Fatigue in multiple sclerosis is associated with multimodal interoceptive abnormalities

SALAMONE, PAULA C; HERRERA, EDUAR; SINAY, VLADIMIRO; SEDEÑO, LUCAS; GONZALEZ CAMPO, CECILIA; RICHTER, FABIAN; PAGANI CASSARA, FÁTIMA; IBÁÑEZ, AGUSTÍN; RODRÍGUEZ-ARRIAGADA, NICOLÁS; BRUNO, DIANA; GARCÍA, ADOLFO M

MULTIPLE SCLEROSIS

SAGE PUBLICATIONS LTD

Año: 2019

1352-4585

Background: Fatigue ranks among the most common and disabling symptoms in multiple sclerosis (MS).Recent theoretical works have surmised that this trait might be related to alterations across interoceptivemechanisms. However, this hypothesis has not been empirically evaluated.Objectives: To determine whether fatigue in MS patients is associated with specific behavioral, structural, and functional disruptions of the interoceptive domain.Methods: Fatigue levels were established via the Modified Fatigue Impact Scale. Interoception wasevaluated through a robust measure indexed by the heartbeat detection task. Structural and functionalconnectivity properties of key interoceptive hubs were tested by magnetic resonance imaging (MRI) andresting-state functional MRI. Machine learning analyses were employed to perform pairwise classifications.Results: Only patients with fatigue presented with decreased interoceptive accuracy alongside decreasedgray matter volume and increased functional connectivity in core interoceptive regions, the insula, andthe anterior cingulate cortex. Each of these alterations was positively associated with fatigue. Finally,machine-learning analysis with a combination of the above interoceptive indices (behavioral, structural,and functional) successfully discriminated (area under the curve>90%) fatigued patients from both nonfatigued and healthy controls.Conclusion: This study offers unprecedented evidence suggesting that disruptions of neurocognitivemarkers subserving interoception may constitute a signature of fatigue in MS.