Pathogenetic and etiologic considerations of febrile seizures

BBB proteomic analysis reveals that complex febrile seizures in infancy enhance susceptibility to epilepsy in adulthood through dysregulation of ECM-receptor interaction signaling pathway

BACKGROUND

Complex febrile seizures (CFS) have been associated with an increased risk of epilepsy in adulthood. However, the specific link between blood-brain barrier (BBB) and the predisposition to epilepsy in adults who experienced CFS during infancy remains unclear. The objective of this study was to investigate the alteration of BBB in adult mice who had experienced CFS during infancy, and to explore the mechanisms of increased susceptibility to epilepsy after CFS.

METHODS

The CFS pup model was induced using hot air, and the seizure susceptibility was examined using low-dose pentylenetetrazole (PTZ) after 8 W. The brain microvessels representing BBB function were isolated and their protein expression changes were analyzed using data-independent acquisition (DIA) proteomic techniques. Subsequently, the bioinformatic analyses were performed using ClusterProfiler, STRING, Gene Set Enrichment Analysis (GSEA), etc. The enriched pathways, changes in the expression of BBB-related proteins, and alterations in metabolites including certain neurotransmitters were subsequently validated by Western Blotting, quantitative real-time polymerase chain reaction (qRT-PCR), and mass spectrometric imaging (MSI). In addition, we selected the MMP inhibitor Incyclinide to verify that dysregulation of the ECM-receptor interaction signaling pathway increases epilepsy susceptibility in adult mice.

RESULTS

Mice that experienced CFS in infancy show increased susceptibility to epilepsy in adulthood, and BBB proteomic profile was significantly altered in the CFS mice. The network analysis suggests that dysregulation of the extracellular matrix (ECM)-receptor interaction pathway is a key mechanism. Moreover, MSI analysis uncovered notable changes in differential metabolites, including amino acids and nucleotide-derived neurotransmitters associated with the function of BBB maintaining neuronal homeostasis. Subsequent validation experiments showed that dysregulation of the ECM-receptor interaction signaling pathway exacerbated epilepsy susceptibility in adult mice.

CONCLUSION

Our research represents the pioneering demonstration of the modified BBB proteomics associated with epilepsy susceptibility in adult mice previously exposed to CFS in infancy. Notably, the increased susceptibility is attributed to the dysregulation of the ECM-receptor interaction pathway. These findings may help to elucidate the role of BBB alterations in the progression of epilepsy susceptibility, and provide new orientations for subsequent prevention and treatment of epilepsy.

Identification of Genetic Variants in Status Epilepticus Associated With Fever

PURPOSE

Status epilepticus associated with fever (SEF) is often encountered in pediatric emergency departments, and some patients develop neurological emergencies, such as acute encephalopathy (AE). Although numerous genetic variants of developmental and epileptic encephalopathy (DEE) have been reported, the frequency of these disease-associated variants of SEF is unknown. The first aim of this study was to investigate the associated genetic variants of SEF. The second aim was to compare the variations in genes between SEF and DEE.

METHOD

This retrospective, clinical observational study included patients with SEF or DEE who visited Kobe University Hospital or Kobe University affiliated hospitals and provided consent for a genetic diagnosis of SEF or DEE between January 1, 2021, and December 31, 2022.

FINDING

Fifteen patients with SEF and 27 patients with DEE consented to a genetic diagnosis and were included in the study. The detection rate of genetic variants was lower in patients with SEF (26.7%) than in those with DEE (63.0%), although there is no statistically significant difference (p = 0.05, Fisher's exact test). Analysis of patients with DEE revealed a wide variety of causative genes for DEE (16 different genes), whereas in SEF cases, only SCN1A variants were detected.

CONCLUSION

Our study is the first to clarify the detection rates of different genetic variants in SEF. Patients with SEF may have less genetic involvement in the onset of epileptic seizures, compared to those with DEE.

