Transcranial Direct-Current Stimulation in Subacute Aphasia: A Randomized Controlled Trial

Abstract

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 No patients were withdrawn due to adverse events.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.

Individual Differences in Response to Transcranial Direct Current Stimulation With Language Therapy in Subacute Stroke

“…We also administered the Stroke Impact Scale 25 (SIS), a disease-specific quality of life questionnaire. 9 All participants with no contraindication were asked to complete structural and functional magnetic resonance imaging (fMRI) to support localization of the lesion and identification of a stimulation site of healthy tissue. If they consented to research MRI, they were randomized to (1) have the site of stimulation based on greatest area of activation on fMRI during a naming task (as in Fridriksson et al 26 ) or (2) have the site of stimulation based on the area of lesion (from clinical imaging or research MRI).…”

“…Two planned exploratory subgroup analyses were conducted on the sample of study completers to follow up with the primary outcome findings. 9 The first analysis examined the influence of age (<55 vs ≥55 years), sex, education (<11 years completed vs ≥12 years), and time since stroke onset to initiation of CoDeLT (<1 month vs ≥1 month), and BDNF status on response to CoDeLT by treatment group (collapsing across stimulation sites that targeted healthy tissue). The software package SAS was used.…”

“…We also administered the Stroke Impact Scale 25 (SIS), a disease-specific quality of life questionnaire. 9…”

“…SLISSE was a randomized, single-center, double-blind, sham-controlled, efficacy study of A-tDCS combined with a computer-delivered speech and language therapy (SALT) for subacute stroke-induced aphasia completed at Johns Hopkins Hospital and Johns Hopkins Bayview Medical Center in Baltimore, Maryland, previously reported on in Stockbridge et al 9 All procedures were approved by the Johns Hopkins Medicine Institutional Review Board (IRB00089018). The study was registered with ClinicalTrials.gov (NCT02674490).…”

“…However, tDCS did augment the more ecologically valid secondary measure of how much information patients provided and how efficiently they did so when asked to describe a picture. 9 A pre-specified secondary analysis of these data was to examine whether individual differences in age, sex, education, time since stroke onset, and genotype influenced the effect of tDCS on language recovery. Age-related decline in cortical thickness is thought to widen the distance between the scalp and cortex, thus reducing the focal specificity of current when tDCS is applied.…”