Social and Environmental Triggers of Multiple Sclerosis onset: A Retrospective Study from Iran

ABSTRACT

Introduction: Multiple sclerosis (MS) is an often-disabling disease of the central nervous system (CNS). The possible triggers of its first presentation such as stressful events, viral infections, vaccinations, and labor are still a matter of debate among scientists. Considering the possible role of infections in MS onset and the reported cases of CNS demyelination following COVID-19 infection and variety of COVID-19 vaccines, this study was conducted to investigate and compare the possible social, environmental, and physical triggers of MS onset before and during the COVID-19 pandemic. Material(s) and Method(s) A cross-sectional study was conducted from 28 February 2022 to 9 June 2022. A researcher-made questionnaire was designed in MS research center of Iran and distributed as an online google form on social media among 1340 Iranian MS patients. Demographic information, MS disease-related data, possible MS triggers (stressful life events, COVID-19 and other infections, COVID-19 and other vaccines, pregnancy or labor, head trauma, surgery, weight loss) were recorded. Patients were divided into two groups regarding the time of MS diagnosis (before and during the COVID-19 pandemic). Binary logistic regression method was used to determine the possible association between patient-reported triggers and diagnosis time (before and during the pandemic) adjusting for possible confounders. Result(s) Of 920 participants, 670 (72.8 %) were female, and the mean age (SD) was 35.63 (+/-8.1). The majority of participants 637 (69.2%) had non-progressive forms of MS, and only 70 (7.6 %) needed assistance for ambulation. The time of MS diagnosis was before the start of the COVID-19 pandemic in 635 (69 %) participants. The differences between the most common first symptoms which led to MS diagnosis, visual type (n 317 (49.9 %)) before the pandemic and sensory type (n 170 (59.6 %)) after the pandemic were significant (p-values 0.008 and <0.01 respectively). A stressful life event was the most common patient-reported MS trigger in both groups, (n 356 (56.1%)) in patients who were diagnosed before the COVID-19 pandemic, and (n 156 (54.7%)) in the latter group. Comparing two groups (MS diagnosed before and during the pandemic), economic problems (AOR 1.81;95%ACI 1.23-2.65) and job loss (AOR 2.89;95%ACI 1.37-6.08) were significantly more frequent stressful life event which trigger MS onset in the latter group while, the stress of occupational or educational exams (AOR 0.52;95%ACI 0.34-0.79) was more prevalent in the first group. Conclusion(s) Social triggers such as stressful life events are closely associated with MS onset that had been increased in some categories after the COVID-19 pandemic. If truly recognized, they could be used to prevent the development and exacerbation of the disease.Copyright © 2022