Although the absolute risks remain reassuringly low (<1%), today we have another study showing that even a `mild' bout of COVID can have profound impacts, as if finds the relative risks of having seizures or developing epilepsy over the first 6 months following a COVID diagnosis to be roughly 55% greater than after an influenza diagnosis.
This increased risk was most pronounced in patients under the age of 16 and among those who were not hospitalized for their illnesses, showing that even mild illness can cause serious, and sometimes lasting, sequelae.
Children and adolescents - while generally less severely affected by COVID - are not immune to serious illness, as we've seen from thousands of reports of multisystem inflammatory syndrome in children (MIS-C) across the nation, and around the world.
MIS-C isn't the only adverse outcome for children and adolescents with COVID.
Last January the MMWR reported on increased risk among those 18 and younger of developing diabetes within 30 days of COVID infection, and we've seen studies indicating elevated rates of COVID-19–Associated Pulmonary Embolism in Pediatric Patients.
Three months ago we looked at an MMWR report on Post-COVID conditions in children and adolescents, and found that the risks of experiencing several rare conditions rose sharply following COVID infection. While the absolute risk of these complications remains low, the relative risk in some cases more than doubles.
While many continue to push the narrative that COVID is, and always has been, a mild illness in the young - for a small, but significant number of children and adolescents - it sadly isn't so.
All of which brings us to the following open-access report in the journal Neurology that finds the incidence of seizures and epilepsy - particularly among adolescents and children - over the six months following a COVID diagnoses to be significantly higher than following an influenza diagnosis.
Incidence of Epilepsy and Seizures Over the First 6 Months After a COVID-19 Diagnosis: A Retrospective Cohort Study
Maxime Taquet, Orrin Devinsky, J. Helen Cross, Paul J Harrison, Arjune Sen
First published November 16, 2022, DOI: https://doi.org/10.1212/WNL.0000000000201595Abstract
Background: The relationship between COVID-19 and epilepsy is uncertain. We studied the potential association between COVID-19 and seizures or epilepsy in the six months after infection.
Methods: We applied validated methods to an electronic health records network (TriNetX Analytics) of 81 million people. We closely matched people with COVID-19 infections to those with influenza. In each cohort, we measured the incidence and hazard ratios (HRs) of seizures and of epilepsy. We stratified data by age and by whether the person was hospitalized during the acute infection. We then explored time-varying HRs to assess temporal patterns of seizure or epilepsy diagnoses.
Results: We analyzed 860,934 electronic health records. After matching, this yielded two cohorts each of 152,754 patients. COVID-19 was associated with an increased risk of seizures and epilepsy compared to influenza. The incidence of seizures within 6 months of COVID-19 was 0.81% (95% CI, 0.75-0.88; HR compared to influenza 1.55 (1.39-1.74)). The incidence of epilepsy was 0.30% (0.26-0.34; HR compared to influenza 1.87 (1.54-2.28)). The HR of epilepsy after COVID-19 compared to influenza was greater in people who had not been hospitalized and in individuals aged under 16 years. The time of peak HR after infection differed by age and hospitalization status.
Conclusions: The incidence of new seizures or epilepsy diagnoses in the six months following COVID-19 was low overall, but higher than in matched patients with influenza. This difference was more marked in people who were not hospitalized, highlighting the risk of epilepsy and seizures even in those with less severe infection. Children appear at particular risk of seizures and epilepsy after COVID-19 providing another motivation to prevent COVID-19 infection in pediatric populations. That the varying time of peak risk related to hospitalization and age may provide clues as to the underlying mechanisms of COVID-associated seizures and epilepsy.
STUDY FINDS RISK OF SEIZURES IS HIGHER AFTER COVID-19 THAN AFTER INFLUENZA
MINNEAPOLIS – People who have a COVID-19 infection are more likely to develop seizures or epilepsy within the next six months than people who have an influenza infection, according to a study published in the November 16, 2022, online issue of Neurology®, the medical journal of the American Academy of Neurology. The increased risk was more noticeable in children than adults. It was also more noticeable in people who did not need hospitalization for COVID-19 infections.“While the overall risk of developing seizures or epilepsy was low—less than 1% of all people with COVID-19, given the large number of people who have been infected with COVID-19, this could result in increases in the number of people with seizures and epilepsy,” said study author Arjune Sen, MD, PhD, of the University of Oxford in England. “In addition, the increased risk of seizures and epilepsy in children gives us another reason to try to prevent COVID-19 infections in kids.”For the study, researchers looked at a health records network for people with COVID-19 infections. They were matched to people who were diagnosed with influenza during the same time period and who were similar in age, sex and other factors, such as other medical conditions. None of the participants had previously been diagnosed with epilepsy or recurrent seizures. The researchers then looked to see whether people developed epilepsy or seizures in the following six months.There were 152,754 people in each of the COVID-19 and the influenza groups.People who had COVID-19 were 55% more likely to develop epilepsy or seizures over the next six months than people who had influenza. The rate of new cases of epilepsy or seizures was 0.94% in the people who had COVID-19, compared to 0.60% in those who had influenza.“People should interpret these results cautiously since the overall risk is low,” Sen said. “We do, however, recommend that health care professionals pay particular attention to individuals who may have more subtle features of seizures, such as focal aware seizures, where people are alert and aware of what is going on, especially in the three months following a less severe COVID-19 infection.”A limitation of the study was that researchers were unable to identify which specific virus variants people were infected with, which could have influenced results.The study was supported by the British National Institute for Health and Care Research Oxford Health Biomedical Research Centre.
Since the summer of 2020 we've seen a steady parade of studies and articles on the long-term detrimental impacts from COVID infection. Perhaps most concerning are recent findings that repeated infections substantially increase the risk of death or serious illness (see Nature: Acute and Postacute Sequelae Associated with SARS-CoV-2 Reinfection).
It may take another 5 or 10 years before we can truly assess the impact of COVID infection on society's health and well being.
But the evidence continues to suggest that COVID - even when it only produces `mild' acute illness - is an infection best avoided whenever possible.