Effect of seasonal fluctuation of ambient temperature on fatigue in multiple sclerosis patients living in Attica, Greece.

Fatigue limits daily functioning of patients with multiple sclerosis (MS) and has a severe impact on their quality of life. Fatigue is considered a result of biological, psychological and environmental factors. This study investigated the effect of the ambient temperature on the levels of fatigue during each season of the year in MS patients and a healthy population. Forty-five MS patients and 42 healthy people matched for age and sex participated in the study. Measurement of fatigue was based on the Fatigue Severity Scale. Patients were asked which season they felt the worst fatigue. The measurements were conducted every 3 months in November, February, May and August on the last day of the month. MS patients (mean=4.20, standard error [SE]=0.22) exhibited a higher mean fatigue severity than the control group (mean=2.68, SE=0.22). MS patients did not present any significant differentiation in fatigue between seasons. However, the control group exhibited a tendency for fatigue severity to significantly increase in August, and actually experienced fatigue levels higher than the MS group during the last week of August. Significant fluctuation of fatigue was not observed in patients with MS. Patients may avoid worsening fatigue caused by climatic conditions with appropriate organization of their life routine.