Table 3.
Transcranial direct current stimulation studies in aphasia recovery. Abbreviation: L left; R: right; IFG: inferior frontal gyrus; ST: superior temporal; M1: motor cortex; PPR: posterior perisylvian region; DLPFC: dorsolateral-prefrontal cortex, Bihemisph: bihemispheric; Generaliz: generalization; Periles: perilesional; Individ: Individualized.
| Articles | Patients | Task | tDCS vs. Sham | Target (Areas) |
tDCS Stimulation Parameters |
Generaliz. | Follow-Up | Effects |
|---|---|---|---|---|---|---|---|---|
| Guillouët et al., 2020 [132] |
14 aphasics (7 non-fluent, 4 fluent 3 mixed), but 10 patients completed the study | Personalized speech and language therapy | No | Bihemisph Anode: L IFG Cathode: R IFG |
2 mA, 20 min 2–5 sessions a week for 3 weeks |
No | No | no improvement in spontaneous speech |
| Fiori et al., 2019 [133] |
2 groups of 10 non-fluent aphasics | Verb naming | Yes, only after cathodal stimulation at 2 mA | Cathode: R IFG | 1 mA, 20 min 2 mA, 20 min 5 sessions |
Not investigated | Yes, at 1 week | improvement in verb recovery |
| Stahl et al., 2019 [134] |
130 aphasics | Computer-assisted naming therapy and face-to-face communicative-pragmatic therapy | Yes | Anode: L M1 | 1 mA, 20 min Two daily sessions over three consecutive weeks |
Yes | Yes, at 6 months and 12 months | improvement in communicative ability |
| Vila-Nova et al., 2019 [135] |
12 (5 non-fluent, 5 fluent, 2 transcortical not defined) | Articulatory accuracy, syllable repetition, and word production | Yes, only for articulatory accuracy | Anode: L IFG | 1 mA, 20 min 5 sessions |
No | Yes, at 1 week and 4 months qualitative follow up |
improvement in articulatory accuracy |
| Branscheidt et al., 2018 [136] |
16 (6 non-fluent, 5 fluent, 5 mixed) | Lexical decision task | Yes | Anode: L M1 | 2 mA, 20 min 1 session |
No | No | improvement of accuracy in lexical decision, especially for action words |
| Silva et al., 2018 [137] |
14 non-fluent | Naming task | Yes, only at Boston test (mean time for correct responses with strategy) | Cathode: R IFG | 2 mA, 20 min 5 sessions |
No | Yes, at 4 weeks | only improvement in Boston test performance |
| Fridriksson et al., 2018 [138] | 74 (43 non-fluent, 31 fluent) | Computerized behavioral treatment of anomia | Yes | Anode: L Temporal cortex | 1 mA, 20 min 15 sessions |
Yes | Yes, at 6 months | improvement in anomia |
| Fridriksson et al., 2018 [139] | 74 aphasics | Computerized picture-word matching task | Yes | Anode: L Temporal cortex | 1 mA, 20 min 15 sessions |
Yes | Yes, at 4 weeks and 24 weeks | improvement in naming |
| Spielmann et al., 2018 [19] |
13 aphasics | Word finding Therapy | Yes | Anode: L IFG or L ST | 1 mA; 20 min 3 sessions |
No | No | improvement in word finding |
| Marangolo et al., 2018 [140] |
12 non-fluent | Verb naming and verb generation | Yes, only for verb generation | Cathode: R cerebellar cortex | 2 Am, 20 min 5 sessions |
No | Yes, at 1 week | improvement in verb generation |
| Pestalozzi et al., 2018 [141] |
14 (10 non-fluent, 4 fluent) | Picture naming, phonemic fluency task, and repetition task | Yes | Anode: L DLPFC | 1 mA, 20 min 1 session |
No | No | improvement in high-frequency word fluency |
| Woodhead et al., 2018 [142] |
21 aphasics with central alexia | iReadMore training | Yes | Anode: L IFG | 2 mA, 20 min 5 sessions |
Yes | Yes, at 3 months | facilitation in reading ability |
| Darkow et al., 2017 [143] | 16 mild aphasics | Noun picture naming | No | Anode: L M1 | 1 mA, 20 min 1 session |
Not investigated | No | No differences between real and sham condition; |
| Santos et al., 2017 [144] |
13 non-fluent | Picture naming | No | Anode: L IFG | 2 mA, 20 min 1 session |
No | No | No improvement in picture naming |
| Norise et al., 2017 [145] | 9 non-fluent | Noun picture naming based on constraint-induced language therapy (CILT) | Yes | Anode/Cathode: L IFG Anode/Cathode: RIFG |
2 mA, for 20 min 10 sessions |
No | Yes, at 2 weeks and 2 months | improvement in speech fluency |
| Marangolo et al., 2016 [26] | 9 non-fluent | Repetition | Yes | Bihemisph Anode: L IFG Cathode: R IFG |
2 mA, 20 min 15 sessions |
Yes | Yes, at 1 week | improvement in speech articulation |
| Meinzer et al., 2016 [146] | 26 (15 non-fluent, 11 fluent) | Computer-assisted naming treatment | Yes | Anode: L M1 | 1 mA, 20 min for Two daily treatment for 8 sessions |
