Efficacy of cumulative high-frequency rTMS on freezing of gait in Parkinson’s disease

Abstract

PURPOSE: Freezing of gait (FOG) affects mobility and balance seriously. Few reports have investigated the effects of repetitive transcranial magnetic stimulation (rTMS) on FOG in Parkinson's disease (PD). We investigated the efficacy of high-frequency rTMS for the treatment of FOG in PD. METHODS: Seventeen patients diagnosed with PD were recruited in a randomized, double-blinded, cross-over study. We applied high frequency rTMS (90% of resting motor threshold, 10 Hz, 1,000 pulses) over the lower leg primary motor cortex of the dominant hemisphere (M1-LL) for five sessions in a week. We also administered alternative sham stimulation with a two-week wash out period. The primary outcomes were measured before, immediately after, and one week after the intervention using the Standing Start 180° Turn Test (SS-180) with video analysis and the Freezing of Gait Questionnaire (FOG-Q). The secondary outcome measurements consisted of Timed Up and Go (TUG) tasks and the Unified Parkinson's Disease Rating Scale part III (UPDRS-III). Motor cortical excitability was also evaluated. RESULTS: There were significant improvements in the step required to complete the SS-180 and FOG-Q in the rTMS condition compared to the sham condition, and the effects continued for a week. The TUG and UPDRS-III also showed significant ameliorations over time in the rTMS condition. The MEP amplitude at 120% resting motor threshold and intracortical facilitation also increased after real rTMS condition. CONCLUSIONS: High frequency rTMS over the M1-LL may serve as an add-on therapy for improving FOG in PD.