Neural bases of recovery after brain injury

Substantial data have accumulated over the past decade indicating that the adult brain is capable of substantial structural and functional reorganization after stroke. While some limited recovery is known to occur spontaneously, especially within the first month post-stroke, there is currently significant optimism that new interventions based on the modulation of neuroplasticity mechanisms will provide greater functional benefits in a larger population of stroke survivors. To place this information in the context of current thinking about brain plasticity, this review outlines the basic theories of why spontaneous recovery occurs, and introduces important principles to explain the effects of post-stroke behavioral experience on neural plasticity.Learning outcomes: Readers will be able to: (a) explain the three classic theories to explain spontaneous recovery after focal brain injury, (b) explain the neurophysiological effects of post-injury rehabilitative therapy on functional organization in motor cortex, (c) readers will be able to describe some of the variables that impact the effects of post-stroke behavioral experience on neuroplasticity, and (d) readers will be able to explain some of the current laboratory-based approaches to modifying brain circuits after stroke that might soon be translated to human application.

► Mechanisms underlying spontaneous recovery after stroke include reversal of diaschisis, behavioral compensation and adaptive plasticity.
► The organization of motor cortex in the healthy brain is modifiable based on motor experience.
► After stroke, intact portions of the motor cortex expand their representations as a function of post-injury motor experience.
► The entire network of sensorimotor structures in the brain is altered after stroke.
► Artificial electrical coupling of different nodes in the cortical network may provide a new restorative treatment approach.