Clinical features of late-onset idiopathic aqueductal stenosis

BACKGROUND Although late-onset idiopathic aqueductal stenosis (LIAS) is considered a g ood indication for endoscopic third ventriculostomy (ETV), the characterist ics of this clinical entity have seldom been reported in the magnetic reson ance (MR) imaging era. The authors reviewed their patients with LIAS who we re treated by ETV to confirm its clinical features and response to treatmen t. METHODS The study group was composed of 31 patients diagnosed with LIAS who were pr eviously untreated. Both anatomic and cine phase-contrast MR studies were u sed to detect the obstruction of the aqueduct canal. The preoperative sympt oms were statistically analyzed in relation to the age of the patients and the degree of preoperative ventriculomegaly. RESULTS The overall success rate of ETV was 83.9% with mean follow-up duration of 2 6.2 months. Only two patients had acute onset (within one month) without an y predisposing chronic symptoms. The patients with chronic symptoms (longer than 6 months [n = 25]) can be divided into two major groups: a headache g roup (n = 12) and a normal pressure hydrocephalus (NPH)-symptom group (n = 11). Two patients had both headaches and NPH symptoms. The patients in the headache group were significantly younger and had smaller ventricles than t he patients in the NPH group. With multivariate regression analysis, age in dependently affected the type of chronic symptoms. CONCLUSIONS LIAS typically presents with chronic onset, with younger patients tending t o have headaches, and older patients tending to have NPH symptoms. ETV is c onsidered the best surgical option, with more than an 80% success rate. (C) 2001 by Elsevier Science Inc.