N-tert-butyl-alpha-phenylnitrone reduces the number of microinfarctions inthe rabbit brain cortex

Dementia due to cerebral ischemic lesions is relatively common in the elder ly. Since many of these lesions are probably caused by emboli, studying emb oli-induced cerebral lesions in rabbits should, hopefully, provide informat ion that is useful when searching for a means of preventing and treating va scular dementia in humans. Using magnetic resonance imaging we have found t hat N-tert-butyl-alpha-phenyl-nitrone (a free radical scavenger) reduced th e number of emboli-induced cerebral microinfarctions in the rabbit cortex b ut did not have any impact on the number of infarctions found in the subcor tical structures. The results suggest that significant amount of free radic als are produced in the ischemic foci located in the cortex, but not in the ischemic foci located in the subcortical structures. This finding may be o f importance when considering treatments for cerebral ischemia in humans.