Altered Coupling of Psychological Relaxation and Regional Volume of Brain Reward Areas in Multiple Sclerosis.
Background: Psychological stress can influence the severity of multiple sclerosis (MS), but little is known about neurobiological factors potentially counteracting these effects. Objective: To identify gray matter (GM) brain regions related to relaxation after stress exposure in persons with MS (PwMS). Methods: 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. Results: Relaxation was differentially linked to heart rate in both groups (t = 2.20, p = 0.017), i.e., both markers were only related in HCs. Relaxation was positively linked to depressive symptoms across all participants (t = 1.99, p = 0.045) although this link differed weakly between groups (t = 1.62, p = 0.108). Primarily, the volume in medial temporal gyrus was negatively linked to relaxation in PwMS (t = -5.55, pfamily-wise-error(FWE)corrected = 0.018). A group-specific coupling of relaxation and GM volume was found in ventromedial prefrontal cortex (VMPFC) (t = -4.89, pFWE = 0.039). Conclusion: 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.
['Wakonig|Katharina|K|', 'Eitel|Fabian|F|', 'Ritter|Kerstin|K|', 'Hetzer|Stefan|S|', 'Schmitz-Hübsch|Tanja|T|', 'Bellmann-Strobl|Judith|J|', 'Haynes|John-Dylan|JD|', 'Brandt|Alexander U|AU|', 'Gold|Stefan M|SM|', 'Paul|Friedemann|F|', 'Weygandt|Martin|M|']
psychological relaxation multiple sclerosis gray matter ventromedial prefrontal cortex (vmPFC) brain reward system autoimmunity neuroinflammation psychophysiological stress responses