Observational retrospective analysis of vaccination against SARS-CoV-2 and seizures: VACCI-COVID registry.

Background: We aimed to assess the risk of developing new-onset seizures or seizure decompensations in people with epilepsy (PWE) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines.

Methods: A retrospective observational study in a tertiary hospital was conducted. Clinical records of all patients attended because of seizures or epilepsy at outpatient clinics, emergency department, or admitted to our hospital from January to December 2021 were reviewed, including patients older than 16 years who received some dose of coronavirus disease 2019 (COVID-19) vaccines.

Results: A total of 418 vaccinated PWE were analyzed: 6.2% presented an increase in seizure frequency and 1% reported different seizure types during the next month after vaccination. However, 61.5% had another possible cause for this decompensation. Having monthly seizures (1-3/month) was the only associated risk factor (OR 4.9, p < 0.001) while being seizure free > 1 year had a protective role (OR 0.36, p = 0.019). Patients with epileptic encephalopathies or a history of COVID-19 infection were not at increased risk of seizure decompensation. Besides this, 15 patients presented new-onset seizures within the first month post-vaccination, mean time from vaccination 15 ± 8 days, 67% after the second dose. Again, 53.3% had another possible trigger for seizures. Eight debuted with status epilepticus or cluster of seizures.

Conclusions: A small proportion of PWE (6.2%) had an increase in seizure frequency after COVID-19 vaccination and 15 patients had new-onset seizures during the first month after vaccination, though another reason for seizure exacerbation was identified in 61.5% and 53.3%, respectively. Severe acute respiratory syndrome COVID-19 vaccines appear to have little impact on the generation or decompensation of seizures.