Mechanisms of motor recovery after stroke.

Recovery from motor deficit after a sroke remains a puzzling scientific que stion as well as public health problem. The natural history of deficits aft er stroke is given to us through published series of patients and we know f rom them that neurological deficits, spontaneously but most of the time par tially, recover. Neuroimaging modern techniques (PETscan, fMRI, evoked pote ntials) allowed us to identify the main aspects of the post-stroke intracer ebral reorganisation. Reorganisation of basal cerebral metabolism, changes in the somatotopia of primary motor cortex, recruitment od remote cortices, participation of associative cortices are clearly part of the rearrangemen t processes. It is likely that such mechanisms represent the basis of clini cal recovery of our patients. However, despite those important advances, ve ry few is known about the effect of treatments on the recovery phenomenon. Some lines of evidence appear now to give rationale to rehabilitation proce dures and to drugs suspected to improve clinical recovery.