The Effect of rTMS Over the SMA on Gait Performance in Parkinson's Disease

The Effect of Repetitive Transcranial Magnetic Stimulation Over the Supplementary Motor Area on Gait Performance in Parkinson's Disease: A Randomized Controlled Trial

This study aims to investigate the effects of high-frequency and low-frequency repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA) on gait performance, especially gait initiation, in individuals with Parkinson's disease (PD). Furthermore, the investigators will explore the impact of rTMS over the SMA on walking speed, functional mobility, and limits of stability in PD. It is hypothesized that rTMS over the SMA will improve gait performance in PD.

The goal of this clinical trial is to investigate the effects of high-frequency and low-frequency rTMS over the SMA on gait performance, especially gait initiation, in individuals with PD. The primary outcome will be anticipatory postural adjustments (APAs) during gait initiation. The secondary outcome will include walking speed, the timed up-and-go test (TUG), and limits of stability.

The hypotheses are:

1. Both 25 Hz and 1 Hz rTMS will have a significant effect on gait performance, especially the gait initiation phase, as assessed by APAs in PD, compared with sham stimulation.
2. 25 Hz and 1 Hz rTMS will have a different effect on gait initiation in PD.

This study will be a three-arm, randomized, double-blind, placebo-controlled study examining the effect of 25 Hz or 1 Hz SMA-TMS compared with that observed after sham TMS. A total of 81 individuals with PD will be recruited and allocated into three different groups: 1 Hz TMS group, 25 Hz TMS group, and sham TMS group. Participants in each group will receive 10 TMS sessions over 2 weeks. Assessors will conduct evaluations at baseline, post-intervention, and 4-week post-intervention. The primary outcome will be APAs during gait initiation. The secondary outcome will include walking speed, TUG , and limits of stability.

Inclusion Criteria:

1. diagnosed with PD according to thecriteria set by Movement Disorder Committee,
2. with Hoehn and Yahr stages II-III, which are recognized as representing mild to moderate disease severity,
3. have self-reported difficulty in gait initiation, assessed by item 5 of the freezing of gait questionnaire (FOGQ),
4. have used a dopaminergic medication dose in the last month,
5. a minimum score of 23 of 30 points on the Montreal Cognitive Assessment (MoCA).

Exclusion Criteria:

1. patients with unstable medical conditions,
2. unable to provide informed consent,
3. other neurological conditions including stroke,
4. contraindications for TMS,
5. experienced deep brain stimulation treatment,
6. no recordable motor evoked potentials (MEPs) with TMS.