Anaerobic change of bloody CSF in subarachnoid haemorrhage. Its relation to cerebral vasospasm.

In our in vitro study of subarachnoid haemorrhage, the anaerobic incubation of CSF-blood mixture led to marked fall in the pH value thereof, which suggested to us that intracranial focal acidosis may play some role in the pathogenesis of cerebral vasospasm or disturbance of consciousness after the haemorrhage. To test this hypothesis, we treated 16 clinical cases of such disorders with carotid injection of 7% sodium bicarbonate solution. The treatment resulted in considerable improvement of the disturbance of consciousness by dilating the cerebral peripheral arteries; this we could observe angiographically 15 minutes after carotid injection. We found no morphological changes, however, in the spastic vessel itself up to 30 minutes after the injection. Given the result both of this study and of our previous experiments, we offer the hypothesis that the synthesizing process of thromboxane A2 and intracranial focal acidosis might play an important role in the pathogenesis of cerebral vasospasm.