Abstract
Although it is well known that the prognosis of child hydrocephalus has been improved by shunting operations, little is known about the question of why these children die after a long period. Between 1966 and 1980 at the Tokyo Medical College, the shunting procedure was carried out in 95 cases of infantile hydrocephalus. In 14 cases, death occurred more than three years after the operation for hydrocephalus. In eight cases an autopsy was performed. Six out of 14 cases died suddenly in spite of the shunt functioning well and these cases presented the so-called “hydrocephalic crisis”. On the other hand, eight cases deteriorated gradually and died despite the most intensive and ingenious neurosurgical care. The 14 cases were classified into two types as follows:
1) Sudden death type; most of the cases were combined with myelomeningoceles and the ArnoldChiari malformation or dysgenetic changes of the brain.
2) Gradual deterioration to death type; these cases were combined with intracranial inflammation such as severe meningo-ventriculitis. In the radiological examination of the skull, the posterior cranial fossa was studied. The index value was less than the lower limit (0.25) of the normal level by Schey's method, and a significant difference was observed. Sudden death cases always showed the picture of “hydrocephalic crisis” without any increase in the supratentorial pressure. Autopsy cases showed the posterior cranial fossa to be small and the clival slope to be steep, abnormal deformation of the condiloid, and a concentric osseous ring around the foramen magunum. Such an anatomically abnormal structure of the posterior fossa plays a role in producing an abortive form of craniocerebral dysproportion, together with the cerebral dysplasia such as the Arnold-Chiari malformation. The state of craniocerebral dysproportion is easily affected by elevation of the supratentorial cerebrospinal fluid pressure. These structural changes are the major factors causing acute compression of the brain stem.
On the other hand, gradual deterioration to death cases presented cerebral dysplasia and hydrocephalic change with severe meningoventriculitis. Inflammatory changes in the brain were observed extending even to the basal ganglia. Gradually irreversible changes of the brain structures are considered to be caused by repeated chronic intracranial inflammatin itself or by maldevelopment of the central nervous system and a decrease of immunological resistance of the host. The inflammatory changes of the basal cisterns and brain stem region may play a vital role in the gradually fatal outcome. Thus, the gradually deteriorating condition may be produced.
