| Study | Modality | Study timing | Time points | Intervention |
|---|---|---|---|---|
| Weiller et al. (1995) | PET (rCBF) | Cross-sectional | — | — |
| Belin et al. (1996) | PET (rCBF) | Cross-sectional | — | — |
| Ohyama et al. (1996) | PET (rCBF) | Cross-sectional | — | — |
| Heiss et al. (1997) | PET (rCMRgl) | Longitudinal—recovery | T1: ~4 weeks; T2: ~12-18 months | Not stated |
| Karbe et al. (1998) | PET (rCMRgl) | Longitudinal—recovery | T1: mean 24 ± 11 days, ~3-4 weeks; T2: mean 19 ± 2 months, > 1 year | Not stated |
| Cao et al. (1999) | fMRI | Cross-sectional | — | — |
| Heiss et al. (1999) | PET (rCBF) | Longitudinal—recovery | T1: ~2 weeks; T2: ~8 weeks | Not stated |
| Kessler et al. (2000) | PET (rCBF) | Longitudinal—mixed | T1: pre-treatment, ~2 weeks post onset; T2: post-treatment, ~8 weeks post onset | SLT, 1 hour/day, 5 days/week, 6 weeks; 12 patients received piracetam and 12 received placebo; note that the two groups are not directly compared in any imaging or behavioral analyses |
| Rosen et al. (2000) | PET and fMRI | Cross-sectional | — | — |
| Blasi et al. (2002) | fMRI | Cross-sectional | — | — |
| Leff et al. (2002) | PET (rCBF) | Cross-sectional | — | — |
| Blank et al. (2003) | PET (rCBF) | Cross-sectional | — | — |
| Cardebat et al. (2003) | PET (rCBF) | Longitudinal—recovery | T1: 58 ± 35 days, range 11-113 days; T2: 11.7 ± 1.6 months, range 320-460 days; T1 varies considerably from early to late subacute | Not stated |
| Sharp et al. (2004) | PET (rCBF) | Cross-sectional | — | — |
| Zahn et al. (2004) | fMRI | Cross-sectional | — | — |
| Crinion & Price (2005) | fMRI | Cross-sectional | — | — |
| de Boissezon et al. (2005) | PET (rCBF) | Longitudinal—recovery | T1: mean 53 ± 35 days, range 11-108 days; T2: mean 12.2 ± 1.4 months; T1 varies considerably from early to late subacute | Not stated |
| Connor et al. (2006) | fMRI | Cross-sectional | — | — |
| Crinion et al. (2006) | PET (rCBF) | Cross-sectional | — | — |
| Saur et al. (2006) | fMRI | Longitudinal—recovery | T1 acute: mean 1.8 days, range 0-4 days; T2 subacute: mean 12.1 days, range 3-16 days; T3 chronic: mean 321 days, range 102-513 days | Standard SLT throughout the observation period including at least 3 weeks inpatient |
| Meinzer et al. (2008) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later | CIAT, 3 hours/day, 5 days/week, 2 weeks |
| Raboyeau et al. (2008) | PET (rCBF) | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~4 weeks later | Lexical training, 15 minutes/day, 5 days/week, 4 weeks; the control group were trained to relearn foreign words that they had learned in school but since mostly forgotten |
| Richter et al. (2008) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later | CIAT, 3 hours/day, 10 days |
| de Boissezon et al. (2009) | PET (rCBF) | Longitudinal—recovery | T1: mean 64 ± 32 days; T2: mean 11.8 ± 1.4 months; T1 varies considerably from early to late subacute | Community SLT; 45 minutes/day, 1-3 days/week |
| Fridriksson et al. (2009) | fMRI | Cross-sectional | — | — |
| Menke et al. (2009) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later; T3: 8 months after the end of treatment | Intensive anomia training; 3 hours/day; 2 weeks |
| Specht et al. (2009) | PET (rCBF) | Cross-sectional | — | — |
| Warren et al. (2009) | PET (rCBF) | Cross-sectional | — | — |
| Chau et al. (2010) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~10 weeks later | Acupuncture, 3 sessions/week, 8 weeks |
| Fridriksson (2010) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment/~4 weeks later; note that there were two separate sessions per time point, as well as another two sessions midway through treatment that are not analyzed in this paper | Anomia treatment using a cueing hierarchy, 3 hours/day, 5 days/week, 2 weeks, with a 1-week gap between the two weeks |
| Fridriksson et al. (2010) | fMRI | Cross-sectional | — | — |
| Sharp et al. (2010) | PET (rCBF) | Cross-sectional | — | — |
| Thompson et al. (2010) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, 9-15 weeks later | Treatment of underlying forms |
| Tyler et al. (2010) | fMRI | Cross-sectional | — | — |
| van Oers et al. (2010) | fMRI | Cross-sectional | Behavioral data (TT and a naming measure) were also acquired subacutely (mean 26 ± 18 days, range 5-56 days) | — |
| Papoutsi et al. (2011) | fMRI | Cross-sectional | — | — |
| Sebastian & Kiran (2011) | fMRI | Cross-sectional | — | — |
| Szaflarski et al. (2011) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later | RTMS to residual activation near Broca's area, 5 sessions/week, 2 weeks |
| Tyler et al. (2011) | fMRI | Cross-sectional | — | — |
