Pediatric emergency medicine trisk 1004

SHUNT FAILURE
Goals of Treatment
Accurate identification of the pathology of a child in distress with a shunt
versus other etiology.
CLINICAL PEARLS AND PITFALLS
Clinicians depend heavily on radiographic imaging to evaluate for
shunt malfunction.
The diagnosis may be challenging for even the most experienced
clinician, especially in nonverbal patients.
Unfortunately, shunt malfunction is one of the most common clinical
problems in pediatric neurosurgery. Children with hydrocephalus, and a
CSF shunt, often have significant neurologic abnormalities and
developmental delays. Symptoms are nonspecific making shunt obstruction
a routine consideration in this patient population. Moreover, the neurologic
examination may be limited and unreliable in these patients.

Clinical Considerations
Clinical Recognition. Shunt malfunction can manifest with a multitude of
acute or chronic signs and symptoms ( Table 122.1 ). The most notable
signs and symptoms of shunt failure are nausea and vomiting (positive
predictive value 79%), irritability (positive predictive value 78%),
decreased level of consciousness (positive predictive value 100%), and a
bulging fontanel (positive predictive value 92%).


TABLE 122.1
CLINICAL MANIFESTATIONS OF SHUNT MALFUNCTION
Acute

Subacute or chronic

Nausea
Vomiting
Irritability
Seizures
Headache
Lethargy
Coma
Stupor

Change in behavior
Neuropsychological signs
Change in feeding patterns
Developmental delay
Change in school performance
Change in attention span
Daily headaches
Increase in head size

Diagnostic Imaging. CT of the brain and a shunt series x-rays are
routinely used to aid in the diagnosis of shunt malfunction. More recently,
brain MRI has emerged as a reasonable alternative to CT of the brain for the
evaluation of ventricular morphology. MRI to evaluate CSF flow and
morphology of choroid plexus in patients who have undergone ETV with or
without choroid plexus cauterization (CPC) should also be considered. The
size of the ventricles may be small, normal, or enlarged in the presence of
shunt malfunction. Comparing ventricular morphology on presentation to
the morphology of the ventricular system at the time of the first or
subsequent shunt obstructions is imperative and may be predictive in
determining the present status of the shunt system.
Management. The urgency of referral to a neurosurgeon is based on the

patient’s clinical presentation and radiographic signs. In general, patients
should be referred for asymptomatic radiographic changes, such as mildly
enlarging ventricles, in a semiurgent manner or as an outpatient.
Asymptomatic patients with changes in physical examination findings, such
as increasing head circumference, tense anterior fontanelle, upgaze or CN
VI palsies or papilledema, require urgent neurosurgical consultation.
Immediate neurosurgical consultation is mandated for symptomatic patients
or the presence of radiographic changes.


SPINAL HEMORRHAGE
Spinal epidural hematoma is a rare cause of symptomatic spinal cord
compression.
Spontaneous, or nontraumatic, spinal epidural hematomas are seen in
association with congenital or acquired bleeding disorders, hemorrhagic
tumors, spinal AVMs, following lumbar puncture or instances of increased
intrathoracic pressure. MRI of the spine is the definitive diagnostic measure
for establishing the presence of spinal epidural hematoma ( Fig. 122.5 ).
Decompression of the spinal cord is the key procedure for improving
patient outcome. Treatment outcome was favorable for patients with
incomplete preoperative sensorimotor deficit, and recovery was
significantly better when decompression was performed within 36 hours in
patients with complete deficits and within 48 hours in patients with
incomplete deficits. There are advocates for conservative management in a
very select patient population: those with no or mild deficits; those that
demonstrate early, rapid, and progressive improvement in neurologic
function within the first 24 hours despite an initial severe neurologic deficit;
or those with small or noncompressive spinal epidural hematoma.

FIGURE 122.5 T2-weighted sagittal MRI of the cervical and thoracic spine
demonstrates a heterogeneous epidural hematoma causing compression of the
cervicothoracic junction. Normal thecal sac morphology can be seen cranial and caudal
to the lesion.

CENTRAL NERVOUS SYSTEM INFECTION
Meningitis
Meningitis is an infection of the leptomeninges (pia, dura matter, arachnoid)
and thus of the subarachnoid space. This space is continuous from the
hemispheric convexities to the lumbosacral subarachnoid space (see
Chapter 94 Infectious Disease Emergencies ).