[Effect of the Ca antagonist nimodipine on global and regional cerebrovascular circulation]

The effects of Nimodipine on the global and regional cerebral blood flow were studied in 42 patients with cerebrovascular disorders. In 25 patients with focal deficits such as transitory ischemic attack (TIA), prolonged reversible ischemic neurological deficit (PRIND), and minor stroke due to arteriosclerosis, and in eleven patients with cerebral vasospasm after subarachnoid hemorrhage, the cerebral blood flow was measured by 133Xenon inhalation technique 60 min after oral administration of 40, 60, or 80 mg Nimodipine. In 6 patients with vasospasm the effects of Nimodipine i.v. were examined. The result in twelve patients with minor stroke who were only given placebo (lactose; "test-retest") was identical regional (rCBF) and global (CBF) cerebral blood flow before and 60 min after; placebo, blood pressure, and arterial pCO2 remained constant as well. After Nimodipine, however, the CBF increases, the increase after vasospasm being significant when taking the pCO2 in the Wilcoxon test into account. The rCBF increases much more in the regions with low perfusion rates than in well-perfused areas. This is also observed in the patients with TIA, PRIND, or minor stroke, most clearly after oral administration of 60 mg, whereas regions with normal perfusion rates show little reaction. The blood pressure was lowered, depending on the initial pressure. There was no evidence of a steal phenomenon.