The slit ventricle syndrome

The term slit ventricle syndrome should only be applied to children with a malfunctioning shunt and a CT scan pattern of slit-like ventricles that does not change from scans obtained during a period of shunt function. These children must be recognized and treated immediately, because they are at risk for waves of intracranial hypertension and possible death. The best treatment is revision of the blocked portion of the shunt and a change in the valve either to a different type of valve, a higher pressure system, or a system with an antisiphon device. The surgery can be difficult because of the stuck ventricular catheter and the small size of the ventricles. It is usually necessary to pass the new catheter down the old tract to safely enter the ventricular system. The use of frameless stereotaxy or endoscopy may turn out to be helpful in replacing the catheter. In children with subacute or recurrent episodes of headache, vomiting, and lethargy as well as a CT scan that demonstrates small ventricles, ICP monitoring may be necessary to separate those with chronic shunt malfunction and raised ICP from those with chronic overdrainage and low ICP. The treatment of these children usually consists of shunt revision and alteration of the valve in the group with raised ICP and presumed intermittent or partial shunt malfunction, in whom most of the ventricular catheter side holes are occluded or the small ventricles collapse on the tubing, producing intermittent function. In those with low pressure, changing the valve or removing the shunt after third ventriculostomy is a surgical option. There is a group of children who have raised ICP in the presence of an apparently functioning shunt, and they represent a separate group as far as therapy is concerned. Some of these children respond well to antimigraine therapy and some respond well to upgrading the valve system; in a few of these children, actual expansion of the bony cranium may be necessary.