Febrile seizures prior to sudden cardiac death: a Danish nationwide study

The fundamental need for unifying phenotypes in sudden unexpected pediatric deaths

A definitive, authoritative approach to evaluate the causes of unexpected, and ultimately unexplained, pediatric deaths remains elusive, relegating final conclusions to diagnoses of exclusion in the vast majority of cases. Research into unexplained pediatric deaths has focused primarily on sudden infant deaths (under 1 year of age) and led to the identification of several potential, albeit incompletely understood, contributory factors: nonspecific pathology findings, associations with sleep position and environment that may not be uniformly relevant, and the elucidation of a role for serotonin that is practically difficult to estimate in any individual case. Any assessment of progress in this field must also acknowledge the failure of current approaches to substantially decrease mortality rates in decades. Furthermore, potential commonalities with pediatric deaths across a broader age spectrum have not been widely considered. Recent epilepsy-related observations and genetic findings, identified post-mortem in both infants and children who died suddenly and unexpectedly, suggest a role for more intense and specific phenotyping efforts as well as an expanded role for genetic and genomic evaluation. We therefore present a new approach to reframe the phenotype in sudden unexplained deaths in the pediatric age range, collapsing many distinctions based on arbitrary factors (such as age) that have previously guided research in this area, and discuss its implications for the future of postmortem investigation.

Electrocardiography Parameters Changes in Epilepsy and Febrile Convulsion Children Compared with Controls

Epilepsy and febrile convulsion are the most common neurological diseases with significant effect on cardiac functions. This study aimed to evaluate electrocardiography parameters alterations in epilepsy and febrile convulsion children compared with controls. In this comparison study, 270 children analyzed who shared equally in epilepsy, febrile convulsion, and healthy that aged from 0.5 to 5 years. The participants were collected from Ali ibn Abi Talib Hospital of Zahedan, Iran. Epilepsy confirmed based on definition of having at least two unprovoked seizures in 24 hours. Febrile convulsion was confirmed based on its definition by the International League against Epilepsy. Healthy children selected from those referred to the hospital with fever and without any underline diseases. Electrocardiography was performed by a pediatric cardiologist. Data were analyzed using SPSS 19 with p < 0.05 significant level. Heart rate was higher in epilepsy (129.64 ± 27.63) compared with control (108.78 ± 26.01) and febrile convulsion (125.79 ± 25.38; X 2 = 28.701, p < 0.001). S wave in lead V1 was higher in controls (0.72 ± 0.36) compared with epilepsy (0.58 ± 0.45) and febrile convulsion (0.58 ± 0.36). QT dispersion and QTc dispersion levels were higher in epilepsy than febrile convulsion children that both were higher than controls. Concluded that R in aVL, LV mass (LVM), QT dispersion, and QTc dispersion were higher significantly in epilepsy compared with febrile convulsion children. To maintain a good strategic treatment in patients with epilepsy and febrile convulsion, there is a need to assess alternations in ECG parameters, especially QT interval changes that lead to better comprehensive autonomic changes.

Low Birth Weight Increases the Risk of Sudden Cardiac Death in the Young: A Nationwide Study of 2.2 Million People

Background Sudden cardiac death (SCD) constitutes a major health problem worldwide. We investigated whether birth weight (BW), small for gestational age (SGA), and large for gestational age are associated with altered risk of SCD among the young (aged 1-36 years). Methods and Results We included all people born in Denmark from 1973 to 2008 utilizing the Danish Medical Birth Register. All SCDs in Denmark in 2000 to 2009 have previously been identified. We defined 5 BW groups, SGA, and large for gestational age as exposure and SCD as the outcome. We estimated the age-specific relative risk of SCD with 95% CI. Additionally, we investigated if SGA and large for gestational age are associated with pathological findings at autopsy. The study population for the BW analyses comprised 2 234 501 people with 389 SCD cases, and the SGA and large for gestational age analyses comprised 1 786 281 people with 193 SCD cases. The relative risk for SCD was 6.69 for people with BW between 1500 and 2499 g (95% CI, 2.38-18.80, P<0.001) and 5.89 for people with BW ≥4500 g (95% CI, 1.81-19.12, P=0.003) at age 5 years. BW 2500 to 3400 g was the reference group. Compared with an appropriate gestational age, the relative risk for SGA was 2.85 (95% CI, 1.35-6.00, P=0.006) at age 10 years. For the autopsied cases, the relative risk of sudden arrhythmic death syndrome at age 5 years was 4.19 for SGA (95% CI, 1.08-16.22, P=0.038). Conclusions We found an association between BW and SCD in the young, with an increased risk among SGA infants. In addition, we found an association between SGA and sudden arrhythmic death syndrome.

