The role of EEG in febrile status epilepticus (FSE)

Infant with Loeys-Dietz syndrome treated for febrile status epilepticus with COVID-19 infection: first reported case of febrile status epilepticus and focal seizures in a patient with Loeys-Dietz syndrome and review of literature

Loeys-Dietz syndrome (LDS) is a rare, autosomal dominant multisystem disorder that is caused by mutations of transforming growth factor-β receptors. Mutations inSMAD3andTGFB3have been recently reported.

LDS is characterised by the triad of arterial tortuosity, hypertelorism and a bifid uvula or cleft palate among other cardiovascular, craniofacial and orthopaedic manifestations. Patients with LDS show clinical and genetic variability and there is a significant risk of reduced life expectancy due to widespread arterial involvement, aortic root dilation, aneurysms and an aggressive vascular course. Thus early genetic testing is warranted if clinical signs and history are suggestive of this potentially catastrophic disorder.

LDS predisposes patients to aortic aneurysms and early death due to vascular malformations, but neurological emergencies, such as seizures and febrile status epilepticus, have not been reported.

Febrile status epilepticus is the most common neurological emergency in childhood. Neurological manifestations of COVID-19 in the paediatric population are not as well described in medical literature.

To the best of our knowledge, this is the first reported case of febrile status epilepticus with COVID-19 infection in an infant with LDS. Our patient had focal epileptiform activity emanating over the left posterior hemisphere, which evolved into an electrographic seizure on video EEG. Such patients have a heightened risk of epilepsy in the future, and this occurrence is consistent with a diagnosis of focal epilepsy. Neurological complications such as epilepsy and status epilepticus in a patient with LDS have never been reported before.

A brief review of literature is also given here.

Predictive Value of Epileptiform Discharges for Subsequent Epilepsy After Febrile Seizures

The predictive value of epileptiform discharges for subsequent epilepsy after febrile seizures was studied in 140 children: 72 children (51%) had simple febrile seizures and 68 children (49%) had complex febrile seizures. Electroencephalography (EEG) was performed in 103 children (74%), it was normal in 66 (47%) and with epileptiform patterns in 37 patients (26%). At follow-up in 2017, 10 children developed epilepsy, 1 had a single epileptic seizure, 9 of them had epileptiform EEGs. Of the patients with normal EEGs after complex febrile seizures, none developed epilepsy, and 92% of patients with normal EEGs after recurrent febrile seizures did not develop epilepsy. Therefore, patients with normal EEGs were unlikely to develop epilepsy. Fifteen percent of patients with complex and 31% of patients with recurrent febrile seizures and epileptiform EEGs developed epileptic seizures. The positive predictive value of epileptiform discharges was low in complex and twice as high in recurrent febrile seizures.

Risk factors for subsequent febrile seizures in the FEBSTAT study

OBJECTIVES

To identify risk and risk factors for developing a subsequent febrile seizure (FS) in children with a first febrile status epilepticus (FSE) compared to a first simple febrile seizure (SFS). To identify home use of rescue medications for subsequent FS.

METHODS

Cases included a first FS that was FSE drawn from FEBSTAT and Columbia cohorts. Controls were a first SFS. Cases and controls were classified according to established FEBSTAT protocols. Cumulative risk for subsequent FS over a 5-year period was compared in FSE versus SFS, and Cox proportional hazards regression was conducted. Separate analysis examined subsequent FS within FSE. The use of rescue medications at home was assessed for subsequent FS.

RESULTS

Risk for a subsequent FSE was significantly increased in FSE versus SFS. Any magnetic resonance imaging (MRI) abnormality increased the risk 3.4-fold (p < 0.05), adjusting for age at first FS and FSE and in analyses restricted to children whose first FS was FSE (any MRI abnormality hazard ratio [HR] 2.9, p < 0.05). The risk for a second FS of any type or of subsequent FS lasting >10 min over the 5-year follow-up did not differ in FSE versus SFS. Rectal diazepam was administered at home to 5 (23.8%) of 21 children with subsequent FS lasting ≥10 min.

SIGNIFICANCE

Compared to controls, FSE was associated with an increased risk for subsequent FSE, suggesting the propensity of children with an initial prolonged seizure to experience a prolonged recurrence. Any baseline MRI abnormality increased the recurrence risk when FSE was compared to SFS and when FSE was studied alone. A minority of children with a subsequent FS lasting 10 min or longer were treated with rectal diazepam at home, despite receiving prescriptions after the first FSE. This indicates the need to further improve the education of clinicians and parents in order to prevent subsequent FSE.

