. In patients with
an impaired renal function, gadolinium-based
contrast agents have been linked to the occurrence
of nephrogenic systemic fibrosis and nephrogenic
fibrosing dermopathy. To prevent this potentially
debilitating or life-threatening complication, the
estimated glomerular filtration rate (eGFR) should
be calculated prior to the injection of gadolinium-
based contrast agents. In children, the eGFR is best
calculated using the Schwartz equation, which
employs the serum creatinine concentration (mg/
dL), the child’s height (cm), and an age-dependent
constant k: eGFR= k ×height/serum creatinine. In
the first year of life, for preterm neonates k= 0.33
and for full-term neonates k = 0.45. For infants and
children age 1 to 12 years, k =0.55. In adolescent
males, k =0.70, and in females k remains 0.55
because of the presumed increase in male muscle
mass. If the calculated eGFR is below 30 mL/min/
1.73 m 2, no contrast should be given, even when
the patient is on dialysis. If the eGFR is between 30
35

and 60 mL/min/1.73 m 2, the benefits must out-
weighted the potential risks and an informed con-
sent should be obtained. If the eGFR is above
60 mL/min/1.73 m 2, contrast can be given at a reg-
ular dose.
6.4 Fat-saturated T1- and
T2-weighted Sequences
The diagnostic sensitivity of T1- and T2-weighted
sequences may be further enhanced by the simul-
taneous use of a fat saturation pulse. The selective
suppression of the fat signal can be especially help-
ful for contrast-enhanced T1-weighted sequences
if a focal lesion is embedded within T1-hyperin-
tense fat. Contrast-enhancing metastatic lesions
within the diploic space of the skull are typically
better appreciated, as well as lesions within the
fat-containing epidural space of the vertebral col-
umn. Finally, comparing T1-weighted images
before and after a fat saturation pulse may prove
the presence of fat within a lesion, facilitating
diagnosis of, for example, a teratoma.
6.5 Fluid-attenuated Inversion
Recovery
In fluid-attenuated inversion recovery (FLAIR)
sequences, the signal intensity of free, mobile
water is suppressed (e.g., CSF), which facilitates
diagnosis of focal or di use white matter lesions
such as multiple sclerosis plaques along the ven-
tricles, inflammation, trauma, acute or chronic
(hemorrhagic) stroke, or white matter gliosis. In
addition, FLAIR is beneficial to identify pathology
within the subarachnoid space, such as subarach-
noid hemorrhage or metastatic seeding of malig-
nancies. Signal suppression of the CSF within the
brain sulci may be limited if the study is per-
formed in general anesthesia. The anesthetics and
hyperventilation may impair signal suppression.
FLAIR imaging is of little value in the neonate
because the brain is still very watery.
6.6 T2* - Gradient Echo and
Susceptibility-weighted
Imaging
T2*-weighted gradient echo (T2*-GRE) and sus-
ceptibility-weighted imaging (SWI) are exquisitely
sensitive for the magnetic susceptibility e ects of
blood products and calcifications. These sequences
should be added to the standard sequences in chil-
dren with traumatic brain injury, intracranial
hemorrhage, vascular malformations (e.g., caver-
nomas), TORCH (toxoplasmosis, other, rubella,
cytomegalovirus, herpes) infection, calcifying or
hemorrhaging brain tumors (e.g., oligoden-
droglioma, primitive neuroectodermal tumor,
teratoma), and any other pathology that may be
complicated by calcifications or hemorrhages. SWI
sequences should be preferred above T2*-GRE
sequences because of their higher sensitivity.
Because the basic design of these sequences is to
enhance the magnetic susceptibility e ects of sub-
stances that interfere with the magnetic field, they
are also very susceptible to image distortion
related to metallic implants including adjacent
dental braces.
6.7 Inversion Recovery
Sequences
Inversion recovery (IR) T1-weighted sequences are
heavily T1-weighted sequences. Main advantage is
that these sequences enhance the contrast between
gray and white matter and are consequently fre-
quently used in the diagnostic workup of children
with seizures secondary to congenital developmen-
tal disorders including cortical dysplasia, polymicro-
gyria, pachygyria, band heterotopia, or focal nodular
heterotopia. In addition, IR T1-weighted sequences
enhance detection of gray matter injury secondary
to acquired pathologies.
6.8 Heavily T2-weighted MRI
Heavily T2-weighted, thin-sliced, high-resolution
three-dimensional MRI (CISS [constructive inter-
ference in steady state]) renders images with a
high contrast between solid tissues and fluid. This
sequence is especially helpful to study detailed
anatomical structures containing or outlined by
CSF. This sequence is typically used to study the
cranial nerves crossing the basal cisterns, the vesti-
bulocochlear nerves within the internal auditory
canal, the intraorbital segment of the optic nerve,
the spinal cord, and nerve roots of the cauda
equine as well as the inner ear structures such as
cochlea, vestibule, and semicircular canals. Be-
cause this sequence is a three-dimensional acquis-
ition, multiplanar two- and three-dimensional
images can be generated. Major limitation is
that the sequence does not allow studying subtle
Neuroradiology
36

di erences in T2 relaxation times between struc-
tures. Consequently, the sequences cannot be used
to study subtle white and gray matter lesions. The
gray and white matter appear isointense, for
example, the extent of acute stroke may be under-
estimated.
6.9 Ultrafast MRI
Single-shot, ultrafast half-Fourier acquisition MR se-
quences is a valuable alternative for imaging chil-
dren who have di culty to hold still (young age,
anxiety, limited cognitive function). These sequences
render images within 400 to 800 ms per slice. Most
sequences are T2-weighted. Because this acquisition
is a single-shot technique, only those slices will be
degraded by motion artifacts that were acquired
while the child was moving. The total acquisition
time of a triplanar, ultrafast MRI of the brain ranges
between 5 and 8 minutes. These sequences are typi-
cally used for a rapid evaluation of children with
shunted hydrocephalus or to exclude major compli-
cations, for example, after surgery.
6.10 Contraindications for MRI
There are various absolute and relative contraindi-
cations for MRI. They may vary depending on the
magnetic field strength used.
Absolute contraindications:
1. Cardiac pacemaker, implanted
neurostimulators, cochlear implants, insulin
pumps, baclofen pumps.
2. Ferromagnetic vascular occlusion devices
including clips.
3. Ferromagnetic implants or foreign bodies
including shrapnel.
4. Metallic fragments within the orbits.
Relative contraindications:
1. Programmable ventricular shunts.
2. Intracranial pressure devices.
3. Claustrophobia.
4. Critically sick, unstable children.
5. Morbid obesity.
6. Ferromagnetic implants within regions adjacent
to the field of interest (dental braces).
Care should be taken to inform the MR team
m em bers in advance which implants are present,
if they are MR compatible, and if they have to be
reprogram m ed after im aging. Several devices
have been FDA-approved for 1.5-tesla MR scan-
ners but m ay not be im aged at higher field
strengths. If there is a clinical concern, the ven-
dor of the device should be contacted prior to
im aging. Finally, in rare occasions a conventional
radiography m ay be necessary to rule out, local-
ize, or identify the kind of implanted device or
foreign body.
Finally, care should be taken not to have any
external electrical wires arranged within a loop
close to the patient’s skin. These may act as
receivers for the used radiofrequency pulses dur-
ing scanning, and the induced electrical current
may heat the wires with possible skin burning.
This is of special importance in sedated or intu-
bated children who cannot give a direct feedback.
Clothes should always be checked for ferromag-
netic objects (e.g., buttons, jewelry).
Conventional Magnetic Resonance Imaging
37

