Background and Purpose-Studies on adult stroke patients have demonstrated functional changes in cortical excitability, metabolic rate, or blood flow after motor therapy, measures that can fluctuate rapidly over time. This study evaluated whether evidence could also be found for structural brain changes during an efficacious rehabilitation program. Methods-Chronic stroke patients were randomly assigned to receive either constraint-induced movement therapy (nϭ16) or a comparison therapy (nϭ20). Longitudinal voxel-based morphometry was performed on structural MRI scans obtained immediately before and after patients received therapy. Results-The group receiving constraint-induced movement therapy exhibited far greater improvement in use of the more affected arm in the life situation than the comparison therapy group. Structural brain changes paralleled these improvements in spontaneous use of the more impaired arm for activities of daily living. There were profuse increases in gray matter in sensory and motor areas both contralateral and ipsilateral to the affected arm that were bilaterally symmetrical, as well as bilaterally in the hippocampus. In contrast, the comparison therapy group failed to show gray matter increases. Importantly, the magnitude of the observed gray matter increases was significantly correlated with amount of improvement in real-world arm use. Conclusions-These findings suggest that a previously overlooked type of brain plasticity, structural remodeling of the human brain, is harnessed by constraint-induced movement therapy for a condition once thought to be refractory to treatment: motor deficit in chronic stroke patients. Key Words: constraint-induced movement therapy Ⅲ hemiplegia Ⅲ imaging Ⅲ motor activity Ⅲ MRI Ⅲ stroke rehabilitation Ⅲ voxel-based morphometry M erzenich et al 1 and other investigators 2 showed in animals that altering behaviorally relevant afferent input to the central nervous system can produce plastic changes in the function and organization of the brain. Sustained increased use of a body part by an animal leads to an increase in the brain's cortical representation of that body part, 3 whereas decreased input reduces the representational zone of that body part, as occurs after amputation of a digit 1 or somatosensory deafferentation of an entire forelimb in monkeys. 4 Similar phenomena have been demonstrated in humans after both increased use 5 and decreased use resulting from upper extremity amputation 6 or stroke 7 using functional imaging or mapping techniques.A neurorehabilitation technique termed Constraint-Induced Movement therapy (CI therapy) was developed in this laboratory from basic research with monkeys. 8 This treatment has been shown to substantially increase the amount of use of an affected upper extremity after stroke 9 -12 and also greatly alter the size of the regional brain activity or activation pattern associated with the more affected arm. 7,[13][14][15] Until now, neuroanatomical evaluations of treatment changes in humans have relied solely on funct...

BACKGROUND AND PURPOSE:Methods have not been well developed and tested to predict the extent of remote degeneration in the central nervous system that follows cerebral infarction. We hypothesized that the extent of infarction overlap with the cerebral hemispheric course of the corticospinal tract (CST) on structural MR imaging predicts the extent of ipsilateral cerebral peduncular atrophy in patients with chronic stroke.

Background and Purpose-Disruption of the corticospinal tract at various locations in the brain has been shown to predict worse spontaneous motor recovery after stroke. However, the anatomic specificity of previous findings was limited by the categorical classification of infarct locations. Here we used computational methods to more precisely determine the specific anatomic locations associated with impaired motor ability. More important, however, our study also used these techniques to evaluate whether infarct location could influence motor outcomes after Constraint-Induced Movement therapy (CI therapy), a specific and controlled form of physical therapy. Methods-Quantitative voxel-based analyses were used to determine whether infarct location could predict either initial motor ability or clinical improvement after CI therapy in chronic stroke patients. Results-Although corona radiata infarcts were associated with worse in-laboratory motor ability at pretreatment, infarct location did not predict improvement in either the laboratory or the life situation after CI therapy. Conclusions-The extent of improvement from CI therapy does not depend on the location of neurological damage, despite there being a pretreatment relationship between infarct location and in-laboratory motor ability. This dissociation could be explained by brain plasticity induced by CI therapy.

Peripheral nerves of the mutant mouse Trembler are characterized by a severe myelin deficit and an increased number of Schwann cells. On the basis of radioautographic and quantitative morphologic investigations, the present study documents: i an abnormal persistence of post-natal Schwann cell proliferation in Trembler mouse nerves which, in unaffected animals, are composed of myelinated fibres; ii normal morphology, numbers and proliferation of Schwann cells in the unmyelinated (Remak) fibres of Trembler mice; and iii replication of the increased rate of Schwann cell multiplication as well as the myelin deficit, when segments of Trembler sciatic nerves are transplanted into the sciatic nerves of normal mice. Thus, the continued proliferation of Trembler Schwann cells must be related to the primary inability of these cells to produce and maintain a normal myelin sheath; axonal or general systemic abnormalities do not appear to play a major role in the pathogenesis of these disorders in the Trembler mouse.

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