Effects of coronavirus disease 2019 vaccination on seizures in patients with epilepsy.

BACKGROUND: Given that seizures may be triggered by vaccination, this study aimed to evaluate the risk and correlative factors of seizures in patients with epilepsy (PWE) after being vaccinated against coronavirus disease 2019 (COVID-19). METHODS: This study retrospectively enrolled PWE who were vaccinated against COVID-19 in the epilepsy centers of 11 hospitals in China. We divided the PWE into two groups as follows: (1) patients who developed seizures within 14 days of vaccination were assigned to the SAV (with seizures after vaccination) group; (2) patients who were seizure-free within 14 days of vaccination were assigned to the SFAV (seizure-free after vaccination) group. To identify potential risk factors for seizure reccurence, the binary logistic regression analysis was performed. Besides, 67 PWE who had not been vaccinated were also included for elucidating the effects of vaccination on seizures recurrence, and binary logistic regression analysis was performed to determine whether vaccination would affect the recurrence rate of PWE who had drug reduction or withdrawal. RESULTS: The study included a total of 407 patients; of which, 48 (11.8%) developed seizures within 14 days after vaccination (SAV group), whereas 359 (88.2%) remained seizure-free (SFAV group). The binary logistic regression analysis revealed that duration of seizure freedom ( P  < 0.001) and withdrawal from anti-seizure medications (ASMs) or reduction in their dosage during the peri-vaccination period were significantly associated with the recurrence of seizures (odds ratio = 7.384, 95% confidence interval = 1.732-31.488, P  = 0.007). In addition, 32 of 33 patients (97.0%) who were seizure-free for more than three months before vaccination and had a normal electroencephalogram before vaccination did not have any seizures within 14 days of vaccination. A total of 92 (22.6%) patients experienced non-epileptic adverse reactions after vaccination. Binary logistic regression analysis results showed that vaccine did not significantly affect the recurrence rate of PWE who had the behavior of ASMs dose reduction or withdrawal ( P  = 0.143). CONCLUSIONS: PWE need protection from the COVID-19 vaccine. PWE who are seizure-free for >3 months before vaccination should be vaccinated. Whether the remaining PWE should be vaccinated depends on the local prevalence of COVID-19. Finally, PWE should avoid discontinuing ASMs or reducing their dosage during the peri-vaccination period.

Effect of inactivated COVID-19 vaccines on seizure frequency in patients with epilepsy: A multicenter, prospective study.

Objectives: Several COVID-19 vaccines list "uncontrolled epilepsy" as a contraindication for vaccination. This consequently restricts vaccination against COVID-19 in patients with epilepsy (PWE). However, there is no strong evidence that COVID-19 vaccination can exacerbate conditions in PWE. This study aims to determine the impact of COVID-19 vaccination on PWE. Methods: PWE were prospectively recruited from 25 epilepsy centers. We recorded the seizure frequency at three time periods (one month before the first vaccination and one month after the first and second vaccinations). A generalized linear mixed-effects model (GLMM) was used for analysis, and the adjusted incidence rate ratio (AIRR) with 95% CI was presented and interpreted accordingly. Results: Overall, 859 PWE were included in the analysis. Thirty-one (3.6%) and 35 (4.1%) patients were found to have increased seizure frequency after the two doses, respectively. Age had an interaction with time. The seizure frequency in adults decreased by 81% after the first dose (AIRR=0.19, 95% CI:0.11-0.34) and 85% after the second dose (AIRR=0.16, 95% CI:0.08-0.30). In juveniles (<18), it was 25% (AIRR=0.75, 95% CI:0.42-1.34) and 51% (AIRR=0.49, 95% CI:0.25-0.95), respectively. Interval between the last seizure before vaccination and the first dose of vaccination (ILSFV) had a significant effect on seizure frequency after vaccination. Seizure frequency in PWE with hereditary epilepsy after vaccination was significantly higher than that in PWE with unknown etiology (AIRR=1.95, 95% CI: 1.17-3.24). Two hundred and seventeen (25.3%) patients experienced non-epileptic but not serious adverse reactions. Discussion: The inactivated COVID-19 vaccine does not significantly increase seizure frequency in PWE. The limitations of vaccination in PWE should focus on aspects other than control status. Juvenile PWE should be of greater concern after vaccination because they have lower safety. Finally, PWE should not reduce the dosage of anti-seizure medication during the peri-vaccination period.