Clinical Characteristics and Brain Activation Patterns of Mirror Movements in Patients with Corona Radiata Infarct

Objective: Mirror movements (MMs) are a phenomenon of involuntary movements that accompany physically intended movements of the opposite side of the body. In the current study, we investigated the clinical characteristics and cortical activation patterns of MMs in patients with corona radiata (CR) infarct, using functional MRI. Subjects and Methods: We recruited 31 consecutive hemiparetic stroke patients with CR infarct. Functional MRI was performed to verify brain activation patterns during grasp-release movements of the affected hand, and MM of the unaffected hand was observed simultaneously. Results: The prevalence of MMs was 54.8% (17 out of 31 patients), and the intensity of MMs ranged from mild to moderate. The severity of MM in the unaffected hand is closely related to the poor motor function of the affected upper extremity and to activations of the unaffected motor cortex and both supplementary motor areas (SMAs) during the movement of the affected hand. In addition, the activations of unaffected motor cortex and both SMAs were closely related to poor motor function of the affected upper extremity. Conclusions: The results suggest that MMs, poor motor function, and the activations of ipsilateral motor cortex and both SMAs are closely interconnected in patients with CR infarct.