Abstract
Cerebral vasospasm plays an important role in determining the prognosis of the patient, but the true nature and cause of it is still a great mystery. The course and the degree of cerebral vasospasm in cats is discussed in this report.
Vasospasm of the basilar artery is induced by application of fresh blood, or blood and cerebrospinal fluid mixture incubated at 37°C for 2 to 16 days in 57 cats. In the group with fresh blood or mixtures incubated for over 15 days, the severity of induced vaso-constriction is light and the duration is short. Mixtures incubated for 5 to 10 days induced severe and prolonged vasoconstriction. The prolongation of severe vaso-constriction induced by the 7-days incubated mixture with clotted components is definitely longer than one by the mixture without clotted components. This incubation period for inducing severe vasospasm coincides with the course of vasospasm after the onset of subarachnoid hemorrhage in our clinical experience.
This experimental study strongly suggests the existance of vasospasmogenic substance in the blood liberated into the subarachnoid space of the patient. It begins to act on about 3 days after subarachnoid hemorrhage, acts strongly during about 5 to 10 days, and disappears after 15 days.
