TABLE 3.

The specific parameters of tDCS interventions.

References	Study design	Intervention type	Stimulation parameters					The total duration of treatment	Follow up
			Session	Anodal electrode site	Intensity	Duration	Areas
Bueno et al. (2019)	Crossover	tDCS	2	DLPFC	2 mA	20 min	35 cm2	NR	No
Costa-Ribeiro et al. (2017)	Parallel	tDCS	NR	MC	2 mA	13 min	35 cm2	4 weeks	Yes (1 month)
Benninger et al. (2010)	Parallel	tDCS	8	PMC, MC	2 mA	20 min	97.5 cm2	2.5 weeks	Yes (1, 3 months)
Hu et al. (2021)	Parallel	tDCS	1	DLPFC	2 mA	25 min	35 cm2	NR	No
Kaski et al. (2014)	Crossover	tDCS	NR	M1	2 mA	15 min	40 cm2	NR	Nr
Liu and Zhang (2021)	Parallel	tDCS	1	Bi	1.4 mA	20 min	24 cm2	14 days	No
Qiao et al. (2018)	Parallel	tDCS	1	DLPFC	2 mA	20 min	NR	5 days	No
Qiao et al. (2019)	Parallel	tDCS	1	DLPFC	2 mA	20 min	35 cm2	5 days	No
Schabrun et al. (2016)	Parallel	tDCS	9	M1	2 mA	20 min	35 cm2	3 weeks	Yes (12 weeks)
Swank et al. (2016)	Crossover	tDCS	2	DLPFC	2 mA	20 min	NR	7 ± 2 days	No
Chang et al. (2017)	Parallel	tDCS	5	DLPFC	1 mA	20 min	NR	5 days	Yes (12 weeks)
Wong et al. (2022)	Parallel	tDCS	NR	M1, DLPFC, Cerebellum	2 mA	20 min	35 cm2	NR	No
Yotnuengnit et al. (2018)	Parallel	tDCS + Physical Therapy	6	MC	2 mA	30 min	35 cm2	2 weeks	Yes (2, 4, 8 weeks)
Zhang and Mao (2021)	Parallel	tDCS	1	DLPFC	2 mA	20 min	NR	20 days	No

tDCS, transcranial direct current stimulation; Bi, bilateral brain region; DLPFC, dorsolateral prefrontal cortex; M1, primary motor cortex; PMC, premotor cortex; MC, motor cortex; NR, not reporting.