Brain activity, regional gray matter loss, and decision-making in multiple sclerosis

作者：Weygandt Martin^*; Wakonig Katharina; Behrens Janina; Meyer Arndt Lil; Soeder Eveline; Brandt Alexander U; Bellmann Strobl Judith; Ruprecht Klemens; Gold Stefan M; Haynes John Dylan; Paul Friedemann

来源：Multiple Sclerosis, 2018, 24(9): 1163-1173.

DOI：10.1177/1352458517717089

• Multiple sclerosis
• decision-making
• functional magnetic resonance imaging
• Iowa Gambling Task
• brain activity
• gray matter loss

Background: Decision-making (DM) abilities deteriorate with multiple sclerosis (MS) disease progression which impairs everyday life and is thus clinically important.
Objective: To investigate the underlying neurocognitive processes and their relation to regional gray matter (GM) loss induced by MS.
Methods: We used a functional magnetic resonance imaging (fMRI) Iowa Gambling Task to measure DM-related brain activity in 36 MS patients and 21 healthy controls (HC). From this activity, we determined neural parameters of two cognitive stages, a deliberation (choice) period preceding a choice and a post-choice (feedback) stage reporting decision outcomes. These measures were related to DM separately in intact and damaged GM areas as determined by a voxel-based morphometry analysis.
Results: Severely affected patients (with high lesion burden) showed worse DM-learning than HC (t=-1.75, p=0.045), moderately affected (low lesion burden) did not. Activity in the choice stage in intact insular (t=4.60, p(Family-Wise Error [FWE] corrected)=0.034), anterior cingulate (t=4.50, p(FWE)=0.044), and dorsolateral prefrontal areas (t=4.43, p(FWE)=0.049) and in insular areas with GM loss (t=3.78, p(FWE)=0.011) was positively linked to DM performance across patients with severe tissue damage and HC. Furthermore, activity in intact orbitofrontal areas was positively linked to DM-learning during the feedback stage across these participants (t=4.49, p(FWE)=0.032). During none of the stages, moderately affected patients showed higher activity than HC, which might have indicated preserved DM due to compensatory activity.
Conclusion: We identified dysregulated activity linked to impairment in specific cognitive stages of reward-related DM. The link of brain activity and impaired DM in areas with MS-induced GM loss suggests that this deficit might be tightly coupled to MS neuropathology.

• 出版日期2018-8