Seizures and Epilepsy occur more often after COVID-19 than after the flu
Therapy
Oxford – Seizures or epilepsy occur more frequently after COVID-19 than after influenza.
This was revealed in an analysis of electronic medical records. According to a publication in the journal Neurology (2022; DOI: 10.1212/WNL.0000000000201595), children were affected more often than adults, and outpatient patients were affected more often than hospitalized patients.
Severe infections are a known risk factor for seizures, although it is generally a rare complication. The exact pathomechanism is not known. Metabolic disturbances due to severe illness may increase the excitability of cortical neurons. In the worst case, stroke could also be a cause. Epileptiform activity has been detected on EEG in patients with COVID-19 in previous studies.
Therefore, a team led by Arjun Sen from the Department of Clinical Neurology Nuffield at the University of Oxford in England conducted a search in electronic medical records to identify cases of seizures or epilepsy in patients with COVID-19. The data source comprised 81 million individuals. Patients (mostly from the USA) whose electronic data are processed by TriNetX Analytics In the analysis of propensity score matching 152,754 patients with influenza and COVID-19, who were identical in all characteristics and comorbidities, were compared. Since all data relating to the comparison are never available, such a retrospective analysis is only conditionally informative, but it can provide initial clues.
Researchers found that within the first 6 months after being diagnosed with COVID-19, 0.81% of patients were treated for seizures. The diagnosis of epilepsy was made in 0.30% of the cohort. Thus, both events were more common than in patients with influenza, of whom 0.51% developed seizures and 0.17% developed epilepsy.
Sen defines the risk ratio for the occurrence of seizures as 1.55 for patients with COVID-19 (compared to those with influenza). This was statistically significant with a 95% confidence interval from 1.39 to 1.74. For epilepsy, the risk ratio was a significant 1.87 (1.54-2.28).
Children were affected more frequently – 1.34% versus 0.69% (risk ratio 1.85; 1.54-2.22), than adults – 0.84% versus 0.54% (risk ratio 1.56; 1.37-1.77). This is surprising because children usually have milder cases of COVID-19 than adults.
Moreover, data showing that seizures and manifest epilepsy occurred more often in outpatient than in hospitalized patients contradict the commonly held belief that the severity of the infection is the main risk factor.
One possible explanation is the delay in the occurrence of seizures and epilepsy. On average, children experienced seizures 50 days after being diagnosed with COVID-19, while the interval for adolescents and adults was 21 days, for outpatient patients – 41 days, and for hospitalized patients – 9 days.