The association of upper respiratory infections with neuro-radiological course and attack rate of multiple sclerosis: Results from a large prospective cohort

Abstract

Background Although upper respiratory infections (URIs) are linked to multiple sclerosis (MS) attacks, SARS-COV2 has not been compared to URIs for attack rates. Objectives This study aimed to evaluate the attack rate and the results of neuroimaging in MS patients with URIs caused by COVID-19 and non-COVID-19 infections (NC-URI). Methods From May 2020 to April 2021, we followed 362 patients with relapsing-remitting MS in a prospective cohort design. Patients were monitored regularly every 12 weeks; an magnetic resonance imaging (MRI) scan was performed at enrollment and every time a relapse occurred. Poisson analysis was used to determine exacerbation rate ratios (RR) and the MRI parameters were tested using chi-square analysis. Results 347 patients with an average age of 38 and a female ratio of 86% were included. A RR of 2.24 ( p < 0.001) was observed for exacerbations during the at-risk period (ARP). Attacks related to COVID-19 (RR = 2.13, p = 0.001) and NC-URIs (RR = 2.39, p < 0.001) were comparable regarding the increased risk of exacerbation ( p = 0.62). Exacerbations within or outside the ARP did not significantly alter the number of baseline GAD-enhancing lesions ( p > 0.05 for both). Conclusion COVID-19 has been shown to increase the risk of MS exacerbations, like other viral URIs.