Future perspectives in functional neuroimaging in stroke recovery

Neurological damage and stroke in particular is the leading cause of long-term disability worldwide. Recovery of function after stroke is a consequence of many factors including resolution of oedema and survival of the ischaemic penumbra. In addition, there is a growing interest in how reorganisation of the surviving tissue might subserve the improvements in function that are commonly seen over weeks, months, and sometimes years after stroke. Noninvasive techniques such as functional magnetic resonance imaging, electroencephalography, magnetoencephalography and transcranial magnetic stimulation allow the study of this reorganisation in humans. Currently, results suggest that functionally relevant reorganisation does occur in cerebral networks in human stroke patients. This reorganisation can only occur in structurally and functionally intact brain regions. Because these vary depending on the location of the infarction, it is likely that different therapeutic strategies will be required to promote reorganisation depending on residual functional anatomy. This review maps out the attempts to describe functionally relevant adaptive changes in the human brain following focal damage. A greater understanding of how these changes are related to the recovery process will facilitate the development of novel therapeutic techniques designed to minimise impairment based on neurobiological principles and how to target these treatments to individual patients.