Corticospinal reserve and disability predict efficacy of repetitive transcranial stimulation on walking abilities in people with progressive multiple sclerosis undergoing rehabilitation

Walking impairment has a strong impact on quality of life of multiple sclerosis (MS) patients. Excitatory Transcranial-Repetitive-Ma gnetic-Stimulation (rTMS) enhances corticospinal excitability and plasticity, potentially favouring the effects of neurorehabilitation. The aim of this study is to explore the impact of neurophysiological and clinical features on rTMS efficacy on walking in progressive MS patients undergoing neurorehabilitation. 42 progressive MS patients, randomized into real and sham-placebo rTMS, underwent 11 rTMS sessions during neurorehabilitation. Motor-threshold (RMT), duration of disease progression, walking speed (10mt-walking-test) and endurance (2 and 6 mwt) were assessed at baseline and at the end of treatment, as well as Modified-Ashworth-Scale (MAS), pain and spasticity VAS, Fatigue-Severity-Scale, EDSS, MS-walking-scale-12, PASAT and nine-hole-peg-test. Real rTMS patients showed greater improvement both in 10mt (p = 0.007) and 6mwt (p = 0.04). Greater disability was associated with greater 6mwt improvement in all patients (p = 0.01) and in the real-rTMS subgroup (p = 0.04), not in sham. In real-rTMS group, RMT negatively correlated with 6mwt improvement (p = 0.003). The potential for improvement, greater in more disabled patients after rTMS, can be exploited using this treatment associated with neurorehabilitation. RMT, resulting from combination of corticospinal excitability and of corticomotor fibres available for conduction, could be considered a predictive marker of therapeutic response to rTMS neuromodulation.