A pilot safety study of repetitive transcranial magnetic stimulation (rTMS) in Tourette's syndrome

Objective: We designed a randomized, blinded, crossover study to assess safety and test whether transcranial magnetic stimulation at specific regions and frequencies might modify tics. We administered repetitive transcranial magnetic stimulation over prefrontal cortex or motor cortex, with either fast or slow repetitive transcranial magnetic stimulation, to 8 Tourette's syndrome patients. Methods: Over 5 days, we applied repetitive transcranial magnetic stimulation at 110% of the motor threshold over left motor cortex (twice) or left prefrontal cortex (twice), using either 1 Hz or 15 Hz transcranial magnetic stimulation, or sham transcranial magnetic stimulation (once). Results: All 8 subjects completed the study with minimal side effects and no worsening of tics or other involuntary movements. Ignoring site and frequency, tic symptoms improved significantly over the week of the study. The study design does not allow one to address whether this was due to the presence or frequency of transcranial magnetic stimulation or to nonspecific factors involved in study participation. Conclusions: Repetitive transcranial magnetic stimulation at these sites, doses, and use parameters appears to be safe in adults with Tourette's syndrome. Further studies using repetitive transcranial magnetic stimulation in Tourette's syndrome are warranted, using balanced parallel designs.