膜様構造物が原因となった成人発症中脳水道狭窄症の1例

Adult-onset aqueductal stenosis caused by membranous occlusion in the aqueduct:a case report

I．はじめに

　中脳水道狭窄症は，通常小児期に先天性奇形として水頭症で発症するが，青年期から成人期にかけて発症する中脳水道狭窄症も稀ならず存在する．われわれは，中脳水道の膜様構造物が原因と診断し得た成人期発症の中脳水道狭窄症の1例を経験したので文献的考察を加えて報告する．

The authors report a case of adult-onset aqueductal stenosis caused by membranous occlusion of the aqueduct.

The patient was a 35-year-old man, who suffered from progressive headache. On admission, computed tomography (CT) scan showed marked dilatations of the lateral and third ventricles. Midsagittal T1-weighted magnetic resonance imaging (MRI) scan showed a membranous occlusion at the lower end of the aque-duct, with dilatation of the proximal aqueduct and ele-vation of the tectum. Midsagittal cine-MRI demon-strated the cerebrospinal fluid flow in the aqueduct. The patient was diagnosed as having hydrocephalus result-ing from membranous stenosis of the aqueduct by MRI. A ventriculo-peritoneal shunt operation was per-formed and his symptoms improved markedly. The membranous occlusion of the aqueduct is a rare cause of hydrocephalus. The etiology and therapy of aqueductal stenosis are discussed.