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✓ This study reports a new method for producing acute intracranial vascular spasm and compares it with the commonly used technique of injecting blood into the subarachnoid space. The data from this investigation provide angiographic evidence that extracts of hypothalamic tissue when injected into the cisterna magna of mongrel dogs will produce a high incidence (86%) of diffuse spasm in most intracranial vessels. Extracts of cerebral cortical tissue produced no constriction. The onset of spasm initiated by hypothalamic extract was later (1½ hours postinjection) and the duration of spasm longer (up to 5 or 6 hours) than that produced by the presence of blood. This indicates, then, that there are substances in certain brain tissues that could also be released into the cerebrospinal fluid and add to spasm produced by blood in the subarachnoid space.
Wilson et al. (Mon,) studied this question.