Repetitive Transcranial Magnetic Stimulation (rTMS) for the Improvement of Upper Limb Function in Stroke Patients

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation technique able to influence cortical excitability. In stroke patients, both excitatory and inhibitory protocols have been used to favour functional recovery of the upper limb function. In more than 30 clinical trials, inhibitory rTMS of the unaffected (contralesional) primary motor cortex (M1) has been shown effective to improve function of the affected hand in mild stroke patients. Excitatory rTMS of the affected (ipsilesional) M1 has been less investigated. Nonetheless, its safety and the possible clinical efficacy is supported by several data. However, there is considerable heterogeneity across studies in the stimulation protocols, patient populations, lesion site, outcome measures, stroke aetiology and duration. That means that the studies are not readily comparable, the reproducibility of the results can be limited, and an analysis of the real clinical significance is very difficult. For these reasons, the need for a multicentre clinical trial is advocated by many authors.