Cortical Reorganization of Hand Motor Function to Primary Sensory Cortex in Hemiparetic Patients With a Primary Motor Cortex Infarct

Abstract

Jang SH, Ahn SH, Yang DS, Lee DK, Kim DK, Son SM. Cortical reorganization of hand motor function to primary sensory cortex in hemiparetic patients with a primary motor cortex infarct. Objective To show cortical reorganization in hemiparetic patients with a primary motor cortex (M1) infarct including the precentral knob by using functional magnetic resonance imaging (fMRI). Design Case-control. Setting Outpatient clinics in the rehabilitation department of a university hospital. Participants Two stroke patients and 20 control subjects. Interventions By using fMRI, we evaluated the hand motor function of 2 hemiparetic stroke patients, who had made some recovery from complete paralysis of the affected hand, and 20 control subjects. Main Outcome Measures fMRI was performed by using the blood oxygen level-dependent technique at 1.5T with a standard head coil. The motor task paradigm consisted of hand grasp-release movements. Results The contralateral primary sensorimotor cortex was activated by the hand movements of the control subjects and of the unaffected side of the 2 patients. Only the contralateral (infarct side) primary sensory cortex (S1) was activated by the movements of the affected hand of the 2 patients, a result that was not observed in the control subjects or with the unaffected hand in the stroke patients. Conclusions The hand motor function associated with the infarcted M1 in our patients was reorganized into the S1. These results suggest cortical reorganization in patients with an M1 infarct.