Spontaneous subarachnoid hemorrhage and negative cerebral panangiography. Review of 140 cases.

One hundred and forty consecutive patients who sustained proven spontaneous subarachnoid hemorrhage (SAH) with negative cerebral panangiography were studied retrospectively. Attention was directed to the presence, amount, and distribution of subarachnoid blood on computerized tomography (CT) scans. It was determined that the finding of blood on CT had a significant association with clinical grade, loss of consciousness, ventricular ratio, fixed ischemic deficit, and total of all complications, but not with epilepsy, hypertension (previously known or detected on admission), treated hydrocephalus, rebleeding, angiographic spasm, and eventual outcome (which was generally excellent on follow-up examination). The distribution of blood, predominantly around the basal cisterns, suggests leakage from ventriculostriate and thalamoperforating vessels as the cause of SAH, and closer study of these vessels is suggested.