Sensitivity to increased temperature in individuals with Multiple Sclerosis: a key symptomatic factor shown in a survey

MSOffice1] Background: Many individuals diagnosed with Multiple Sclerosis (MS) are sensitive to increased body temperature, which has been recognized to correlate with the symptom of fatigue. The need to investigate this association has been highlighted. The aim of the study was to investigate the occurrence of heat sensitivity and its relations to disease course, disability, common MS-related symptoms and ongoing immunosuppressive treatments among individuals 65 years or younger diagnosed with MS. Method: A cross-sectional designed survey was undertaken. A questionnaire was sent to MS-patients with an Expanded Disability Status Score (EDSS) in the interval 0-6.5 and who were between 20 and 65 years of age, living in an eastern region of Sweden (n=334). Besides occurrence of heat sensitivity (Yes/No) and corresponding questions, the Fatigue Severity Scale (FSS), the MS-related symptom checklist and the Perceived Deficit Questionnaire (PDQ) was included. Data were analysed in relation to data level by Chi-square, Mann Whitney Utest, and Student’s t-test. Pearson’s and Spearman’s correlations were calculated. In logistic regression analyses (enter) dichotomized MS-symptoms were used as dependent variables, and EDSS, disease-course, heat-sensitivity, age and sex (female/male) were independent variables. In linear regression analyses, enter, summated FSS and PDQ were entered as dependent variables and EDSS, disease-course, heat-sensitivity, age and sex (female/male) were independent variables. Results: Of the responding patients (n=256), 58% reported heat sensitivity. The regression analyses revealed heat sensitivity as being a significant factor correlating not only with fatigue (p<0.001), but also with several other common MS symptoms such as pain (p<0.001), concentration difficulties (p<0.001), and urination urgency (p=0.009). Sensitivity to increased temperature in individuals with Multiple Sclerosis: a key symptomatic factor shown in a survey Discussion/Conclusion: The findings are discussed in relation to hypothesized explanations which need further investigation.