Training-induced changes of motor cortex representations in stroke patients

Objective - To study changes in motor cortex representations after a single session of physiotherapy in stroke patients. Methods - TMS mapping was use d to evaluate the motor output map of the abductor pollicis brevis (APB) in both hemispheres. Stroke patients (4-8 weeks after the infarction) were st udied prior to a training session aimed at improving dexterity and 1 h and 1 day after the training. Results - Prior to the training, the APE represen tation area in the affected hemisphere was significantly smaller than on th e non-affected side. After therapy, the cortical motor output to the pareti c APE was significantly enlarged, and motor function was improved. One day later, these effects were partially reversed. Motor thresholds remained sig nificantly increased in the affected hemisphere before and after the therap y. Conclusion - A single session of physiotherapy produces a use-dependent enlargement of motor cortex representations paralleled by an improvement of motor function in stroke patients.