Recent Research on Febrile Seizures: A Review

Impact of Respiratory Viruses and SARS-CoV-2 on Febrile Seizures in Saudi Children: Insights into Etiologies, Gender, and Familial Associations

BACKGROUND Childhood febrile seizures occur between 5 months and 6 years of age in children without a previous history of seizure and are associated with high temperature in the absence of intracranial infection. This retrospective study identified 71 children aged 6 months to 5 years with febrile seizures between 2017 and 2021 at a single center in Saudi Arabia and aimed to identify an association between common respiratory virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. MATERIAL AND METHODS Pediatric nasopharyngeal specimens were tested using a multiplex PCR respiratory panel detecting human coronaviruses (NL63, 229E, OC43, HKU1), influenza A/B, human adenovirus, parainfluenza viruses 1-4, respiratory syncytial virus, human metapneumovirus, rhinovirus/enterovirus, Middle East respiratory syndrome coronavirus, and, as of September 2021, SARS-CoV-2, confirmed using the Cepheid Xpert Xpress SARS-CoV2 RT-PCR kit. RESULTS In a cohort of 71 pediatric patients (median age, 19 months; 54.9% female), dominant pathogens included human rhinovirus/enterovirus (23.9%), influenza A/B (26.8%), and SARS-CoV-2 (14.1%). Concurrent infections were noted in 28.2%. Simple seizures occurred in 69%, and complex seizures in 31%. Females exhibited an 8.18-fold increased risk for complex seizures. Each additional fever day reduced complex seizure risk by 36%. Familial seizure history increased risk 8.76-fold. Human rhinovirus/enterovirus or parainfluenza infections inversely affected complex seizure likelihood compared with adenovirus. CONCLUSIONS In Saudi children with febrile seizures, distinct viral etiologies, sex, and familial links play pivotal roles. Given regional viral variations, region-tailored diagnostic and therapeutic strategies are paramount. A multicenter prospective cohort study is essential for comprehensive understanding.

Tumor Necrosis Factor Alpha (TNFα) Gene Promoter Polymorphisms and Haplotypes are Associated with the Febrile Seizure (FS) and TNFα Serum Levels

Objectives

Febrile seizure (FS) is a neuroinflammatory disease involving fever-induced seizures affecting children in the early stages of life. TNFα is a pro-inflammatory cytokine reported to be elevated in FS. Specific promoter variants of TNFα could be associated with its elevated cytokine expression and susceptibility to FS. The present study analyzed the association of specific TNFα variants, including TNFα -238 G/A (rs361525), TNFα -308 G/A (rs1800629), and TNFα -376 G/A (rs1800750) promoter polymorphisms, with FS susceptibility, and TNFα serum levels in an Iranian population.

Materials & Methods

Sixty-eight FS patients and 136 controls were enrolled. The SSP-PCR method was utilized to analyze TNFα promoter genotypes. This research also confirmed the genotyping results by sequencing samples of ten patients and normal controls.

Results

The GG genotype of -238 SNP was associated with the increased risk of FS [OR = 12.65, 95% CI (2.83-56.60), P-value = 0.0012]. The AA genotype in the-308 region was increased in patients with FS and associated with the disease [OR = 4.62, 95% CI (1.46-14.56), P-value = 0.028]. The increased occurrence of heterozygous AG in the -376 SNP among control groups has been linked to a decreased risk of FS [OR = 0.22, 95% CI (0.11-0.43), P-value = 0.0001]. This study revealed that AGA (-238/ -308/ -376) haplotype with the highest frequency in controls was associated with a decreased risk of FS, while GAA (-238/ -308/ -376) carriers were more susceptible to FS.

Conclusion

The current study suggested that TNFα gene promoter variants at rs361525, rs1800629, and rs1800750 could be associated with the susceptibility to FS and altered serum levels of TNFα.

Extracting Temporal Expressions of First Seizure Onset from Epilepsy Patient Discharge Summaries

Early onset of seizure is a potential risk factor for Sudden Unexpected Death in Epilepsy (SUDEP). However, the first seizure onset information is often documented as clinical narratives in epilepsy monitoring unit (EMU) discharge summaries. Manually extracting first seizure onset time from discharge summaries is time consuming and labor-intensive. In this work, we developed a rule-based natural language processing pipeline for automatically extracting the temporal information of patients' first seizure onset from EMU discharge summaries. We use the Epilepsy and Seizure Ontology (EpSO) as the core knowledge resource and construct 4 extraction rules based on 300 randomly selected EMU discharge summaries. To evaluate the effectiveness of the extraction pipeline, we apply the constructed rules on another 200 unseen discharge summaries and compare the results against the manual evaluation of a domain expert. Overall, our extraction pipeline achieved a precision of 0.75, recall of 0.651, and F1-score of 0.697. This is an encouraging initial result which will allow us to gain insights into potentially better-performing approaches.

