[Clinical study on developmental hydrocephalus and its operative timing in lumbo-sacral meningomyelocele].

Nine infants with lumbo-sacral meningomyelocele were evaluated in the diagnosis and the operative timing of hydrocephalus. Seven cases received early operation for meningomyelocele within 36 hours after birth. Two cases with closed meningomyelocele were operated on 8 days and 32 days after birth. All of them were not infected in the central nervous system before and after its surgery. Five out of nine cases had rapidly developed hydrocephalus within a few weeks, and received ventriculo-peritoneal shunt (Shunt group: Case1-5). Two cases with gradual enlargement of the lateral ventricles and two cases with normal development have been observed without shunt procedure (Non-shunt group: Case 6-9). The authors recorded the head circumference, Evans' index on CT, and intracranial pressure of those infants at birth and following days. The head circumference at birth was almost within a normal size in both groups. On the other hand, an average of Evans' index in shunt group at birth was greater than that of non-shunt group. Moreover, the growth rate of head circumference and lateral ventricle of shunt group were more markedly increased than that of non-shunt group. The head circumference and the ventriculomegaly on a computed tomography at birth were poor prediction of hydrocephalus, however, there was positive correlation between the rate of head growth and the rate of hydrocephalic development. That is to say, the growth rate of a head circumference and growth of Evans' index suggested the prediction of a progressing hydrocephalus during the first few weeks.