Neuroimaging of recovery from aphasia

This paper is a selective review of neuroimaging studies about recovery from aphasia. Two basic mechanisms, i.e., regression of diaschisis and functional reorganisation, have been considered to play an important role in language recovery. The results of recent investigations using positron emission tomography and other functional imaging modalities are reviewed, from the point of view of their contribution to the understanding of the respective role of these mechanisms. Finally, an integration is attempted between these findings and general theories of functional recovery, underlining the crucial role of the spared areas in the language-dominant hemisphere, and the limits to brain plasticity in the adult brain.