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 )