Yes | Yes, at 6 months | improvement in naming |
| Campana et al., 2015 [27] | 20 non-fluent | Conversational therapy | Yes | Anode: L IFG | 2 mA, 20 min 10 sessions |
Not investigated | No | improvement in picture description, noun and verb naming |
| Cipollari et al., 2015 [147] | 6 non-fluent | MIT | Yes | Anode: R IFG | 2 mA, 20 min 15 sessions |
Yes | Yes, at 1 week | improvement in repetition accuracy for words and sentences. |
| de Aguiar et al., 2015 [148] | 9 (3 fluent, 6 non fluent) | Verb treatment “ACTION” | Yes | Bihemisph. Anode and Cathode: left periles. area |
1 mA, 20 min 10 sessions |
Yes | No | improvement in verb production |
| Richardson et al., 2015 [149] | 8 non-fluent | Computerized noun naming | Yes | Individ. electrode placement by fMRI |
1 mA, 20 min 22 sessions spread out in 5 weeks |
No | Yes, at 1 week | Improvement in naming accuracy after HD-tDCS and CS-tDCS |
| Shah-Basak et al., 2015 [20] | 12 non-fluent | Picture naming | Yes | Anode: L/R DLPFC, Cathode: L/R DLPFC |
2 mA, 20 min 10 sessions |
Yes | Yes, at 2 weeks and 2 months | improvement in naming |
| Marangolo et al., 2014a [29] | 7 non-fluent | Conversational therapy | Yes | Bihemisph Anode: L IFG Cathode: R IFG |
2 mA, 20 min 10 sessions |
Yes | Yes, at 1 week | improvement in picture description, noun and verb naming |
| Marangolo et al., 2014b [30] | 8 non-fluent | Conversational therapy | Yes | Anode: L IFG or L ST | 1 mA, 20 min 10 sessions |
Yes | No | improvement in cohesive elements (pronouns, ellipses, word repetitions, conjunctions) after a-tDCS over LIFG. |
| Vestito et al., 2014 [150] | 3 (2 non-fluent aphasics, 1 fluent anomic) | Noun and Verb picture naming | Yes | Anode: L IFG | 1.5 mA, 20 min 10 sessions |
Yes | Yes, at 6 weeks | improvement in naming |
| Fiori et al., 2013 [21] | 7 non-fluent | Noun and Verb picture Naming | Yes | Anode: L IFG or L ST | 1 mA, 20 min 5 sessions |
Yes | Yes, at 1 week and 4 weeks | A-tDCS over L IFG improved verb naming; A tDCS over L ST improved noun naming |
| Lee et al., 2013 [151] | 11 (6 non-fluent and 5 fluent) | Picture naming, reading short paragraphs | Yes | Anode: L IFG or Bihemisph Anode: L IFG Cathode: R IFG | 2 mA, 30 min 1 session |
Not investigated | No | Improvement in naming accuracy after bihemispheric and single tDCS. |
| Marangolo et al., 2013 a [25] | 12 non-fluent | Repetition | Yes | Bihemisph Anode: L IFGCathode: R IFG |
1 mA, 20 min 5 sessions |
Yes | Yes at 1 week | improvement in speech articulation |
| Marangolo et al., 2013 b [28] | 12 non-fluent | Conversational therapy | Yes | Anode: L IFG, L ST | 1 mA, 20 min 10 sessions | Yes | Yes, at 4 weeks | improvement in informative speech, content units, verbs, and sentences |
| Marangolo et al., 2013 c [23] | 8 non-fluent | Picture naming | Yes | Anodal: L IFG or L ST | 1 mA, 20 min 5 sessions |
Not reported | Yes, at 4 weeks | improvement in verb naming after A-tDCS over the LIFG |
| Flöel et al., 2011 [152] | 12 (9 non-fluent and 3 fluent) | Computerized picture naming | Yes | Anode vs. Cathode over R TP cortex; | 1 mA, 20 min 3 session |
No | Yes, at 2 weeks | improvement in picture naming |
| Fridriksson et al., 2011 [153] | 8 fluent | Computerized picture naming | Yes | Anode: L posterior cortex | 1 mA, 20 min 5 sessions |
No | Yes, at 3 weeks | improvement in picture naming |
| Fiori et al., 2011 [22] | 3 non-fluent | Noun picture naming | Yes | Anode: L ST | 1 mA, 20 min 5 sessions |
Not reported | Yes, at 3 weeks | improvement in picture naming |
| Kang et al., 2011 [154] | 10 (8 non-fluent and 2 fluent) | Noun picture naming | Yes | Cathode: R IFG | 2 mA, 20 min 5 sessions |
No | No | improvement in picture naming |
| Marangolo et al., 2011 [24] | 3 non fluent | Repetition | Yes | Anode: L IFG | 1 mA, 20 min 5 sessions |
Yes | Yes, at 1 week and at 2 months | improvement in speech accuracy and fluency |
| Vines et al., 2011 [155] | 6 non-fluent | MIT | Yes | Anode: R IFG | 1.2 mA, 20 min 3 sessions |
Yes | No | improvement in speech fluency |
| Baker et al., 2010 [156] | 10 (6 fluent and 4 non-fluent) | Computerized picture naming | Yes | Anode: L F | 1 mA, 20 min 5 sessions |
Yes | Yes, at 1 week | improvement in picture naming |