Simple and complex febrile seizures: is there such a difference? Management and complications in an emergency department

Objective: We aimed to analyse the prevalence, characteristics, and management of simple and complex febrile seizures. The secondary objective was to compare the risk of underlying organic lesion and epilepsy in both types of seizures, with a particular focus on the different subtypes defining a complex febrile seizure.

Material and methods: We performed a retrospective cohort study including patients aged 0--16 years who were treated for febrile seizures in the paediatric emergency department of a tertiary hospital over a period of 5 years. Epidemiological and clinical variables were collected. Patients were followed up for at least 2 years to confirm the final diagnosis.

Results: We identified 654 patients with febrile seizures, with a prevalence of 0.20% (95% CI, 0.18-0.22); 537 (82%) had simple febrile seizures and 117 (18%) had complex febrile seizures. The clinical and epidemiological characteristics of both types were similar. Significantly more complementary tests were requested for complex febrile seizures: blood tests (71.8% vs 24.2% for simple febrile seizures), urine analysis (10.3% vs 2.4%), lumbar puncture (14.5% vs 1.5%), and CT (7.7% vs 0%). Similarly, admission was indicated more frequently (41.0% vs 6.1%). Underlying organic lesions (central nervous system infection, metabolic disease, tumour/intracranial space-occupying lesion, intoxication) were diagnosed in only 11 patients, 5 of whom had complex forms (4.3%; 95% CI, 0.6-7.9). Risk factors for developing epilepsy, identified in the multivariate analysis, were complex forms with recurrent seizures in a single attack (odds ratio [OR]: 4.94; 95% CI, 1.29-18.95), history of seizures (OR: 17.97; 95% CI, 2.26--143.10), and seizures presenting at atypical ages (OR: 11.69; 95% CI, 1.99-68.61).

Conclusions: The systematic indication of complementary tests or hospital admission of patients with complex febrile seizures is unnecessary. The risk of epilepsy in patients with complex forms gives rise to the need for follow-up in paediatric neurology departments.