Experimental DMSO and Glycerol Treatment for Postischemic Brain Edema : The Difference between Cerebral Mantle and Basal Ganglia

The extension pattern of vasogenic brain edema after focal cerebral ischemia was investigated. In the cat, a trans. orbital proximal clipping of MCA was performed for 3 hours with hemorrhagic hypotension to 50-80mmHg (MAP). After r-CBF measurements were taken on the middle ectosylvian gyrus and the caudate nucleus by the hydrogen clearance method, restration and evans blue infusion were performed. The animal was sacrificed 24 hours later and each coronal brain slice was investigated. The animals were divided into four groups. (I) no teratment (n=12), (II a) preischemic teratment with DMSO before MCA clipping (n=8) (II b) postischemic treatment with DMSO (n=8) and (III) postischemic treatment with glycerol (n=6) Results : During followup, the high mortality in group I (6/12) was due to extended vasogenic brain edema. Low mortality was found in groups II a (1/8), II b (1/8) and III (1/6). The extension pattern of vasogenic brain edema showed heterogenicity. Between cerebral mantle and basal ganglia, the significant difference concerning effects of DMSO and glycerol was proved. The extension pattern was ameliorated more easily in the cerebral mantle than in the basal ganglia. The cause of the difference was discussed from the decrease of tissue water in the cerebral mantle of group II a-b, r-CBF improvement during ischemia in the middle ectosylvian gyrus and long-standing postischemic low perfusion in the basal ganglia. It is suggested that the difference may be based on the difference of arterial distribution between the cerebral mantle and the basal ganglia.