Cortical activation changes associated with motor recovery in patients with precentral knob infarct

We investigated the cortical activation changes associated with motor recovery in six hemiparetic patients with precentral knob infarct. fMRI at 1.5 T with finger movements at a fixed rate was performed twice in each patient, 1 and 6 months after stroke onset. From the images obtained, the LI (laterality index) for the primary sensorimotor cortex (SM1) was calculated to measure the degree of the cortical activity concentration in the contralateral hemisphere. Our results showed that a greater improvement in motor function scores was significantly correlated with a greater increment in LI induced by affected finger movements (p < 0.05). Motor recovery after precentral knob infarct was found to be positively related with the concentration of SM1 activity in the ipsilesional hemisphere. This finding may imply motor recovery through cortical reorganization after precentral knob infarct in the human brain.