Comparing the effects of multi-session cerebellar and prefrontal trans-cranial direct current stimulation on postural balance in patients with multiple sclerosis

Abstract

Multiple sclerosis (MS) is a progressive autoimmune disease, characterized by a destructive inflammatory process in the myelin sheaths (1). Multiple disorders are associated with MS, which typically include muscle weakness, spasticity, cognitive disorder, sensory symptoms, movement disorders, fatigue, and gait disorders (2). Generally, gait and balance disorders are common in patients with MS (3). Approximately 80% of these patients, even in the early stages of disease, show deficits in postural control, which in turn affect their quality of life (3). Therefore, the aim this study was to comparing the effects of multi-session anodal trans-cranial direct current stimulation of cerebellar and dorsolateral prefrontal cortices on postural balance in patients with multiple sclerosis Which area of cerebellum tDCS or prefrontal tDCS will have a greater effect on postural balance in MS patients? In this double-blind randomized controlled trial, 20 patients with multiple sclerosis were randomly divided into two groups: dorsolateral prefrontal cortex (DLPFC) tDCS (n=11) and cerebellum tDCS (n=9). Treatment in both groups consisted of 20 minutes tDCS with 2 mA intensity and 10 minutes’ balance training, for 10 sessions, over four weeks. Dynamic balance was assessed with Berg Balance Scale (BBS), Timed Up and Go test (TUG) and static balance using force plate before and after treatment. In both groups, a significant increase in BBS and a significant decrease in TUG was observed (P <0.05). A significant decrease found in sways path in the anterior-posterior direction and total sway path in the cerebellum group (P <0.05). A significant improvement was found in BBS, sway speed in the anterior-posterior direction, and total sway speed in the cerebellum group compared to the DLPFC group (P <0.05). Findings suggest that tDCS can use in combination with physical therapy to treat balance disorders in MS patients.