Fatigue during multiple sclerosis relapse and its relationship to depression and neurological disability.

BACKGROUND Fatigue is a common symptom of multiple sclerosis patients that may be present at all stages of the disease. The aim of this study was to determine presence of fatigue in multiple sclerosis patients during relapse and its relation to neurological disability and depression. SUBJECTS AND METHODS This cross-sectional study included 120 patients who were assessed during the acute relapse of relapsing-remitting multiple sclerosis. Applied research instruments were: general questionnaire, Expanded Disability Status Scale (EDSS), Beck Depression Inventory-II (BDI-II) and Fatigue Severity Scale (FSS). All patients were examined at the same appointment. RESULTS 54 (45%) patients were grouped into MS fatigue (MSF) group (FSS≥5) and 48 (40%) as non-fatigue (MSNF) group (FSS≤4). Mean FSS score was 4.83+/-1.49. Difference between MSF and MSNF patients was significant considering age (p<0.001), relapse severity (p=0.044), BDI score (p<0.001) and EDSS score (p<0.001). Positive correlations of fatigue (FSS) with age (rho=0.41, p<0.001), depression (BDI score) (rho=0.61, p<0.001) and neurological disability (EDSS score) (rho=0.55, p<0.001) were confirmed. After adjusting for depression, there was only weak positive correlation between fatigue and neurological disability (rs=0.38; P<0.001), while after adjusting for EDSS score, fatigue continued to correlate moderately with depression (r=0.48; p<0.001). Multiple linear regression analysis showed that BDI score (beta=0.380; p<0.001), EDSS score (beta=0.336, p<0.001) and the age (beta=0.202; p<0.05) are independently related to fatigue severity in this patients. CONCLUSION Fatigue is a frequent symptom during multiple sclerosis relapse. Depression and, to a lesser degree, disability but not relapse severity are independently related to the presence of fatigue. Depression and fatigue should be recognized and treated during standard relapse treatment. Further research might focus on other factors influencing fatigue during multiple sclerosis relapse including evaluation of fatigue at the different time points.