HF-rTMS Primed Balance Training on Corticomotor Excitability, Balance, and Gait in Parkinson's

This study plans to recruit 20 patients with Parkinson's disease. The experimental design is a double-blinded, randomized controlled trial, where neither the participants nor the evaluators will know the group assignments. All participants will receive rTMS "activation" followed by a modified Otago exercise program (balance training) specifically targeting Parkinson's disease. The intervention will last for 5 weeks, with sessions twice a week, totaling 10 treatments.

Before the intervention, participants will be randomly and evenly assigned to two groups: a high-frequency stimulation group (HF-rTMS) and a sham control group. This study will use the "Magstim Rapid² TMS system" for repetitive transcranial magnetic stimulation provided by the Department of Rehabilitation at Chung Shan Medical University Hospital.

For the sham control group, based on recommendations from previous related studies, participants will receive the same stimulation intensity as the experimental group, but the treatment coil will be placed on the head rotated by 90°, minimizing possible neurophysiological responses. This approach ensures a safe and humane experimental design.

Additionally, assessments will be conducted before the intervention, after all treatment sessions are completed, and at a one-month follow-up.

After completing the pre-test, the subjects will be randomly assigned to receive either high-frequency or sham rTMS treatment. The stimulation site is based on several recent systematic reviews and meta-analyses investigating the effects of repetitive transcranial magnetic stimulation on motor symptoms of Parkinson's disease (Conte D et al., 2025; Yang et al., 2018; Li et al., 2022), targeting the bilateral primary motor cortex for the lower limbs (M1-LL). The treatment lasts approximately 25 minutes. Immediately after the magnetic stimulation treatment, a 60-minute modified Otago exercise program (balance training) will be conducted. The balance training will be guided by a professional physical therapist.

• high-frequency repetitive transcranial magnetic stimulation (Device): A painless, non-invasive, and well-tolerated non-pharmacological treatment method-Repetitive Transcranial Magnetic Stimulation (rTMS)-delivers repeated and systematic magnetic field stimulation to specific brain regions through a stimulation coil placed on the scalp. These repeated magnetic pulses not only alter the excitability of the targeted area but also affect anatomically connected brain regions. The parameters are as follows: Frequency: 10 Hz; Intensity: 90% RMT; Duration: 4 seconds; Rest: 26 seconds; Trains: 25 times; Pulses: 1000*2; Total time: 25 minutes.
• Sham rTMS (Device): In this study, the sham stimulation group was designed based on previous related research and expert recommendations. Participants in this group will receive 20% of the stimulation intensity used in the treatment group, which is significantly lower than the treatment group's 90%, ensuring a safe and humane experimental design. The parameters are as follows: Frequency: 10 Hz; Intensity: 20% RMT; Duration: 4 seconds; Rest: 26 seconds; Trains: 25 times; Pulses: 1000*2; Total time: 25 minutes.

Primary outcomes

• Corticospinal inhibition : Cortical silent period (CSP) (ms) [Baseline, week 5 and follow-up 1 month]: Cortical silent period (CSP) measured by Transcranial Magnetic Stimulation (TMS), with higher ms indicating stronger corticospinal inhibitory effect
• Intracortical inhibition : Short-interval intracortical inhibition (SICI) (%) [Baseline, week 5 and follow-up 1 month]: Short-interval intracortical inhibition (SICI) measured by Transcranial Magnetic Stimulation (TMS), with higher percentage indicating stronger intracortical inhibitory effect
• Mini-Balance Evaluation Systems Test (Mini-BESTest) [Baseline, week 5 and follow-up 1 month]: Mini-Balance Evaluation Systems Test (Mini-BESTest) is used to assess balance performance. Total scores range from 0 to 28, with higher scores indicating better balance and functional mobility.
• Falls Efficacy Scale-International (FES-I) [Baseline, week 5 and follow-up 1 month]: Falls Efficacy Scale-International (FES-I) is used to assess confidence in balance. Total scores range from 16 to 64, with higher scores indicating more balanced confidence

Secondary outcomes

• Gait speed (m/s) measured by GAITRite [Baseline, week 5 and follow-up 1 month]
• Step length (m) measured by GAITRite [Baseline, week 5 and follow-up 1 month]
• Movement Disorder Society-Unified Parkinson's Disease Rating Scale, Part III: Motor Examination (MDS-UPDRS-III) [Baseline, week 5 and follow-up 1 month]: MDS-UPDRS-III is used to assess motor symptoms in patients with Parkinson's disease. Total scores range from 0 to 132, with higher scores indicating more severe motor symptoms.

Sex: All, ages: 40 Years to 80 Years

Inclusion Criteria:

* Diagnosed with idiopathic PD
* Aged between 40-80 years
* Stable on antiparkinsonian medication ( > 3 months)
* H\&Y I-III
* Able to walk continuously for at least 10 minutes
* The ability to follow commands and instructions

Exclusion Criteria:

* Neurological diseases other than PD
* Severe musculoskeletal, cardiopulmonary disorders
* MMSE < 24
* Contraindications for TMS
* Have undergone or are scheduled to undergo neurological surgery during the study participation period