Investigating the neural basis of post-stroke aphasia therapy; a systematic review of neuroscience-based therapy studies

Background A variety of therapies for aphasia can be found in the current literature. However, the questions of which changes in the brain are most linked with improvement of language abilities, and how alterations in neural activation are affected by different approaches to therapy, require further exploration. This systematic review therefore aimed to investigate the effects of different therapies on both language deficits and brain function and structure.Methods & Procedures Studies utilising neuroimaging and language testing before and after neuroscience-based treatment were identified using a 2-stage analysis. From an initial 506 citations, 483 were excluded, leaving 23 studies to be included in the review.Outcomes & Results The resulting studies covered therapies ranging in approach from targeting specific stages of language processing, to employing alternative modalities of communication, to facilitating activation of specific regions of the brain. Many studies found changes in both hemispheres following treatment, particularly those with datasets including mild deficits.Conclusions Overall, this review shows that manifold changes in the brain may occur, stemming from therapy and improvement in language abilities, although which changes are most important in facilitating improvement for participants with different specific profiles of damage and language deficit remains unclear.