At the 2022 ACTRIMS Forum, three groups presented data on acute demyelinating events following COVID-19 vaccination.
A Canadian case series at the BARLO Centre, Toronto, identified 13 patients (mean age 43 years) with an acute demyelinating event within 60 days after COVID vaccination (Lee et al. ACTRIMS 2022;P121). Eleven of 13 had no prior history of demyelination; two patients had pre-existing multiple sclerosis. The series comprised nine cases of transverse myelitis, three cases of brain demyelination, and two cases of optic neuritis. The subsequent diagnoses were new-onset MS (n=5), post-vaccine transverse myelitis (n=4), and one case each of MS relapse, clinically isolated syndrome, NMO spectrum disorder and MOG-antibody disease. Treatments included pulse corticosteroids and plasma exchange. Six were started on a DMT; two treated MS patients were switched to another DMT.
A separate study reported five cases of demyelinating syndromes post-vaccination (Belliston et al. ACTRIMS 2022;P127). A case of optic neuritis and one of sixth nerve paresis were subsequently diagnosed with MS. The other three cases presented with transverse myelitis, of which one was seropositive for NMO.
The Cleveland Clinic also reported five cases of new-onset MS post-vaccination (Toljan et al. ACTRIMS 2022;P144). Symptom onset was 1-35 days after vaccination. Four of 5 patients had Gd+ lesions; three had CSF pleocytosis and an elevated IgG index. One patient had a prior history of optic neuritis.
A systematic review of 32 cases of CNS demyelination following COVID-19 vaccination was published just prior to ACTRIMS (Ismail et al. J Neuroimmunol 2022;362:577765). The cases were reported in 12 countries (Canada was not among them). Median patient age was 44 years. Most cases (71.8%) occurred after the first vaccination; median time to onset of neurological symptoms was 9 days post-vaccination. As in the above series, transverse myelitis was a common presentation (12 of 32 cases). MS-like symptoms or MS relapses occurred in 12 patients. ADEM- and NMOSD-like symptoms accounted for five and three cases, respectively. About 53% of cases had a prior history of immune disorder such as MS (n=7), new-onset MS (n=1) and CIS (n=1). Three patients had a history of thyroid dysfunction.
In the group of patients with MS-like symptoms, 6 of 12 had a prior history of MS. Four patients had new-onset MS and one was newly-diagnosed with CIS. One case had a history of neurological symptoms but had not yet received an MS diagnosis. Eleven of 12 cases were female (median age 33.5 years). Brain MRI revealed demyelinating lesions in all 12 patients; 3 of 12 had spinal-cord lesions. Treatments included high-dose methylprednisolone (with or without oral tapering), PLEX and IVIg. Improvement was marked or complete in 25 cases (78%); the remainder were stabilized or achieved partial recovery.
Three cases of transverse myelitis (11,636 vaccinated) were reported in clinical trials of the AstraZeneca vaccine; one case was considered to be possibly related to the vaccine and two were considered to be previously undiagnosed MS (Voysey et al. Lancet 2021;397:99-111).
An analysis of the Vaccine Adverse Events Reporting System database found 328 cases of suspected transverse myelitis following vaccination (all types) (von Csefalvay C. medRxiv, June 17, 2021). This was considered to be within the normal incidence range for transverse myelitis (1.34 to 4.60 per 1 million population) (Beh et al. Neurol Clin 2013;31:79-138).
Recent studies investigating whether COVID vaccination is associated with worsening MS have reported conflicting results. An Israeli study reported no increase in disease activity in MS patients following COVID vaccination (Dreyer-Alster et al. ECTRIMS 2021;P187). A separate retrospective study found no increased risk of relapses, although patient-reported pseudo-relapses were more common after vaccination (Chou et al. ECTRIMS 2021;P133). In contrast, an insurance database analysis noted an increase in new CIS/MS diagnoses during the two-week period after COVID vaccination (Marcus J. ECTRIMS 2021;P371).