Cortical reorganization--effects of intensive therapy.

Recovery from hemiparesis after stroke largely depends on widespread functional and structural neuronal plasticity. Based on animal studies of rehabilitative and pharmacological interventions on recovery, recent neuroscientific findings suggest that new rehabilitative interventions may also have benefits by modulating neuroplastic mechanisms in stroke patients. Neurofunctional imaging methods such as Positron Emission Tomography (PET) and functional Magnetic Resonance Imaging (fMRI) as well as transcranial magnetic stimulation (TMS) now permit direct studies of training-induced plasticity in stroke patients. Prospectively conducted studies using these techniques have investigated how plasticity relates to recovery of motor function and how intensive training modulates cortical reorganization. Despite technical and methodological differences, consistent neuroanatomic findings on training-induced reorganization of the motor system have been reported. These discoveries have important implications for the future development of neurorehabilitative training methods. With continuously improving methods to study cortical reorganization and over 100 randomized clinical trials on stroke rehabilitation published during the past five years, this promises to be an exciting time in stroke rehabilitation research.