The optimal stimulation site for high-frequency repetitive transcranial magnetic stimulation in Parkinson's disease: A double-blind crossover pilot study

Many reports have shown improvements in motor symptoms after repetitive transcranial magnetic stimulation (rTMS). However, the best stimulation area in the brain has not currently been determined. We assessed the effects of high-frequency rTMS (HF-rTMS) on the motor and mood disturbances in Parkinson's disease (PD) patients and attempted to determine whether the primary motor area (M1), the supplementary motor area (SMA), and the dorsolateral prefrontal cortex (DLPFC) were the best treatment targets. In this randomized, double-blind crossover design study, we investigated the efficacy of 3 consecutive days of HF-rTMS over the M1, SMA, and DLPFC and compared these HF-rTMS to sham stimulations. We used motor and non-motor scales to evaluate the parkinsonian symptoms. The changes in the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) scores after the application of HF-rTMS over the M1 and SMA were significantly greater than those after the sham stimulation. However, after the application of HF-rTMS over the DLPFC, the UPDRS-III scores were similar to those after the sham stimulation. No significant improvements were demonstrated in the mood disturbances after the stimulations over any of the targets. In conclusion, the application of HF-rTMS over the M1 and SMA significantly improved the motor symptoms in the PD patients but did not alter the mood disturbances.