The microscopic effects of ventricular dilatation without increase in head size.

Eleven brains were studied from patients in whom there was some degree of ventricular dilatation due to obstruction of the cerebrospinal fluid pathways. Six further cases from the files of the Department of Neurosurgery were reviewed. Very few microscopic changes were seen in the gray or white matter even in the presence of marked ventricular dilatation. These findings, although surprising in view of the gross apparent reduction in white matter, are in accordance with the known beneficial results of shunting procedures for relief of ventricular dilatation due solely to obstruction. This study provides a pathological anatomical background for the good prognosis in patients with ventricular dilatation without other neurological disease.