Disproportionately large,communicating fourth ventricleの2症例

Disproportionately Large, Communicating Fourth Ventricle: Report of two cases

I．はじめに

　第4脳室が髄液路で孤立することが原因となり異常に拡大し，それに起因する種々の後頭蓋窩症状を呈するものにtrapped fourth ventricleがある^7）．CTの普及によりその病態も解明されつつある．一方，このtrappedfourth ventricleの報告例のなかに，明らかに中脳水道の開存している特異な症例が報告された．この症例に対して1980年，Harwood-Nash^2）はtrapped fourth ven-tricleとは区別すべきだとし，"disproportionatelylarge,communicating fourth ventricle"と呼ぶべきだと提唱した．

　今回，われわれはHarwood-Nashの提唱するdis-proportionately large, communicating fourth ventricle（DLCFVと略す）と考えられた2症例を経験したので若干の考察を加えて報告する．

A term of 'disproportionately large, communicatingfourth ventricle' (DLCFV) was first proposed by inHarwood-Nash in 1980.

It is somewhat different from the well known clini-cal entity of 'isolated or trapped fourth ventricle',because of apparent patency of aqueductal canal.Two cases of typical DLCFV encountered in ourclinic were described. First patient was a 24 yearold man in whom this condition developed followingoperations for lumber disc and second patient was 22year old woman in whom the disease developed aftersubarachnoid hemorrhage.