7 Advanced MRI Techniques
Thierry A.G.M. Huisman
7.1 Introduction
In addition to the anatomical magnetic resonance
imaging (MRI) sequences, a multitude of advanced
MRI sequences are available that give important
additional information about arterial or venous
blood flow (magnetic resonance angiography
[MRA], magnetic resonance venography [MRV]),
cerebrospinal flow dynamics (cerebrospinal fluid
[CSF] flow), microstructural neuroarchitecture
(di usion-weighted imaging [DWI]/di usion ten-
sor imaging [DTI]), brain perfusion (perfusion-
weighted imaging [PWI]), biochemical processes
(1H magnetic resonance spectroscopy [1H-MRS]),
and functional centers (functional MRI [fMRI]).1
This additional information may help better char-
acterization of the findings or may narrow di er-
ential diagnosis. In addition, these functional
techniques may show pathology at the microstruc-
tural level which remains undetected on anatomi-
cal MRI or show pathology before they become
apparent on conventional MRI.
7.2 Magnetic Resonance
Angiography and Venography
Various two- and three-dimensional MRA and
MRV techniques allow study of the vasculature of
the central nervous system noninvasively. Depend-
ing on the expected hemodynamics, vascular path-
ology, vasculature of interest, and location of the
imaged lesion, time-of-flight (TOF) or phase-con-
trast (PC) angiographic techniques are applied. In
these angiographic techniques, blood flow is trans-
lated into an MRI signal. Typically, two-dimen-
sional raw images are generated in which the MRI
signal of stationary tissue (gray or white matter) is
suppressed, while the signal of moving blood is
enhanced. The resultant raw images are subse-
quently reconstructed as axial, coronal, and sagit-
tal maximum intensity projection (MIP) images or
three-dimensional rotational images similar to
catheter angiography. Both the raw images and the
reconstructed MIP and three-dimensional MRA or
MRV images should be studied for pathology.
MRA and MRV su er from some important limi-
tations. In TOF-MRA/MRV, the short T1 relaxation
time of a fresh thrombus may mimic blood flow;
slow blood flow, calcifications, or vascular clips
may mimic or overestimate a stenosis; small ves-
sels may be overlooked; and finally, blood flow
direction and blood flow velocity cannot be deter-
mined for certainty. In PC MRA/MRV, inadequate
selection of the velocity encoding may result in ali-
asing artifacts and patency of vessels may be
underestimated. In addition, the acquisition time,
especially for three-dimensional PC MRA/MRV, is
significant.
Dynamic contrast-enhanced MRA/MRV is a val-
uable alternative angiographic technique in which
a bolus of gadolinium-based contrast is injected
while images are scanned in a rapid sequence to
resolve the various angiographic phases (arterial,
parenchymal, venous, and delayed venous). This
technique is especially helpful for the hemody-
namic analysis of vascular malformations; how-
ever, the spatial resolution is somewhat limited.
7.3 Cerebrospinal Fluid
Flow Imaging
PC flow–sensitive sequences can also be used to
study the CSF flow noninvasively. PC CSF flow
techniques are typically used to evaluate flow of
CSF at the level of the foramen of magnum (e.g.,
in Chiari I malformation), sylvian aqueduct (e.g., in
aqueductal stenosis), and across the floor of the
third ventricle after third ventriculostomy. PC CSF
flow imaging gives quantitative information about
the CSF flow velocity, direction, and pulsatility.
7.4 Di usion-weighted
Imaging and Di usion
Tensor Imaging
7.4.1 Di usion-weighted Imaging
In DWI, di erences in the di usion characteristics
between various tissues are translated into di er-
ences in assigned signal intensity per voxel.2
Regions with high degree of water mobility or high
degree of di usion such as CSF will be suppressed
in their signal, while regions with limited water
mobility or low degree of di usion such as gray
and white matter will be less suppressed in their
signal. On the resultant trace of di usion or DWI
images, CSF will be hypointense in contrast to the
38

more signal-intense gray and white matter. In
addition to the DWI images, an apparent di usion
coe cient (ADC) is being calculated. This quantita-
tive scalar is similarly mapped as a two-dimen-
sional image in which regions with high ADC
values or high degree of di usion are represented
bright and regions with low ADC values or low dif-
fusion are displayed dark. Major advantage of this
ADC map is that this image is a true image of di u-
sion and no residual T1 or T2 relaxation phenom-
ena are incorporated. In addition, the ADC values
can be extracted by a region of interest approach.
These ADC values can be compared between stud-
ies and subjects.
The use of DWI and ADC maps has revolution-
ized early detection of cerebral stroke. In ischemic
stroke, cytotoxic edema occurs before vasogenic
edema develops. Cytotoxic edema results from a
failure of the ischemic membrane pumps with
influx of water into the cells; the resultant cell
swelling limits di usion, which can be detected by
DWI. The ischemic tissue appears DWI-hyperin-
tense and ADC-dark. The overall amount of water
has, however, not changed, explaining why in this
early phase conventional T1- and T2-weighted
imaging is unremarkable. Within the next phase,
e ux of water from the vessels into the extracellu-
lar space, known as vasogenic edema, will increase
overall di usion of the ischemic tissue (DWI-hypo-
intense and ADC-bright). Because of the increased
overall amount of water, conventional T1- and
T2-weighted imaging reveals the ongoing ischemic
injury.
DWI has also proven to be helpful in di erenti-
ating intracerebral abscesses from necrotic brain
tumors. Di usion within an abscess is typically
restricted (DWI-hyperintense, ADC-dark), while
di usion is increased in necrotic tumor (DWI-
hypointense, ADC-bright).
7.4.2 Di usion Tensor Imaging
DTI is a more advanced DWI in which in addition
to the magnitude of di usion (ADC values), the
three-dimensional shape and direction of di usion
is also sampled.1,3 Di usion within tissues is deter-
mined by many factors including the specific
microstructural environment. Along white matter
tracts, the di usion of water is predominantly
occurring along the main axis of the tract, while
the di usion is limited perpendicular to the main
axis of the tract because of the myelin sheet. This
directional di usion is also known as anisotropic
di usion. In CSF, di usion is equal in all directions,
known as isotropic di usion. In DTI, the entire ten-
sor of di usion is sampled by applying di usion-
encoding gradients along at least six directions in
space. In DTI, in addition to the DWI and ADC
images, maps of anisotropic di usion are gener-
ated. Most frequently, a scalar known as fractional
anisotropy (FA) is calculated. The FA scalar varies
between 0 and 1. Zero refers to equal di usion in
all direction in space (maximum isotropic di u-
sion), while an FAvalue of 1 refers to complete ani-
sotropic di usion. The magnitude of the FA value
can be mapped as a grayscale map similar to the
ADC maps. The corpus callosum appears conse-
quently bright on the FA maps matching a high FA
value, while CSF appears dark matching a low FA
value.
In addition, because not only the three-dimen-
sional shape and magnitude of di usion, but also
the predominant direction of anisotropic di usion
in space is sampled, these FA maps can be color
coded. By convention, predominant di usion from
left to right is color coded in red, di usion from
superior to inferior in blue, and anterior to poste-
rior in green.
Finally, powerful postprocessing programs allow
reconstruction of fiber tracts from these DTI data.
This technique, which is also known as fiber trac-
tography, allows study of the course and integrity
of fiber tracts within the brain noninvasively. This
technique is helpful in the detailed workup of
complex brain malformations but can also be used
in the preoperative workup of children who
require brain surgery. Displaced, interrupted, or
fiber tracts adjacent to a tumor can be studied.
7.5 Perfusion-weighted
Imaging
PWI aims to study brain perfusion noninvasively.4
Various techniques are available. A robust and
frequently used approach is the first-pass con-
trast-enhanced PWI technique. The passage of a
compact bolus of gadolinium-based contrast
agents through the capillary network of the central
nervous system results in a signal loss within the
tissue, which gives indirect information about the
local hemodynamics. Multiple semi-quantitative
maps of cerebral blood flow (CBF), cerebral blood
volume, mean transit time, time to peak, and vari-
ous other hemodynamic parametric maps can be
calculated. Alternatively, arterial spin labeling
(ASL) labels a volume of blood upstream of the re-
gion of interest by a short radiofrequency pulse.
Advanced MRI Techniques
39

Signal acquisition is carried out after a delay TI
(time of inversion of 1–2 seconds). The di erence
in signal between measurements with and with-
out ASL reflects the amount of labeled blood arriv-
ing in the volume of interest during the delay TI, to
calculate maps of CBF. Major advantages of this
technique are that the patient’s blood is used as an
intrinsic contrast agent, multiple vascular territo-
ries can be studied separately, and the study can
be repeated as often as necessary because no con-
trast agent is injected. Disadvantage is that the
method renders only maps of CBF and that multi-
ple measurements are necessary to boost the sig-
nal-to-noise ratio, which lengthens the imaging
time.
The combined use of DWI/DTI and PWI has pro-
ven to be beneficial especially in the diagnostic
workup of children with an ischemic stroke. The
typically irreversible core of infarction is charac-
terized by an area of restricted di usion on DWI/
DTI, which matches a region of hypoperfusion on
PWI. The surrounding ischemic penumbra which
is believed to represent tissue at risk for infarct
progression but which can potentially be salvaged
with adequate treatment is characterized by a re-
gion of hypoperfusion without matching restricted
di usion.
Furthermore, PWI is helpful in the hemody-
namic characterization of brain tumors and vascu-
lar malformations. Finally, PWI is being used in the
preoperative diagnostic workup of children with
chronic progressive vasculopathy such as in moya-
moya disease.
7.6 1H-Magnetic Resonance
Spectroscopy
1H-MRS allows identification and quantification of
various metabolites within the brain noninva-
sively. Various approaches are available including a
semi-quantitative versus quantitative single or
multivoxel technique. In the semi-quantitative
technique, ratios between the various metabolites
are being calculated. Typically, the metabolites are
correlated against creatine, because this marker of
energy metabolism is in most instances stable. In
the quantitative approach, the exact concentration
of the measured metabolite is determined. Typi-
cally, following metabolites are determined by
1H-MRS: lactate (marker of anaerobic metabo-
lism), N-acetyl aspartate (NAA; marker of neuronal
density and integrity), creatine (marker of energy
metabolism), and choline (marker of membrane
turnover). In many disease processes, the ratios or
concentrations of these major metabolites are
altered. In ischemic stroke, lactate is typically ele-
vated, while NAA is reduced; in highly malignant
brain neoplasms, choline is elevated and NAA
may be reduced. Furthermore, various additional
metabolites (e.g., myo-inositol, glycine) may be
detected or are significantly increased in their con-
centrations.
7.7 Functional MRI
fMRI allows study of functional processes within
the brain noninvasively. fMRI relies on the blood-
oxygen-level dependent (BOLD) technique. Areas
of brain that are activated typically receive more
oxygenated blood than necessary for the increased
metabolic demands. This overshoot in oxygenated
hemoglobin versus deoxygenated hemoglobin—
the two di erent kinds of hemoglobin that have
di erent magnetic susceptibility characteristics—
results in a cortical activation–related decrease of
MRI signal. Combining ultrafast fMRI sequences
with conventional anatomical MRI sequences
allows localization of functional centers within the
brain. The function-related signal change is mini-
mal (1–2% at 1.5-tesla field strength) but signifi-
cant enough to give reliable data. This technique,
however, requires robust and reproducible func-
tional paradigms to study these functional centers.
In pediatric neurosurgery, these techniques may
be valuable to identify important functional cen-
ters in close proximity to surgical fields.
7.8 Digital Subtraction
Angiography
Digital subtraction angiography (DSA) allows study
of the vasculature of the central nervous system
by selective injection of iodinated contrast agents
into the vessels of interest via an endovascular
catheter. By subtracting a “mask” image obtained
prior to contrast injection from the contrast-
injected images, the vessels are displayed in high
detail, free of overlying or obscuring bony struc-
tures. Multiple images are collected at a rapid rate
after injection in order to have multiple contrast
phases including an arterial, venous, and late
venous phase. Depending on the positioning of the
catheter, selective or superselective vascular imag-
ing is possible. DSA remains the gold standard of
vascular imaging and can be combined with a sub-
sequent endovascular intervention (e.g., aneurysm
Neuroradiology
40

