Cerebral Cortex Advance Access originally published online on June 29, 2007
Cerebral Cortex 2008 18(3):638-647; doi:10.1093/cercor/bhm096
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Enhanced Cortical Activation in the Contralesional Hemisphere of Chronic Stroke Patients in Response to Motor Skill Challenge
1 MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129, USA, 2 Department of Radiology, Harvard Medical School, Boston, MA, USA
Address correspondence to Judith D. Schaechter, PhD, MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Room 2301, Building 149, 13th Street, Charlestown, MA 02129, USA. Email: judith{at}nmr.mgh.harvard.edu.
The brain processes involved in the restoration of motor skill after hemiparetic stroke are not fully understood. The current study compared cortical activity in chronic stroke patients who successfully recovered hand motor skill and normal control subjects during performance of kinematically matched unskilled and skilled hand movements using functional magnetic resonance imaging. We found that cortical activation during performance of the unskilled movement was increased in the patients relative to controls in the contralesional primary sensorimotor cortex. Performance of the skilled movement elicited increased activation in the patients relative to controls in the contralesional primary sensorimotor cortex, ventral premotor cortex, supplementary motor area/cingulate, and occipitoparietal cortex. Further, the activation change in the contralesional occipitoparietal cortex was greater in the patients relative to controls with the increase in motor skill challenge. Kinematic differences, mirror movements, and residual motor deficits did not account for the enhanced activation in the contralesional cortices in the patients. These results suggest that activation in the contralesional cortical network was enhanced as a function of motor skill challenge in stroke patients with good motor recovery. The findings of the current study suggest that successful recovery of motor skill after hemiparetic stroke involves participation of the contralesional cortical network.
Key Words: cerebral ischemia functional recovery motor tasks MRI/fMRI neuroplasticity