A functional magnetic resonance imaging study of brain functional reorganization in patients with cerebral infarction

Abstract

Objective To investigate activation patterns in the motor cortex of patients with cerebral infarction by blood oxygen level dependent-functional magnetic resonance imaging ( BOLD-fMRI) , and to explore the brain's functional reorganization mechanism. Methods Sixteen patients ( 12 men and 4 women, age 37 to 80, mean 61.0±11.3) who had suffered a subcortical infarction within the previous 3 months were studied. All the patients received fMRI scanning during passive flexion-extension movement of both the affected and unaffected wrist separately.Brain functional mapping was acquired with SPM2 software. Activation patterns in the brain were compared between the affected and unaffected hands. Results The volume and intensity of the activated areas were diverse, but showed some order. When the affected hand moved, the fMRI map showed general hyperactivation. When the unaffected hand moved, the contralateral M1 and S1 were activated. Conclusions After cerebral infarction, the brain cortex showed compensatory changes. As the main motor cortex (M1) was deactivated, the subsidiary motor areas such as the PMC, SMA, CMA, IPL, PFC and CRB were activated. The activated motor areas could shift to the area around the lesion, and the non-motor area was activated also. Key words: Cerebral infarction; Functional reorganization; Blood oxygen level dependent functional magnetic resonance imaging