Sylvian aqueduct syndromeが一過性に出現した，中脳水道閉塞症の1例

THE SYLVIAN AQUEDUCT SYNDROME IN A CASE OF NON-TUMORAL OCCLUSION OF THE AQUEDUCT

I．はじめに

　中脳水道の狭窄や閉塞は，中脳水道のforking, septalformationなどの先天異常，炎症や外傷によるgliosisの発生，中脳水道周辺部の腫瘍性病変によつておこることはよく知られている。これらのうち，非腫瘍性中脳水道狭窄あるいは閉塞症の臨床症状は，内水頭症に起因する頭蓋内圧亢進症状が主なものである。

　ところで，われわれは非腫瘍性中脳水道閉塞症の患者で，経過中に輻輳痙攣，瞳孔不同，上方注視麻痺などの特異な眼症状が一過性に出現した興味ある症例を経験した。これらの眼症状は，Sylvian aqueduct syndromeと考えられる。本症候群が，非腫瘍性中脳水道閉塞症で一過性に出現することは比較的稀であるので報告し，あわせて本症候群の発現機序につき若干の文献的考察をおこなう。

The Sylvian aqueduct syndrome in a case of non-tumoral occlusion of the aqueduct is reported. A three-year-old boy was admitted because ofheadache, vomiting and drowsiness which haddeveloped after measles two months previously.Angiography and ventriculography revealed markedinternal hydrocephalus and non-tumoral occlusionof the aqueduct. Ventriculoperitoneal shunt wasperfomed. Postoperative course was uneventfulexcept for gradual impairment of visual acuity dueto bilateral optic nerve atrophy. Postoperativeventriculography showed moderate dilatation of therostral portion of the aqueduct. About two monthslater revision of ventriculoperitoneal shunt wasperfomed because of malfunction of the peritonealtubing. On the first postoperative day the patientbecame irritative and complained of headache. Healso had bilateral blepharoptosis and divergence ofboth eyes. But about eight hours later these eyesigns spontaniously disappeared. And then on thefifth postoperative day it was noted that he hadthe Sylvian aqueduct syndrome, namely, upwardgaze palsy associated with convergence spasms oc-curring in attempted upward gaze and pupillaryabnomality. Puncture of shunt reservoir disclosedbloody cerebrospinal fluid which suggested acci-dental bleeding from scalp wound into the ventriclesat the previous operation. The Sylvian aqueductsyndrome as well as irritability disappeared com-pletely in the following two weeks. Underlyingperiaqueductal dysfunction and ependymal irritationdue to intraventricular blood are postulated as thecauses for these ocular abnormalities.

Mechanism of the Sylvian aqueduct syndrome isalso discussed.