Chiasmal apoplexy. Report of four cases.

Four patients with chiasmal syndromes were found to have intrachiasmal hematomas. Computerized tomography scans showed high-density suprasellar masses in all cases. Cryptic vascular anomalies were presumed to be responsible for spontaneous bleeding into the chiasm in three of the cases. In the remaining case, hemorrhage was due to an occult optic glioma. Surgical evacuation of clotted blood resulted in improved visual function in three of the four cases.