The management of slit ventricle syndrome and shunt-related headache is reviewed by researchers at the Barrow Neurological Institute, St Joseph's Hospital, Phoenix, AZ. Five syndromes of shunt-related headache are described: 1) Intracranial hypotension with headache that develops later in the day and with the erect position and is relieved by lying down. Treatment involves replacement of the valve mechanism and incorporating a device that retards CSF siphoning (DRS). 2) Intermittent proximal obstruction with sudden increase in intracranial pressure (ICP) with activity. As ICP increases, the headache worsens until the ventricular catheter reopens and the pressure is normalized. In chronically shunted patients, proximal shunt failure is most commonly caused by over-drainage of CSF and collapse of the ventricular walls around the catheter. The valve and DRS system are replaced. 3) Normal volume hydrocephalus with symptoms of ICP and headaches developing in the morning and progressing, a common problem with congenital hydrocephalus. All have elevated venous sinus pressure. Older patients have symptoms of pseudotumor cerebri. Treatment involves lumboperitoneal or cisternal shunt. 4) ICP with working shunt associated with Chiari 1 malformation and hindbrain herniation. Some cases are associated with craniofacial abnormalities and cephalocranial disproportion. 5) Migraine headaches complicating shunted hydrocephalus may require ICP monitoring to exclude slit ventricle syndrome as the cause of headache. The author estimates that one third of his patients with shunted hydrocephalus followed more than 5 years will have chronic headache disorder requiring intervention. In 20% of cases of shunt-related headache the ventricles do not enlarge with shunt failure and the headaches are associated with normal volume hydrocephalus. 
COMMENT. The cause of headache in shunted hydrocephalus is often not identified with a CT scan. Headache relieved by lying down may point to over-drainage of CSF, intracranial hypotension and slit ventricle syndrome. Headache exacerbated by exercise points to an intermittent obstruction of CSF flow. If the ventricles do not expand with shunt failure, a normal volume hydrocephalus with increased ICP is suspected. All require immediate neurosurgical intervention. Seizures are an additional complication of slit ventricle syndrome. The development of spike and sharp wave EEG abnormality following a shunting operation for hydrocephalus may indicate shunt malfunction and over-drainage of CSF (Ped Neur Briefs May 1989).