Acute cerebellar hemorrhage and CT evidence of tight posterior fossa.

We studied 14 patients with cerebellar hemorrhage and a tight posterior fossa, defined by the following CT criteria: effacement of the basal cisterns and ventricular enlargement consistent with obstructive hydrocephalus. In 10 patients, the fourth ventricle was not seen; in 4, it was enlarged and filled with blood. Six patients died before surgery, and eight were treated surgically. Six patients with cerebellar hemorrhage but no CT evidence of a tight posterior fossa survived without surgery.