Structural and functional plasticity in the somatosensory cortex of chronic stroke patients

Animal studies have demonstrated that motor recovery after hemiparetic stroke is associated with functional and structural brain plasticity. While studies in stroke patients have revealed functional plasticity in sensorimotor cortical areas in association with motor recovery, corresponding structural plasticity has not been shown. We sought to test the hypothesis that chronic hemiparetic stroke patients exhibit structural plasticity in the same sensorimotor cortical areas that exhibit functional plasticity. Functional MRI during unilateral tactile stimulation and structural MRI was conducted in chronic stroke patients and normal subjects. Using recently developed computational methods for high-resolution analysis of MRI data, we evaluated for between-group differences in functional activation responses, and cortical thickness of areas that showed an enhanced activation response in the patients. We found a significant (P