Abstract
Eighty-four patients with intracranial ruptured aneurysms were analyzed to investigate the relationship of cerebral vasospasms to subarachnoid clots, to cerebral circulation and to cerebral metabolism and the effect of vasospasms upon the development of cerebral infarction.
The extent of vasospasms was classified into four types: diffuse, peripheral, multi-local and local. The diffuse type of vasospasm was further divided into two grades of severity, diffuse severe and diffuse mild. The extent of vasospasm was estimated by angiography performed 4 to 20 days after the subarachnoid hemorrhage. Measurement of the rCBF was undertaken by the intra-arterial xenon-133 injection method. The degree of subarachnoid clot was graded according to the high density area in the CT from 0 to II.
The results were as follows. 1) There was a good correlation between the degree of subarachnoid clot within 3 days after the subarachnoid hemorrhage and the types and the severity of the vasospasm. 2) Most of the patients with the diffuse type of vasospasm, especially with the diffuse severe type, showed decreases of mean CBF and impaired CO2 response, while mean CBF of the patients with the multi-local and the local type of vasospasm showed no meaningful decrease when compaired to the patients without vasospasms. Increase of cerebrovascular resistance was seen in patients with a diffuse severe type of vasospasm. 3) The value of CMRO2 showed a good correlation to vasospasm : diffuse mild and diffuse severe, 1.42±0.79; local and none, 2.27±0.52ml/100g brain/min. CMR glucose correlated also with vasospasm: diffuse mild and diffuse severe, 2.44±1.19; local and none, 3.26±1.20mg/100g brain/min.
4) Twenty out of 38 patients with a diffuse type of vasospasms developed cerebral infarction (12/10 severe, 4/14 mild and 4/4 peripheral), while none of the 14 patients with no vasospasm or local and multilocal type of vasospasm: developed cerebral infarctions. 5) Development of cerebral infarctions depended not only on the severity of vasospasms but also on the duration of the vasospasm and interval between onset of the vasospasm and the subarachnoid hemorrhage.