coiling, embolization of a vascular malformation,
chemoembolization of a malignant tumor).
DSA in pediatric neuroimaging should be per-
formed by an experienced angiography team.
Frequently, the studies are performed in general
anesthesia. Alternative angiographic imaging
should always be pursued whenever possible. DSA
may not be suitable for children with renal insu -
ciency because of the side e ects of iodinated con-
trast agents. In addition, this technique relies on
the use of ionizing radiation.
References
[1] Huisman TA, Tekes A. Advanced MR brain imaging. Why?
Pediatr Radiol. 2008; 38 Suppl 3:S415–S432
[2] Huisman TA. Di usion-weighted imaging: basic concepts and
application in cerebral stroke and head trauma. Eur Radiol.
2003; 13(10):2283–2297
[3] Poretti A, Meoded A, Rossi A, Raybaud C, Huisman TA.
Di usion tensor imaging and fiber tractography in brain
malformations. Pediatr Radiol. 2013; 43(1):28–54
[4] Huisman TA, Sorensen AG. Perfusion-weighted magnetic
resonance imaging of the brain: techniques and application
in children. Eur Radiol. 2004; 14(1):59–72
Advanced MRI Techniques
41

(Trang không có chữ)

III
Section III
Neurology
8 The Neurological Examination
of the Infant and Child

44
9 Spinal Cord Tracts and
Development

58
10 Migration Disorders

63
11 Neurofibromatosis Type 1

68
12 Medical Management for
Epilepsy

77

8 The Neurological Examination of the Infant
and Child
Neil R. Friedman
8.1 Introduction
A complete neurological assessment includes a
meticulous, precise, and comprehensive history
and detailed neurological examination. The goal of
such an approach is to establish, and narrow, a
di erential diagnosis, thereby helping to direct
further evaluation and investigations. This is par-
ticularly important given the breadth and extent
of investigational studies, including metabolic,
genetic, neurophysiology, and neuroimaging stud-
ies available to the practitioner. The old clinical
adage that most diagnoses can be made on the
basis of the history alone still holds true despite
technological advances. The three fundamental
questions to be addressed through the history and
examination of a patient are the following: (1) Is
the problem neurological? (2) If so, where within
the neuroaxis can the problem be localized to? (3)
What is the nature or pathophysiology of the pro-
blem?
There are fundamental di erences between the
neurological assessment of newborns, infants, and
young children and that of adolescents or adults,
given the rapidly developing and maturing brain,
both structurally (e.g., maturation of myelin) and
physiologically (e.g., the formation of neural net-
works), of newborn, infants, and young children.
These developmental di erences not only impact
the history and examination, but also are subject
to di erent pathophysiological processes and
manifestations of disease states compared to those
seen in a “mature” brain. Development, therefore,
is an important variable in the evaluation of
infants and young children, and delay in achieving
age-specific developmental milestones and abnor-
mal patterns of development are important indica-
tors of underlying neurological disease.
One of the most important hallmarks of these
developmental di erences is white matter myeli-
nation in the brain. Progressive myelination occurs
from early in the second trimester of pregnancy
until well into childhood and adolescents. This is
best reflected by brain magnetic resonant imaging
studies, where white matter maturation on
T2-weighted imaging does not reach a “mature
pattern” until age 2. It is myelination of the corti-
cospinal tracts in the first year of life that
ultimately allows the infant to sit and subse-
quently to walk independently. Head growth,
another reflection of brain development and
maturation, on average is 12 cm during the first
2 years of life, compared with approximately 5 cm
during the subsequent 16 years.
The age-dependent acquisition of gross motor,
fine motor, speech and language, and social skills,
inability of an infant or younger child to recount
the history, and diverse nature of neurological
conditions a ecting children are fundamental dif-
ferences between the pediatric and adult neuro-
logical assessment.
8.2 History
Know or listen to those who know.
Baltasar Gracián
Obtaining a good history is crucial to the neurolog-
ical examination and requires a good rapport
between the physician and the family. An accurate
history also provides focus to the physical exami-
nation. While it is not always possible to obtain
the history directly from the child, every e ort
should be made, when possible, to allow the child
to express himself or herself in his or her own
words in describing his or her symptoms. When
the parent or guardian provides the history, it is
important to distinguish the subjective interpreta-
tion of symptoms from direct observation of
symptoms. Since the history is often a composite
of the child’s own words and third-party observa-
tion, every e ort should be made to clarify the
symptoms in simple, descriptive language rather
than rely on medical jargon. The history should be
informed by recognizing patterns of disease and
disease processes, and as the history develops,
directed questioning may be necessary to explore
di erential diagnostic possibilities. It is often help-
ful to consider this by taking into account the
underlying pathophysiological basis of disease,
namely:
● Congenital.
● Traumatic.
● Inflammatory.
● Infectious.
44

● Ischemic/vascular.
● Toxic/drug.
● Metabolic.
● Endocrine.
● Neoplastic.
8.2.1 History of Presenting
Problem
A systematic approach to the history is important
and begins with elucidating the nature of the pre-
senting problem(s). This may involve a chronologi-
cal or symptom-based approach. Important details
include symptom onset (acute, subacute, chronic),
duration of symptoms, temporal pattern of the
problem (static, progressive, recurrent, diurnal
variation, or regressive), potential modifying fac-
tors (exacerbation or relieving factors), and/or any
associated symptoms. It is important to know
what, if any, prior interventions have been tried
and the results of these interventions, as this may
impact the presentation of the current problem.
Establishing a child’s prior baseline functioning
from current level of functioning helps in deter-
mining the severity and potential degenerative
nature of an illness. The history should also help
establish whether the symptoms can be localized
to one region of the neuroaxis, or whether a com-
bination of systems is involved. One distinguishing
feature in the pediatric history is the frequent
involvement of developmental concerns. Not only
must one be aware of normal developmental
milestones to know whether any deviation is
abnormal, but also determining whether the
developmental concern is global or limited to one
or more of the four specific domains of develop-
ment, that is, gross motor, fine motor, social, or
speech/language, is crucial in generating a di er-
ential diagnosis and directing further testing.
Genetic contribution to pediatric neurological dis-
ease is increasingly important, so knowing
whether other family members are involved can
narrow the di erential diagnosis by considering
potential X-linked or autosomal inheritance of a
problem being addressed. When a metabolic dis-
order is suspected, parents should be asked
whether the child’s breath or urine has a strange
odor, especially at times of illness. Marked decom-
pensation at the time of illness, with vomiting,
pallor, and delayed recovery, is suggestive of a dis-
order of intermediary energy metabolism or urea
cycle defect. It is important to determine what
prior testing or investigations have been under-
taken so as to reduce unnecessary duplication of
studies and potentially help eliminate certain diag-
nostic considerations.
8.2.2 Birth History
The birth history is an integral part of the neuro-
logical history of the infant and young child and
may provide an etiological clue to the di erential
diagnosis in this age group. Many chronic neuro-
logical problems have their origins in the prenatal
period at the time of prosencephalic development,
migration, and maturation of the immature brain.
Problems in the perinatal and peripartum period
are also potentially important factors in subse-
quent neurological development. Genetic disor-
ders, hypoxic-ischemic events, infection, drug use
or abuse, toxins, trauma, and malnutrition all
impact the developing brain and are important to
inquire about in the history. More than one-half of
the cases of cerebral palsy have an antenatal cause.
The birth history can best be considered in three
discreet periods—the antenatal course, labor and
delivery, and the postnatal period. Problems dur-
ing these periods are not always mutually exclu-
sive. For example, a child with an underlying
neuromuscular or genetic disorder may not be as
resilient in withstanding the process of labor and
delivery, resulting in potential fetal distress.
Antenatal/Prenatal Period
There are a number of pertinent factors to inquire
about during the antenatal period. This includes:
● Conception: It is important to determine if
conception was natural or achieved through
assisted reproductive technology (ART), as the
latter has been associated with an increased risk
for adverse neurological outcome. Whether the
risk is related to the indication for ART, rather
than the ART itself, is often unclear. Multiple
births increase the risk for prematurity and
unique situations such as twin-to-twin
transfusion, thereby increasing the risk for brain
injury.
● Maternal factors:
– Age: Maternal age at both ends of the
spectrum, namely, teenage years and woman
over 40, has both been implicated in
subsequent neurodevelopmental problems. In
women over 40, there is also an increased risk
for genetic abnormalities, the most common of
which is Down’s syndrome.
Neurodevelopmental outcome of children born
The Neurological Examination of the Infant and Child
45

