rTMS and Multi-Modality Aphasia Therapy for Post-Stroke Aphasia

Many stroke survivors experience aphasia, a loss or impairment of language affecting the production or understanding of speech. One common type of aphasia is known as non-fluent aphasia. Patients with non-fluent aphasia have difficulty formulating grammatical sentences, often producing short word fragments despite having a good understanding of what others are trying to communicate to them. Speech language pathologists (SLPs) play a central role rehabilitating persons with aphasia and administer therapy in an attempt to improve communication skills. Despite standard therapy, approximately 50% of individuals who experience aphasia acutely continue to have language deficits more than 6 months post-stroke. In most people, Broca's area is dominant in the left side of the brain. Following a left-sided stroke, the right-sided homologue of Broca's area (the pars triangularis), may adopt language function. Unfortunately, reorganizing language to the right side of the brain seems to be less effective than restoring function to the left hemisphere. Repetitive transcranial magnetic stimulation (rTMS), a form of non-invasive brain stimulation, can be used to suppress activity of specific regions in the right side of the brain to promote recovery of function in the perilesional area. Despite preliminary success in existing studies using rTMS in post-stroke aphasia, there is much work to be done to better understand the mechanisms underlying recovery. Responses to rTMS have been positive, yet heterogenous, which may be related to timing of treatments following stroke.