Increase in sensorimotor cortex response to somatosensory stimulation over subacute poststroke period correlates with motor recovery in hemiparetic patients.

BACKGROUND . Somatosensory input to the motor cortex may play a critical role in motor relearning after hemiparetic stroke. OBJECTIVE . The authors tested the hypothesis that motor recovery after hemiparetic stroke relates to changes in responsiveness of the sensorimotor cortex (SMC) to somatosensory input. METHODS . A total of 10 hemiparetic stroke patients underwent serial functional magnetic resonance imaging (fMRI) during tactile stimulation and testing of sensorimotor function over 1 year-at early subacute, late subacute, and chronic poststroke time points. RESULTS . Over the subacute poststroke period, increased responsiveness of the ipsilesional SMC to tactile stimulation of a stroke-affected digit correlated strongly with concurrent gains in motor function. Increased responsiveness of the ipsilesional and contralesional SMC over the subacute period also correlated strongly with motor recovery experienced over the first year poststroke. CONCLUSIONS . These findings suggest that increased responsiveness of the SMC to somatosensory stimulation over the subacute poststroke period may contribute to motor recovery.