What is the incidence of COVID-19-associated febrile seizures in children?

By Pooja Toshniwal PahariaReviewed by Danielle Ellis, B.Sc.Feb 2 2023

In a recent study published in the Journal of Clinical Medicine, researchers investigated the incidence of febrile seizures (FS) among severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive children.

Background

FS refers to a neurological condition disorder commonly observed among children between six months and five years, wherein a febrile patient develops convulsions without intracranial infections. Febrile seizures have been reported in patients with COVID-19 (coronavirus disease 2019), especially after the SARS-CoV-2 Omicron variant emerged.

About the study

In the present study, researchers determined the incidence of febrile seizures among SARS-CoV-2-positive children.

The study included children aged below five years with confirmed SARS-CoV-2 infections residing in the Jeonbuk province of Korea between January 2020 and June 2022. Data were provided by the ministry of security and public administration. In addition, data were obtained on SARS-CoV-2-positive children who developed FS from five hospitals that provided treatment for FS treatment.

The team excluded epileptic patients, afebrile individuals, and those individuals with no other cause of convulsion, such as electrolyte imbalance or structural abnormalities, confirmed by MRI (magnetic resonance imaging) of the brain. To calculate COVID-19-related FS incidence, the number of COVID-19 patients presenting with FS was divided by the total pediatric COVID-19 case counts.

Data concerning individual demographics, laboratory results, seizure type, seizure duration, electroencephalography findings, and duration of hospital admission were also analyzed. Laboratory tests were performed for each participant at the time of hospitalization. Further, to evaluate the impact of SARS-CoV-2 infections on FS severity, data from COVID-19 patients with PFS (prolonged febrile seizures) were evaluated.

Results

Out of 62,722 children residing in Jeonbuk who were aged below five years, 53% (n=33,457) were infected with SARS-CoV-2, of which 1.0% (n=476) children required hospital admission, and 0.2% (n=64) developed febrile seizures. Among children with FS, 44 were male (69%), and 20 were female (31%). The mean age of the participants developing febrile seizures was 37 months.

All FS patients developed symptoms post-SARS-CoV-2 Omicron variant emergence. In the pre-Omicron COVID-19 period, 23% of COVID-19 patients (89 patients out of 381 patients) required hospital admissions. Nevertheless, none of the SARS-CoV-2-positive children were admitted for febrile seizures. Further, 39% (n=25) of patients presented with complex febrile seizures, whereas a single child developed febrile status epilepticus.

Among the study participants, 66% (n=42) developed FS for the first time with a mean of two convulsions, and a maximum of 10 convulsive episodes over three days was reported in a patient. The median value for FS duration was three minutes, with the longest FS duration reported being one hour, which required ventilation support. Among the participants, 20% (n=13) had immediate family members with an FS history, and the average duration of hospitalization was four days.

Most of the FS children did not require ASM post-hospital admission; however, 11% of FS patients (n=7.0) needed primary ASM, including intravenous lorazepam (0.10 mg per kg) administration. Of the seven children, two needed secondary ASM, including intravenous 20.0 mg per kg fosphenytoin administration, and one child needed continuous intravenous midazolam (5.0 µg per kg per minute ) infusions.

The majority of the children showed normal white blood cell counts (7.50 × 10³ per µL) and normal lymphocyte counts (23% %), with median serological CRP (C-reactive protein) levels of 1.7 mg per liter. Among six children with prolonged febrile seizures of >15 minutes duration, five were male, and four developed seizures for the first time in association with SARS-CoV-2 infections.

All four children showed normal brain MRI findings, and 75% (three children) exhibited slow background activities in the electroencephalography analysis; however, none of them showed epileptiform-type discharge. In spite of the long FS duration in the participants, only 33% (two children) needed anticonvulsant medications (ASM), and the hospitalization duration was less than eight days.

Among those with ASM requirements, elevated blood glucose values of 232.0 milligrams per decilitre and 291.0 milligrams per decilitre were observed. The serological lactate levels in the corresponding patients were 3.0 mmol per liter and 26.0 mmol per liter, respectively. The events of convulsion in all the other FS children were found to be of self-limiting type. COVID-19-associated FS incidence may have been higher during Omicron predominance due to the greater transmissibility and infectivity of Omicron compared to previously circulating SARS-CoV-2 variants.

Conclusion

Based on the study findings, febrile seizures could occur in nearly 0.20% of SARS-CoV-2-positive children aged below five years, more frequently among males in the Omicron dominance period. Moreover, a higher number of febrile status epilepticus and complex febrile seizure cases were associated with Omicron infections.