Seizure-related deaths in children: The expanding spectrum

Although seizures are common in children, they are often overlooked as a potential cause of death. Febrile and nonfebrile seizures can be fatal in children with or without an epilepsy diagnosis and may go unrecognized by parents or physicians. Sudden unexpected infant deaths, sudden unexplained death in childhood, and sudden unexpected death in epilepsy share clinical, neuropathological, and genetic features, including male predominance, unwitnessed deaths, death during sleep, discovery in the prone position, hippocampal abnormalities, and variants in genes regulating cardiac and neuronal excitability. Additionally, epidemiological studies reveal that miscarriages are more common among individuals with a personal or family history of epilepsy, suggesting that some fetal losses may result from epileptic factors. The spectrum of seizure-related deaths in pediatrics is wide and underappreciated; accurately estimating this mortality and understanding its mechanism in children is critical to developing effective education and interventions to prevent these tragedies.

Evaluation of Long-term Risk of Epilepsy, Psychiatric Disorders, and Mortality Among Children With Recurrent Febrile Seizures: A National Cohort Study in Denmark

IMPORTANCE

Febrile seizures occur in 2% to 5% of children between the ages of 3 months and 5 years. Many affected children experience recurrent febrile seizures. However, little is known about the association between recurrent febrile seizures and subsequent prognosis.

OBJECTIVE

To estimate the risk of recurrent febrile seizures and whether there is an association over long-term follow-up between recurrent febrile seizures and epilepsy, psychiatric disorders, and death in a large, nationwide, population-based cohort in Denmark.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study evaluated data from all singleton children born in Denmark between January 1, 1977, and December 31, 2011, who were identified through the Danish Civil Registration System. Children born in Denmark who were alive and residing in Denmark at age 3 months were included (N = 2 103 232). The study was conducted from September 1, 2017, to June 1, 2019.

EXPOSURES

Hospital contacts with children who developed febrile seizures between age 3 months and 5 years.

MAIN OUTCOMES AND MEASURES

Children diagnosed with epilepsy were identified in the Danish National Patient Register and children diagnosed with psychiatric disorders were identified in the Psychiatric Central Research Register. Competing risk regression and Cox proportional hazards regression were used to estimate the cumulative and relative risk of febrile seizures, recurrent febrile seizures, epilepsy, psychiatric disorders, and death.

RESULTS

Of the 2 103 232 children (1 024 049 [48.7%] girls) in the study population, a total of 75 593 children (3.6%) were diagnosed with a first febrile seizure between 1977 and 2016. Febrile seizures were more common in boys (3.9%; 95% CI, 3.9%-4.0%) than in girls (3.3%; 95% CI, 3.2%-3.3%), corresponding to a 21% relative risk difference (hazard ratio, 1.21; 95% CI, 1.19-1.22). However, the risks of recurrent febrile seizures, epilepsy, psychiatric disorders, and death were similar in boys and girls. The risk of (recurrent) febrile seizures increased with the number of febrile seizures: 3.6% at birth, 22.7% (95% CI, 22.4%-23.0%) after the first febrile seizure, 35.6% (95% CI, (34.9%-36.3%) after the second febrile seizure, and 43.5% (95% CI, (42.3%-44.7%) after the third febrile seizure. The risk of epilepsy increased progressively with the number of hospital admissions with febrile seizures. The 30-year cumulative risk of epilepsy was 2.2% (95% CI, (2.1%-2.2%) at birth compared with 15.8% (95% CI, 14.6%-16.9%) after the third febrile seizure, while the corresponding estimates for risk of psychiatric disorders were 17.2% (95% CI, 17.2%-17.3%) at birth and 29.1% (95% CI, 27.2%-31.0%) after the third febrile seizure. Mortality was increased among children with recurrent febrile seizures (1.0%; 95% CI, 0.9%-1.0% at birth vs 1.9%; 95% CI, 1.4%-2.7% after the third febrile seizure), although this risk was associated primarily with children who later developed epilepsy.

CONCLUSIONS AND RELEVANCE

A history of recurrent febrile seizures appears to be associated with a risk of epilepsy and psychiatric disorders, but increased mortality was found only in individuals who later developed epilepsy.

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.

Febrile seizures: an overview

Background

Febrile seizures are the most common neurologic disorder in childhood. Physicians should be familiar with the proper evaluation and management of this common condition.

Objective

To provide an update on the current understanding, evaluation, and management of febrile seizures.

Methods

A PubMed search was completed in Clinical Queries using the key terms ‘febrile convulsions’ and ‘febrile seizures’. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews.

Results

Febrile seizures, with a peak incidence between 12 and 18 months of age, likely result from a vulnerability of the developing central nervous system to the effects of fever, in combination with an underlying genetic predisposition and environmental factors. The majority of febrile seizures occur within 24 hours of the onset of the fever. Febrile seizures can be simple or complex. Clinical judgment based on variable presentations must direct the diagnostic studies which are usually not necessary in the majority of cases. A lumbar puncture should be considered in children younger than 12 months of age or with suspected meningitis. Children with complex febrile seizures are at risk of subsequent epilepsy. Approximately 30–40% of children with a febrile seizure will have a recurrence during early childhood. The prognosis is favorable as the condition is usually benign and self-limiting. Intervention to stop the seizure often is unnecessary.

Conclusion

Continuous preventative antiepileptic therapy for the prevention of recurrent febrile seizures is not recommended. The use of intermittent anticonvulsant therapy is not routinely indicated. Antipyretics have no role in the prevention of febrile seizures.