Correlation of fatigue with disability and accelerometer-measured daily physical activity in patients with relapsing-remitting MS.

Abstract

Fatigue is one of the most common symptoms in patients with multiple sclerosis (MS). Furthermore, measuring its effects on patients in daily life is challenging. This study aimed to discover the association between relapsing-remitting MS (RRMS) patients' disability, fatigue, and accelerometer-measured physical activity. A total of 41 patients with RRMS with an Expanded Disability Status Scale (EDSS) level of 0-5.5 and 20 healthy controls completed the Modified Fatigue Impact Scale (MFIS) and the Fatigue Severity Scale (FSS) questionnaires. The EDSS was evaluated for all patients with RRMS, and all participants performed the MS Functional Composite (MSFC) test and six-min walk test and wore an accelerometer for seven days. Patients with an EDSS level of 0-2.5 were found to have higher fatigue levels (p < 0.001) than healthy controls but lower levels than patients with an EDSS level of 3-5.5 (p < 0.001). A significant correlation was found to exist between fatigue and disability level measured by the EDSS (EDSS/FSS, r=0.750/p=0.001; EDSS/MFIS, r=0.661/p=0.001) and with the MSFC test in the patient group (MSFC/FSS, r=-0.350 p=0.025; MSFC/MFIS, r=-0.423/p=0.007). Total daily activity correlated with fatigue as measured by the FSS (MVPS/FSS r=-0.357/p=0.028, step count/FSS r=-0.463/p=0.003), but no correlation was found between the EDSS or the MSFC. A lower disability rate, better physical condition, and higher daily-living activity were found to predict lower fatigue levels.