AUTHOR=Garipelli Gangadhar , Rossy Tamara , Perez-Marcos Daniel , Jöhr Jane , Diserens Karin 

TITLE=Movement-Related Cortical Potentials in Embodied Virtual Mirror Visual Feedback

JOURNAL=Frontiers in Neurology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2021.646886

DOI=10.3389/fneur.2021.646886

ISSN=1664-2295

ABSTRACT=<p><bold>Background:</bold> Mirror therapy is thought to drive interhemispheric communication, resulting in a balanced activation. We hypothesized that embodied virtual mirror visual feedback (VR-MVF) presented on a computer screen may produce a similar activation. In this proof-of-concept study, we investigated differences in movement-related cortical potentials (MRCPs) in the electroencephalogram (EEG) from different visual feedback of user movements in 1 stroke patient and 13 age-matched adults.</p><p><bold>Methods:</bold> A 60-year-old right-handed (Edinburgh score &gt;95) male ischemic stroke [left paramedian pontine, National Institutes of Health Stroke Scale (NIHSS) = 6] patient and 13 age-matched right-handed (Edinburgh score &gt;80) healthy adults (58 ± 9 years; six female) participated in the study. We recorded 16-electrode electroencephalogram (EEG), while participants performed planar center-out movements in two embodied visual feedback conditions: (i) direct (movements translated to the avatar's ipsilateral side) and (ii) mirror (movements translated to the avatar's contralateral side) with left (<italic>direct left</italic>/<italic>mirror left</italic>) or right (<italic>direct right/mirror right</italic>) arms.</p><p><bold>Results:</bold> As hypothesized, we observed more balanced MRCP hemispheric negativity in the <italic>mirror right</italic> compared to the <italic>direct right</italic> condition [statistically significant at the FC4 electrode; 99.9% CI, (0.81, 13)]. MRCPs in the stroke participant showed reduced lateralized negativity in the <italic>direct left</italic> (non-paretic) situation compared to healthy participants. Interestingly, the potentials were stronger in the <italic>mirror left</italic> (non-paretic) compared to <italic>direct left</italic> case, with significantly more bilateral negativity at FC3 [95% CI (0.758 13.2)] and C2 [95% CI (0.04 9.52)].</p><p><bold>Conclusions:</bold> Embodied mirror visual feedback is likely to influence bilateral sensorimotor cortical subthreshold activity during movement preparation and execution observed in MRCPs in both healthy participants and a stroke patient.</p>