| Weiduschat et al. (2011) | PET (rCBF) | Longitudinal—mixed | T1: pre-treatment/subacute (range 18-97 days post onset); T2: post-treatment, ~2 weeks later | Individualized SLT, 45 minutes/day, 5 days/week, 2 weeks; 6 patients underwent rTMS to the R IFG pars triangularis; 4 received vertex (sham) rTMS |
| Allendorfer et al. (2012) | fMRI | Cross-sectional | — | — |
| Fridriksson, Hubbard, et al. (2012) | fMRI | Cross-sectional | — | — |
| Fridriksson, Richardson, et al. (2012) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment/~4 weeks later; note that there were two separate sessions per time point, as well as another two sessions midway through treatment that are not analyzed in this paper | Anomia treatment using a cueing hierarchy, 3 hours/day, 5 days/week, 2 weeks, with a 1-week gap between the two weeks |
| Marcotte et al. (2012) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, 3-6 weeks later (after 80% performance on trained items, or 6 weeks) | Semantic feature analysis, 1 hour/day, 3 days/week, 3-6 weeks |
| Schofield et al. (2012) | fMRI | Cross-sectional | — | — |
| Wright et al. (2012) | fMRI | Cross-sectional | — | — |
| Szaflarski et al. (2013) | fMRI | Cross-sectional | — | — |
| Thiel et al. (2013) | PET (rCBF) | Longitudinal—mixed | T1: pre-treatment/subacute (rTMS group: mean 37.5 ± 18.5 days post onset; sham group: mean 50.6 ± 22.6 days post onset); T2 post-treatment, ~2.5 weeks later | RTMS group: inhibitory rTMS over the R IFG pars triangularis + SLT for 45 minutes/day, 5 days/week, 2 weeks; control group: sham TMS + SLT |
| Abel et al. (2014) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~6 weeks later (labeled T2 and T3 in paper) | Lexical therapy, alternating between weeks with phonological and semantic treatment, 4 weeks; 60 out of the 132 items were trained |
| Benjamin et al. (2014) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment; T3: 3 months after the end of treatment | Word finding therapy for both groups, but the intention group had to produce complex left hand movements, while the control group did not; note that groups were not directly compared in any imaging analyses |
| Brownsett et al. (2014) | fMRI | Longitudinal—chronic treatment | Patients: T1: acclimatization/chronic (but used in some analyses); T2: pre-treatment/chronic (not stated how long after T1); T3: post-treatment/~4 weeks later; controls: T1: pre-training; T2: post-training/~2 weeks later | Patients: home-based therapy consisting of auditory discrimination and repetition tasks for 3 or 4 weeks between T2 and T3; control: 2 weeks of similar training using noise vocoded speech |
| Mattioli et al. (2014) | fMRI | Longitudinal—mixed | T1: pre-treatment, mean 2.2 ± 1.3 days post onset; T2: post-treatment, mean 16.2 ± 1.3 days post onset; T3: mean 190 ± 25.5 days post onset | 6 patients were randomized to receive treatment focusing on verbal comprehension and lexical retrieval for 1 hour/day, 5 days/week between T1 and T2; no patient received treatment after T2 |
| Mohr et al. (2014) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later | CIAT, 3-4 hours/day, 5 days/week, 2 weeks |
| Robson et al. (2014) | fMRI | Cross-sectional | — | — |
| Szaflarski et al. (2014) | fMRI | Cross-sectional | — | — |
| van Hees et al. (2014) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, 5-6 weeks later; note that "immediate improvement" was measured at the end of SLT, a week or two prior to T2 scan | SLT with alternating semantic and phonological sessions, 3 days/week, 4 weeks |
| Abel et al. (2015) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~6 weeks later (labeled T2 and T3 in paper) | Lexical therapy, alternating between weeks with phonological and semantic treatment, 4 weeks; 60 out of the 132 items were trained |
| Kiran et al. (2015) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~10 weeks later | Semantic feature-based treatment, 10 weeks |
| Sandberg et al. (2015) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, up to 10 weeks later | Semantic feature-based treatment, 2 hours/day, 2 days/week, up to 10 weeks (depending on when criterion reached) |
| Geranmayeh et al. (2016) | fMRI | Cross-sectional | — | — |
| Griffis et al. (2016) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~2 weeks later | RTMS to residual activation near Broca's area, 5 sessions/week, 2 weeks |
| Sims et al. (2016) | fMRI | Cross-sectional | — | — |
| Darkow et al. (2017) | fMRI | Longitudinal—chronic treatment | T1/T2: chronic; tDCS and sham sessions in randomized order | — |
| Geranmayeh et al. (2017) | fMRI | Longitudinal—recovery | T1: 15 ± 7.6 days (range 5-35 days); T2: 108 ± 26 days (range 87-200 days) | Variable modest amounts of SLT (range 0-18 hours) reported in Supplementary Table 1 |
