The slit ventricle syndrome: advances based on technology and understanding.

Despite many articles on slit ventricle syndrome (SVS) over the last 25 years, accepted terminology regarding the definition of this condition is lacking. Any shunted individual with a severe headache disorder in the context of ventricles that are normal or smaller than normal can be said to suffer from SVS, even though there are at least five forms of the condition. Logical management of SVS requires an understanding of the specific pathogenesis of the problem in individual patients, whether based on monitoring of intracranial pressure (ICP) or observation at the time of shunt failure or symptoms. Overdrainage syndromes, whether intermittent proximal obstruction or low pressure states, are best managed with valve upgrades and the addition of devices that retard siphoning. Increased ICP without ventriculomegaly at the time of shunt failure is best managed by shunting devices that access the cortical subarachnoid space such as lumboperitoneal shunts or shunts involving the cisterna magna. Cranial expansion operations and subtemporal decompression should be limited to patients with craniofacial syndromes.