Frequency and risk factors for febrile seizures during COVID-19 pandemic waves: an observational study

Febrile seizures (FS) are well-known manifestations of viral illnesses. The purpose of this study is to assess the prevalence and factors associated with FS among pediatric patients with COVID-19 admitted to the National Isolation Centre in Brunei Darussalam. All pediatric patients (< 12 years) during the first (n = 12), second (n = 418), and third (n = 219) waves were included in the study. In Brunei, the first, second, and third waves were caused by the original SARS-CoV-2, Delta, and Omicron variants, respectively. Data was extracted from a prospective database and the national electronic health record system. Patients with and without FS were compared to identify any significant risk factors. FS were only encountered in the third wave (n = 29, 13%) giving an overall prevalence of 4.5%; 24 (83%) occurring in the typical age group for FS (≥ 6 months to < 6 years). Five cases (17%) occurred in children 6 years and older. Comparing patients in the third wave, univariate analyses showed typical age group, previous history of FS, family history of FS, higher temperature (> 38.6 °C), and fewer symptoms on presentation (3 or less) were associated with FS. On multivariate analyses, typical age group, family history of FS, and fewer reported symptoms remained significant (all p < 0.05).  Conclusions: The overall prevalence of FS in COVID-19 patients is comparable to rates reported. However, in Brunei Darussalam, FS only occurred in the third wave that has been associated with Omicron variant. Younger age group, family history of FS, and fewer symptoms on presentation are correlated with risk of FS. What is Known: • Viral infections are the most common cause of FS in children. •Young age and a personal and family history of FS are correlated with the risk of FS. What is New: • There were high rates of FS (13%) among pediatric patients admitted with COVID-19 due to the Omicron variant but not with the original and Delta variants. • FS with COVID-19 were correlated with reporting fewer symptoms on presentation.

Suppressive effects of a transient receptor potential melastatin 8 (TRPM8) agonist on hyperthermia-induced febrile seizures in infant mice

Background: Febrile seizures (FSs) are the most frequent type of seizures in infancy and childhood. Epileptiform discharges (EDs) on electroencephalogram at the time of first FS recurrence can increase the risk of epilepsy development. Therefore, inhibition of EDs is important. Recently, WS-3, a transient receptor potential melastatin 8 (TRPM8) agonist, reportedly suppressed penicillin G-induced cortical-focal EDs. However, the effects of TRPM8 agonists on FSs remain unknown. In this study, we aimed to clarify the effects of the TRPM8 agonist, and the absence of TRPM8 channels, on hyperthermia-induced FS by analyzing the fast ripple band.

Methods: Hyperthermia (43°C for 30 min) induced by a heating pad caused FSs in postnatal day 7 wild-type (WT) and TRPM8 knockout (TRPM8KO) mice. FSs were defined as EDs occurring during behavioral seizures involving hindlimb clonus and loss of the righting reflex. Mice were injected with 1% dimethyl sulfoxide or 1 mM WS-3 20 min before the onset of hyperthermia, and electroencephalograms; movies; and rectal, brain and heating pad temperatures were recorded.

Results: In wild-type mice, WS-3 reduced the fast ripple amplitude in the first FS without changing rectal and brain temperature thresholds. In contrast, the anti-FS effect induced by the TRPM8 agonist was not observed in TRPM8KO mice and, compared with wild-type mice, TRPM8 deficiency lowered the rectal and brain temperature thresholds for FSs, exacerbated the fast ripple amplitude, and prolonged the duration of the initial FS induced by hyperthermia.

Conclusion: Our findings suggest that TRPM8 agonists can be used to treat hyperthermia-induced FSs.