to teenage mothers is confounded by other
variables such as typically lower
socioeconomic status. Increasingly, attention is
being focused on paternal age and risk of
neurodevelopmental disability.
– Maternal health: Pregnancy predisposes
women to transient medical disease such as
gestational diabetes or pregnancy-induced
hypertension. Uncontrolled, this places the
developing fetus at risk for neurological
impairment and malformations, either directly
or through risk factors such as prematurity
and intrauterine grow th retardation (IUGR). In
addition to acquired medical problems during
pregnancy, chronic medical illness, such as
diabetes, thyroid disorders, malnutrition,
obesity, and congenital heart disease, also
places the fetus at risk for impaired
neurological outcomes.
– Infection: Congenital infections, specifically
the toxoplasmosis, rubella, cytomegalovirus,
herpes simplex, and syphilis (TORCHS),
lymphocytic choriomeningitis virus (LCMV),
human parechovirus, and HIV infections are
well-known causes of neurological
impairment including cortical migration
abnormalities, microcephaly, cognitive
impairment, spastic quadriplegic cerebral
palsy, and epilepsy. Almost any virus, however,
may be implicated. These infections may be
relatively silent in the mother.
– Drug or toxin exposure: It is important to ask
about, and document, both illicit and
prescription drug usage during pregnancy.
Many prescription drugs, especially
antiepileptic medications, are teratogenic and
associated with well-established syndrom es
and phenotypes (e.g., phenytoin and fetal
hydantoin syndrome, valproic acid and fetal
valproate syndrome). Illicit drugs such as
cocaine or “crack” may be associated with
neonatal stroke or intracranial hemorrhage.
Smoking and alcohol both a ect fetal
developm ent. Cigarette sm oking m ay result
in IUGR and fetal distress at delivery. Alcohol
abuse m ay result in fetal alcohol syndrom e
or fetal alcohol e ects, w hich have
neurological complications, especially
im paired cognitive developm ent and
behavioral disturbances.
● Pregnancy factors: It is important to ask about
the health of the pregnancy. Specific questions
directed at fetal movement and amniotic fluid
status may provide crucial clues to diagnosis.
Diminished fetal movement, especially when
abrupt, may be indicative of a fetus at risk or in
distress, whereas decreased fetal movement
throughout the pregnancy may be more
indicative an underlying neuromuscular
disorder. Excessive fetal movement, especially in
short bursts, has been associated with in utero
seizures. Oligohydramnios may result in
diminished fetal movement and subsequent
joint contractures (arthrogryposis), whereas
impaired swallowing may result in
oligohydramnios and provide a clue to an
underlying brain/brainstem m alform ation or
injury, or potential neurom uscular disorder.
Prenatal ultrasound scans are now routine, and
increasingly, fetal m agnetic resonance im aging
(MRI) is being done for better delineation of
detected fetal central nervous system
anom alies including brain m alform ations,
hydrocephalus, ischem ic or destructive brain
injury, choroid plexus cysts, and spinal
dysraphism .
Labor and Delivery
A number of factors during the peripartum period
may potentially provide clues to subsequent neu-
rological or neurodevelopmental problems in the
child. Chief among this is the gestational age at the
time of birth. A term pregnancy is 37 to 42 weeks
of completed gestation, late preterm 34 to 36
weeks of completed gestation, and preterm <34
weeks of gestation. The preterm brain is vulner-
able to white matter hypoxic-ischemic injury and
resultant periventricular leukomalacia (PVL) lead-
ing to typical spastic diplegic cerebral palsy. It is
also susceptible to germinal matrix-intraventricu-
lar hemorrhage (IVH) with the potential conse-
quence of obstructive hydrocephalus and/or
hemiplegia in the case of a grade IV IVH or peri-
ventricular echodensity. Birth weight is relevant in
so far as it relates to prematurity, with babies
weighing <1,500 g being at highest risk for PVL
and IVH, and may also be indicative of IUGR, sug-
gesting possible placental insu ciency. Other
important factors to consider and document
include Apgar score and the need for resuscitation,
type of resuscitation, and the presence or absence
of meconium, all of which may indicate potential
fetal distress and/or perinatal depression. Mode of
delivery may be of some relevance in that an
emergency cesarean section may indicate concerns
for fetal distress, whereas forceps delivery has
been implicated in facial nerve palsy at birth.
Neurology
46

Placental size and pathology, when available, may
provide important clues to potential placental
insu ciency, chorioamnionitis, placental calcifica-
tions, infarct(s), and/or prior placental abruption.
Chorioamnionitis is especially important as it is
a frequent cause of preterm labor and has inde-
pendently been implicated in IVH. It also increases
the risk for cerebral palsy in the term infant
through a number of pathophysiological processes,
including sepsis resulting in shock, hypoxic-
ischemic injury, or even meningitis. Identifying
whether perinatal hypoxia and ischemia are pri-
marily the result of a peripartum complication,
versus the stress of labor exacerbating a preexist-
ing condition, is crucial as the former situation
does not require further neurological workup as to
etiology, whereas with the latter situation further
evaluation as to etiology may be necessary to con-
sider a primary metabolic, genetic, or neuromus-
cular etiology.
Postnatal Course
Information regarding postnatal complications,
newborn screen, and potential neurological stud-
ies should be asked about. Factors to consider
include the need for mechanical ventilation,
extracorporeal membrane oxygenation, whole-
body or brain cooling, sepsis, hypoglycemia, and/
or a history of neonatal seizures. Feeding di cul-
ties, hypotonia, and neonatal encephalopathy are
other important factors that may have relevance to
the di erential diagnostic consideration. Ence-
phalopathy developing a few days after birth raises
the concern and inborn error of metabolism or
possible late-onset sepsis.
Neonatal seizures may be indicative of hypoxic-
ischemic encephalopathy, especially when occur-
ring within the first 24 hours after birth, and fre-
quently within 12 hours of birth. Twelve to fifteen
percent of all neonatal seizures occurring in term
babies are secondary to a perinatal stroke. Other
causes include electrolyte disturbances (hypogly-
cemia, hypocalcemia), metabolic disorders (such
as nonketotic hyperglycinemia and neonatal adre-
noleukodystrophy), malformations of cortical
development, meningitis, and potential drug with-
drawal e ects. Determining the etiology of the
seizures can be helpful when considering the dif-
ferential diagnosis. History of a burst suppression
electroencephalogram at birth is invariably associ-
ated with poor neurological outcome.
8.2.3 Developmental History
Development is a defining feature of childhood
and di erentiates the pediatric neurological his-
tory from that of the adult. The intellectual, social,
and motor developments of the child follow pre-
dictable patterns and meeting these developmen-
tal milestones is an important indication of the
maturation of the child’s nervous system and
neurological function. Delay in obtaining age-
appropriate developmental milestones and
abnormal patterns of development are therefore
important indicators of underlying neurological
disease. An appreciation of normal developmental
milestones is critical when evaluating an infant or
child. Assessing development is an essential part
and core component of the pediatric neurological
examination.
In assessing developmental delay, it is important
to distinguish between four functional domains,
namely, gross motor, fine motor, social, and speech
and language arenas. Global developmental delays
involving all four arenas should be distinguished
from disorders a ecting specific functional
domains or specific patterns of delay, for example,
pervasive developmental disorders. History should
provide a sense of mild, moderate, or severe devel-
opmental delay based on deviation from normal. It
is important to remember to correct for gesta-
tional age for the first 12 to 18 months in a child
born prematurely. It is important to determine
whether there is regression of skills in any arena,
as this could indicate a neurodegenerative process
(e.g., leukodystrophy) and focuses the di erential
diagnosis. As this history may not be evident on a
child’s initial evaluation, subsequent follow-up
and observation are important.
A number of standardized developmental scree-
ning tests are available (e.g., the Denver develop-
mental screening test, Gesell developmental test,
and the Binet test). For school-aged children, infor-
mation about cognitive functioning is often avail-
able from school proficiency tests or multifactorial
evaluations that include psychometric and
achievement tests. A strong hand preference in an
infant younger than 12 to 18 months of age is
always abnormal and suggests weakness or
apraxia of the opposite hand and side of the body.
Developmental speech and language delay, when
associated with impairments of socialization,
scripted behaviors, and repetitive and stereotyped
behaviors, should raise the concern of a possible
The Neurological Examination of the Infant and Child
47

