Effect of endoscopic third ventriculostomy on neuropsychological outcome in late onset idiopathic aqueduct stenosis: a prospective study

Objective: To undertake a prospective study of the long term neuropsychological outcome in patients with late onset idiopathic aqueduct stenosis (LIAS) after endoscopic third ventriculostomy. Methods: Six patients with LIAS were evaluated pre- and postoperatively using magnetic resonance imaging (MRI) and standardised psychometric testing procedures. Endoscopic third ventriculostomy was done using standard surgical techniques. The mean long term follow up was 81.2 weeks. Results: Preoperatively, all patients had cognitive impairment, four of them showing deficits in several cognitive domains. After endoscopic third ventriculostomy, all patients improved clinically and had ventricular size reduction on MRI. Postoperative neuropsychological testing showed that five patients achieved normal or near normal cognitive functions, and one improved moderately. Conclusions: Endoscopic third ventriculostomy caused a substantial improvement in the neuropsychological deficit of LIAS patients. This was also true for patients with enlarged ventricles that might be diagnosed radiologically as "arrested hydrocephalus."