Hydrocephalus Resulting from Late-Onset Aqueductal Membranous Occlusion: A Case Report and Review of the Literature.

BACKGROUND: Late-onset aqueductal membranous occlusion (LAMO) is 1 of the few causes of noncommunicating hydrocephalus. Here, we report a case of LAMO and review the associated literature. CASE DESCRIPTION: A 36-year-old man had complained of headache and loss of consciousness. Conventional magnetic resonance imaging (MRI) showed dilatation of the lateral and third ventricles but not of the fourth ventricle. Phase-contrast cine MRI confirmed cessation of cerebrospinal fluid (CSF) flow in the aqueduct of Sylvius. Sagittal and coronal turbo spin echo T2-weighted imaging with 3-dimensional driven equilibrium pulse (3D-DRIVE) revealed a membranous occlusion at the aqueduct of Sylvius and LAMO was diagnosed. The patient underwent endoscopic third ventriculostomy. Occlusion of the aqueduct of Sylvius by a thin membrane was observed and endoscopic aqueductoplasty was also conducted. The patient's symptoms were ameliorated shortly after the operation. Postoperative phase-contrast cine and 3D-DRIVE MRI showed restored CSF flow in the aqueduct of Sylvius and at the bottom of the third ventricle. CONCLUSIONS: We treated a case of LAMO, which usually presents with headache as an initial symptom. 3D-DRIVE MRI is useful for detecting membranous occlusions and for evaluating pre- and postoperative CSF flow. LAMO can be cured by endoscopic third ventriculostomy and/or endoscopic aqueductoplasty.