pervasive developmental disorder or autistic
spectrum disorder. A history of true language
regression raises the possibility of an acquired epi-
leptic aphasia such as Landau–Kle ner syndrome.
8.2.4 Past Medical and Surgical
History
The presenting problem must be viewed in the
context of the patient’s past medical and surgical
history, as this often provides insights into the cur-
rent problem. Pertinent aspects of the past history
may provide additional clues or pattern recogni-
tion in generating a di erential diagnosis; for
example, in a child being investigated for proximal
muscle and neck flexor weakness, a history of aca-
demic di culties and hypertrophic cardiomyop-
athy should raise the diagnostic consideration of
Danon’s disease, and in a child with short stature,
failure to thrive, hearing loss, and retinal dys-
trophy, being evaluated with microcephaly and
developmental delay, a diagnosis of Cockayne’s
syndrome is considered.
Chronic underlying illness may also be a factor in
considering treatment options (e.g., avoiding beta-
blockers in patients with migraine headache who
have asthma, diabetes mellitus, or depression).
All prior hospitalizations and surgeries should
be noted.
8.2.5 Family and Social History
As genetic medicine is increasingly providing an
etiological basis for many pediatric neurological
diseases, obtaining a complete and accurate family
history is increasingly important in establishing a
possible autosomal, X-linked, or mitochondrial
inheritance pattern for the problem under investi-
gation. This may help in directing targeted gene
testing or identifying a condition that might not
otherwise be considered. Many other disorders are
also clearly familial, even in the absence of an
identified gene, for example, migraine headache,
learning disability, epilepsy, and Tourette’s syndro-
me, and their presence in a family may help with
the di erential diagnosis.
Social circumstances and environmental factors
may also contribute toward and a ect the expres-
sion of certain disorders. In adolescents, it is
important to inquire about alcohol, tobacco,
potential illicit drug use, and sexual history as it
pertains to the presenting problem.
8.2.6 Review of Systems
A systematic review of all major organ systems
should complete the medical history, and serves as a
symptom checklist to assure that all important areas
of the patient’s physical and psychological health
have been considered and not overlooked or forgot-
ten. The review of systems may also help illuminate
the diagnosis by eliciting information that the pa-
tient may not otherwise have perceived as being
important or related to the presenting problem.
8.3 Examination
At its essence, the neurological examination of the
infant and child is similar to the adult examination
and incorporates the same elements. What is dif-
ferent, however, is the approach. Instead of a sys-
tematic systems approach, one needs to approach
the child in a nonthreatening manner, and much
of the examination involves “games” and the use
of ancillary devices such as toys or puppets. Obser-
vation is key and many aspects of the neurological
examination can be gleaned from watching the
child play. Those parts of the examination that
may be perceived by the child as threatening, for
example, ophthalmological examination, should be
deferred until the end of the examination so as to
not destroy the trust between examiner and child.
Observing the child at play, at rest, and interacting
with his/her caregivers often reveals key elements
of the examination such as interactions with their
environment, behaviors, and asymmetries or ab-
normalities in posture or movement, for example,
dystonia, posturing, tremor, or infantile spasms. In
an older child and adolescent, a more traditional
system approach to the child is possible.
8.3.1 General Examination
Three features of the general examination of the
child that are important di erentiating factors from
the adult examination are attention to dysmorphol-
ogy, neurocutaneous findings, and head size and
shape. These areas should be addressed in all chil-
dren, especially given the importance of genetic
syndromes in pediatric neurological disease.
Dysmorphology
Many common genetic syndromes have neurologi-
cal involvement as part of the syndrome, and
Neurology
48

many primary neurological conditions have a
genetic basis as their etiology. More common
examples of the former include trisomy 21
(Down’s syndrome), Turner’s syndrome, fragile X
syndrome, Angelman’s syndrome, Prader–Willi
syndrome, Cornelia de Lange’s syndrome, and
velocardiofacial/DiGeorge’s syndrome. Craniofacial
and/or systemic dysmorphology usually give clues
to these diagnoses and the phenotypic appearance
is usually stereotyped. Midline defects such as cleft
lip and/or palate, central incisors, and certain con-
genital heart defects may be associated with
abnormalities of cortical migration, for example,
cerebellar atrophy or polymicrogyria in q22 micro-
deletion syndromes, and a 30% incidence of major
(agenesis of the corpus callosum, holoprosence-
phaly) or minor developmental brain anomalies in
hypoplastic left heart syndrome.
Neurocutaneous Stigmata
The association between neurocutaneous lesions
and central and/or peripheral nervous systems
abnormalities is well established. The diversity of
neurological symptoms is extensive and, as such, all
children should have their skin closely examined as
part of the neurological examination. Wood’s lamp is
usually more sensitive than visual inspection alone
and should be utilized if there is any suspicion for
birthmarks. The nature of the birthmark provides
clues as to the specific neurocutaneous syndrome or
phakomatoses (Table 8.1). Eye involvement is a fre-
quent accompaniment of these conditions.
Head Size and Shape
Measuring and plotting the head circumference is
an important part of the pediatric neurological
examination at all ages. Measurement should be in
absolute terms as well as expressed as a centile for
age. Relationship to weight and height centiles is
also important as it may reflect a relative micro-
or macrocephaly. Head size directly reflects intra-
cranial contents and the most dramatic increase in
brain volume occurs in the last trimester of preg-
nancy through the first two years after birth.
Microcephaly is present when head circumfer-
ence is 2 standard deviations below the mean. It
may be either primary, i.e., congenital or present
from birth, or secondary/acquired. Di erentiating
the two can be helpful in establishing a di erential
diagnosis, for example, the acquired microcephaly
seen in Rett’s syndrome as opposed to microce-
phaly polycythemia (rubra) in which the microce-
phaly is present at birth. Microcephaly may be
familial, so measurement of the parent’s head
circumference is important. Microcephaly may
also be due to malformations of cortical develop-
ment (e.g., schizencephaly, lissencephaly, and
polymicrogyria), hypoxic-ischemic brain injury,
congenital infections (e.g., cytomegalovirus, toxo-
plasmosis, and rubella), or premature fusion of the
sutures (craniosynostosis).
Macrocephaly is defined as 2 standard devia-
tions above the mean. In PTEN gene mutations,
head circumference is typically 3 standard devia-
tions above the mean. Macrocephaly is often a
familial genetic trait inherited from one parents,
so, when present, one should attempt to document
the parents’ head circumference measurements.
Benign macrocrania of infancy (also known as
Table 8.1 Neurocutaneous skin lesions and associated
syndromes
Skin findings

Syndrome
Café-au-lait macule

Neurofibromatosis
Legius’ syndrome
Tuberous sclerosis
Hypomelanosis of Ito
McCune–Albright
syndrome
Hypopigmented macule

Tuberous sclerosis
Hypomelanosis of Ito
Hyperpigmented macules
(following lines of Blaschko)
Incontinentia pigmenti
Shagreen patch

Tuberous sclerosis
Adenoma sebaceum

Tuberous sclerosis
Nevus flammeus

Sturge–Weber syndrome
Klippel–Trénaunay
syndrome
Gottron’s papules

Dermatomyositis
Unilateral linear nevus
(usually face)
Linear sebaceous nevus
syndrome
Papulovesicular lesions
(following lines of Blaschko)
Incontinentia pigmenti
Telangiectasia

Ataxia-telangiectasia
Xeroderma pigmentosum
Freckling

Neurofibromatosis
(LEOPARD syndrome)
Xeroderma pigmentosum
Axillary/inguinal freckling

Neurofibromatosis
Penile freckling

PTEN gene mutation
Multiple lentigines
syndrome (LEOPARD
syndrome)
The Neurological Examination of the Infant and Child
49

benign external hydrocephalus) is another com-
mon cause of macrocephaly and is also often fami-
lial in nature. It has a distinctive radiographic
appearance (increased extra-axial cerebrospinal
fluid spaces predominantly over the frontal con-
vexities and extending into the interhemispheric
fissure) and may be associated with mild motor
developmental delay. This needs to be distin-
guished from communicating or obstructive hydro-
cephalus, which may produce signs and symptoms
of increased intracranial pressure (lethargy, vomit-
ing, and “sun-setting” sign). Unlike benign macro-
crania of infancy in which the head circumference
follows its own appropriate centile, with hydroce-
phalus there is crossing of centile lines. Sequential
measurement of head circumference is therefore
important and may provide additional important
information. Macrocephaly may occur in some of
the neurocutaneous syndromes, especially neurofi-
bromatosis type 1. Other rare causes of macro-
cephaly include Alexander’s disease, Canavan’s
disease, glutaric aciduria type I, and thickening of the
skull (e.g., myelodysplasias or sickle cell disease).
Abnormalities of skull shape should also be
noted. Positional plagiocephaly is increasingly
being encountered with the “back to sleep” policy
for infants. Plagiocephaly may also occur secondary
to torticollis or may be seen in children with devel-
opmental delay and decreased mobility due to
hypotonia and/or weakness. Abnormal head shape
may be seen in isolated craniosynostosis with pre-
mature fusion of one or more of the sutures, or as
part of a craniofacial syndrome including Pfei er’s
syndrome (turribrachycephaly), Crouzon’s disease
(acrocephaly), Saethre–Chotzen syndrome (brachy-
cephaly), and Apert’s syndrome (brachycephaly).
The anterior fontanelle typically closes between
12 and 18 months of age, although this is variable
and closure at 6 months may be normal. Premature
closure may be associated with microcephaly or cra-
niosynostosis. Persistence of the anterior fontanelle
beyond 18 months, or a large anterior fontanelle,
raises the suspicion of hypothyroidism. Alarge fonta-
nelle may also be associated with increased intracra-
nial pressure, although this is usually also associated
with bulging of the fontanelle. The posterior fonta-
nelle typically closes between 3 and 6 months of age.
8.3.2 Neurological Examination
Mental Status
The mental status examination in the newborn,
infant, and child should include references to level
of consciousness, cognition, behaviors, and age-
based language ability. Identified deficits may
require more specialized neuropsychometric or
psychiatric testing, or completion of neurobeha-
vioral or autism ratings scales. A child’s aware-
ness of their environment, alertness, and appro-
priateness of interaction with the examiner
serves as a basis for level of consciousness.
Altered awareness in an encephalopathic patient
requires a more detailed assessm ent of level of
consciousness, including whether the patient is
confused or disoriented (tim e, place, or person),
sedated (requiring external stimulus to maintain
interaction), stuperose, or comatosed. It is very
important to docum ent the level of alertness
when examining the newborn baby, as the
examination may be very di erent depending on
whether the baby is awake/alert, drowsy, light
sleep, or in deep sleep.
A child’s cognitive ability, and whether age
appropriate or not, can usually be assessed from
the examiner’s direct interaction with the child
and the child’s ability to follow simple or more
complex commands with or without need for vis-
ual or other clues. Poor eye contact may be indica-
tive of an autistic spectrum disorder. With stranger
anxiety, a young infant will typically turn to
parents for reassurance when presented an object
from a “stranger,” whereas children with autistic
spectrum disorders often do not display this phe-
nomenon. Attention to task, impulsiveness, and
motor hyperactivity are particularly important to
note if academic di culties or disorders of behav-
ior are of concern. This should always be inter-
preted, however, in the context of the age of the
child and with reasonable expectations, given the
circumstances of a clinical examination. An assess-
ment of mood may be important, particularly for
patients with behavioral problems, chronic head-
ache, or chronic pain syndromes. Language assess-
ment should include age expressive and receptive
language ability, fluency, and articulation. Aware-
ness of age-related speech norms is important,
such as cooing in infants less than 6 months of age,
babbling with initial vowel sounds and then subse-
quently consonances and bisyllables between
6 and 12 months of age, cumulative word acquisi-
tion in the second year of life, and the joining of
words or short phrases by 2 years of age.
A more detailed mental status examination is
rarely necessary and should be dictated by the
presenting symptoms and history. With older
children and adolescents, a formal mini-mental
assessment can be performed if necessary.
Neurology
50

