The object of this investigation was to study the effects of mannitol and high dose of methylprednisolone (MP) upon evolution of cerebral infarction incats after acute left middle cerebral artery (MCA) occlusion and following reperfusion.
The acute occlusion of left proximal MCA of thirty cats for 2, 4 and 6 hours respectively were accomplished by applying the Heifetz clip through the retro - orbital extradural approach and followed by 2 hours of recirculation. Fifteen cats were untreated as a control group and the fifteen cats were given a combination of mannitol (2g/kg) and NT (15mg/kg) at 30 minutes after occlusion initially, and then every one and a half hour.
Results of morphologic examination of the brain demonstrated that intreated cats undergoing 2hour or 4hour occlusion mannitol and NT improved the ischemic
S
j edema and infarction, but in treated cats undergoing 6hour occlusion they had
} little protective effect in ischemic brain injury(swelling, neuronal damage and hemorrhagic infarction ). Electroencephaiography (EEG) in cats undergoing 2 or 4 -
hour occlusion showed more
activities and voltage than in. untreated
groups, but in cats undergoing 6hour occlusion low voltage and slowwaves with poor activity, Le, generally suppressed pattern; were observed and were not significantly different between treated and untreated groups.
Our experimental studies of the therapeutic beneficial ´effects of mannitol and NT
were observed in cats of 2- or 4-hour occlusion of MCA with 2 hour recircula.
tion. Therefore, it was suggested that mannitol and W will prolong the period
of potential reversibility of cerebral ischemia following reperfusion within 4 hours
of ischemia.
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