Relapses In multiple sclerosis.

Abstract

Exact causes of contradictions in the understanding of relapsing course as characteristic phenomenon of multiple sclerosis (MS) and primarily relapsing-remitting type are still considered to be “sub rosa”. We tried to determine connection and correlation between seasonal dynamic factors, chronometric parameters of disease progression (age, disease duration) and frequency of relapses and the role of gender differences as well. A four-year prospective study included complete registration of all cases of MS exacerbations in resident patients with a relapsing-remmiting course of the disease according to McDonald criteria in Volyn region of Ukraine in 2010. Each patient had neurological score based on EDSS scale to ensure compliance with inclusion criteria. 128 patients (44 males and 84 females) with a remitting-recurring course of the disease were involved in this study. Statistical analysis was performed using SPSS 18, MedCalc and Microsoft Excel software using standard descriptive statistics, correlation and regression analysis. In total, 197 cases of MS relapses were registered. Episodes of relapses prevailed in winter-spring period. Multiple regression model including suggested climate factors showed multiple correlation coefficient – 0.55 (p<0.01). The prevalence of MS was higher in females, while general incidence of recurrences was similar to males. However, relapse rate in different age groups differs: the rate of recurrence increases in women aged after 50 years (mean annualized relapse rate (ARR)=0.66), while it slowly decreases in men with aging. The duration of the disease did not have significant effect on the course of MS in women, whereas weak negative relationship (0.24, p<0.001) between the duration of the disease and the frequency of MS in men was showed. Correspondingly, the average negative correlation (-0.37, p<0.001) was detected between the age of disease onset and the incidence of MS recurrence in males, while this connection was not observed in females. We established that the recurrence of MS is a result of multifactorial influence of external and internal factors. Individual seasonal climate variability did not have sufficient force of influence. Therefore, combined effect of corresponding climate changes played a significant role. Furthermore, it is quite probable that interactions of MS with external factors influencing the human body can be mutually integrated.