Background: Transcranial direct-current stimulation (tDCS) is a promising adjunct to therapy for chronic aphasia. Methods: This single-center, randomized, double-blind, sham-controlled efficacy trial tested the hypothesis that anodal tDCS augments language therapy in subacute aphasia. Secondarily, we compared the effect of tDCS on discourse measures and quality of life and compared the effects on naming to previous findings in chronic stroke. Right-handed English speakers with aphasia <3 months after left hemisphere ischemic stroke were included, unless they had prior neurological or psychiatric disease or injury or were taking certain medications (34 excluded; final sample, 58). Participants were randomized 1:1, controlling for age, aphasia type, and severity, to receive 20 minutes of tDCS (1 mA) or sham-tDCS in addition to fifteen 45-minute sessions of naming treatment (plus standard care). The primary outcome variable was change in naming accuracy of untrained pictures pretreatment to 1-week posttreatment. Results: Baseline characteristics were similar between the tDCS (N=30) and sham (N=28) groups: patients were 65 years old, 53% male, and 2 months from stroke onset on average. In intent-to-treat analysis, the adjusted mean change from baseline to 1-week posttreatment in picture naming was 22.3 (95% CI, 13.5–31.2) for tDCS and 18.5 (9.6–27.4) for sham and was not significantly different. Content and efficiency of picture description improved more with tDCS than sham. Groups did not differ in quality of life improvement. No patients were withdrawn due to adverse events. Conclusions: tDCS did not improve recovery of picture naming but did improve recovery of discourse. Discourse skills are critical to participation. Future research should examine tDCS in a larger sample with richer functional outcomes. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02674490.

A clinical diagnosis of primary progressive aphasia relies on behavioral characteristics and patterns of atrophy to determine a variant: logopenic; nonfluent/agrammatic; or semantic. The dual strea...

Altered functional connectivity is related to severity of language impairment in poststroke aphasia. However, it is not clear whether this finding specifically reflects loss of functional coherence, or more generally, is related to decreased structural connectivity due to cortical necrosis. The aim of the current study was to investigate this issue by factoring out structural connectivity from functional connectivity measures and then relating the residual data to language performance poststroke. Ninety-seven participants with a history of stroke were assessed using language impairment measures (Auditory Verbal Comprehension and Spontaneous Speech scores from the Western Aphasia Battery–Revised) and MRI (structural, diffusion tensor imaging, and resting-state functional connectivity). We analyzed the association between functional connectivity and language and controlled for multiple potential neuroanatomical confounders, namely structural connectivity. We identified functional connections within the left hemisphere ventral stream where decreased functional connectivity, independent of structural connectivity, was associated with speech comprehension impairment. These connections exist in frontotemporal and temporoparietal regions. Our results suggest poor speech comprehension in aphasia is at least partially caused by loss of cortical synchrony in a left hemisphere ventral stream network and is not only reflective of localized necrosis or structural connectivity.

Background: It is estimated that ∼30% of stroke survivors have aphasia, a language disorder resulting from damage to left-hemisphere language networks. In acute care settings, efficient identification of aphasia is critical, but there is a paucity of efficient bedside assessments. Objective: To determine whether objective measures on a picture description task administered within 48 hours post stroke (a) predict language recovery, (b) estimate left-hemisphere lesion volume and location, and (c) correlate with other bedside language assessments. Method: Behavioral data were scored at acute and chronic time points. Neuroimaging data were used to determine associations between the picture description task, other language assessments, and lesion volume and location. Results: Acute content units, age, and total lesion volume predicted communication recovery; F _3,18 = 3.98, P = 0.024; r ² = 0.40. Significant correlations were found between the picture description task and lesion volume and location. Picture description outcomes were also associated with other clinical language assessments. Discussion: This picture description task quickly predicted the language performance (communication recovery and outcome) for patients who suffered a left-hemisphere stroke. Picture description task measures correlated with damage in the left hemisphere and with other, more time-consuming and cumbersome language assessments that are typically administered acutely at bedside. Conclusion: The predictive value of this picture description task and correlations with existing language assessments substantiate the clinical importance of a reliable yet rapid bedside measure for acute stroke patients that can be administered by a variety of health care professionals.

Transcranial direct current stimulation (tDCS) has emerged as a possible neuromodulatory tool to augment language therapy in post-stroke aphasia. However, there is limited information on whether tDCS may help to improve everyday functional communication. To investigate whether cerebellar tDCS combined with computerized aphasia treatment improves functional communication skills in individuals with chronic aphasia. In a randomized, double-blind, sham-controlled, within-subject crossover study, participants received 15 sessions of anodal (n=14) or cathodal (n=14) cerebellar tDCS plus computerized aphasia treatment then sham plus computerized aphasia treatment, or the opposite order. Linear mixed-effects regression models were performed to evaluate (1) the effect of tDCS treatment on change in functional communication skills on the two dimensions of the American Speech-Language-Hearing Association Functional Assessment of Communication Skills for Adults (ASHA-FACS): Communication Independence (CI) scale and Qualitative Dimension of Communication (QDC) scale, and (2) the relationship between functional communication skills and trained and untrained naming abilities. The results showed significant tDCS-induced gains for the overall QDC mean score, but not for the overall CI mean score. Cerebellar stimulation was more effective than sham for the overall QDC mean score immediately post-treatment, 2-weeks post-treatment and 2-months post-treatment. Follow up analysis separated by group showed that the change in the overall QDC mean score (combining both phases) were similar in participants receiving anodal or cathodal stimulation. We also found a significant linear association between ASHA-FACS overall CI mean change scores and trained and untrained naming change scores for the tDCS condition but not sham. Our study provides preliminary evidence that cerebellar tDCS coupled with computerized aphasia treatment has the potential to improve the overall qualitative dimensions of functional communication skills in individuals with chronic aphasia.

Purpose: Hemispheric specialization for the comprehension and expression of linguistic and emotional prosody is typically attributed to the right hemisphere. This study used techniques adapted from meta-analysis to critically examine the strength of existing evidence for hemispheric lateralization of prosody following brain damage. Method: Twenty-one databases were searched for articles published from 1970 to 2020 addressing differences in prosody performance between groups defined by right hemisphere damage and left hemisphere damage. Hedges's g effect sizes were calculated for all possible prosody comparisons. Primary analyses summarize effects for four types: linguistic production, linguistic comprehension, emotion comprehension, and emotion production. Within each primary analysis, Hedges's g values were averaged across comparisons (usually from a single article) based on the same sample of individuals. Secondary analyses explore more specific classifications of comparisons. Results: Out of the 113 articles investigating comprehension and production of emotional and linguistic prosody, 62 were deemed appropriate for data extraction, but only 21 met inclusion criteria, passed quality reviews, and provided sufficient information for analysis. Evidence from this review illustrates the heterogeneity of research methods and results from studies that have investigated aprosodia. This review provides inconsistent support for selective contribution of the two cerebral hemispheres to prosody comprehension and production; however, the strongest finding suggests that right hemisphere lesions disrupt emotional prosody comprehension more than left hemisphere lesions. Conclusion: This review highlights the impoverished nature of the existing literature; offers suggestions for future research; and highlights relevant clinical implications for the prognostication, evaluation, and treatment of aprosodia. Supplemental Material: https://doi.org/10.23641/asha.20334987