[Ventricular dilatation and hydrocephalus following subarachnoid hemorrhage]

A retrospective study of the clinical aspects of chronic hydrocephalus was undertaken by examining 141 patients with subarachnoid hemorrhage (SAH). To predict, in particular, the incidence of chronic hydrocephalus after SAH, prediction tree techniques were employed. In the chronic stage, only 5.7% of ruptured middle cerebral artery (MCA) aneurysm and SAH cases of unknown origin needed a shunt operation for chronic hydrocephalus. Also, of ruptured anterior cerebral artery (ACA), internal carotid artery (ICA) and vertebro basilar artery (V-B) aneurysm cases which showed no acute ventricular dilatation, only 7.5% developed chronic hydrocephalus. On the other hand, 22.9% of the ACA, ICA, and V-B aneurysm cases, which showed acute ventricular dilatation, became chronic hydrocephalus (P < 0.001). In cases of ACA, ICA and V-B aneurysm with acute ventricular dilatation, the presence of a periventricular lucency (PVL) was a good indicator of chronic hydrocephalus. 55.8% of PVL positive cases became chronic hydrocephalus. However, only 3.3% (P < 0.001) of PVL negative cases developed it. From these data, the prediction of chronic hydrocephalus after SAH was possible from a) the site of the ruptured aneurysm, b) the existence of the acute ventricular dilatation, c) the existence of the PVL during the follow-up period.