AUTHOR=Grothe Matthias , Gross Stefan , Süße Marie , Strauss Sebastian , Penner Iris Katharina 

TITLE=The Seasonal Fluctuation of Fatigue in Multiple Sclerosis

JOURNAL=Frontiers in Neurology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2022.900792

DOI=10.3389/fneur.2022.900792

ISSN=1664-2295

ABSTRACT=Background: Fatigue is a common symptom in patients with multiple sclerosis. Several studies suggest that heat can impact fatigue severity, but we lack a systematic investigation of seasonal fluctuations.
Methods: Fatigue was assessed with the Fatigue Score for Motor and Cognition (FSMC). This study included 258 patients with multiple sclerosis from 572 visits temporally distributed over the year. The data were adjusted for age, sex, cognition, depression, disease severity, and follow-up time. Linear regression models were performed to determine whether the temporal course of fatigue was time-independent, linearly time dependent, or non-linearly time dependent.
Results: Fatigue was lowest during January (mean FSMC: 49.84) and highest during August (mean FSMC: 53.88). The regression analysis showed the best fit with a model that included months + months², which was a non-linear time dependency. 
Conclusion: In multiple sclerosis, fatigue showed a natural temporal fluctuation. Fatigue was higher during summer compared to winter. This finding should be carefully taken into account when monitoring multiple sclerosis.