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