COVID-19 and Radiological Progression of Multiple Sclerosis.

Background/Objectives: SARS-CoV-2 infection may exacerbate neuroinflammation in patients with multiple sclerosis (MS) and thus accelerate MS progression. Previous studies have reported an increased risk of disability and lesion burden among those infected with SARS-CoV-2 while others reported no differences compared to COVID- controls. We aimed to determine whether COVID-19 is associated with accelerated radiological progression of MS. Methods: This single-center, retrospective longitudinal study included patients with pre-existing relapsing-remitting MS. We identified 34 SARS-CoV-2-positive MS patients (COVID+) who had at least one brain MRI prior to, and one after, their first positive PCR test. These patients were matched 2:1 by index date to 67 SARS-CoV-2-negative MS patients (COVID-). Baseline demographics and comorbidities were comparable between groups. Two radiologists independently scored pre- and post-index MRIs for new or enlarging T2 lesions, T1 gadolinium-enhancing lesions, and parenchymal brain volume loss. Logistic regression analyses evaluated group differences, adjusting for demographic and clinical covariates. Results: Across an average imaging interval of approximately two years, no significant differences were observed between COVID+ and COVID- patients in new lesions (8.8% vs. 9.0%), enlarging lesions (2.9% vs. 6.0%), T1-enhancing lesions (5.9% vs. 1.5%), or brain volume loss (35.3% vs. 47.8%; all p > 0.05). Conclusions: There was no detectable association between SARS-CoV-2 infection and accelerated radiological progression in patients with MS over an average two-year follow-up. Longer-term investigations are warranted to clarify whether certain subgroups or more severe COVID-19 cases might be at heightened risk.