Abstract
Aphasia is a common consequence of stroke that typically results from injury to the extended network of cortical and subcortical structures perfused by the middle cerebral artery in the left hemisphere. Although most patients shows some degree of spontaneous recovery, usually notably during the first 3months following stroke onset, the majority of patients are left with some degree of chronic deficits for which current various rehabilitative treatments are marginally effective. The understanding of the mechanism of post-stroke aphasia recovery is essentially important for developing the effective therapy to promote the improvement. The recruitment of lesioned and perilesional regions in the left damaged hemisphere is most important for aphasia recovery, for which the role of non-dominant right hemisphere is controversial. Overactivity of the right hemisphere due to transcallosal disinhibition following stroke gives beneficial effect in some cases, but in others shows maladaptive and detrimental effect to aphasia recovery.
Recently, non-invasive brain stimulation such as repetitive transcranial magnetic stimulation (rTMS) or transcranial direct current stimulation (tDCS) is applied to post-stroke aphasia rehabilitation as supplementary therapy. In this paper, the author reviewed the efficacy of low-frequency rTMS over the Broca's area (BA45) homologue of unaffected right hemisphere for post-stroke aphasia.
