The effects of three
calcium antagonists on the recovery from neurologic damages after complete global
brain ischemia were examined by evaluating the change of a electroencephalogram (EEG), evoked potentials (EP) and a neurologic recovery score (NRS) in dogs. Fifteen minutes global
brain ischemia was achieved by occluding the ascending aorta and the caval veins.
Nicardipine (NC),
flunarizine (FL) and
diltiazem (DL) were administered with continuous infusions for three days after the
ischemia. The EEG-EP scores (0 : no response - 6 : normal) 3 hr after the
ischemia were 1.4 +/- 0.4 (mean +/- SE) in the control, 2.2 +/- 0.3 in the NC, 2.2 +/- 0.4 in the FL and 2.1 +/- 0.2 in the DL. There were no significant differences between the 4 groups. The survival rates on the 7th day after the
ischemia were 67% (6/9) in the control, 78% (7/9) in the NC, 56% (5/9) in the FL and 89% (8/9) in the DL. No significant differences were presented between the 4 groups. The NRSs (0 : death - 100 : normal) on the 7th day were 40.3 +/- 7.3 in the control, 59.0 +/- 8.5 in the NC, 63.2 +/- 9.7 in the FL and 55.7 +/- 3.3 in the DL. Each treated group showed a tendency to have a higher NRS than that in the untreated control group. The NRS in all dogs treated by the Ca(++) antagonists on the 7th day was 58.7 +/- 4.1, which was significantly higher than that in the control group ( P < 0.05). We conclude that the continuous administration of
calcium antagonists for three days after the global
brain ischemia would be beneficial for the neurologic recovery.