Flu-related neurologic events pose greater risk for children with pre-existing neurologic conditions

Many clinicians do not consider neurologic complications of the flu when discussing vaccination or treatment of influenza with families.

A recent study that explored the neurologic impact of flu in children aims to change that.

"Serious Neurologic Events with Seasonal Influenza in Young Children," published in Academic Pediatrics, the official journal of the Academic Pediatric Association, looked at the population-based incidence of underrecognized influenza-associated serious neurologic events in children less than 5 years of age.

While serious neurologic complications are uncommon in young children, the study showed a much higher incidence, almost 50 times greater, in those with underlying neurologic conditions, which surprised the research team.

Before this study, we had no idea how common these events were. This study is the first to put a number to how often young children with influenza have these complications. Awareness of these events is critical."

James Antoon, MD, PhD, MPH, assistant professor of Pediatrics at Monroe Carell Jr. Children's Hospital at Vanderbilt

According to the study, the primary outcome of influenza-associated serious neurologic events was defined as an influenza-associated hospitalization with a neurologic diagnosis. Neurologic events included seizures, meningitis, encephalitis or encephalopathy, altered mental status, and ataxia and movement disorders.

"These findings stress the need for improved vaccination and treatment efforts targeted towards the most vulnerable children who are at highest risk for these complications," said Brooke Quertermous, MD, a third-year Pediatrics resident at Monroe Carell and lead author on the study.

The study looked at a retrospective cohort of children less than 5 years old enrolled in a Tennessee Medicaid program during the 2016-2020 influenza seasons. A total of 79,727 cases of influenza among 70,258 unique children were included.

"Young children are at high risk for complications from influenza," said Quertermous. "Improved understanding of these events is necessary to inform preventative public health efforts. Better awareness of incidence rates and risk factors within this vulnerable population can improve prevention and treatment interventions in at-risk populations."

Tennessee is one of the top five states for influenza illnesses in the country, said Antoon.

According to the Centers for Disease Control and Prevention (CDC), Tennessee was in the highest tier of the "very high" activity level for flu-like illnesses for the week ending Feb. 1.

The higher rate of flu demands a higher level of importance in communicating about flu complications.

"The Massachusetts Department of Public Health, as well as other agencies, have put out public health advisories about increased serious neurologic complications in children related to influenza this season," added Antoon.

 "Specifically, necrotizing encephalitis and encephalopathy appear to be reported at higher rates this flu season compared to previous years."