The spread of SARS-CoV-2 raised concern of infection susceptibility in patients with autoimmune diseases, multiple sclerosis (MS) in particular. The effects of SARS-CoV-2 on MS disease activity are still unknown. To our knowledge, no increased risk of relapses during or after the infection has been reported.
The aim of the present report is to describe the case of a woman with longstanding secondary progressive MS presenting with optic neuritis 4 weeks after SARS-CoV-2 infection.
A 60-year-old patient was diagnosed with MS in 1999. Her first symptom (diplopia) dated back to 10 years earlier. In the following 10 years she reported 3 episodes of paraparesis. She was treated with interferon beta from 2000. She had no relapses nor new T2 lesions during treatment, but she developed a disease progression. In 2012 a diagnosis of secondary progressive diseases was made and treatment was stopped.
In the following years the EDSS remained stable at 6.5, without relapses. Her 2016 MRI scan revealed 2 new small brain lesions compared to the previous one (2012).
On 19th March 2020 the patient developed fever and hypogeusia, resolved spontaneously in 3 days. Seven days earlier she had made contact with her mother, who was diagnosed with COVID-19 infection. On 21th her orofaringeal swab resulted positive for SARS-CoV-2.
On 7th May a sudden reduction of visual acuity in the left eye (20/50) was reported. Left eye visual evoked potentials showed increased latency, with preserved amplitude. A diagnosis of optic neuritis was made. Visual acuity improved in less than a week. A brain MRI performed 20 days later and did not unveil any new lesion or contrast enhancement.
Inflammatory response via cytokine storm is a key feature in SARS-CoV-2 infection. Some immunomodulating drugs such as tociliziumab, an IL-6 receptor blocker, seem to be effective in this condition. Cytokine storm could also be a trigger for CNS autoimmunity: the increased frequency of acute disseminated encephalomyelitis and the reports of “probable” or seropositive autoimmune encephalitides in SARS-CoV-2 patients further suggest this hypothesis. As far as we know, this is the first report of a relapse after SARS-CoV-2 infection. Intriguingly, the relapse occurred in stabile non active progressive MS.
In conclusion, we report the case of acute ON in a secondary progressive MS patient 50 days after SARS-CoV-2 confirmed infection. We hypothesize a possible role of the infection in MS immune activity resurgence.