TABLE 1.
The detailed characteristics of each included study.
| References | Study design | Sample size | Sex (M/F) | Age (Mean ± SD) | PD duration, years (Mean ± SD) | Medication | H and Y stage |
| Benninger et al. (2011) | Parallel | E: 13 | 7/6 | 62.1 ± 6.9 | 10.8 ± 7.1 | ON | 2–4 |
| C: 13 | 11/2 | 65.6 ± 9.0 | 6.5 ± 3.4 | ||||
| Bueno et al. (2019) | Crossover | Total: 20 | 12/8 | 64.45 ± 8.98 | 7.80 ± 5.32 | NR | 1.5–3 |
| Chang et al. (2016) | Crossover | Total: 8 | 6/2 | 71.9 ± 7.8 | 4.3 ± 1.8 | ON | NR |
| Chen et al. (2014) | Parallel | E-L: 21 | 10/11 | 65.81 ± 9.38 | 5.88 ± 5.29 | ON | NR |
| E-H: 21 | 10/11 | 63.19 ± 8.16 | 6.60 ± 5.53 | ||||
| C: 18 | 9/9 | 66.61 ± 8.00 | 6.22 ± 3.96 | ||||
| Chen and Li (2021) | Parallel | E: 52 | 30/22 | 66.96 ± 11.46 | 3.54 ± 1.21 | ON | 1–4 |
| C: 52 | 29/23 | 66.32 ± 5.27 | 3.41 ± 1.13 | ||||
| Costa-Ribeiro et al. (2017) | Parallel | E: 11 | NR | 61.1 ± 9.1 | 6.1 ± 3.8 | ON | 1–3 |
| C: 11 | 62.0 ± 16.7 | 6.3 ± 3.7 | |||||
| Benninger et al. (2010) | Parallel | E: 13 | 9/4 | 63.66 ± 9.0 | 10.66 ± 7.1 | ON | 2–4 |
| C: 12 | 7/5 | 64.26 ± 8.8 | 9.16 ± 3.3 | ||||
| Benninger et al. (2012) | Parallel | E: 13 | 11/2 | 55.8 ± 9.1 | 8.6 ± 4.1 | ON | 2–4 |
| C: 13 | 9/4 | 54.3 ± 12.5 | 9.3 ± 6.8 | ||||
| Guo (2021) | Parallel | E: 33 | 23/10 | 62.02 ± 6.79 | 2.61 ± 0.68 | ON | 1–2.5 |
| C: 32 | 24/8 | 60.71 ± 7.38 | 2.53 ± 0.70 | ||||
| Hu et al. (2021) | Parallel | E: 49 | 28/21 | 63.68 ± 5.22 | NR | ON | 1–5 |
| C: 49 | 30/19 | 64.23 ± 4.78 | |||||
| Huang et al. (2021) | Parallel | E: 30 | 18/12 | 60.15 ± 3.15 | 3.66 ± 1.63 | NR | NR |
| C: 30 | 17/13 | 60.13 ± 3.13 | 3.59 ± 1.59 | ||||
| Kaski et al. (2014) | Crossover | Total: 8 | NR | NR | NR | ON | NR |
| Kim et al. (2015) | Crossover | Total: 17 | 12/5 | 64.5 ± 8.4 | 7.8 ± 4.9 | NR | 2.5–4 |
| Li (2016) | Parallel | E-L: 30 | 16/14 | 66.1 ± 7.6 | 6.1 ± 5.2 | ON | NR |
| E-H: 30 | 15/15 | 65.3 ± 8.1 | 6.6 ± 5.3 | ||||
| C: 30 | 16/14 | 66.5 ± 7.5 | 6.4 ± 4.9 | ||||
| Li et al. (2022) | Parallel | E: 30 | 19/11 | 62.36 ± 9.26 | 7.82 ± 3.31 | ON | 1–4 |
| C: 30 | 17/13 | 60.87 ± 8.93 | 6.79 ± 2.86 | ||||
| Liu and Zhang (2021) | Parallel | E: 30 | 18/12 | 59.7 ± 9.1 | NR | ON | NR |
| C: 30 | 16/14 | 60.2 ± 8.9 | |||||
