抄録
The mechanism of poststroke motor functional recovery remains to be elucidated. We used functional MRI (fMRI) and near-infrared spectroscopic topography (NIRS) to evaluate the compensatory motor activation of cortical regions during a hand movement task in patients who recovered from poststroke hemiparesis. 1) We evaluated 9 patients with various types of stroke with mild-moderate hemiparesis using fMRI within 1 month of stroke onset and after 2-3 months. At the first examination, the activation of the contralateral hemisphere (primary sensorimotor cortex and supplementary motor area) was markedly reduced during the paretic hand movement. At the second examination, the contralateral activation had recovered in 8 of 9 patients. It addition, activation of ipsilateral motor cortex was seen during the paretic hand movement in 4 of 9 patients. 2) We evaluated 6 patients with massive cerebral infarction in the territory of middle cerebral artery without severe residual hemiparesis using both fMRI and NIRS. Both techniques showed that the activation of ipsilateral primary motor cortex was activated during the paretic hand movement in addition to activation of extended motor areas of the contralateral hemisphere. These observations suggest that motor cortical reorganization, including the ipsilateral hemisphere, contributes to the recovery from poststroke hemiparesis.
