Associative Diaschisis and Skilled Rehabilitation-induced Behavioral Recovery following Focal Ischemic Infarct

The time course of peri-infarct diaschisis following a focal ischemic infarct and the effects of delayed rehabilitation on behavioral and functional recovery were examined. Intracortical microstimulation (ICMS) was used to derive topographical maps of forelimb representations within the rat motor cortex and ischemia was induced via bipolar coagulation of surface vasculature. At one hour there was a dramatic expansion of representations in control but not ischemic animals. A significant loss of forelimb representations within peri-infarct cortex was observed in ischemic animals at twentyfour hours after insult. Delayed rehabilitation alleviated diaschisis in peri-infarct cortex. A lack of rehabilitation prevented functional and behavioral recovery. The rapid development of peri-infarct dysfunction indicates the need for immediate administration of therapeutic interventions following an ischemic event. These results indicate that the timing of rehabilitation does not effect functional and behavioral recovery but does support the need for rehabilitative interventions to facilitate these types of recovery.