Research progress on pathogenesis and treatment of febrile seizures

Febrile seizures (FSs) are the most common pediatric neurological disorder, affecting approximately 5 % of children aged 6 months to 5 years. While most FSs are self-limiting and benign, about 20-30 % present as complex FSs (CFSs), which pose a risk of acute brain injury and the development of temporal lobe epilepsy. Various factors, including age, geographical distribution, and type of infection influence the occurrence of FS. Infection is the primary external trigger for FS, while the underlying intrinsic factors are linked to the immature and incomplete myelination of the brain during specific developmental stages. Although the precise pathogenesis of FS is not yet fully understood, it is likely caused by the interaction of immature brain development, fever, neuroinflammation, and genetic susceptibility. This review discussed the pathogenesis of febrile seizures, focusing on factors such as age, fever, neuroinflammation, genetics, and intestinal microbiota, and summarized existing therapeutic approaches. Our review may facilitate the identification of new targets for mechanistic studies and clinical treatment of febrile seizures.

Frequency and characteristics of seizures precipitated by febrile urinary tract infections in neonates and infants

BACKGROUND

A febrile urinary tract infection (UTI) is a minor febrile seizure (FS) determinant. Seizures precipitated by febrile UTIs in neonates and infants frequently surprise parents, as they are vulnerable to bacterial meningitis and younger than the usual ages of FS. However, their frequency and characteristics are relatively unknown.

METHODS

This study screened 1059 children (≤12 months) with febrile UTIs admitted to Chonnam National University Children's Hospital from January 2015 to June 2023. Patients with seizures precipitated by febrile UTIs were enrolled, and their medical records were reviewed. The frequency and clinical characteristics of seizures effectuated by febrile UTIs were investigated by comparing FS, FS+, and afebrile seizure (aFS).

RESULTS

Twenty-eight patients (2.6%) were enrolled: 19 with early-onset FS+ (2.3% of 814 patients <6 months), nine with FS (3.7% of 245 patients), but there were none with aFS. Acute pyelonephritis was found in 80.8% of 26 patients. Clustered seizures (47.4% vs. 22.2% in FS, P = 0.197) and complex types (73.7% vs. 22.2%; P = 0.015) were frequent in early-onset FS+. Among 42 seizure episodes, bilateral tonic seizures were noted only in FS+ (44.8%; P = 0.001), but bilateral tonic-clonic seizures were frequent in FS (69.2% vs. 27.6%; P = 0.011).

CONCLUSION

Seizures precipitated by febrile UTIs occurred in 2.6% of neonates and infants: all were febrile and were predominantly with acute pyelonephritis. Infantile FS characteristics of febrile UTIs resembled those of usual FS, whereas early-onset FS + differed significantly as usually occurring in complex types and bilateral tonic ones.

Effect of environmental exposome and influenza infection on febrile seizure in children over 22 years: a time series analysis

Febrile seizures are convulsions predominately occurring in young children. The effects of various exposomes, including influenza infection and external environmental factors, on febrile seizures have not been well-studied. In this study, we elucidated the relationships between ambient temperature, air pollutants, influenza infection, and febrile seizures using 22-year territory-wide hospitalization data in Hong Kong. The aggregated data were matched with the meteorological records and air pollutant concentrations. All-type and type-specific influenza-like illness positive (ILI+) rates were used as proxies for influenza activity. Distributed lag non-linear model in conjunction with the quasi-poisson generalized additive model was used to examine the associations of interest. According to the results, all-type influenza infections were significantly associated with an increased risk of hospital admissions for febrile seizures (cumulative adjusted relative risk [ARR] = 1.59 at 95th percentile vs. 0; 95% CI, 1.51-1.68). The effect of ILI + A/H3N2 on febrile seizure was more pronounced than other type-specific ILI + rates. A low mean ambient temperature was identified as a significant risk factor for febrile seizures (cumulative ARR = 1.50 at 5th percentile vs. median; 95% CI, 1.35-1.66), while the redox-weighted oxidant capacity and sulfur dioxide were not associated with febrile seizures. In conclusion, our study underscores that influenza infections and exposure to cold conditions were related to an increased risk of febrile seizures in children. Thus, we advocate for influenza vaccination before the onset of the cold season for children to mitigate the burden of febrile seizures.