| Maruo et al. (2013) | Crossover | Total: 21 | 10/11 | 63.0 ± 11.3 | NR | ON | 2–4 |
| Qiao et al. (2018) | Parallel | E: 15 | 7/8 | 62.00 ± 10.26 | 4.03 ± 4.94 | ON | 1–2.5 |
| C: 15 | 9/6 | 58.40 ± 9.13 | 3.51 ± 2.51 | ||||
| Qiao et al. (2019) | Parallel | E: 25 | 11/14 | 63.00 ± 9.20 | 5.22 ± 4.46 | ON | 1–3 |
| C: 24 | 15/9 | 62.04 ± 9.69 | 6.07 ± 5.25 | ||||
| Ren and He (2022) | Parallel | E: 25 | 14/11 | 61.6 ± 1.3 | 4.2 ± 0.8 | ON | 1–3 |
| C: 25 | 15/10 | 61.2 ± 1.1 | 4.1 ± 0.6 | ||||
| Schabrun et al. (2016) | Parallel | E: 8 | 8/0 | 72 ± 4.9 | 6.9 ± 4.4 | ON | 2–3 |
| C: 8 | 6/2 | 63 ± 11.0 | 4.6 ± 3.9 | ||||
| Swank et al. (2016) | Crossover | Total: 10 | 8/2 | 68.7 ± 10.2 | 7.9 ± 7.1 | ON | NR |
| Tang et al. (2015) | Parallel | E: 25 | Total:27/23 | Total: 68.5 ± 11.2 | 6.8 ± 2.5 | ON | 1–3 |
| C: 25 | |||||||
| Wang et al. (2019) | Parallel | E: 8 | 7/1 | 53.5 ± 13.7 | NR | NR | NR |
| C: 6 | 4/2 | 54.7 ± 12.2 | |||||
| Chang et al. (2017) | Parallel | E: 16 | 9/7 | 63.6 ± 7.5 | 9.8 ± 4.7 | ON | 1.5–4 |
| C: 16 | 11/5 | 63.8 ± 8.3 | 9.1 ± 5.3 | ||||
| Wong et al. (2022) | Parallel | M1 group: 9 | 8/1 | 54.20 ± 4.1 | NR | NR | 1–3 |
| DLPFC group: 9 | 6/3 | 50.09 ± 2.4 | |||||
| Cerebellum group: 9 | 2/7 | 61.30 ± 7.9 | |||||
| C:9 | 3/6 | 58.30 ± 8.0 | |||||
| Wu et al. (2019) | Parallel | E: 50 | 30/20 | 59.6 ± 6.1 | 5.8 ± 1.6 | ON | 1–3 |
| C: 50 | 31/19 | 60.2 ± 6.3 | 6.0 ± 1.7 | ||||
| Yang et al. (2013) | Parallel | E: 10 | 5/5 | 65.20 ± 11.08 | 6.40 ± 2.76 | ON | 2–3 |
| C: 10 | 7/3 | 67.00 ± 13.21 | 6.35 ± 3.58 | ||||
| Yotnuengnit et al. (2018) | Parallel | tDCS: 18 | 10/8 | 64.4 ± 7.8 | 7.9 ± 3.9 | ON | 2–3 |
| tDCS + PT: 17 | 11/6 | 68.2 ± 9.8 | 9.4 ± 5.3 | ||||
| Physical therapy:18 | 12/6 | 62.7 ± 8.8 | 6.6 ± 3.6 | ||||
| Yu et al. (2017) | Parallel | E: 31 | NR | 60.32 ± 9.63 | 2.62 ± 0.86 | ON | 1–2 |
| C: 30 | 60.16 ± 10.14 | 1.64 ± 0.52 | |||||
| Zhang and Mao (2021) | Parallel | E: 111 | 62/49 | 63.8 ± 6.1 | NR | ON | 1–2.5 |
| C: 110 | 57/53 | 64.3 ± 6.8 | |||||
| Zhang et al. (2020) | Parallel | E: 37 | 21/16 | 59.42 ± 5.02 | 3.62 ± 0.81 | ON | 1–3 |
| C: 37 | 20/17 | 59.74 ± 4.84 | 3.45 ± 0.77 |
E, experimental group; C, control group; NR, not reported.