Aphasia recovery: The role of physiological dysfunction in perilesional tissue: Commentary on Billot and Kiran

Although many of the language deficits exhibited by people with aphasia are directly caused by the total destruction of certain brain regions by a stroke (i.e. the lesion), strokes can exert widespread physiological effects in other areas beyond the lesion. These effects can include loss of neuronal integrity in the absence of a frank infarct, and a shift in the balance of excitatory and inhibitory neurotransmission within perilesional tissue. Such changes can further exacerbate the long-term cognitive and linguistic impact of a stroke event, but on the other hand, they are potentially reversible and represent a promising target for interventions such as pharmaceuticals and noninvasive brain stimulation. This commentary gives an overview of findings related to perilesional dysfunction, outlines potential mechanisms of impairment and recovery, and surveys the possibilities for new interventions to reverse perilesional dysfunction and thereby improve communication in people with aphasia.