Fatigue in patients with multiple sclerosis (MS) was predicted by myriad indirect factors rather than by baseline fatigue and disease severity, according to study data published in Multiple Sclerosis and Related Disorders.

Individuals with adult-onset MS were identified from a neuroinflammatory patient database in South Wales, United Kingdom, and invited to complete study questionnaires during a home visit. The Modified Fatigue Impact Scale, Fatigue Assessment Instrument, and visual analog scale (VAS) were used to capture baseline perceived fatigue.

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The VAS and Conners Continuous Performance Test 3 (CCPT3) were administered before and after questionnaire administration; score differences between baseline and postassessment were used as measures of cognitive performance fatigability and perceived fatigue change. Regression analyses were performed to identify predictors of perceived fatigue and performance change.

The study cohort comprised 61 individuals with adult-onset MS, among whom 45 (73.8%) were women. The mean age of participants was 42.5±11.3 years. Persons classified as having fatigue according to the Modified Fatigue Impact Scale had greater fatigue on the baseline VAS, more anxiety and depression, poorer sleep quality, greater pain, more emotion-focused coping, less self-efficacy, more disability, and greater response variability on the initial CCPT3. Baseline perceived fatigue had a positive correlation with depression (P =.019) and emotion-focused coping (P =.014) and a negative correlation with sleep quality (P =.017).

The regression model incorporating these factors explained 53.5% of the variance in perceived fatigue. Comparing preintervention and postintervention CCPT3 scores, the majority of baseline clinical, psychological, and fatigue variables did not appear to be associated with performance change. According to linear regression, perseveration change and reaction time change each had a positive relationship with estimated intelligence (P =.001; P =.037, respectively).

Perseveration change was negatively associated with self-efficacy (P =.005). Only postintervention fatigue was a predictor of a single CCPT3 change variable, accounting for 8% of variance in response speed consistency change.

These results suggest that many indirect factors contribute to perceived fatigue and cognitive performance, and that these factors may be appropriate targets for intervention in the treatment of MS-related fatigue. Further research should account for these factors in developing appropriate fatigue assessment tools.

Reference

Hu M, Muhlert N, Robertson N, Winter M. Perceived fatigue change and cognitive performance change in multiple sclerosis: uncovering predictors beyond baseline fatigue [published online April 15, 2019]. Mult Scler Relat Disord. doi:10.1016/j.msard.2019.04.011