Connaissances actuelles sur les mécanismes physiopathologiques des convulsions fébriles

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.

[AFSSAPS 2005 recommendations have not modified the way parents take care of children's fever]

INTRODUCTION

Fever in children is frequent. Often mild, initial care is the parents' responsibility: medicinal treatments and medical consultations. Unfortunately, the efficiency of parental care is poor. Therefore, in 2005 the AFSSAPS updated its recommendations. One and 6 years after publication of the guidelines, this study rates their impact by describing and comparing parents' knowledge and behavior when faced with fever in their children.

MATERIAL AND METHODS

This survey was conducted in families whose children were attending preschool in and near Metz (France) in 2006 and 2012. The same questionnaire was given to assess the knowledge, care, and symptoms of serious fever. The results were processed based on the number of children in the family and the family's socioeconomic category.

RESULTS

In 2006, 1038 questionnaires were distributed and 1273 in 2012. The fever threshold was not better known in 2012. Bathing and uncovering children remained the predominant physical methods used. Treatment was based on the use of ibuprofen and alternating treatments. However, the conditions of administering medication were well known to parents. The causes and motives for consultation were not better understood in 2012 however. The main source of information was physicians.

DISCUSSION

The message disseminated since 2005 has not been efficient. Its complexity has not eradicated old beliefs and inappropriate parental practices. A campaign based on a brief, simple message has to be organized, providing better chances of being assimilated by the public. Medical practices should be standardized.

Inflammation and epilepsy in the developing brain: clinical and experimental evidence

There is an increasing evidence to support a role of inflammatory processes in epilepsy. However, most clinical and experimental studies have been conducted in adult patients or using adult rodents. The pediatric epilepsies constitute a varied group of diseases that are most frequently age specific. In this review, we will focus on the possible role of inflammation in pediatric epilepsy syndromes. We will first describe the clinical data available and provide an overview of our current understanding of the role of inflammation in these clinical situations. We will then review experimental data regarding the role of inflammation in epilepsy in the developing brain. To summarize, inflammation contributes to seizure precipitation, and reciprocally, prolonged seizures induce inflammation. There is also a relationship between inflammation and cell injury following status epilepticus, which differs according to the developmental stage. Finally, inflammation seems to contribute to epileptogenesis even in the developing brain. Based on the available data, we highlight the need for further studies dissecting the exact role of inflammation in epilepsy during development.

Relationship between common viral upper respiratory tract infections and febrile seizures in children from Suzhou, China

This study aimed to determine the potential predisposing factors for the development of febrile seizures among children with upper respiratory tract infection in the eastern Chinese region. Participants were individuals aged 6 months and 6 years (n = 189) who were diagnosed with febrile seizure, complicated with upper respiratory tract infection, and 174 age-matched children who had upper respiratory tract infection without seizures as controls. The viral antigens including influenza A and B, parainfluenza, adenovirus, and respiratory syncytial virus were detected from nasopharyngeal aspirates. The incidence of influenza A infection was much higher in patients with febrile seizure than controls, especially those children aged >36 months. Patients with influenza A infection had higher body temperatures at seizure occurrence, shorter seizure duration, and shorter fever duration before seizure onset. Influenza A infections are frequently associated with febrile seizure in children with upper respiratory tract infection. During an influenza epidemic, effective vaccination of children, especially those with a past history of febrile seizure, may minimize the development of febrile seizure.

Febrile seizures: an epidemiological and outcome study of 482 cases

INTRODUCTION

Febrile seizures (FSs) are the most common type of seizures seen in children. After the first FS, 3 to 12% of children develop epilepsy, and 30% of these patients present with recurrent FS. The purpose of this study was to describe the epidemiological aspects of FS in order to better define the long-term outcomes in children with first FS and to identify the risk factors associated with the recurrence of FS as well as the development of epilepsy.

METHODS

A retrospective study of 482 children with FS was conducted from January of 2004 to December of 2009 in the pediatric department of Hedi Chaker University Hospital in Sfax, Tunisia. The medical records for each patient were first collected and then analyzed at a later time.

