Noninvasive brain stimulation and motor recovery after stroke

Purpose: Upper limb function is the best predictor of long-term disability after stroke. Despite extensive rehabilitation, recovery of upper limb motor function is frequently incomplete after stroke. Methods: We review the pertinent literature on functional reorganization within the cerebral motor network after stroke and noninvasive techniques to modulate brain function towards beneficial plasticity. Results: Direct current stimulation and repetitive transcranial magnetic stimulation are powerful tools to (i) modulate cortical excitability, (ii) induce remote changes within the cortical motor system and (iii) thereby improve upper limb motor function after stroke. Today no relevant side effects have been reported. Conclusions: Neuromodulation, by means of noninvasive brain stimulation techniques, has been shown to be a safe, feasible and effective method to promote recovery of motor function after stroke. However, several methodological and theoretical issues remain to be addressed in future work.