Abstract Details

Title Interoception as a neurocognitive mechanism underlying fatigue in Multiple Sclerosis

Topic Multiple Sclerosis

Presentation(s) P5 - Poster Session 5 (5:30 PM-6:30 PM)

Poster/Presentation
Number 15-090

Objective To conduct a systematic and multidimensional assessment of the relationship between interoception and fatigue in MS, integrating behavioral and neuroimaging evidence.

Background Fatigue is one of the most common and disabling symptoms in multiple sclerosis (MS). Although the pathophysiology of MS-related fatigue is poorly understood, abundant evidence points to a key role of altered interoceptive mechanism. Yet, no previous study has empirically evaluated the neurocognitive relationship between interoception and fatigue symptoms in MS.

Design/Methods We studied 29 patients with relapsing-remitting MS. Sixteen patients surpassed the cut-off of the Fatigue Severity Scale (FSS > 37) and were classified as fatigued MS (F-MS) patients, 13 presented normal FSS values (< 37) and were classified as non-Fatigued MS (nF-MS) patients. 28 sociodemographically matched healthy subjects presented no fatigue symptoms (FSS < 37) (control group). Interoceptive accuracy was evaluated through a heartbeat detection task. Participants underwent a neuroimaging protocol (MRI and resting-state fMRI) to evaluate the link between fatigue levels and anatomical and functional connectivity (FC) properties of key interoceptive regions.

Results

F-MS patients presented significant decreased interoceptive accuracy compared to controls (Tukey’s HSD test p < .05) and nF-MS (Tukey’s HSD test p < .05), no differences were found between the latter two groups (Tukey’s HSD test p > .05). Only F-MS patients showed decreased gray matter volume and FC alterations in key interoceptive areas (cingulate cortex and the insula, uncorrected p-value < .001, extent threshold = 50 voxels). Fatigue scores in F-MS patients were negatively correlated with grey matter volume and FC in those areas (uncorrected p-value < .001, extent threshold = 50 voxels).

Conclusions This study offers unprecedented evidence that fatigue symptoms in MS are linked to behavioral, structural, and FC dysfunctions in the interoceptive domain. Disruptions in neural regions and networks subserving interoception may constitute a neurocognitive signature of fatigue in MS patients.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
Vladimiro Sinay, MD	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
	No disclosure on file
Agustin Ibanez, PhD (Universidad Adolfo Ibáñez, Latin American Brain Health Institute)	Dr. Ibanez has nothing to disclose.

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