Assessing recovery in middle cerebral artery stroke using functional MRI

To understand the temporal evolution of brain reorganization during recovery from stroke.

A patient who suffered left middle cerebral artery stroke 9 months earlier was studied on three occasions, approximately 1 month apart.

Brain activation was studied using functional Magnetic Resonance Imaging (fMRI). During each session, the patient performed a finger-to-thumb opposition task, which involved one bimanual and two unimanual conditions. Each condition consisted of overt movement of fingers and imagery of the same task.

With recovery, greater recruitment was observed of the affected primary motor cortex (M1) and a decrease in activation of the unaffected M1 and supplementary motor area. In addition, the widespread activation of brain areas seen during the initial session changed to a more focused pattern of activation as the patient recovered. Imagery tasks resulted in similar brain activity as overt execution pointing to imagery as a potential tool for rehabilitation.