Fever-Associated Seizures or Epilepsy: An Overview of Old and Recent Literature Acquisitions

Best practices for the management of febrile seizures in children

Febrile seizures (FS) are commonly perceived by healthcare professionals as a self-limited condition with a generally 'benign' nature. Nonetheless, they frequently lead to pediatric consultations, and their management can vary depending on the clinical context. For parents and caregivers, witnessing a seizure can be a distressing experience, significantly impacting their quality of life. In this review, we offer an in-depth exploration of FS management, therapeutic interventions, and prognostic factors, with the aim of providing support for physicians and enhancing communication with families. We conducted a comprehensive literature search using the PubMed and Web of Science databases, spanning the past 50 years. The search terms utilized included "febrile seizure," "complex febrile seizure," "simple febrile seizure," in conjunction with "children" or "infant." Only studies published in English or those presenting evidence-based data were included in our assessment. Additionally, we conducted a cross-reference search to identify any additional relevant data sources. Our thorough literature search resulted in a compilation of references, with carefully selected papers thoughtfully integrated into this review.

Febrile seizures and convulsions with mild gastroenteritis: age-dependent acute symptomatic seizures

Background

Febrile seizures (FS) and benign convulsions in children with mild gastroenteritis (CwG) are acute symptomatic seizures, transiently occurring in infants and young children, probably related to the immaturity of the brain. Our paper aims to review the literature data on patients with FS and CwG.

Methods

A review of series of patients with FS and CwG was performed by literature search on PubMed January 1960 to October 2022. Several parameters were considered, including epidemiology, pathophysiology, clinical features, electroencephalographic findings and other diagnostic studies, and treatment.

Results

FS and CwG share an age-dependent course, but they show significant differences in the pathophysiology, clinical features, diagnostic studies, and treatment.

Conclusion

Acute symptomatic seizures include seizures that are caused by acute structural brain pathologies, such as stroke, as well as seizures that are provoked by a reversible factor, such as hyponatraemia, although the two groups should be not equated. Furthermore, FS and CwG should be set apart as "age-dependent acute symptomatic seizures", reinforcing the concept of their self-limited course over a certain period.

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.

Febrile infection-related Epilepsy Syndrome (FIRES): a severe encephalopathy with status epilepticus. Literature review and presentation of two new cases

FIRES is defined as a disorder that requires a prior febrile infection starting between 2 weeks and 24 h before the onset of the refractory status epilepticus with or without fever at the onset of status epilepticus. The patients, previously normal, present in the acute phase recurrent seizures and status epilepticus followed by a severe course with usually persistent seizures and residual cognitive impairment. Boundary with "new onset refractory status epilepticus (NORSE) has not clearly established. Pathogenetic hypothesis includes inflammatory or autoimmune mechanism with a possible genetic predisposition for an immune response dysfunction.Various types of treatment have been proposed for the treatment of the acute phase of the disorder to block the rapid seizures evolution to status epilepticus and to treat status epilepticus itself. Prognosis is usually severe both for control of the seizures and for cognitive involvement.FIRES is an uncommon but severe disorder which must be carefully considered in the differential diagnosis with other epileptic encephalopathy.

Respiratory Syncytial Virus: An Uncommon Cause of Febrile Seizures-Results from a Systematic Review and Meta-Analysis

Human Respiratory Syncytial Virus (RSV) is a highly contagious viral pathogen. In infants, it is usually listed among the main causes of medical referrals and hospitalizations, particularly among newborns, and a considerable base of evidence associates RSV infections and bronchiolitis with long-term neurological sequelae. We specifically performed a systematic review and meta-analysis in order to ascertain whether RSV infections may be associated with an increased risk for febrile seizures (FS) in infected infants. According to the PRISMA statement, Pubmed, Embase, and pre-print archive medRxiv.og were searched for eligible observational studies published up to 1 July 2022. Raw data included the incidence of FS among children admitted for influenza-like illness (ILI) and/or bronchiolitis, with a confirmed diagnosis of RSV or seasonal influenza virus (SIV) infection. Data were then pooled in a random-effects model. Heterogeneity was assessed using the I² measure, while reporting bias was assessed by means of funnel plots and regression analysis. A total of 11 studies including 6847 cases of RSV infections were retrieved, with a pooled prevalence of 29.975 cases of FS per 1000 RSV cases (I² = 88.5%). The prevalence was not substantially greater in studies performed in pediatric intensive care units (53.817 per 1000 RSV cases vs. 23.552, p = 0.12). Higher occurrence of FS was reported from studies performed after 2010 (Risk Ratio [RR] 1.429, 95% Confidence Interval [95%CI] 1.049-1.948), and in China (RR 2.105, 95%CI 1.356-3.266) and South Africa (RR 1.722, 95%CI 1.060-2.824) than in Europe, while a lower occurrence was reported form the USA (RR 0.414, 95%CI 0.265-0.649). Eventually, FS were less likely reported from RSV cases compared to subjects affected by seasonal influenza (RR 0.402; 95%CI 0.228-0.708). Although RSV is often associated with high risk of neurological complications, substantially less cases of FS are reported than in SIV infections. However, the paucity of available studies recommends a cautious appraisal of aforementioned results.