Augmented impulsive behavior in febrile seizure-induced mice

Febrile seizure (FS) is one of the most prevalent etiological events in childhood affecting 2-5% of children from 3 months to 5 years old. Debates on whether neurodevelopmental consequences rise in later life following a febrile seizure or not are still ongoing however there is limited evidence of its effect, especially in a laboratory setting. Moreover, the comparative study using both male and female animal models is sparse. To examine the effect of FS on the behavioral features of mice, both sexes of ICR mice were induced with hyperthermic seizures through exposure to an infrared heat lamp. The mice were divided into two groups, one receiving a single febrile seizure at postnatal day 11 (P11) and one receiving three FS at P11, P13, and P15. Starting at P30 the FS-induced mice were subjected to a series of behavioral tests. Mice with seizures showed no locomotor and motor coordination deficits, repetitive, and depressive-like behavior. However, the FS-induced mice showed impulsive-like behavior in both elevated plus maze and cliff avoidance tests, which is more prominent in male mice. A greater number of mice displayed impaired CAT in both males and females in the three-time FS-induced group compared to the single induction group. These results demonstrate that after induction of FS, male mice have a higher susceptibility to consequences of febrile seizure than female mice and recurrent febrile seizure has a higher chance of subsequent disorders associated with decreased anxiety and increased impulsivity. We confirmed the dysregulated expression of impulsivity-related genes such as 5-HT1A and tryptophan hydroxylase 2 from the prefrontal cortices of FS-induced mice implying that the 5-HT system would be one of the mechanisms underlying the increased impulsivity after FS. Taken together, these findings are useful in unveiling future discoveries about the effect of childhood febrile seizure and the mechanism behind it.

Neurological and neurodevelopmental symptoms in children with familial Mediterranean fever and their siblings

Familial Mediterranean fever is a common autoinflammatory disease characterized by periodic attacks of fever and serositis. There are few reports describing neurological symptoms in patients with FMF. The aim of this study was to systematically assess the neurologic and developmental involvement in pediatric patients with FMF. Between the years 2016 and 2019, parents of children with FMF were asked to complete a questionnaire regarding the presence of neurological and developmental symptoms in their children with and without FMF. Demographic data, clinical characteristics, and disease course of FMF patients were collected from the medical charts. Neurodevelopmental manifestations were compared between the children with FMF and their siblings. A total of 205 children were enrolled (11.6 ± 4.7 years of age): 111 children with FMF and 94 healthy siblings in the control group. Neurological morbidity was frequently reported in children with FMF: 44 (40%) had recurrent headaches, 31 (28%) ADHD symptoms, 27 (24%) learning disabilities, and 10 (9%) febrile convulsions. Headaches and febrile convulsions were significantly more prevalent in children with FMF as compared to their siblings (ps < 0.05). ADHD and learning disabilities were associated with poor adherence to colchicine treatment.Conslusions: The present study found an increased prevalence of ADHD, learning disabilities, headaches, and febrile seizures in children with FMF. The findings underscore the importance of addressing the neurodevelopmental domain in children with FMF. In addition, detection and treatment of ADHD and learning disabilities could improve adherence with therapy and control of the underlying disease. What is Known: • Familial Mediterranean fever (FMF) is the most common inherited auto-inflammatory disease, characterized by recurrent attacks of fever, serositis, and arthritis. • Some previous case reports also described rare neurological manifestations in children with FMF. What is New: • The study found an increased prevalence of headaches, febrile seizures, ADHD, and learning disabilities, in children with FMF. • The findings underscore the importance of addressing the neurological domain in this population, which could potentially improve adherence with therapy and control of the underlying disease.

Evaluation of Patients Presenting With First Febrile Seizure

Introduction

Febrile seizure (FS) is the most common cause of convulsion in children. In the present study, we evaluated patients presenting with FS.

Methods

Eighty-two patients aged between 6-60 months who presented to Mersin City Training and Research Hospital with the first febrile seizure between January 2020 and May 2021 were included in the study.

Results

Of the 82 patients included in our study, 42 (51,2%) were male and 40 were female (48,8%). Their average age at presentation of first febrile seizure was 21,05 ± 16,22 months. Fever focus was found in 32 patients (39,1%) with upper respiratory tract infection. Epileptic abnormality was observed in the EEG of six patients (7,3%) and antiepileptic medication was started in three of these patients.

Conclusions

Upper respiratory tract infection, family history of FS, and family history of epilepsy are the main risk factors for the development of FS. Complex FS is a serious risk factor for the development of epilepsy.

Brain Perfusion, Hippocampal Volumetric, and Diffusion-weighted Imaging Findings in Children with Prolonged Febrile Seizures and Focal Febrile Seizures

Background:

The current study was conducted to describe the findings of brain perfusion, hippocampal volumetric, and diffusion-weighted imaging (DWI) in children aged six months to seven years with febrile status epilepticus (FSE) and focal febrile seizures (FFS) when compared with age and gender-matched controls.

