Effects of motor rehabilitation on mobility and brain plasticity in multiple sclerosis: a structural and functional MRI study

Background: Rehabilitation seems to promote brain plasticity, but objective measures of efficacy are lacking and there is a limited understanding of the mechanisms underlying functional recovery. Objective: To study functional and structural brain changes induced by gait rehabilitation. Methods: We enrolled MS inpatients (EDSS 4.5–6.5) undergoing a 4-week neurorehabilitation. Several clinical measures were obtained, including: 2-min walk test (2MWT), dynamic gait index (DGI), Berg balance scale (BBS). Furthermore, motor-task functional MRI (fMRI) of plantar dorsiflexion, resting state fMRI, and regional diffusion tensor imaging (DTI) metrics were obtained. All the assessments were performed at baseline (T0), after the end of the rehabilitation period (T1) and 3 months later (T2). Results: Twenty-nine patients were enrolled at T0, 26 at T1, and 16 completed all timepoints. At T1, there was a significant improvement of 2MWT, DGI, and BBS scores, along with a reduced extent of the widespread activation related to the motor task at the fMRI and an increased functional connectivity in the precentral and post-central gyrus, bilaterally. None of these changes were maintained at T2. Conclusions: Our findings show a short-term beneficial effect of motor rehabilitation on gait performances in MS, accompanied by brain functional reorganization in the sensory-motor network.