Arnold-Chiari氏畸形に就て—（成人に見られた1症例を中心に）

On the Arnold-Chiari Malformation : (Report of a Case in Adult)

I．緒言

　1891年Chiariが脳水腫の小児に第四脳室の位置の変化が第五頸椎の高さに迄及んで居るのを見出し，又1894年Arnoldが小脳の発育異常に就き記載し，翌年Chiariが別に21例に就き報告した。即ち彼等は別個に脳水腫の成因を探求中，偶々該畸形を発見したもので，このArnold-Chiari氏畸形なる語は1907年Schwalbe　＆　Gredigの命名になり，同時に彼等は本症の胎生学的，解剖学的研究を報告した。

　本症は後脳の先天的畸形で，小脳及び脳幹の一部が舌の様な形となつて大後頭孔を通つて脊髄管内に入り込み，第四脳室もこれに依つて著しく引き延された形となる。

This malformation was named by Scnwalbe & Gredig in 1907 after Arnold and Chiari who dependently described the anomaly of the hindbrain 1894 and 1895, in which ton-gue-like projection comes down into upper cervical canal through the foramen magnum. In a patient operated in our clinic, we have found the same deformity of the cerebellum, 4th ventricle and medulla oblongata as follo-wed to report. Patient: N. S., a 32 year old female, was admitted for complaining of occasional headaches and unsteadiness of gait without apparent progression for several years. Since about 6 momths those symptoms. have becomes severe and more persistent with nystagmus and numbness of right fin-gers Clinical examinations were confused by complicated form of cerebellar and posterior column type ataxia.

Roentgenogram of the skull showed the abnormal dilatation of vertebral arches of 1st and 2nd cervical vertebra and there were no increase of the intracranial pressure and no finding of platyhasia, spina bifida or other bony anomalies which had been reported pre-viously.