Administration of MgSO4 failed to improve the neurological recovery after complete global brain ischemia in dogs

Abstract

The cerebral protective effects of MgSO₄ after complete global brain ischemia were evaluated with EEG, evoked potentials (EP) and the neurological recovery score (NRS) in the dog. Complete global brain ischemia for 15 min was achieved by occluding the ascending aorta and the caval veins. The MgSO₄ group (N=7) were injected with a 10% MgSO₄ solution and the control group (N=7) were administered a normal saline intravenously from the beginning of the resuscitation to 48 h after ischemia. The EEG grades (1=normal, 5=flat) in the control group and the MgSO₄ group were 3.9±0.1 (mean ±SEM) and 3.7±0.3, and the EEG-EP scores (6=normal, 0=serious deterioration) were 2.6±0.4 and 2.7±0.4 4h after ischemia, respectively. The 7-day survival rates for ischemia were equal in both groups (5/7:71%). The NRSs (0=death, 100=normal) in the control group and the MgSO₄ group were 50±3 (n=7) and 43±9 (n=7) on the 3rd day after ischemia, and were 56±5 (n=5) and 42±12 (n=5) on the 7th day. The differences between the two groups were not significant. We conclude that MgSO₄ administered after ischemia has no beneficial effects on the recovery of EEG, EP and the NRS after 15 min of complete global brain ischemia in the dog.

Keywords: Complete brain ischemia; EEG; Evoked potentials; Mg2+; Neurological recovery.