The impact of social and environmental factors on triggering multiple sclerosis onset, before and during the COVID-19 pandemic: a retrospective study from Iran.

Background: Multiple sclerosis (MS) is a chronic, inflammatory, and demyelinating disease of the central nervous system. The first presentation's possible triggers are still controversial among scientists. The objective of this study is to investigate and compare the potential social, environmental, and physical factors that may have contributed to the onset of MS before and during the Coronavirus Disease 2019 (COVID-19) pandemic.

Methods: A questionnaire was designed in the MS research center of Sina Hospital and also distributed as an online Google Form on social media among Iranian MS patients. Demographic information, MS disease-related data, and possible patients reported MS triggers were recorded. They were containing stressful life events, COVID-19 and other infections, COVID-19 and other vaccines, pregnancy or labor, head trauma, surgery, and weight loss. Patients were divided into two groups regarding the time of MS diagnosis (before and during the COVID-19 pandemic).

Results: Of 920 participants, 670 (72.8%) were female, and the mean age ± SD was 35.63 ± 8.1. The majority of patients (69.2%) had non-progressive forms of MS, and only 7.6% needed assistance for ambulation. 69% of participants were diagnosed with MS before the onset of the COVID-19 pandemic. There was a statistically significant difference between the most common first MS symptom before and after the beginning of the pandemic (visual type (n: 317 (49.9%)) before and sensory type (n: 170 (59.6%)) after the COVID-19 pandemic). A stressful life event was the most common patient-reported trigger of MS first presentation in both groups. (56.1% before and 54% after the COVID-19 pandemic). Comparing two groups, economic problems (AOR: 1.81; 95% ACI: 1.23-2.65) and job losses (AOR: 2.89; 95% ACI: 1.37-6.08) were significantly more common triggers for the initial presentation of MS after the pandemic, while the stress of occupational or educational exams (AOR: 0.52; 95% ACI: 0.34-0.79) was more prevalent before the pandemic.

Conclusion: Patients believe that stressful life events are closely linked to triggering their first MS symptoms. Since the beginning of the COVID-19 pandemic, economic problems and job losses have increased; however, occupational or educational exams stress decreased. Caring for social stress by societies may affect MS development or delay MS onset.