pediatrics
Hydrocephalus
Treatment of Hydrocephalus
Sometimes observation or serial lumbar punctures For severe cases, a ventricular shunt procedure Treatment of hydrocephalus depends on etiology, severity, and whether hydrocephalus is progressive (ie, size of the ventricles increases over time relative to the size of the brain). Mild, nonprogressive cases may be observed with serial imaging studies and measurement of head size. To temporarily reduce CSF pressure in infants, ventricular taps or serial lumbar punctures (if the hydrocephalus is communicating) may be used. These procedures are often used to treat and may reverse hydrocephalus with intracranial hemorrhage. Progressive hydrocephalus usually requires a ventricular shunt. Shunts typically connect the right lateral ventricle to the peritoneal cavity or, rarely, to the right atrium via a plastic tube with a one-way, pressure-relief valve. When a shunt is first placed in an infant or older child whose fontanelles are closed, rapid withdrawal of fluid can cause subdural bleeding as the brain shrinks away from the skull. When the fontanelles are open, the skull can decrease in circumference to match the decrease in brain size; thus, some clinicians recommend an early decision regarding shunt placement so that it can be done before fontanelle closure. In a third ventriculostomy, an opening is created endoscopically between the 3rd ventricle and the subarachnoid space, allowing CSF to drain. This procedure is often combined with ablation of the choroid plexus and is becoming more commonly used in the United States. It is particularly useful in countries where access to consistent neurosurgical care and follow-up is limited. In certain cases (eg, hydrocephalus caused by primary aqueductal stenosis), third ventriculostomy may be adequate primary treatment. A ventricular shunt that goes to the subgaleal space may be used in infants as a temporary measure for those who may not require a more permanent shunt. Although some children do not need the shunt as they age, shunts are rarely removed because of the risk of bleeding and trauma. Fetal surgery to treat congenital hydrocephalus has not been successful. The type of ventricular shunt used depends on the neurosurgeon’s experience, but ventriculoperitoneal shunts cause fewer complications than ventriculoatrial shunts. Shunt complications include Infection Malfunction Any shunt has a risk of infection. Manifestations include chronic fever, lethargy, irritability, headache, seizures, or other symptoms and signs of increased intracranial pressure; sometimes redness becomes apparent over the shunt tubing. Antibiotics effective against the organism infecting the shunt, which may include skin flora, are given, and typically the shunt must be removed and replaced. Shunts can malfunction because of a mechanical obstruction (typically blockage at the ventricular end) or because of fracture of the tubing. In either case, intracranial pressure can increase, which, if sudden, can be a medical emergency. Children most often present with headache, vomiting, lethargy, irritability, esotropia, or paralysis of upward gaze. Seizures may occur. If the obstruction is gradual, more subtle symptoms and signs can occur, such as irritability, poor school performance, and lethargy, which may be mistaken for depression. To assess shunt function, a shunt series (x-rays of the shunt tubing) and neuroimaging studies are done. The ability to compress the bulb that is present on many shunt systems is not a reliable sign of shunt function. After the shunt is placed, head circumference and development are assessed, and imaging is done periodically. 