RESULTS

The study included 482 children. Simple FSs were found in 55.2% of children, and complex FSs were observed in 44.8%. The mean duration for follow-up examinations was 2 years and 4 months, and ranged from 1 to 5 years. No deaths or permanent neurological deficits due to FSs were observed, and only six children (1%) developed epilepsy. A total of 57 children (11.7%) developed recurrent seizures. Our findings suggest that a family history of FS, young age at onset, and a low degree of fever were predictive of recurrent FSs.

CONCLUSION

Children with FSs encounter a minor risk of mortality and morbidity. While recurrent seizures are observed in these children, only a minority of these patients develop epilepsy.

Hemiconvulsion-hemiplegia-epilepsy syndrome: current understandings

Hemiconvulsion-Hemiplegia (HH) syndrome is an uncommon consequence of prolonged focal febrile convulsive seizures in infancy and early childhood. It is characterized by the occurrence of prolonged clonic seizures with unilateral predominance occurring in a child and followed by the development of hemiplegia. Neuroradiological studies showed unilateral edematous swelling of the epileptic hemisphere at the time of initial status epilepticus (SE). This acute phase is followed by characteristic cerebral hemiatrophy with subsequent appearance of epilepsy, so called Hemiconvulsion-Hemiplegia-Epilepsy (HHE) syndrome. The etiologies and the underlying mechanisms remain to be understood. Using a review of the literature, we summarized the data of the last 20 years. It appears that idiopathic HH/HHE syndrome is the most common reported form. The basic science data suggest that immature brain is relatively resistant to SE-induced cell injury. Several factors might contribute to the pathogenesis of HH/HHE syndrome: 1. prolonged febrile seizure in which inflammation may worsen the level of cell injury; 2. inflammation and prolonged ictal activity that act on blood-brain-barrier permeability; 3. predisposing factors facilitating prolonged seizure such as genetic factors or focal epileptogenic lesion. However, these factors cannot explain the elective involvement of an entire hemisphere. We draw new hypothesis that may explain the involvement of one hemisphere such as maturation of brain structure such as corpus callosum or genetic factors (CACNA1A gene) that are specifically discussed. An early diagnosis and a better understanding of the underlying mechanisms of HHE are needed to improve the outcome of this condition.

Novel animal models of pediatric epilepsy

When mimicking epileptic processes in a laboratory setting, it is important to understand the differences between experimental models of seizures and epilepsy. Because human epilepsy is defined by the appearance of multiple spontaneous recurrent seizures, the induction of a single acute seizure without recurrence does not constitute an adequate epilepsy model. Animal models of epilepsy might be useful for various tasks. They allow for the investigation of pathophysiological mechanisms of the disease, the evaluation, or the development of new antiepileptic treatments, and the study of the consequences of recurrent seizures and neurological and psychiatric comorbidities. Although clinical relevance is always an issue, the development of models of pediatric epilepsies is particularly challenging due to the existence of several key differences in the dynamics of human and rodent brain maturation. Another important consideration in modeling pediatric epilepsy is that "children are not little adults," and therefore a mere application of models of adult epilepsies to the immature specimens is irrelevant. Herein, we review the models of pediatric epilepsy. First, we illustrate the differences between models of pediatric epilepsy and models of the adulthood consequences of a precipitating insult in early life. Next, we focus on new animal models of specific forms of epilepsies that occur in the developing brain. We conclude by emphasizing the deficiencies in the existing animal models and the need for several new models.

Perceptions of fever and fever management practices in parents of children with Dravet syndrome

OBJECTIVE

The first seizure in Dravet syndrome is often considered a febrile seizure (FS), but shortly thereafter, both FSs and seizures without fever occur, leading to diagnosis. Fever remains a factor that easily precipitates seizures. We studied the perception and management of fever of parents of children with Dravet syndrome.

METHODS

We conducted this survey using an anonymous, self-administered questionnaire.

RESULTS

A total of 20 parents returned the questionnaire. Fever remains a trigger of seizures in 90% of patients. All parents have an accurate knowledge of fever and its management. The familial and socioprofessional impact of fever attacks appears to be very strong.

CONCLUSION

Fever represents a significant concern of parents of children with Dravet syndrome. The level of parental anxiety is high in case of fever. The anxiety seems related to fear of seizure recurrence leading to significant modification of parental behavior.