Materials and Methods:

This cross-sectional study was conducted among children aged six months to seven years presenting with FSE or FFS within 72 h of the seizure. Cases were subjected to magnetic resonance imaging (MRI) brain and sleep-deprived electroencephalography. Age and gender-matched children who were subjected to MRI brain for nonepileptic indications served as their control. Hippocampal volumes, T2 values, cerebral blood flow, and diffusion characteristics were compared between the cases and controls and also between those with FSE and FFS.

Results:

A total of 31 cases (FFS = 20, FSE = 11) and 30 controls were enrolled. There was no significant difference between right and left hippocampal volumes and T2 relaxometry values between cases and controls and also between children with FSE and FFS. Similarly, the cerebral blood flow was also comparable in cases and controls. There was a single case of FSE with hippocampal malrotation; one child showed diffusion restriction in the hippocampus after prolonged (>60 min) FSE.

Conclusion:

Children with FSE and FFS had comparable hippocampal volume and brain perfusion to healthy children. However, one child with FSE had hippocampal malrotation and another had diffusion restriction. The study findings need to be interpreted in the context of small sample size, and lack of follow-up neuroimaging.

Seasonal distribution of febrile seizure and the relationship with respiratory and enteric viruses in Korean children based on nationwide registry data

PURPOSE

The seasonal distribution patterns of febrile seizures and of respiratory and enteric viral pathogens are similar. In this study, we analyzed trends in febrile seizures and viral infection in Korean children, using big data from the Korean Health Insurance Review and Assessment Service (HIRA).

METHODS

We analyzed children younger than 6 years who visited the hospital and were diagnosed with febrile seizures from 2009 to 2016, using medical records in the HIRA database. A total of 666,136 medical records of children with a main or subdiagnosis of febrile seizure from 2008 to 2016 were included. Of these records, patients younger than 1 month and records before 2009 were excluded. Finally, 558,130 records were extracted.

RESULTS

The medical records included 315,774 male children and 242,356 (43.4%) female children, with a mean age of 2.31 ± 1.31 years. The annual incidence of febrile seizure was 25.4 per 1000 person-years (27.9 for boys and 22.7 for girls). The ratio of male to female children was 1.30: 1, and records of 1-year-old children comprised the highest proportion (n = 210,400, 33.70%). The total monthly number of patients was highest in May (n = 64,969, 11.6%), and peaks were formed from April to July. The fewest patients were seen in October (n = 34,424, 6.17%). The most common viral pathogens were influenza in April and enterovirus during May-July.

CONCLUSION

The seasonal distribution of febrile seizures was high from late spring to summer, and influenza virus and enterovirus were most frequently associated.

Cost-Effectiveness Analysis of Topiramate versus Phenobarbital in the Treatment of Children with Febrile Seizure

OBJECTIVES

Febrile seizure is common disorder in childhood, with a prevalence of 2% to 5%. There are many drugs for treatment of this disease; however, the most common prescribed medication in Iran is phenobarbital that is cheap, but it has many side effects. We aimed to compare the cost-effectiveness of topiramate versus phenobarbital in patients with febrile seizure in the south of Iran.

MATERIALS & METHODS

This econometric cost-effectiveness and cost-utility study were conducted on 91 patients with febrile seizure to assess two strategies of oral drug therapy including phenobarbital and topiramate in 2016-2017. Of all, 51 patients were treated with phenobarbital and 40 patients received topiramate. We followed up the patients for six months, using a randomized and single-blinded approach. A decision tree model was used. The outcomes of the model included febrile seizure and utility. The study was conducted from the perspective of the community; therefore, direct and indirect costs were included in the study. Excel and Tree Age software (2011) were used to analyze the results.

RESULTS

Topiramate was cheaper and more effective than phenobarbital. In patients in the phenobarbital and topiramate groups, the mean costs were $740 and $674 per PPP, utility scores were 0.72 and 0.82, and febrile seizure without side effects were 0.3 and 0.6, respectively. Moreover, one-way sensitivity analysis confirmed the robustness of the results of the study.

CONCLUSION

Topiramate in patients with febrile seizure is a fully cost-effective and cost-efficient strategy suggested as a better alternative for children with febrile seizure.

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.

Prevalence, Incidence, and Recurrence of Febrile Seizures in Korean Children Based on National Registry Data

Background and Purpose

Febrile seizures (FS) are the most common type of seizure during childhood, reportedly occurring in 2–5% of children aged 6 months to 5 years. However, there are no national data on the prevalence of FS in Korea. This study determined the prevalence, incidence, and recurrence rates of FS in Korean children using national registry data.

