Recovery from post-stroke aphasia: lessons from brain imaging and implications for rehabilitation and biological treatments.

Aphasia, a condition defined as the partial or complete loss of language function after brain damage, is one of the most devastating cognitive deficits produced by stroke lesions. Over the past decades, there have been great advances in the diagnosis and treatment of post-stroke language and communication deficits. In particular, the advent of functional brain imaging and other brain mapping methods has advanced our understanding of how the intact and lesioned brain takes over the activity of irretrievably damaged networks in aphasic patients. This review examines the contribution of these ancillary methods to elucidate the neural changes that take place to promote improvement of language function in early, late, and very late stages of recovery. Also, functional neuroimaging is helpful to identify brain areas involved in language recovery as well as to characterize the plastic reorganization of neural networks produced by scientifically-based language therapies and biological treatments (drugs, transcranial magnetic stimulation).