Cranial Nerves
Although examination of the cranial nerves in a
child is similar to that of the adult, there are some
notable exceptions.
Cranial nerve I (olfactory nerve): It is rarely
tested in children except when anosmia is an
important consideration (e.g., Kallmann’s syndro-
me). As it requires di erentiation of di erent
smells, it is hard to test in very young children but
can be tested by presenting the child with familiar
smells (for age) and asking the child to identify it
with his/her eyes closed.
Cranial nerve II (optic nerve): There are four
components in the examination of the optic nerve,
namely, visual acuity, visual fields, pupillary light
reflex, and fundoscopic examination. In the
newborn, the absence of a red reflex on direct
ophthalmoscopic examination raises the concern
of retinoblastoma. Confrontational visual field
testing is not possible in a very young child, but a
blink response to a threat provides a crude assess-
ment of visual field integrity. In slightly older
children, having them fixate on an object in the
midline while bringing in a bright toy from the
periphery will also provide an assessment of
peripheral visual field based on when they recog-
nize and turn toward the object. Visual acuity can
be tested in the young child by using a Snellen eye
chart or “E” chart.
Cranial nerve III, IV, and VI (oculom otor,
trochlear, and abducens nerves): The extraocular
muscles are tested by having the child look in the
six cardinal directions of gaze, namely, horizon-
tally, vertically, up and out to the left and right,
and down and out to the left and right. Fluidity of
movement and whether there are any saccadic
intrusions into smooth pursuit should be noted.
Although a very young infant will fix on and follow
a face, “doll’s head” movements (oculocephalic)
are usually necessary for assessing extraocular
movements during the neonatal period.
The use of a bright, colorful object is generally
necessary in an infant or older child to sustain
attention. Babies rarely begin to track until about
6 weeks of age. The trochlear nerve (IV nerve)
innervates the superior oblique muscle of each
eye, resulting in medial and downward deviation
with intorsion of the eye. Paresis of the nerve
results in an extorted eye and children often tilt
their head toward the opposite side to accommo-
date for the double vision. A head tilt or torticollis
in a child may therefore be the only clue to a fourth
nerve palsy, because the child may not complain of
diplopia. The abducens nerve (sixth nerve) inner-
vates the lateral rectus muscle, which is responsi-
ble for abduction of the eye. Injury or paresis of
the sixth nerve therefore results in adduction
(medial deviation) of the eye and diplopia. This is
often an accompanying sign and symptom in pseu-
dotumor cerebri. The oculomotor nerve (III nerve)
innervates the remainder of the eye muscles and
also provides parasympathetic fiber innervation of
the pupil responsible for pupillary constriction.
Involvement of the third nerve results in the eye
being in a “down and out” position, namely, later-
ally deviated and depressed, with a dilated pupil
and ptosis. In the older child who can describe dip-
lopia, the degree of diplopia will be greatest when
he/she is looking toward the direction correspond-
ing to the action of the impaired muscle. Ptosis
and ophthalmoplegia raises the possibility of
myasthenia gravis, mitochondrial cytopathy, or a
myotubular myopathy. Exotropia and esotropia are
frequently encountered in the infant and young
child, and latent strabismus can be unmasked by
the cover–uncover test. When these are detected,
the child should be referred to an ophthalmologist
for further evaluation and possible patching to
allow for fusion and the development of binocular
vision.
Cranial nerve V (trigem inal nerve): The trige-
minal nerve is predominately a sensory nerve but
does have a motor component that provides inner-
vations to the muscles of mastication (temporalis
and masseter muscles) and the muscle involved in
keeping the jaw open (lateral pterygoid muscle).
This can be assessed in younger children by having
them chew a cookie and in older children by hav-
ing them clench their teeth. The sensory distribu-
tion of the trigeminal nerve provides three distinct
areas of facial innervation, namely, the ophthalmic
branch (V1), maxillary branch (V2), and mandibu-
lar branch (V3). There branches can be individually
tested for light touch, pinprick, and temperature,
and when necessary vibration sense. The latter is
most helpful when a psychogenic sensory disorder
is suspected and the child or adolescent describes
a “midline splitting” of vibration sense in the
midline of the forehead, i.e., feeling the vibration
up to the midline and then not feeling it as the
midline is crossed. The rooting reflex in the new-
born can provide a crude assessment of nerve
function at birth. Examination of the sixth nerve
also involves the corneal reflex as the a erent
component of the corneal blink reflex is supplied
from the V1 distribution of the corneal nerve.
This is seldom part of the routine neurological
The Neurological Examination of the Infant and Child
51

examination in children, but is an important part
of the examination if a brainstem injury is sus-
pected, or in a comatose or brain dead patient.
Cranial nerve VII (facial nerve): The facial nerve
supplies motor branches to the muscles of facial
expression. There is also a sensory branch supply-
ing the skin over part of the pinna, a patch of skin
behind the ear, and the external surface of the
tympanic membrane. In the newborn, the facial
nerve is tested by direct observation of the baby
feeding and crying, and watching the movement of
the face. In an older child, asking them to make a
“funny face,” pu out their cheeks, smile or reveal
their teeth, close their eyelids tightly against
resistance, and raise their eyebrows or wrinkle up
their forehead (if able to cooperate) allows a good
assessment of facial nerve function. Taste is di -
cult to test in a young child and is generally
unnecessary. An upper motor neuron lesion a ect-
ing the facial nerve causes contralateral weakness
of the lower face, sparing the forehead (upper por-
tions of the orbicularis oculi and the frontalis
muscles) as the facial nuclei project bilaterally to
the forehead muscles. In lower motor neuron
lesions such as a Bell’s palsy, the weakness involves
the whole ipsilateral face, including forehead. In
the newborn period, di erentiating a lower motor
neuron facial lesion from congenital absence or
hypoplasia of the angularis oris muscle (“asym-
metric smiling facies”) is important. In the latter,
there is failure to depress the corner of the mouth
with smiling or crying while the rest of the facial
muscles and nasolabial fold are normal and sym-
metric. Congenital absence or hypoplasia of the
angularis oris muscle may occur in isolation and
be familial (autosomal dominant inheritance), but
may also be associated with Cayler’s syndrome in
which there may be associated congenital heart
disease or central nervous system problems
(including microcephaly, cognitive impairment,
cerebral and cerebellar atrophy).
Cranial nerve VIII (vestibulocochlear or acous-
tic nerve): Examination of the eighth cranial nerve
principally involves assessment of hearing (coch-
lear branch), although in select circumstances the
assessment of inner ear vestibular function is
important. In the first month of life, a neonate will
alert and quieten to a bell presented at his/her ear,
and by 5 or 6 months of age, he/she should turn
and localize the source of sound. In an older child,
gently rubbing one’s fingers at the opening of the
ear canal and asking the patient to identify the
sound, and localize the side of the sound, can be
utilized for screening hearing. If hearing loss is
suspected, it is important to di erentiate sensori-
neural hearing loss from conductive hearing loss.
This can be clinically achieved with the use of a
tuning fork. The Weber test involves placing a
vibrating tuning fork over the vertex of the skull in
the midline and having the patient identify which
ear the vibrating tone is heard best. With normal
hearing, this is equal in both ears. With sensori-
neural hearing loss, the tone is louder on the nor-
mal ear, whereas with conductive hearing loss the
tone is louder on the deaf ear.
The Rinne test assesses the di erence between
bone conduction and air conduction. A vibrating
tuning fork is held adjacent to each canal (air con-
duction) and is compared for intensity to the
sound heard when placing the tuning fork handle
on each mastoid process (bone conduction). In
normal circumstances, air conduction is better
appreciated than bone conduction. If bone conduc-
tion is louder than air conduction, this suggests a
conduction hearing loss in the ipsilateral ear. In
sensorineural hearing loss, however, air conduc-
tion is better than bone conduction in the a ected
ear. Vestibular testing may be necessary in select
circumstances, such as in cases of vertigo to di er-
entiate central from peripheral vertigo (Barany or
Hallpike positional testing), or to assess ocular
movements and intact brainstem function in
comatose patients using the vestibulo-ocular
reflex (“Doll’s eye maneuver”). The vestibulo-ocu-
lar reflex utilizes stimulation of the a erent input
from the vestibular apparatus (either cold caloric
test or Doll’s eye maneuver) with e erent outputs
supplying the muscles involved with lateral eye
movements.
Cranial nerve IX and X (glossopharyngeal and
vagus nerve): Although the glossopharyngeal and
vagus nerves have several branchial and visceral
motor braches as well as sensory branches, from a
practical perspective their integrity is assessed
primarily through the gag reflex and palatal eleva-
tion. The gag reflex receives its a erent nerve sup-
ply from the glossopharyngeal nerve, while the
e erent supply is mediated via the vagus nerve
from the palate. Asking a child to say “AH” assesses
palatal movement and symmetry. Gag reflex does
not necessarily need to be routinely tested unless
there is concern for impaired swallowing, orophar-
yngeal dysfunction, impaired consciousness, or
suspected brainstem pathology. In the newborn
baby or young infant, eliciting the gag response is
often necessary to assess palatal function.
Cranial nerve XI (accessory nerve): The spinal
accessory nerve innervates the trapezius and ster-
Neurology
52

