Fever seizures beyond the typical age: clinical characteristics and subsequent epilepsy risks in children over five

Febrile seizures are classically defined as occurring between six months and five years of age; however, fever-associated seizures may also occur in older children, a group that remains relatively underrecognized. This age group may present with different clinical characteristics and a potentially increased risk of epilepsy or underlying structural abnormalities.

We retrospectively analyzed children older than five years who presented with fever-associated seizures to the pediatric emergency department between July 2019 and July 2024. Demographic characteristics, seizure semiology, family history, electroencephalography(EEG) and neuroimaging results, and long-term epilepsy outcomes were evaluated. Patients with prior epilepsy, neurodevelopmental disorders, or metabolic diseases were excluded.

One hundred ten children (mean age:7.3 years; 73.6% male) were included. Most patients (80%) experienced simple febrile seizures; however, complex seizures occurred in 20%. EEG abnormalities were present in 33.3% of those tested (45/110), and neuroimaging revealed structural abnormalities in 2/51 patients. Over a median follow-up of 18 months, 14 children (12.7%) developed epilepsy, a markedly higher risk being observed in those with complex seizures (40.9% vs. 5.7%) and in children over seven.

Febrile seizures occurring beyond the age of five may represent a clinically relevant subgroup. Although many children present with simple features and follow a favorable course, complex seizure characteristics and older age may be associated with an increased risk of subsequent epilepsy. Selected patients may therefore require careful clinical evaluation and follow-up.