Time Series Modeling of Fatigue in the Stratification of Fatigue Phenotypes in Patients with Multiple Sclerosis

Fatigue is a prominent paralyzing symptom that is often notified by patients with multiple sclerosis (MS). However, it is very difficult to measure fatigue because the symptoms fluctuate throughout the day. We analyzed the fatigue time series of 64 patients with chronic MS and found 6 distinct clusters that represent all patients: patients with low fatigue/ low MESOR (Midline Estimating Statistic Of Rhythm), lower-middle MESOR; positive acrophase, lower-middle MESOR; negative acrophase, middle-high MESOR; positive acrophase, middle-high MESOR; negative acrophase, and high MESOR. We also found that patients who are from the middle-high MESOR; negative acrophase cluster are more likely to be depressed compared to patients who are from the middle-high MESOR; positive acrophase cluster. The stratification of MS patients according to their fatigue phenotype and the difference in depression between different fatigue clusters could help future research on personalized MS treatments.