nocleidomastoid muscles. These muscles are tested
by having the child shrug their shoulders, and turn
their head to the side in both directions against
resistance. Formal testing of these muscles in the
newborn or infant is di cult.
Cran ial n er ve XII (hypoglossal n er ve): The
hypoglossal nerve supplies m otor innervation to
the intrinsic and extrinsic m uscles of the tongue.
Paresis of the hypoglossal nerve results in ipsilat-
eral deviation of the protruded tongue to the side
of weakness and associated ipsilateral atrophy of
the tongue. In the new born or infant, tongue
m ovem ent is best appreciated by placing a finger
in the m outh and getting a sense of tongue m ove-
m ent as the child tries to m anipulate the finger
in its m outh. The older child should be asked to
protrude the tongue m idline (often achieved by
visual m im icking of the exam iner doing the
action), and having them push their tongue into
their cheek against the resistance of the exam -
iner’s fingers. Fasciculation of the tongue is indi-
cative of anterior horn cell disease such as spinal
m uscular atrophy.
Motor Examination
The motor examination involves testing the integ-
rity of the pyramidal, extrapyramidal, and cerebel-
lar systems. The various components include
assessment of muscle bulk and tone, and testing of
strength, reflexes, coordination of movement, and
gait. Reflexes, coordination of movement, and gait
will be dealt with in separate sections below.
Muscle Bulk
Observe for asymmetry, atrophy, or hypertrophy
of muscles. Pseudohypertrophy, particularly of calf
muscles, is in several muscular dystrophies,
including Duchenne’s, Becker’s, and limb-girdle
muscular dystrophy. Generalized muscular hyper-
trophy is seen in myotonia congenita (“Hercules
appearance”). Atrophy of muscle is seen in disuse,
cachexia, neurogenic (e.g., Charcot–Marie–Tooth
disease), or anterior horn cell disease (e.g., spinal
muscular atrophy). Scapular winging due to weak-
ness and wasting of the supraspinatus and
infraspinatus muscles occurs in some forms of
limb-girdle muscular dystrophy as well as in facio-
scapulohumeral muscular dystrophy. Fasciculation
of the muscle are seen in anterior horn cell disease
(e.g., spinal muscular atrophy, polio, Pompe’s dis-
ease). Palpation of the muscles provides a sense of
the underlying muscle mass and can elicit pain or
discomfort. Muscle tenderness may suggest a myo-
sitis. A “doughy” feel to the muscles raises the sus-
picion of an underlying neuromuscular disorder.
Percussion of muscle is not routinely performed
but should be done when history suggests a possi-
ble myotonic muscle disorder. Percussion over the
thenar eminence, tongue, or deltoid muscle may
elicit a sustained muscle contraction (myotonia).
Sustained grip or eye closure may result in di -
culty opening the hand or eyes, respectively, con-
firming myotonia, and may be the only clue to the
diagnosis in a young child.
Muscle Tone
Tone reflects the resistance of a limb to passive
movement. It may be normal, increased (hyper-
tonic), or decreased (hypotonic). When tone is
increased, it is important to di erentiate spasticity
from rigidity. Spasticity results from damage to the
descending corticospinal or pyramidal tracts,
whereas rigidity results from damage to the basal
ganglia. Spasticity is the hallmark of an upper
motor neuron lesion (pyramidal tract injury) and
results in a characteristic pattern of increased tone
in the extremities—flexion of the upper extrem-
ities and extension of the lower extremities. It is
velocity dependent and is assessed by quick flex-
ion/extension of a joint giving rise to the so-called
clasp knife phenomenon (initial resistance to pas-
sive movement of the joint, followed by sudden
reduction in tone allowing the limb to move freely
and unrestricted through the rest of the range of
movement for that joint). Hyperreflexia, Babinski’s
response (extensor toe), and occasionally clonus
are accompanying upper motor neuron signs to
spasticity. Contractures result from muscle imbal-
ance and reduced movement around the joint. An
early sign of spasticity in the infant is extension of
the legs with plantar flexion of the feet with
vertical suspension. With more severe spasticity,
scissoring of the legs occurs. Spasticity typically
develops over the course of the first year of life in
an infant as myelination of the white matter tracts
occurs, and in the first few months of life, upper
motor neuron lesion of the infant may result in
hypotonia before hypertonia develops. Early hand
preference (i.e., a strong hand preference before
12–18 months of age) is abnormal and is generally
indicative of weakness or impairment of the oppo-
site arm. Hypertonia or spasticity present at birth
suggests an early prenatal brain insult, while the
presence of contractures or arthrogryposis sug-
gests in utero onset diminished fetal movement.
The Neurological Examination of the Infant and Child
53

Another subtle sign of early brain insult or injury
is obligatory fisting or the “cortical thumb” sign.
This may be present even in the absence of hyper-
tonia. An infant up to about 3 months of age may
hold the hand fisted, with the thumbs adducted
most of the time, but after 4 months of age, the
hand should be open most of the time, and if not,
it should raise concern of possible injury to the
central nervous system. Damage to the basal gan-
glia (extrapyramidal injury) results in rigidity, dys-
tonia, or extrapyramidal movements (see later).
Rigidity results in increased tone in all directions
of movement of the joint that is not velocity-
dependent (so-called lead pipe rigidity). Resist-
ance is present in both agonist and antagonist
muscles. Cogwheel rigidity is present when there
is a tremor superimposed on the rigidity, giving a
“ratchet” feeling to the increased tone. Hypotonia
or flaccidity is decreased or absent resistance of
passive movement of a limb and is seen with lower
motor neuron or cerebellar/cerebellar pathway
lesions. Hyporeflexia/areflexia and hyperextensi-
bility of the joint may be accompanying features.
Muscle wasting or fasciculation may also be seen.
Hypotonia frequently results in abnormal posture
at rest, for example, the “frog leg” position and
internal rotation of the shoulders seen in spinal
muscular atrophy. A premature infant is hypotonic
because flexor tone develops at about 32 weeks of
gestation and is strongly established by term. Head
lag on pull-to-sit and poor head and trunk posture
with vertical suspension confirm axial hypotonia.
By 3 months of age, an infant should be able to
maintain the head in the horizontal midline posi-
tion with ventral suspension, and after 4 months
of age, an infant should be able to elevate and
maintain the head above the midline. In certain
conditions, a combination of central and periph-
eral nervous system involvement (peripheral neu-
ropathy) may occur, for example, Krabbe’s disease,
metachromatic leukodystrophy, or mitochondrial
cytopathy.
Muscle strength: One can reliably test strength in
children as young as 4 or 5 years of age. Many dif-
ferent scales exist for testing manual strength, but
the most commonly used is the Medical Research
Council 5-point grade scale, with grade 0 repre-
senting complete paralysis of movement and grade
5 representing normal strength. Grade 1 repre-
sents a flicker or trace of movement, grade 2
represents active movement but with gravity elim-
inated, grade 3 represents a full range of antigrav-
ity movement for the joint, and grade 4 strength
represents antigravity movement against varying
degrees of resistance but with some weakness
present. Grades 4 –, 4, 4 +are used to indicate the
degree of force necessary to overcome the muscle
strength being mild, moderate, or strong resist-
ance, respectively. Strength in the lower extrem-
ities is best assessed with the patient supine. A
Gowers sign is indicative of significant proximal
pelvic girdle weakness and is elicited by having
the child lie flat on his/her back and then attempt-
ing to stand as quickly as possible without the
assistance of furniture. In the presence of weak-
ness, the child will first roll over onto the stomach,
adduct, and “lock” the legs at the knees, and then
uses the arms to push o the floor and “walk” or
climb up the legs by pushing on the knee. In the
neonate/infant and young child, direct observation
provides invaluable information about strength. In
the newborn, spontaneous movements and/or
gentle stimulation of the extremities can detect
the presence of at least antigravity strength.
Watching the child walk into the room, climbing
onto and o a chair, reaching for toys, and jumping
and hopping will readily identify marked weak-
ness. Patterns of weakness should be documented
because they provide useful clues about cause, for
example, monoplegia or hemiplegia in focal cere-
bral injury or neonatal stroke, diplegia in injury to
the premature brain, or quadriplegia in di use
cortical or cerebral injury. A proximal-to-distal
distribution of weakness or vice versa may be
helpful in di erentiating myopathy from neuropa-
thy or distinguishing among the various myopa-
thies.
Deep Tendon Reflexes
By convention, reflexes are graded using a 4-point
scale, with 0 being absent, 1 +being reduced or
present with reinforcement only, 2 +being normal,
3 +being increased/hyperactive without clonus,
and 4 +being increased/hyperactive with clonus.
Spreading of reflexes to other muscles not directly
being tested and crossed adduction of the opposite
leg when the medial aspect of the knee (medial
epicondyle of the femur) is tapped (“cross adduc-
tor reflex”) is suggestive of hyperreflexia. The
crossed adductor reflex is normally present, how-
ever, for the first few months of life, but its pres-
ence after about 6 to 8 months of age should be
regarded as pathological. Pathologically brisk
reflexes are indicative of upper motor neuron dys-
function, whereas absent or depressed reflexes are
indicative of a lower motor neuron lesion (e.g.,
anterior horn cell disease, peripheral neuropathy,
Neurology
54

