Purpose: The purpose of this scoping review was to identify and synthesize research on interventions in which noninvasive brain stimulation (NIBS) was used to improve linguistic abilities in individuals with aphasia. NIBS comprising transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are emerging technologies with potential to improve the underlying neurobiology of language in brains with stroke-induced lesions.Methods: The results of a systematic search of electronic literature databases were reviewed in CADIMA software by two authors yielding 57 studies published between 2015 and 2022. Selected articles were reviewed for study characteristics, participant characteristics, intervention details, and outcome measures.Results: NIBS is largely used for non-fluent aphasia during the chronic phase of recovery for improving naming and comprehension using picture naming and auditory comprehension of words, commands, and small paragraphs. Standardized test materials are used to measure treatment efficiency, with neuroimaging gradually emerging as an added measure to assess the neurobiological changes arising as a result of treatment induced linguistic recovery.
Conclusion:The findings from this scoping review describe the design and delivery of NIBS treatment from subacute to chronic stages of recovery in aphasia. Positive results from heterogenous studies show the potential of NIBS in improving linguistic outcomes for people with aphasia. Large scale clinical trials and systematic reviews should further substantiate our findings of NIBS efficiency for specific language skills (e.g., naming accuracy, sentence production, discourse comprehension).