Short-term subarachnoid space drainage: a potential treatment for extraventricular hydrocephalus.

INTRODUCTION: Extraventricular hydrocephalus (EVOH), defined as the enlargement of all CSF compartments in the absence of an obstructing lesion, is usually associated with an increased head circumference and a relatively benign clinical course. Occasionally, because of concern about increased intracranial pressure (ICP), treatment with diuretics is initiated. In most cases, surgical drainage or diversion is not indicated. EVOH may follow a more alarming clinical course and be associated with developmental delay and/or other symptoms of increased ICP. CASE REPORT: We describe a 6-month-old girl with EVOH and developmental delay who was treated with temporary drainage of the subarachnoid space. Clinical response was immediate, with stabilization of the head circumference and improvement in motor performance. We propose that such a surgical procedure might be considered for more frequent use in selected cases.