or myopathy) or cerebellar/cerebellar pathway
dysfunction. Clonus is elicited by flexing the
infant’s or child’s knee and rapidly dorsiflexing the
ankle. Sustained clonus is always abnormal but a
few beats of nonsustained clonus may occasionally
occur in normal people, especially neonates.
Nonpathological brisk reflexes may occasionally
be seen in young people, especially adolescent
females or children who are very anxious. Rein-
forcement maneuvers should be use when reflexes
are di cult to elicit before concluding they are
absent or reduced. These maneuvers include dis-
traction by having the patient perform isometric
contraction of muscles such as clenching of
teeth or having patient clasp flexed fingers and
pulling apart (“Jendrassik’s maneuver”). The major
reflexes tested in infants and children are the same
as those tested in adults (Table 8.2). Additional
specific reflexes are evaluated as appropriate. A
key di erence between adults and children is the
appearance and disappearance of certain primitive
reflexes that serve as important indicators of the
maturation and integrity of the nervous system
(Table 8.3). Asymmetries or persistence of these
reflexes in certain instances is pathological. An
obligate tonic reflex (“fencing posture”) is always
abnormal. Many of these reflexes (e.g., the grasp,
snout, and sucking reflexes) may also reappear in
adults because of a loss of inhibition of the reflex
that occurs in some neurodegenerative conditions.
The plantar response is a polysynaptic superfi-
cial reflex testing the integrity of the corticospinal
tracts. It is elicited by stroking the lateral border of
the foot with the thumb or blunt object from the
heel toward the little toe and then moving medi-
ally toward the big (first) toe. A normal response is
flexion of the toes, while an abnormal pathological
response, indicative of an upper motor neuron le-
sion, involves extension of the big (first) toe with
extension and fanning of the other toes (Babinski’s
sign). The Babinski method is the most reliable
method of eliciting the plantar response, but other
methods exist, including Chaddock’s sign in which
the stimulus is applied along the lateral aspect of
the foot, below the external malleolus, and Oppen-
heim’s reflex in which firm pressure is applied
along the shin of the tibia from below the knee up
to the level of the ankle. There is controversy as to
whether a Babinski sign is abnormal during the
first year of life. A unilateral Babinski response
should, however, be regarded as pathological as
should the presence of a Babinski response after a
child starts walking. The Ho man sign in the
upper extremity is essentially the equivalent of the
Babinski sign in the legs, its presence being abnor-
mal and indicative of an upper motor neuron le-
sion. This sign is elicited by holding the child’s
middle finger loosely and rapidly flicking the fin-
gernail downward, then allowing it to rebound
slightly into extension. If the thumb flexes and
adducts in response, Ho mann’s sign is present.
Coordination of Movement
Coordination of movement is a complex task and
requires the integration of motor, sensory, and
Table 8.2 Main deep tendon reflexes and root innervation
Nerve/root innervation
Reflex
Jaw jerk

Trigeminal nerve
Biceps

C5–C6
Brachioradialis

C5–C6
Triceps

C6–C7 (predominately C7)
Finger jerk

C8–T1
Knee/patellar jerk

L3–L4
Ankle jerk

S1
Superficial reflexes
Corneal reflex

Afferent: V1 branch of
trigeminal nerve (fifth
cranial nerve)
Efferent: facial nerve
(seventh cranial nerve)
Abdominal reflex: above
umbilucus
T8–T10
Abdominal reflex: below
umbilucus
T10–T12
Cremasteric reflex

L1–L2
Anal reflex

S2–S4
Plantar reflex

L4–S2
Table 8.3 Primitive reflexes
Primitive reflex

Appearance
of reflex
Disappearance
of reflex
Moro

Birth

6 mo
Palmar and plantar
grasp
32 wk

2 mo
Rooting and sucking 32 wk

4 mo
Stepping and placing 37 wk

Persists as
voluntary standing
Tonic neck reflex

1 mo

6 mo
Neck righting reflex 4 mo

Persists voluntarily
Parachute

6–9 mo

Persists indefinitely
The Neurological Examination of the Infant and Child
55

cerebellar systems. Dysfunction in any one of these
systems may a ect coordination, for example,
proximal muscle weakness may resemble ataxia.
The motor and sensory systems are generally
tested separately, so tests of coordination predom-
inately a ect testing of the cerebellum and its
pathways. The cerebellum is responsible for
smooth, integrated, coordinated movement of the
limb and gait, and disorders of the cerebellum
therefore result in jerky, nonrhythmic movements
or ataxia. Disorders or lesions of the cerebellar
hemispheres result in ipsilateral appendicular
ataxia, dysmetria (impaired judgment of distance
with past pointing), and dysdiadochokinesia
(abnormal or impaired rapid alternating move-
ments). Midline lesions, on the other hand, pro-
duce gait and truncal ataxia. To be certain that the
ataxia is of cerebellar origin, proprioceptive loss
has to be excluded; however, proprioceptive test-
ing is di cult to test reliably in a child younger
than 5 or 6 years of age. Cerebellar testing can be
very di cult to do in a young child and in the neo-
nate where cooperation is limited. Often, careful
observation of the child playing, undressing, and
doing zippers or buttons provides useful informa-
tion about dexterity, steadiness of reach, accuracy,
and/or presence of abnormal involuntary move-
ments. By 18 months of age, a child should know a
number of body parts and, with the use of a doll,
can be encouraged to go back and forward
between a doll’s nose and his or her own nose.
Rapid alternating movement can be more di cult
to test, but with patience, it is possible to get even
a young child to mimic the action. More “tradi-
tional” finger–nose or heel–shin testing or rapid
alternating movement testing is possible in the
older child. Gently pushing down on the child’s
outstretched arms and then suddenly releasing
the arms, causing the arm on the a ected side sud-
denly to fly upward, can be used to demonstrate
the phenomenon of limb rebound seen in cerebel-
lar lesions. Romberg’s testing is achieved by having
the child stand with both feet touching one
another and having him/her close the eyes. The
test is positive if there is swaying and falling (to
the side of the lesion). Postural stability is tested
by having the child stand with his/her feet com-
fortably apart and then pulling back on the should-
ers quickly while asking the child to maintain his/
her balance (and remaining behind the child so
he/she does not fall). Retropulsion is present if the
child is unable to maintain his/her posture and
steps or falls backward. This may be seen with cer-
ebellar and/or extrapyramidal disorders. Tandem
gait (walking a straight line with one foot in front
of the other) is not reliably performed until a child
is about 8 years old. With gait ataxia, the child tends
to stand with the feet wide apart for stability and
sways side to side with walking, often falling to the
side of the lesion (if unilateral). Impairment of the
visual pathways with resultant nystagmus (maximal
toward side of lesion) and impairment of speech
(scanning dysarthria and staccato speech) are often
accompaniments to cerebellar lesions.
Gait: The gait is assessed by observing the child
walk and run. A normal gait should be narrow
based and steady with good, symmetric arm
swing. Walking is typically achieved by 12 to 18
months of age with fast walking and running by
18 to 24 months of age. The toddler gait tends to
be slightly wide based and unsteady. Watching the
child stoop and recover, such as having them pick
up a toy from the floor, provides useful informa-
tion as to truncal stability. Classic abnormal gait
patterns include hemiplegic, spastic/scissoring,
ataxic, high steppage (footdrop or proprioceptive
loss), waddling (proximal pelvic weakness), and
antalgic patterns. Rarely, astasia-abasia or hysteri-
cal gait patterns may be found, with elaborate
attempts to maintain balance. In the young child,
toe walking requires further evaluation as it may
represent early tightness or contractures of the
Achilles tendon; if unilateral, it may represent a
hemiplegia, and if bilateral, it may represent spas-
tic diplegia or may be secondary to muscle weak-
ness such as muscular dystrophy. Intermittent toe
walking is often seen in the autistic-spectrum dis-
orders and may occasionally be volitional in other-
wise neurologically normal children. Over time,
however, it may result in fixed contractures of the
Achilles tendon. Even before a child can walk,
dragging of a leg or arm when crawling may indi-
cate hemiplegia. The appearance of asymmetric
patterns of shoe wear may be seen even with mild
hemiparesis.
Involuntary Movements
Damage or dysfunction of the basal ganglia results
in involuntary movements (dyskinesias) that may
be broadly classified into either an excess of move-
ments (hyperkinesia) or a paucity of voluntary
movements (hypokinesia) unrelated to weakness
or spasticity. Collectively, these movements are
known as extrapyramidal symptoms.
Hyperkinetic movements include:
● Chorea (fragmented, abrupt, jerky, involuntary
movements of the limbs or face).
Neurology
56