Hemorrhage and epilepsy in cryptic cerebrovascular malformations.

A series of 15 angiographically cryptic, histologically proved, cerebrovascular malformations occurred. Nine patients were admitted to the hospital with evidence of recent neurological deterioration or onset of headache. Six patients had convulsions. Computed tomographic scan and surgical exploration disclosed a substantial cerebral hematoma in eight instances. The pathological diagnosis was arteriovenous malformation in 11 cases, cavernous angioma in three, and venous angioma in one. Histological evidence of previous microhemorrhage was present in the majority of the specimens, including the patients who had seizures. A change in neurological status or onset of seizures probably indicates recent hemorrhage in cryptic cerebrovascular malformations.