[Critical intracranial pressure crises in drained hydrocephalus with minimally enlarged or normal ventricles].

We report on 10 patients between 3 and 18 years of age who had been treated in the neonatal and postneonatal period for hydrocephalus of various causes with a ventriculo-atrial or ventriculo-peritoneal shunt. Between the age of 2 and 17 years these children suffered from recurrent attacks of headache, vomiting bradycardia and lethargy suggesting shunt-obstruction. 8 children showed slowing of electrical activity in their EEG, 4 had papilledema on fundoscopy. Splayed sutures were found in one child by skull x-ray. In all the above cases the CT-headscans assessed by radiologists showed no evidence of shunt-obstruction. Only on direct comparison with previous CT-scans we were able to detect minimally dilated ventricles in 6 children. In all cases conservative treatment failed. Symptoms only ceased after surgical shunt-revision. In all children treated with shunts headache, vomiting and vegetative symptoms must be considered as signs of shunt-obstruction until proved otherwise. A negative CT-scan done while symptoms are present cannot rule out raised intracranial pressure. Only by direct comparison with previous CT-scans carried out during an asymptomatic period a minor dilatation of the ventricles can often be detected. This should be taken as a sign of shunt-obstruction.