AUTHOR=Wakonig Katharina , Eitel Fabian , Ritter Kerstin , Hetzer Stefan , Schmitz-Hübsch Tanja , Bellmann-Strobl Judith , Haynes John-Dylan , Brandt Alexander U. , Gold Stefan M. , Paul Friedemann , Weygandt Martin 

TITLE=Altered Coupling of Psychological Relaxation and Regional Volume of Brain Reward Areas in Multiple Sclerosis

JOURNAL=Frontiers in Neurology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2020.568850

DOI=10.3389/fneur.2020.568850

ISSN=1664-2295

ABSTRACT=<p><bold>Background:</bold> Psychological stress can influence the severity of multiple sclerosis (MS), but little is known about neurobiological factors potentially counteracting these effects.</p><p><bold>Objective:</bold> To identify gray matter (GM) brain regions related to relaxation after stress exposure in persons with MS (PwMS).</p><p><bold>Methods:</bold> 36 PwMS and 21 healthy controls (HCs) reported their feeling of relaxation during a mild stress task. These markers were related to regional GM volumes, heart rate, and depressive symptoms.</p><p><bold>Results:</bold> Relaxation was differentially linked to heart rate in both groups (<italic>t</italic> = 2.20, <italic>p</italic> = 0.017), i.e., both markers were only related in HCs. Relaxation was positively linked to depressive symptoms across all participants (<italic>t</italic> = 1.99, <italic>p</italic> = 0.045) although this link differed weakly between groups (<italic>t</italic> = 1.62, <italic>p</italic> = 0.108). Primarily, the volume in medial temporal gyrus was negatively linked to relaxation in PwMS (<italic>t</italic> = −5.55, p<sub>family−wise−error(FWE)corrected</sub> = 0.018). A group-specific coupling of relaxation and GM volume was found in ventromedial prefrontal cortex (VMPFC) (<italic>t</italic> = −4.89, p<sub>FWE</sub> = 0.039).</p><p><bold>Conclusion:</bold> PwMS appear unable to integrate peripheral stress signals into their perception of relaxation. Together with the group-specific coupling of relaxation and VMPFC volume, a key area of the brain reward system for valuation of affectively relevant stimuli, this finding suggests a clinically relevant misinterpretation of stress-related affective stimuli in MS.</p>