[Cerebral blood flow in subarachnoid hemorrhage: analysis in patients with poor outcomes].

Cerebral blood flow (CBF) of 6 patients with poor outcome after subarachnoid hemorrhage is analyzed. Neurological grades of these patients were grade III in 2 and grade IV in 4 patients, and subarachnoid hemorrhage on CT was diffuse and thick in all patients. Cerebral blood flow was continuously measured for 7 to 19 days by the thermal diffusion flow probe with a peltier stack which was left on the cerebral cortex at the surgery for ruptured aneurysm. Moreover, CBF studies by cold xenon CT and 133Xe inhalation methods were also performed in discussing cases. At the same time intracranial pressure was monitored. Cerebral angiography was carried out in all except for 2 patients who died due to severe cerebral vasospasm. The initial CBF value of all patients was 20 to 40 ml/100 g/min (mean value: 27 ml/100 g/min), and these were significantly low compared to normal value (50 ml/100 g/min). Moreover, these CBF was substantially decreased several days after surgery in all patients, and it was marked in 3 patients who died. From these results it was clear that the degree of vasospasm is important to determine the prognosis. One of 3 patients who died had ruptured left posterior cerebral artery aneurysm with occlusion of bilateral internal carotid arteries. In this case further decrease of CBF due to vasospasm was observed in addition to low initial CBF resulting diffuse low flow in both hemispheres although extracranial to intracranial bypass was performed. On the other hand, it was also shown that the intracranial pressure was an important factor to influence the outcomes.(ABSTRACT TRUNCATED AT 250 WORDS)