Bilateral transcranial magnetic stimulation of the supplementary motor area in children with Tourette syndrome

AIM To explore the feasibility and possible effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) delivered to the supplementary motor area (SMA) on tic severity and motor system neurophysiology in children with Tourette syndrome. METHOD Ten children with Tourette syndrome (eight males, two females; 9-15y) participated in this open-label, phase 1 clinical trial. Treatment consisted of 1800 low-frequency (1Hz) neuronavigated robotic rTMS (100% resting motor threshold) to the SMA, bilaterally for 15 sessions. The primary outcome was a change in Yale Global Tic Severity Scale (YGTSS) total score from baseline to posttreatment. Secondary outcome measures included changes in magnetic resonance spectroscopy metabolite concentrations, TMS neurophysiology measures, TMS motor maps, and clinical assessments (anxiety, depression) from baseline to the end of treatment. RESULTS The YGTSS score decreased from baseline after treatment (p<0.001; Cohen's d=2.9). All procedures were well-tolerated. INTERPRETATION Robot-driven, neuronavigated bilateral rTMS of the SMA is feasible in children with Tourette syndrome and appears to reduce tic severity.