Abstract 3317: Neurofeedback Enhance The Efficacy Of Mental Practice With Motor Imagery In Post-acute Stroke Victims: A Pilot Study.

Abstract

Background/Objective: Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practice with motor imagery has been implemented in the rehabilitation regimes of stroke patients. However, several studies investigating the efficacy of mental practice with motor imagery revealed inconsistent results. We hypothesized that difficulty for monitoring effort and compliance during motor imagery would cause inconsistency, and feedback of cortical activities (neurofeedback) may enhance the efficacy of mental practice with motor imagery. Methods: We recruited 15 post-acute hemiparetic patients with subcortical stroke (9 males, age: 58.7 ± 6.8 years). Averaged duration from onset was 132.1 ± 38.5 days. In addition to the usual training sessions of up to 180 min per day, all participants received 20 min session of the mental practice with motor imagery 3 times a week for 2 weeks. Mental practice consisted of video based motor imagery for 10 min followed by motor imagery with neurofeedback for 10 min. Participants were randomly assigned to the Real group or the Sham group. During neurofeedback, participants performed 16 repetitions of 5 sec motor imagery task, and cortical activation from the contralateral motor cortex was measured by a near infrared spectroscopy (NIRS). In the Real group, cortical activation processed in a real-time fashion was feedbacked, and irrelevant randomized value was feedbacked in the Sham group. Primary outcome measure was the finger and arm subscales of the Fugl-Meyer assessment (FMA), and the action research arm test (ARAT) was also assessed. Upper limb function was assessed at before, immediately after, and two weeks after the mental practice. Motor activity log (MAL), and kinesthetic and visual motor imagery questionnaire was also assessed before and after mental practice. We used repeated measures ANOVA to test the effect of mental practice and neurofeedback. For evaluation of the motor imagery related cortical activation changes during mental practice, contrast between cortical activation in the first and last session was assessed and unpaired t-test for group difference was performed. Results: In the finger function subscale in FMA, there was significant effect of time (F2,13=25.622, p<0.001) and interaction between time and group (F2,13=10.689, p<0.005) with more functional gain in the Real group. Mental practice also affected other outcome measures including arm subscale of FMA, ARAT, and MAL, but there was no significant interaction. Enhancement of finger movement imagery related cortical activation was significantly greater in the Real group than the Sham group (t88 =2.046 p<0.05). Conclusion: Our results imply that NIRS mediated neurofeedback has a positive add-on effect on the efficacy of mental practice with motor imagery and its related cortical activation.