This study aimed to investigate the effect of motor imagery (MI) intervention with action observation (AO) on upper extremity function and corticospinal activation in stroke patients. MI and AO are two forms of motion simulation that activate the motor system without physical activity. There are many studies that show the effect of AO and MI alone, but there are few studies in parallel. This study was conducted on 45 patients who were divided into an experimental group (n = 22) and a control group (n = 23) using a computer randomization program. The experimental group conducted AO with MI, and the control group only AO. All participants received interventions for twenty-five minutes per session, five times a week, for eight weeks. For the pre- and post-evaluation of all participants, motor evoked potential (MEP) amplitude was measured to compare corticospinal activation, and Fugl-Meyer Assessment Upper Extremity (FMA UE), Wolf Motor Function Test (WMFT) and Motor Activity Log (MAL) were evaluated for changes in upper extremity function. In comparing the amount of change before and after the intervention, a significant change was observed in the experimental group's MEP amplitude. In the comparison between groups after the intervention and the amount of change before and after the intervention, the experimental group showed significant changes in FMA UE and MAL Amount of Use (MAL AOU) items. As a result of this study, AO with MI is effective in enhancing upper extremity function and increasing cortical spinal cord activation in patients with severe stroke with limited movement.
Keywords: action observation; corticospinal excitability; motor imagery training; stroke; upper extremity function.