[Long-term results of hydrocephalus with myelomeningocele]

This paper reviews long-term follow-up studies of 78 hydrocephalic patients with myelomeningocele. Seventy-eight (95%) out of 82 patients with myelomeningocele had hydrocephalus. CT, MRI, CT cisternography, and monitoring of intracranial pressure (ICP) with infusion methods were performed to evaluate the indication of shunt insertion or shunt independency. These hydrocephalic patients consisted of the following two groups: (1) Early treated group. Sixty-four cases received initial cerebrospinal fluid (CSF) diversion operation within 2 years of life. Sixty-three patients had a ventriculoperitoneal (VP) or a ventriculoatrial (VA) shunt. All the patients of this group showed progressive signs and symptoms of increased ICP due to hydrocephalus. The mean age at the initial shunt placement was 10 weeks. The mean value of Evans' index before shunting was 47%, which corresponded to moderate ventriculomegaly. 48% of this group showed slit-like ventricles on postoperative CT scans, where 52% had normal or only mildly dilated ventricles subsequent to shunting. There were two instances (3%) of the so-called "slit ventricle syndrome" and one instance of "isolated fourth ventricle", who had undergone multiple shunt revisions. Shunt revisions were performed on fifty-two occasions in this group. The mean number of shunt revisions per child was 2.8. Sixty among 64 patients of this group were suitable for evaluating shunt dependency with long-term follow-up period. Forty-two out of 60 patients were considered to be shunt dependent, who underwent multiple shunt revisions after 6 months of age. These patients had signs and symptoms of increased ICP, neurological deterioration, and enlarged ventricles when their shunts were blocked. There were four cases of slowly progressive (shunt dependent) hydrocephalus, who did not show clinical signs and symptoms of shunts malfunction in spite of progressive ventriculomegaly and abnormal findings of CT cisternography and ICP monitoring. Only two patients (3%) proved to be shunt independent. Consistently their ventricles were mildly dilated. These results suggest a very low incidence of true arrest of hydrocephalus after shunt operation. (2) Late treated group. Fourteen cases were diagnosed or treated for hydrocephalus after 7 years of age. Six out of fourteen patients had remarkable hydrocephalus whose Evans' index exceeded 51%. The mean value of Evans' index was 48% in this group. Six patients had progressive signs and symptoms of hydrocephalus and were shunted. ICP monitoring and studies of CSF dynamics revealed abnormal findings in ten out of 14 cases in spite of preservation of good intelligence.(ABSTRACT TRUNCATED AT 400 WORDS)