Activation Pattern of the Somatosensory Cortex in Subcortical Stroke Patients with Clinical Sensory Recovery of Hand

ABSTRACT

OBJECTIVE: To investigate the activation pattern of somatosensory cortex in subcortical stroke patients underlying recovered somatosensory capacity of hand, using functional MRI (fMRI). METHOD: Four patients with subcortical cerebral hemorrhage or infarction and five normal healthy volunteers were investigated. Sensory task was given on the palm of hand by brushing as a frequency of 1 Hz. In fMRI study, ten slices were obtained using the Echo Planar Imaging technique, data was statistically analyzed using SPM-99 software. RESULTS: During the tactile stimulation of affected hand, contralateral primary somatosensory cortex was activated in all the patients. In the two patients with full recovery of tactile sense, cortical activation for paretic hand was stronger than in nonparetic hand. On the other hand, the other two patients with incomplete recovery showed that cortical activation for nonparetic hand was stronger than in paretic hand and even normal control. CONCLUSION: Our result suggested that functional consequences of the somatosensory cortical area were not limited to the ipsilateral hemisphere to the lesion, but affect the contralateral, nonlesioned hemisphere, in subcortical stroke patients with recovered somatosensory capacity.