医原性脳室憩室—自験2例を中心として

PARAVENTRICULAR DIVERTICULA FOLLOWING VENTRICULAR PUNCTURE:Report of two cases and a review of literature

I．緒言

　1918年Dandy^1）の発表以来pneumoventriculogra—phy （以下PVGと略す）は脳圧亢進の強度のもの，非交通性水頭症においても安全とされこんにちでは最も普遍的な補助診断法の一つとなつている。ことに乳児では大泉門が開存しており，経皮的に容易に脳室穿刺を行ないうるため好んでPVGが施行される。しかし，このPVGあるいは脳室穿刺にも硬膜外，脳内，脳室内出血，穿刺溝に沿つた脳実質の萎縮および石灰化，感染，脳浮腫の増強およびparaventricular diverticulum　（para—ventricular porencephalic cyst,puncture porencepha—ly）など多くの併発症のあることを軽視してはならない。

　Lorber^8）（1951）は結核性髄膜炎の治療のためにくりかえし脳室内にstreptomycinを注入したときに穿刺溝に一致して脳室のdivertlcula （憩室）ができた3例を"puncture porencephaly"と命名し初めて報告している。その後乳児の先天性水頭症に対する治療方法が進歩し，この方面の関心が高まるにつれ診断ならびに治療のためにPVGや脳室穿刺がしばしば行なわれるようになつたが，これに基づく医原性の脳室憩室はLorberとGrainger　（1963）^10）によれば約15％の頻度に起こるとさえいわれるようになつた。

Personal experiences of two cases of paraventricu-lar diverticula following ventricular puncture have been reported and the available literature has been reviewed.

The paraventricular diverticula were first described by Lorber in children who had had preceeding ven-tricular taps for treatment of tuberculous me-ningitis. According to Lorber and Grainger, it was demonstrated as an air-filled track or cavity at the exact site of the first and the only puncture perform-ed in 15% of the cases.

Although most of the infants submitted to the ventricular taps already have neurologic deficits and the paraventricular cavities develop in the silent area of the brain, the development of the large defect in the brain substance might be responsible for further progress in paralytic phenomena, con-vulsions or mental and physical retardation. We are of the opinion that the ventricular tap in hydroce-phalic children should be avoided as far as possible.

With correct technics it is likely that the lumbar injection of air under general anesthesia is safer than the ventricular route for the introduction of air in infants.

When multiple puncture is required for the treat-ment of meningitis and/or ventriculitis, as Salmon Pointed out some sorts of reservoirs, namely Rick-ham's or Mishler-Pudenz double lumen reservoir, should be inserted.

For the purpose of estimation of the ventricular size, it seems that the brain scanning and echoence-phalogram are safe and useful technics much the same as ventricular puncture and ventriculograms.