Functional MRI evidence of cortical reorganization in upper-limb stroke hemiplegia treated with constraint-induced movement therapy

Objective: The purpose of this pilot study was to test constraint-induced m ovement therapy for chronic upper-limb stroke hemiparesis and to investigat e the neural correlates of recovery with functional magnetic resonance imag ing (MRI) in two subjects. Both subjects had been discharged from tradition al therapy because no further improvement was anticipated. Design: Constraint-induced movement therapy consisted of 6 hr of daily uppe r-limb training for 2 wk; a restrictive mitt was worn on the nonparetic lim b during waking hours. Functional MRI was performed on a 1.5-T MRI with ech o-planar imaging; at the same time, the subjects attempted sequential finge r-tapping. Results: Compared with baseline, performance time improved an average of 24 % immediately after training and also continued to improve up to 33% 3 mo a fter training. Lift, grip strength, and Motor Activity Log scores likewise improved. Initially, on functional MRI, subject 1 activated scattered regio ns in the ipsilateral posterior parietal and occipital cortices. Subject 2 showed almost no areas of significant activation. After training, subject 1 showed activity bordering the lesion, bilateral activation in the associat ion motor cortices, and ipsilateral activation in the primary motor cortex. Subject 2 showed activation near the lesion site. Conclusion: Constraint-induced movement therapy produced significant functi onal improvement and resulted in plasticity as demonstrated by functional M RI.