Median Nerve Stimulation Pilot

Inclusion Criteria: * Age 15-64 inclusive at initial screening visit * Informed consent by adult subject; assent by child and informed consent by guardian * Current Tourette's Disorder or Persistent (Chronic) Tic Disorder according to the criteria in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition: DSM-5 * At least 1 tic per minute (average) during the first 5-min. baseline video session on the first visit (as scored during the session by the investigator) Exclusion Criteria: * Unable to complete study procedures for any reason * Has an implanted device that could be affected by electrical current * Pregnancy known to participant or (for children) to the parent * Known or suspected primary genetic syndrome (e.g. Down syndrome, Fragile X) * Intellectual disability (known, or likely from history and examination) * Head trauma with loss of consciousness for more than 5 minutes * Significant neurologic disease, not counting TS (exceptions include febrile seizures or uncomplicated migraine) * Severe or unstable systemic illness * Factors (such as exaggerated signs) that in the judgment of the principal investigator make the video recording or YGTSS an inaccurate assessment of tic severity * Judged by investigator to be unlikely to complete study procedures or to return for later visits * Change in somatic or psychotherapeutic treatment in the 2 weeks preceding the first stimulation visit * Planned change in somatic or psychotherapeutic treatment between t…