Volume of the ventricles in benign intracranial hypertension.

The volume of the lateral and third ventricles was measured by a non-invasive computerised axial tomographic method in 18 patients presenting with characteristic features of benign intracranial hypertension. Values obtained were significantly lower than in 18 controls matched for age and sex. The demonstration of smaller-than-normal ventricles in benign intracranial hypertension indicates that the syndrome is not primarily due to a disorder of cerebrospinal fluid absorption; rather, the increase in intracranial pressure may be caused by cerebral swelling, either due to oedema or engorgement.