Investigating Relationships Among Interoceptive Awareness, Emotional Susceptibility, and Fatigue in Persons With Multiple Sclerosis.

Background: Fatigue is a particularly debilitating symptom for people with multiple sclerosis (MS). Although personality traits and MS have been studied, interoception and emotional susceptibility and their links to fatigue have not yet been explored.

Methods: Study participants provided demographic information and completed standardized patient-reported outcomes of walking function, physical activity, subjective fatigue, interoceptive awareness, and emotional susceptibility. A subset of participants participated in semistructured interviews discussing fatigue, body sensations, emotions, and their effects on exercise. Quantitative data were analyzed using multiple regression. Qualitative data were analyzed using thematic analysis.

Results: Mean ± SD Fatigue Severity Scale scores (5.0 ± 1.3) indicated that fatigue was a problematic symptom. Mean ± SD Multidimensional Assessment of Interoceptive Awareness, Version 2 (2.8 ± 0.6) and Emotional Susceptibility Scale (3.0 ± 1.0) scores indicated lower levels of interoceptive awareness and emotional susceptibility. Quantitative data indicated no relationship between fatigue and interoceptive awareness (β = -0.20; P = .88) and emotional susceptibility (β = 0.03; P = .83), and neither were these related to physical activity (β = -0.07; P = .64). Qualitative themes indicated strong fatigue experiences involving the whole body and individual limbs, anger and frustration, and effects on physical activity.

Conclusions: Physically active people with MS report strong sensations of fatigue closely linked to frustration and helplessness. There was agreement between qualitative and quantitative assessments of fatigue but dissonance regarding interoceptive awareness and physical activity. The practice of clinicians, particularly those involved with facilitating or planning physical activity for persons with MS, would benefit from these findings about fatigue.