The majority of stroke survivors display limb weakness and motor impairments, but will show some measurable recovery of function over time. Regaining some impaired function may be explained by brain plasticity and this holds promise for therapeutic and rehabilitative treatments. A possible strategy for improving functional recovery following cerebral strokes in humans involves augmenting brain plasticity by combining rehabilitative training with mild focal electrical stimulation of peri-infarct cortical areas. The long-term objective is to enhance recovery from stoke by activating and teaching cortical neuronal networks by using cortical stimulation in combination with rehabilitative training. This project has two aims; 1) determine the optimal electrical stimulation parameters (frequency, amplitude, and temporal pattern) on behavioral efficacy, and 2) determine the optimal electrode configuration, duration of therapy and persistence of the enhanced recovery. The effect of the stimulation parameters on movement and seizure thresholds will also be determined in both the lesioned and intact hemisphere. In order to achieve these aims we use a rodent model of stroke. The rats are initially trained on skilled behavioral tasks, undergo a focal ischemic infarct (stroke), receive cortical stimulation with rehabilitative training and are assessed on their recovery. Furthermore, we will determine the stimulation parameters that markedly improve behavioral recovery but minimize unwanted side effects (a maximal therapeutic index). The results from the studies above will then be used to guide the development of clinical applications of the technique in humans that have had strokes.
