Direct Demonstration That Repetitive Transcranial Magnetic Stimulation Can Enhance Corticospinal Excitability in Stroke

Abstract

Background and Purpose— Preliminary studies suggest that electrical stimulation of the damaged cortex may be able to enhance motor recovery after stroke. The hypothesis has been that this increases cortical excitability, making it easier for the system to respond to and learn from conventional physiotherapy. However, there is no direct evidence that the cortex of patients with stroke can respond in this fashion; hence, the basis of these new approaches has been questioned. Methods— We had the opportunity to evaluate directly the effects of noninvasive cortical stimulation on the excitability of corticospinal output from the damaged hemisphere of a chronic stroke patient who had epidural electrodes implanted in the upper dorsal cord for treatment of pain. Results— We found that it was possible to enhance corticospinal activity evoked by single test stimuli. Conclusions— This study confirms directly that it is possible to noninvasively manipulate cortical excitability in stroke.