Introduction: The importance of fatigue in multiple sclerosis (MS) is determined by its high frequency and it is an important cause of disability.
Objective: To determine factors that are related to the presence of chronic fatigue in patients with MS.
Patients and methods: The series comprises patients with MS, consecutively attended in the demyelinizating diseases unit, who met the following criteria: clinically definite MS (RR or SP), MS duration of more than two years, and no relapses during the previous month. Analyzed variables were as follows: chronic fatigue, demographic data, functional systems, EDSS, ISS, ESS, disease activity, Hamilton, depression scale GHQ-28, PSQI, and interferon. Statistical study: bivariate and multivariate analysis by logistic regression.
Results: A hundred patients were included, 72 female and 28 male. Mean age was 39.27 years. Of the 100 patients 88 had RR disease and 12 SP disease. MS mean duration was 11.2 years. Mean EDSS 2.54. Chronic fatigue was 53 %. The presence of depression increased the probability of chronic fatigue 3.6 fold, and every point in PSQI-7 increases it 3.5 fold.
Conclusion: Depression and the PSQI-7 subscale (day sleep dysfunction) are the only variables independently related to chronic fatigue in patients with MS.