A preliminary study on the association between prognostic nutritional index and neutrophil-to-lymphocyte ratio with nutritional status and inflammation in febrile children's susceptibility to seizures

OBJECTIVE

The aim of this study was to evaluate the association between nutritional status, inflammation, and susceptibility to seizures in febrile children.

METHODS

This observational single-center study was carried out from January 2020 to December 2023 with 324 children aged 6 months and 6 years; 106 were diagnosed with febrile seizure, 108 were febrile children, and 110 were healthy controls. The prognostic nutritional index and neutrophil-to-lymphocyte ratio were calculated, and the cutoff threshold was established through receiver operating characteristics. The study utilized correlation and univariate-multivariate logistic regression analysis. The comparison between simple and complex febrile seizure was conducted to analyze differences.

RESULTS

The optimal cutoff values were identified as 61.25 for prognostic nutritional index and 1.04 for neutrophil-to-lymphocyte ratio. Our findings showed a significant negative association between febrile seizure and platelet count, high C-reactive protein, and high ferritin levels. Additionally, the febrile seizure group showed a significant positive correlation with high neutrophil-to-lymphocyte ratio values (≥1.04) and body temperature (≥38). Our findings revealed that high neutrophil-to-lymphocyte ratio, high C-reactive protein, and age less than 18 months were independently associated with seizure susceptibility in febrile children.

CONCLUSION

High neutrophil-to-lymphocyte ratio values and low prognostic nutritional index scores may serve as novel surrogate independent factors for seizure susceptibility in febrile children. Febrile children who are less than 18 months old are more prone to experience seizures than older febrile children. Moreover, there was a correlation between febrile seizures and elevated C-reactive protein levels and neutrophil-to-lymphocyte ratio values.

Serum HMGB1 in febrile seizures

The role of high-mobility group box 1 (HMGB1) in the pathogenesis of febrile seizures (FSs) is unclear. In our controlled follow-up study, we compared serum levels of HMGB1 (s-HMGB1) in the same individuals after the first FS, during febrile episodes without a FS, after recurrent FS, during healthy periods after FS, and between patients and controls. In all, 122 patients with FSs were included in the final analysis, including 18 with recurrent FSs with a complete follow-up protocol. We recruited 30 febrile children and 18 matched febrile children without seizures as controls. S-HMGB1 was lower in patients with recurrent FSs after the first FS than that in matched febrile control children (median 1.12 μg/L (0.14-2.95) vs 1.79 μg/L (0.33-47.90), P<0.04). We did not find any other differences in s-HMGB1 between the groups. S-HMGB1 did not differ in different types of FSs. We updated a meta-analysis of s-HMGB1 in patients with FSs and found that the differences were significant only in the studies conducted in East Asian populations. We conclude that S-HMGB1 does not seem to be a key factor in the pathogenesis of FSs but differences in HMGB1 concentrations could explain some of the ethnicity related susceptibility to FSs.

Determinants of neonatal seizure among neonates admitted to neonatal intensive care units in the Awi Zone hospitals, 2023: A multi-center unmatched case control study

Background

Neonatal seizure is a common medical emergency that signals severe insult to the neonatal brain. It is a major risk factor for neonatal morbidity and mortality. It has a wide worldwide variation, ranging from 5 per 1000 live births in the United States of America to 39.5 per 1000 live births in Kenya. To decrease this significant figure, it is better to investigate its causes further. Therefore, this study aimed to assess its determinants since there was no prior evidence about it in the context of study area.

Objective

Aim to assess the determinants of neonatal seizures among neonates admitted to neonatal intensive care units in the Awi Zone Hospitals, 2023.

Methods

An institution based unmatched case-control study was conducted on 531 admitted eligible neonates from January 1, 2023, to May 30, 2023. A pretested tool was employed to collect data. The collected data were coded, edited, and entered into Epi-data version 3.1 and then exported to SPSS 26. Chi-square and odds ratios were used to assess the relationship between factors associated with the occurrence of neonatal seizure. Model goodness of fit was tested by Hosmer and Lemeshow. Bivariate and multivariate analysis was declared at P < 0.25 and P < 0.05 respectively to show a significant association with neonatal seizure at a 95 % level of significance.