| Griffis, Nenert, Allendorfer, & Szaflarski (2017) | fMRI | Cross-sectional | — | — |
| Griffis, Nenert, Allendorfer, Vannest, et al. (2017) | fMRI | Cross-sectional | — | — |
| Harvey et al. (2017) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, 2 months after treatment; T3: 6 months after treatment (the 2-month time point was not included in analysis because there was no significant behavioral effect at that time) | Inhibitory rTMS to R IFG, 10 days |
| Nardo et al. (2017) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~6 weeks later | Anomia treatment (computer-based practice), 2+ hours/day, 6 weeks |
| Nenert et al. (2017) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~3 weeks later; T3: 3 months after the end of treatment | CIAT, 4 hours/day, 5 days/week, 2 weeks |
| Qiu et al. (2017) | fMRI | Cross-sectional | — | — |
| Skipper-Kallal et al. (2017a) | fMRI | Cross-sectional | — | — |
| Skipper-Kallal et al. (2017b) | fMRI | Cross-sectional | — | — |
| Dietz et al. (2018) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~4 weeks later | AAC group: treatment aimed at teaching participants how to utilize AAC to facilitate discourse; usual care group: traditional SLT, not focused on discourse or AAC specifically |
| Hallam et al. (2018) | fMRI | Cross-sectional | — | — |
| Nenert et al. (2018) | fMRI | Longitudinal—recovery | T1: ~2 weeks; T2: ~6 weeks; T3: ~12 weeks; T4: ~26 weeks; T5: ~52 weeks | Not stated |
| Pillay et al. (2018) | fMRI | Cross-sectional | — | — |
| Szaflarski et al. (2018) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic (1-2 weeks prior to treatment); T2: post-treatment (within 1 week after end of 2-week treatment); T3: 13-20 weeks after end of treatment | Modified CIAT + intermittent theta burst stimulation to residual left hemispheric language activation, 45 minutes/session, 5 days/week, 2 weeks |
| van de Sandt-Koenderman et al. (2018) | fMRI | Longitudinal—mixed | T1: pre treatment/subacute or chronic; T2: post-treatment, ~6 weeks later | MIT, 5+ hours/week |
| van Oers et al. (2018) | fMRI | Longitudinal—recovery | T1: within 2 weeks; T2: ~3 months; T3: ~6 months; T4: ~12 months; specific timing of first time point not stated | Not stated |
| Barbieri et al. (2019) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~12 weeks later | 13 patients were treated and 5 were not; treatment of underlying forms; 90 minutes/session, 2 sessions/week until 80% accuracy met on weekly probe task, then 1 session/week, 12 weeks except for one patient who demonstrated rapid improvement and completed treatment in 6 weeks |
| Johnson et al. (2019) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, ~12 weeks later | Semantic naming treatment, 2 sessions/week |
| Kristinsson et al. (2019) | fMRI | Cross-sectional | — | — |
| Purcell et al. (2019) | fMRI | Longitudinal—chronic treatment | T1: pre-treatment/chronic; T2: post-treatment, 6-24 weeks later | Spelling treatment, 60-80 minutes/day, 2 days/week, range 6-24 weeks |
| Sreedharan, Chandran, et al. (2019) | fMRI | Longitudinal—mixed | Neurofeedback group: T1: pre-treatment/subacute; T2: 1-5 weeks later; T3: 2-6 weeks after T1; T4: 3-11 weeks after T1; T5: 4-12 weeks after T1; T6: 5-12 weeks after T1; no training group: T1: subacute; T2: 2-12 weeks later; controls: T1: start of study; T2: 1-4 weeks later; T3: 3-5 weeks after T1; T4: 4-8 weeks after T1; T5: 7-37 weeks after T1; T6: 12-43 weeks after T1 | 4 patients received 4 additional sessions involving neurofeedback training, while 4 patients received treatment as usual |
| Hartwigsen et al. (2020) | fMRI | Longitudinal—chronic treatment | T1/T2/T3: chronic; sessions consisted of cTBS over left anterior IFG, cTBS over left posterior IFG, or sham; sessions at least 7 days apart in randomized order | CTBS |
| Stockert et al. (2020) | fMRI | Longitudinal—recovery | T1 acute: 1-7 days; T2 subacute: 8-21 days; T3 chronic: > 6 months | Not stated |
Study timing = Is the study cross-sectional or longitudinal?; Time points = If longitudinal, at what time point(s) were imaging data acquired?; Intervention = If longitudinal, was there any intervention between the time points?; AAC = Augmentative and Alternative Communication; CIAT = constraint-induced aphasia therapy; fMRI = functional magnetic resonance imaging; IFG = inferior frontal gyrus; MIT = melodic intonation therapy; PET = positron emission tomography; R = right; rCBF = regional cerebral blood flow; rCMRgl = regional cerebral metabolic rate for glucose; rTMS = repetitive transcranial magnetic stimulation; SLT = speech-language therapy; T1, T2, etc. = first time point, second time point, etc.; tDCS = transcranial direct current stimulation; TT = Token Test; Yellow underline = minor limitation.
