外傷性水頭症の1例

POST-TRAUMATIC NON-COMMUNICATING HYDROCEPHALUS:Report of a case

I．緒言

　水頭症は髄液の生産吸収のバランスが崩れ，そのため頭蓋内に陽圧のもとに髄液が貯溜する状態である。頭部外傷後に脳実質の萎縮をきたし，その結果脳室が拡大した状態はhydrops ex vacuoであつて，ここにいう水頭症とは区別すべきものである。

　くも膜下出血がくも膜の器質化癒着をきたし，水頭症を招来する可能性はBagiey^3）以来認められている。脳動脈瘤，脳動静脈奇形の破裂によるくも膜下出血のため水頭症をきたした症例はかなり報告されているが，頭部外傷後に進行性水頭症が発現したとの報告ははなはだ稀である。われわれは明らかに頭部外傷に基因すると考えられる小児の進行性非交通性水頭症を経験したので報告する。

As a rare, important sequele of head injury has been reported the post-traumatic hydrocephalus which developed from reaction of subarachnoid hemorrhage on the meninges with resultant adhesions and ob-struction to the free flow of the cerebrospinal fluid.

In this paper, we presented a 2-year-old boy who developed a noncommunicating hydrocephalus after a mild head injury without loss of consciousness by a truck. There had been no clinical evidences of organic lesion of the brain until three months later, when drowsiness and vomitings rapidly appeared. Under the diagnosis of an intracranial hematoma the patient received four explorative trephinations with-out disclosing a hematoma. He was transferred to us and a suboccipital craniectomy was carried out as a cerebellar medulloblastoma. There were a super-ficial scar with hemosiderin deposit in the left cerebellar hemisphere, marked arachnoidal adhesion around the cistern and complete obstruction of the foramen of Magendie by membraneous adhesion. The patient quickly recovered after the reconstruction of the for-amen of Magendie and was discharged. He had been in excellent condition until about four months after the first operation, when an ataxic gait and mild headache again appeared. He was re-admitted to us and a re-opening of the posterior fossa was performed. Separation of the more extensive adhesions, re-open-ing of the foramen of Magendie and partial removal of the cerebellar vermis were completed and a Torki-ldsen's shunt was placed as a self-guard. Follow-up result is excellent.

Pathogenesis of the secondary hydrocephalus fol-lowing a subarchno id hemorrhage was discussed with review of the literatures.