A Study of the Seasonal Incidence of Multiple Sclerosis Attacks in Kerman, Iran

Background & Aims: Multiple sclerosis (MS) is a chronic disease of the nervous system, the cause of which remains unknown. Its prevalence rate has been estimated at 2.5 million individuals across the globe, and 31.5 individuals per 100,000 in Kerman province, Iran. Although different studies have reported disparate results, there are many authentic reports claiming that seasonal changes affect MS prevalence in certain months. The presentstudy investigated the rate of MS seizuresin terms of differentseasons. Methods: Patients referring to the Neurology Ward of Shafa medical center, affiliated to Kerman University of Medical Sciences, Iran, were examined in a 5 year period from 2007 to 2011. A specially developed form, containing demographic and background information, and results of examinations, was filled out for each and every patient. A neurology faculty member approved MS seizures or otherwise rejected irrelevant observations. Findings were analyzed through SPSS20 software. Results: In the present study, 802 attacks of MS were detected; 187 cases in men (23.32%) and 615 cases in women (76.68%). The mean age of the participants was 32.69 years. The highest rate of hospitalization occurred in winter and spring. This finding is mostly related to MS attacks in women, but in men the rate of attacks are equal in differentseasons. Conclusion: During the past 5 years, 802 acute cases of multiple were registered (187 cases (23.3%) in men and 615 cases(76.68%) in women). Most cases occurred in winter and spring, which may be due to seasonal infections or other factorstriggered by certain climatic conditionsspecific to these periods.