Transcranial Direct Current Stimulation in Tinnitus Patients: A Systemic Review and Meta-Analysis

Table 1

Summary of the 6 studies that were included in the current study.

Study	Group	𝑛	Anode	Cathode	Current, mA	Duration	Number of sessions	Measure	Mean percentage reduction	Percentage responders	Summary
Randomized controlled studies
Fregni; et al. (2006) [30]	Active, anodal	7	LTA	R SO	1	3 min	2	VAS tinnitus reduction scale (0–4)	30.36%	42.90%
	Active, cathodal	7	R SO	LTA		3 min	2		0	0
	Sham	7	LTA	R SO		5 sec	2		0	0
Faber; et al. (2011) [36]	Active, anode left	8	L DLPFC	R DLPFC	1.5	20 min	3	VAS intensity, VAS distress	27.80%		8 weeks’ wash-out period between active and sham sessions changes measured directly after tDCS
	Active, anode right	7	R DLPFC	L DLPFC	1.5	20 min	3		0.00%	NA
	Sham	15			1.5	30 sec	3		4.50%
Garin; et al. (2011) [37]	Active, anode left	20	L LTA	R VLPFC	1	20 min	1	VAS tinnitus reduction scale (0–4)	9.13%	35%	2 weeks’ wash-out period between active and sham sessions
	Active, anode right	20	R VLPFC	L LTA	1	20 min	1			30%
	Sham	20	L LTA	R VLPFC	110 μA	20 min	1		0
			(or vice versa)
Open label studies
Vanneste et al. (2010) [38]	Active, anode left	448	L DLPFC	R DLPFC	1.5	20 min	1	VAS intensity, VAS distress	0	0.00%	Changes measured directly after tDCS
	Active, anode right	30	R DLPFC	L DLPFC			1		7.95%	29.90%
Vanneste et al. (2011) [39]	Active, anode right	45	R DLPFC	L DLPFC	1.5	20 min	1		14.00%	46.67%	changes measured directly after tDCS
Frank; et al. (2012) [40]	Active, anode right	32	R DLPFC	L DLPFC	1.5	30 min	6	THI, TQ, BDI, CGI	NA	40.63%

S.D.: standard deviation; LTA: left temporal area; SO: supraorbital; min: minutes; sec: seconds; VAS: visual analogue scale; DLPFC: dorsolateral prefrontal cortex; NA: not available; THI: tinnitus handicap inventory; TQ: tinnitus questionnaire; BDI: Beck depression inventory; CGI: clinical global impression scale.