Potential Role of Febrile Seizures and Other Risk Factors Associated With Sudden Deaths in Children

IMPORTANCE: Sudden unexplained death in childhood (SUDC) is the fifth leading category of death among toddlers but remains underrecognized and inadequately studied. OBJECTIVE: To assess the potential role of febrile seizures (FS) and other risk factors associated with SUDC and describe the epidemiology, mechanisms, and prevention of SUDC. DESIGN, SETTING, AND PARTICIPANTS: This case series study reviewed 622 consecutive sudden child death cases aged 1 to 17 years from 2001 to 2017 from 18 countries. Data were collected from family members of children who died suddenly; these families voluntarily registered with the SUDC Foundation. Data analysis was conducted from November 2017 to February 2019. MAIN OUTCOME MEASURES: Certified manner of death characterized as accident, natural, or undetermined. RESULTS: A total of 391 families with decedents aged 1 to 6 years completed a comprehensive interview on medical and social histories, and circumstances of death with forensic evaluations revealing a cause of death (sudden explained death in childhood [SEDC]) or no cause of death (SUDC). Of these children, 231 (59.1%) were male, the mean (SD) age at death was 24.9 (12.8) months, and 104 (26.6%) had a history of FS. Compared with the general population FS prevalence (2%-5%), FS prevalence among SUDC (28.8%; 95% CI, 23.3%-34.2%) and SEDC (22.1%; 95% CI, 14.8%-29.3%) were elevated. The odds of death during sleep was 4.6-fold higher in SUDC than in SEDC cases (odds ratio, 4.61; 95% CI, 1.92-11.09; adjusted P = .008). The siblings of SUDC cases were followed up for 3144 life-years, and none died prematurely from SUDC. CONCLUSIONS AND RELEVANCE: This analysis of the largest SUDC cohort confirmed an increased FS rate and found significantly increased rates of FS among SEDC. This study suggests that seizures may contribute to some SUDC and SEDC deaths. The risk of sudden death in a sibling was low. To develop and assess preventive strategies, population-based studies are needed to define the epidemiology and spectrum of risk factors and identify biomarkers of patients with FS at high risk of sudden death.