Results

A total of 506 (130 cases and 376 controls) of admitted neonates were used in the final analysis model. Neonates admitted within 24 h of birth [AOR; 5.98 (95 %, CI: 2.18-16.43)], gestational age <32 weeks [AOR; 2.89 (95 %, CI: 1.29-6.53)], body temperature >37.5 °C [AOR; 4.82 (95 %, CI: 1.82-12.76)], blood glucose level <40 g/dl [AOR; 4.95 (95 %, CI: 2.06,11.88)], neonatal sepsis [AOR; 2.79 (95 %, CI: 1.46-5.35)] and perinatal asphyxia [AOR; 8.25 (95 %, CI: 4.23, 16.12)] were found to be determinants of neonatal seizure.

Conclusion

and recommendations: In this study, neonatal seizure was determined by the factors of neonatal age, gestational age<32 weeks, body temperature >37.5 °C, blood glucose level <40 g/dl, neonatal sepsis, and perinatal asphyxia. Therefore, the presence of such factors requires prompt recognition and treatment.

Febrile Seizures: A Systematic Review of Different Guidelines

BACKGROUND

Febrile seizures (FS) are the most common neurological disorder in pediatric age. FS affect 2% to 12% of children and result from a complex interplay of genetic and environmental factors. Effective management and unambiguous recommendations are crucial for allocating health care resources efficiently and ensuring cost-effectiveness in treating FS.

METHODS

This systematic review compares existing guidelines to provide insights into FS management. Seven guidelines published between 1991 and 2021, from Japan, United Kingdom, United States, Mexico, India, and Italy, were included. Data extraction covered definitions, diagnostic criteria, hospital admission criteria, diagnostic tests, management, and prophylaxis recommendations.

RESULTS

Hospital admission criteria varied but typically included age <18 months and complex FS. Neuroimaging and lumbar puncture recommendations varied, with most guidelines suggesting limited use. Pharmacologic prophylaxis was generally discouraged for simple FS but considered only for high-risk cases, due to the benign nature of FS and the potential side effects of antiseizure medications.

CONCLUSIONS

Guidelines on FS exhibit similarities and differences, highlighting the need for standardized management and improved parental education to enhance clinical outcomes and reduce economic and social costs associated with FS. Future research should focus on creating updated international guidelines and ensuring their practical implementation.

[Clinical features of children with febrile seizures caused by Omicron variant infection]

OBJECTIVES

To study the clinical features of children with febrile seizures after Omicron variant infection.

METHODS

A retrospective analysis was performed on the clinical data of children with febrile seizures after Omicron variant infection who were admitted to the Department of Neurology, Children's Hospital Affiliated to the Capital Institute of Pediatrics, from December 1 to 31, 2022 (during the epidemic of Omicron variant; Omicron group), and the children with febrile seizures (without Omicron variant infection) who were admitted from December 1 to 31, in 2021 were included as the non-Omicron group. Clinical features were compared between the two groups.

RESULTS

There were 381 children in the Omicron group (250 boys and 131 girls), with a mean age of (3.2±2.4) years. There were 112 children in the non-Omicron group (72 boys and 40 girls), with a mean age of (3.5±1.8) years. The number of children in the Omicron group was 3.4 times that in the non-Omicron group. The proportion of children in two age groups, aged 1 to <2 years and 6-10.83 years, in the Omicron group was higher than that in the non-Omicron group, while the proportion of children in two age groups, aged 4 to <5 years and 5 to <6 years, was lower in the Omicron group than that in the non-Omicron group (P<0.05).The Omicron group had a significantly higher proportion of children with cluster seizures and status convulsion than the non-Omicron group (P<0.05). Among the children with recurrence of febrile seizures, the proportion of children aged 6-10.83 years in the Omicron group was higher than that in the non-Omicron group, while the proportion of children aged 3 years, 4 years, and 5 years in the Omicron group was lower than that in the non-Omicron group (P<0.05).

CONCLUSIONS

Children with febrile seizures after Omicron variant infection tend to have a wider age range, with an increase in the proportion of children with cluster seizures and status convulsion during the course of fever.