Transcranial Direct Current Stimulation and Yoga for Functional Movement Disorders

Background: Functional movement disorder (FMD), a conversion disorder characterized by involuntary movements, is difficult to treat. Methods: We aimed to assess the effects of anodal transcranial direct current stimulation (tDCS) and yoga in FMD patients (n=5). TDCS of the right temporoparietal junction, a brain region relevant in the sense of self-agency, was conducted. Subjects underwent both sham and anodal tDCS with a washout period of 3 weeks. Yoga was used as a mode of exercise, as well as in conjunction with stimulation to sustain potential changes in neural plasticity. Results: A total of 5 subjects completed the study [mean age: 52 (SE: 4) y, disease duration: 5 (SE: 1.6) y], undergoing both sham and anodal tDCS. Anodal tDCS does not appear to be superior to sham tDCS in alleviating symptoms and disability, but combining tDCS and yoga appears to lead to mild improvement noted on clinical observation, based on the change in the efficacy index of Clinical Global Impression found in 4 subjects. Conclusion: Our study results suggest that anodal tDCS is not superior to sham tDCS in alleviating subjective symptoms and disability in FMD. However, interpretation of these results is limited due to the small number of stimulation sessions and number of subjects. Future studies using more frequent stimulation sessions are needed to further determine whether anodal tDCS may have a therapeutic effect in this patient group compared with sham tDCS.