Neural plasticity after acquired brain injury: evidence from functional neuroimaging.

The reorganization of the adult central nervous system after damage is a relatively new area of investigation. Neuroimaging methods, such as functional magnetic resonance imaging, diffusion tensor imaging, and positron emission tomography, have the ability to identify, in vivo, some of the processes involved in these neuroplastic changes and can help with diagnosis, prognosis, and potentially treatment approaches. In this article, traumatic brain injury and stroke are used as examples in which neural plasticity plays an important role in recovery. Basic concepts related to brain remodeling, including spontaneous reorganization and training-induced recovery, as well as characteristics of reorganization in successful recovery, are reviewed. The microscopic and molecular mechanisms that underlie neural plasticity and neurogenesis are briefly described. Finally, exciting future directions for the evaluation, diagnosis, and treatment of severe brain injury are explored, with an emphasis on how neuroimaging can help to inform these new approaches.