Methods

The data were collected from the Korea National Health Insurance Review and Assessment Service for 2009–2013. Patients with febrile convulsion as their main diagnosis were enrolled. The overall prevalence of FS in more than 2 million children younger than 5 years was estimated, and the incidence and recurrence rates of FS were determined for children born in 2009.

Results

The average prevalence of FS in children younger than 5 years based on hospital visit rates in Korea was 6.92% (7.67% for boys and 6.12% for girls). The prevalence peaked in the second to third years of life, at 27.51%. The incidence of FS in children younger than 5 years (mean 4.5 years) was 5.49% (5.89% for boys and 5.06% for girls). The risk of first FS was highest in the second year of life. The overall recurrence rate was 13.04% (13.81% for boys and 12.09% for girls), and a third episode of FS occurred in 3.35%.

Conclusions

Our study determined the overall prevalence of FS using data for the total population in Korea. The prevalence was comparable to that reported for other countries. Patients with three episodes of FS need to be monitored carefully.

Cumulative Incidence of Seizures and Epilepsy in Ten-Year-Old Children Born Before 28 Weeks' Gestation

OBJECTIVE

We evaluated the incidence of seizures and epilepsy in the first decade of life among children born extremely premature (less than 28 weeks' gestation).

METHOD

In a prospective, multicenter, observational study, 889 of 966 eligible children born in 2002 to 2004 were evaluated at two and ten years for neurological morbidity. Complementing questionnaire data to determine a history of seizures, all caregivers were interviewed retrospectively for postneonatal seizures using a validated seizure screen followed by a structured clinical interview by a pediatric epileptologist. A second pediatric epileptologist established an independent diagnosis based on recorded responses of the interview. A third epileptologist determined the final diagnosis when evaluators disagreed (3%). Life table survival methods were used to estimate seizure incidence through ten years.

RESULTS

By age ten years, 12.2% (95% confidence interval: 9.8, 14.5) of children had experienced one or more seizures, 7.6% (95% confidence interval: 5.7, 9.5) had epilepsy, 3.2% had seizure with fever, and 1.3% had a single, unprovoked seizure. The seizure incidence increased with decreasing gestational age. In more than 75% of children with seizures, onset was after one year of age. Seizure incidence was comparable in both sexes. Two-thirds of those with epilepsy had other neurological disorders. One third of children with epilepsy were not recorded on the medical history questionnaire.

SIGNIFICANCE

The incidence of epilepsy through age ten years among children born extremely premature is approximately 7- to 14-fold higher than the 0.5% to 1% lifetime incidence reported in the general pediatric population. Seizures in this population are under-recognized, and possibly underdiagnosed, by parents and providers.

Febrile Convulsion among Hospitalized Children Aged Six Months to Five Years and Its Association With Haemoglobin Electrophoretic Pattern

Background

Febrile convulsion and sickle cell disease are common in tropical countries and both are associated with significant morbidity and mortality. Worldwide, Nigeria has the highest prevalence of sickle cell disease. However, there is a dearth of knowledge on the haemoglobin electrophoresis in patients with febrile convulsions.

Methods

This was a hospital based, descriptive, cross-sectional study of the relationship between haemoglobin genotype and febrile convulsion at the University of Ilorin Teaching Hospital over a period of 12 months. A self-designed pretested questionnaire was administered on the subjects, and necessary examinations and investigations were conducted.

Results

Of a total of 1675 children admitted into the emergency paediatric unit during the study period, children aged 6 months–5 years that presented with febrile convulsions were 167(10%). Of this, 1,212 were aged 6 months–5 years. Thus, the age specific, hospital-based prevalence was 13.8%. The M:F was 1.1:1. Their Haemoglobin genotype distribution was AA 131(78.4%), AS 23(13.8%), AC 6(3.6%), SS 6(3.6%), and 1(0.6%) SC. The mean age of the sickle cell disease patients was higher at 46.0±13.5 months compared to 29.2±15.4 months in the non-sickle cell disease patients (p=0.005). The mean packed cell volume in subjects with sickle cell anaemia was 8.8±1.5%; the only case of haemoglobin SC had packed cell volume of 20%, while the non-sickle cell disease patients had a normal PCV. Malaria was present in 80.4% of them.

Conclusion

Febrile convulsion remains a common cause of hospitalisation. It is uncommon in haemoglobin SS where severe anaemia is always an accompanying derangement. The packed cell volume is nearly normal in children with normal haemoglobin genotype.