Ipsi-lesional motor deficits in hemiparetic patients with stroke

Previous studies have proven that motor deficits are expressed in the ipsi-lesional limbs of the injured hemisphere in a variety of motor tasks. However, it still remained controversial for the distinct characteristics of the motor deficits according to the dysfunction of each hemisphere related to motor control. We evaluated the performance of the ipsi-lesional limb in stroke patients and age-sex matched normal controls. Kinematic components such as the temporal variation and accuracy index were analyzed. Our findings revealed that both groups with right or left hemisphere damage showed poor accuracy in terms of complex visuomotor function. Overall, patients with left hemisphere damage exhibited temporal inconstancies in simple repetitive movement. Accordingly, the non-dominant hemisphere plays a primary role in the function of complex visuospatial accuracy, whereas the dominant hemisphere is mainly involved in the motor control of bilateral upper limbs as well as the performance of complex tasks. Therefore, we assumed that such deficits may be caused by damage of the lateralized hemispheric function, depending on the property of the performed task and hemispheric asymmetry. The manifest understanding of the ipsi-lesional motor abnormalities provides clinicians with useful neurophysiologic information, and with the necessity of careful evaluation and therapeutic intervention on the ipsi-lesional upper limb, often clinically assumed as "the non-affected side".