Kang etal. 2012 |
Double-blind, randomized, crossover |
N=9 |
F3 anodal; right supraorbital (Fp2) cathodal |
5x5 cm |
None |
20 min of anodal tDCS, 2 mA; or sham tDCS; 48-hour washout |
2 |
Attention by computerized contrast reaction time task |
No significative improvement on RT after tDCS |
3 |
Lesniak et al. 2013 |
Double-blind, parallel group, pilot study |
N=26 |
F3 anodal; right supraorbital (Fp2) cathodal |
5x7 cm |
Offline cognitive training |
10 min of anodal tDCS, 1 mA; or sham tDCS |
15 |
Episodic memory, working memory and attention |
Larger effect size after the intervention compared to sham, but no significant difference between groups |
4 |
Angelakis et al. 2014 |
Open-label, case series, blinded dose scalation |
N=10 (DOC due to TBI n=5) |
C3 or F3 anodal; right supraorbital (Fp2) cathodal |
5x5 cm |
None |
Week 1 - 20 min of sham tDCS; Week 2-20 min of anodal tDCS, 1 mA; Weeks 3 and 4 - 20 min of anodal tDCS, 2 mA |
20 |
CRS-R |
Conflicting results. Some patients improved up to 2 weeks after stimulation. One patient received 10 extra sessions of tDCS after 3 months and showed improvement. Better improvement on patients with MCS compared to PVS |
2 |
Middleton etal. 2014 |
Open-label, case series pilot study |
N= 5 (n=2 TBI) |
Ipsilesional anodal at C3 or C4; and contralesional cathodal |
5x5 cm |
24 sessions of online physical therapy (3 times per week) |
15 min of anodal tDCS, 1.5 mA |
24 |
Fugl-Meyer, Purdue Pegboard, Box and Block, Stroke Impact Scale-16 |
Positive effects on motor performance up to 6 months after intervention |
2 |
Thibaut etal. 2014 |
Double-blind, randomized, crossover |
N=55 (n=32 DOC due to TBI) |
F3 anodal; Fp2 cathodal |
5x7 cm |
None |
20 min of anodal tDCS, 2 mA; or sham tDCS; 48-hour washout |
2 |
CRS-R, GOSe |
Improvements for MCS patients on CRS-R total scores. No effect of tDCS on any of the CRS-R subscales on VS/ UWS groups |
5 |
Ulam etal. 2015 |
Double blind, randomized, parallel group |
N=26 (subacute TBI) |
F3 anodal; Fp2 cathodal |
5x5.6 cm |
None |
20 min of anodal tDCS, 1 mA; or sham tDCS |
10 |
EEG, neuropsychological assessments |
Decreased theta with first session; decreased delta and increased alpha after active tDCS. No changes in sham group. Correlation between decreased delta and improved cognitive tasks in active group |
3 |
Naro etal. 2015 |
Cross-sectional open-label study |
N=45 (n= 20 healthy and n=25 DOC due to TBI or anoxia) |
SO anodal (between Fp1 and Fp2); Cz cathodal |
5x5 cm anode; 5x7 cm reference electrode |
None |
10 min of anodal tDCS, 1 mA; or sham tDCS |
1 |
CRS-R, MEP, ICF, ICI, and SICI |
Significant effects in all physiological measurements in healthy controls after the tDCS, and on ICI and ICF in DOC patients |
2 |
Sacco etal. 2016 |
Double-blind, randomized, parallel groups |
N=32 |
F3 or F4 anodal (anode on the lesioned hemisphere and cathode on the other hemisphere); bi-montage F3/ F4 anodal in case of equal hemispheric lesion distribution |
5x7 cm |
Offline cognitive training |
20 min of anodal tDCS, 2 mA; or sham tDCS |
10 (twice a day) |
TEA, BDI-II, RBANS, AES, fMRI |
Shorter reaction times and fewer errors compared to baseline; decreased apathy |
2 |
O'Neil- Pirozzi etal. 2017 |
Double-blind, crossover pilot study |
N=8 (n=4 with chronic severe TBI) |
F3 (anodal, cathodal or sham); right supraorbital (Fp2) reference electrode |
5x7 cm |
None |
20 min of anodal or cathodal tDCS, 2 mA; or sham tDCS. 48-hours washout |
3 |
EEG alpha power, P300 amplitude and latency, working memory test |
Positive effects on working memory after anodal compared to cathodal tDCS in TBI and control group. No EEG changes |
2 |
Wilke etal. 2017 |
Double-blind, semi-randomized, crossover study |
N=39 (n=17 chronic mild TBI) |
C3 anodal; right supraorbital (Fp2) cathodal |
5x7 cm anode, 10x10cm cathode |
None |
20 min of anodal tDCS, 1 mA; or sham tDCS. 7-day washout |
2 |
MRS (GABA concentration), TMS, PCS, cognitive assessment |
No changes in any outcome |
3 |
Martens etal. 2018 |
Double-blind, crossover study |
N=27 (n=12 DOC due to TBI) |
F3 anodal, right supraorbital (Fp2) cathodal |
5x7 cm |
None |
20 min of anodal tDCS, 2 mA; or sham tDCS; 8-week washout |
40 (2-4 weeks stimulation and 8 weeks washout) |
Adverse events adherence, CRS-R |
Safety, feasibility and behavioral effects - increase in CRS-R scores |
5 |
Estraneo etal. 2017 |
Double-blind, crossover study |
N=23 (n=1 VS due to TBI) |
F3 anodal, right supraorbital (Fp2) cathodal |
5x7 cm |
None |
20 min of anodal tDCS, 2 mA; or sham tDCS. One-week washout |
10 sessions (5 active and 5 sham stimulation) |
CRS-R and EEG |
No changes on EEG or CRS-R |
4 |
Thibaut etal. 2017 |
Double-blind, crossover study |
N=21 (n=11 out of 16 DOC due to TBI) |
F3 anodal, right supraorbital (Fp2) cathodal |
5x7 cm |
None |
20 min of anodal tDCS, 2 mA; or sham tDCS. One-week washout |
10 sessions (5 active and 5 sham stimulation) |
CRS-R |
Positive treatment effect (CRS-R scores) after one week of anodal tDCS compared to sham |
5 |
Bai etal. 2017 |
Double-blind, crossover study |
N=16 (n=4 VS or MSC due to TBI) |
F3 anodal, right supraorbital (Fp2) cathodal |
5x5 cm |
None |
20 min of anodal tDCS, 2 mA; or sham tDCS. 3-day washout |
2 |
TMS (MEP) and EEG |
Global cerebral excitability increased in early time windows (0-100 and 100-200 ms) for patients with MCS after anodal tDCS |
4 |