Febrile seizures: emergency medicine perspective

PURPOSE OF REVIEW

The review describes current evidence on the evaluation of febrile seizures in the acute setting, the need for further outpatient assessment, and predictors regarding long-term outcomes of these patients.

RECENT FINDINGS

New evidence has been added in support of limited assessment and intervention: evidence on low utility of lumbar puncture, emergent neuroimaging, and follow-up electroencephalography, as well as low yield for antipyretic prophylaxis and intermittent use of antiepileptic drugs. Finally, there is growing evidence regarding the genetic basis of both febrile seizures and vaccine-related seizures/febrile seizures.

SUMMARY

Routine diagnostic testing for simple febrile seizures is being discouraged, and clear evidence-based guidelines regarding complex febrile seizures are lacking. Thus, clinical acumen remains the most important tool for identifying children with seizures who are candidates for a more elaborate diagnostic evaluation. Similarly, evidence and guidelines regarding candidates for an emergent out-of-hospital diazepam treatment are lacking.

Febrile seizures

Febrile seizure (FS) is the most common seizure disorder of childhood, and occurs in an age-related manner. FS are classified into simple and complex. FS has a multifactorial inheritance, suggesting that both genetic and environmental factors are causative. Various animal models have elucidated the pathophysiological mechanisms of FS. Risk factors for a first FS are a family history of the disorder and a developmental delay. Risk factors for recurrent FS are a family history, age below 18 months at seizure onset, maximum temperature, and duration of fever. Risk factors for subsequent development of epilepsy are neurodevelopmental abnormality and complex FS. Clinicians evaluating children after a simple FS should concentrate on identifying the cause of the child's fever. Meningitis should be considered in the differential diagnosis for any febrile child. A simple FS does not usually require further evaluation such as ordering electroencephalography, neuroimaging, or other studies. Treatment is acute rescue therapy for prolonged FS. Antipyretics are not proven to reduce the recurrence risk for FS. Some evidence shows that both intermittent therapy with oral/rectal diazepam and continuous prophylaxis with oral phenobarbital or valproate are effective in reducing the risk of recurrence, but there is no evidence that these medications reduce the risk of subsequent epilepsy. Vaccine-induced FS is a rare event that does not lead to deleterious outcomes, but could affect patient and physician attitudes toward the safety of vaccination.

Febrile seizures: recent developments and unanswered questions

BACKGROUND

Febrile seizures (FS) are typically observed in infants and children affecting 2-5 % of the pediatric population and are the commonest seizures in childhood.

OBJECTIVES

The present review summarizes epidemiology, etiology, clinical picture, and diagnostic procedures as well as the therapeutic options and the different courses this disorder may take.

METHOD

An extensive review of literature is performed, while views and aspects towards the pathogenesis of FS are stated. Risk factors for multiple recurrences of FS and for subsequent epilepsy are analyzed. Questions regarding the treatment and follow-up of children with FS are answered.

RESULTS

Whereas the frequency of epilepsy following simple FS is estimated to be 1.0-2.2 % of patients, and thus does not differ from the risk of normal population, complicated FS are associated with an increased risk of subsequent epilepsy in 4.1-6.0 %. Febrile status epilepticus with focal symptoms may result in approximately 5 % of cases in complex partial epilepsy. Furthermore, multiple recurrences increase the risk for generalized epilepsy (>4 %). The immediate management of FS, intermittent prophylaxis, and the effectiveness of the treatment in combination with antipyretics are presented in detail.

CONCLUSION

FS can cause a great anxiety and even panic to parents and to the whole family. Parents should be educated about the benign condition and the good prognosis. Although much information has been gained, much remains to be learned.

Complex febrile seizures: a practical guide to evaluation and treatment

Febrile seizures are the most common type of childhood seizures, affecting 2% to 5% of children. A complex febrile seizure is one with focal onset, one that occurs more than once during a febrile illness, or one that lasts more than 10 to 15 minutes. Confusion still exists on the proper evaluation of a child presenting with a complex febrile seizure. There are ongoing research attempts to determine the link between complex febrile seizures and epilepsy. Further clarification and understanding of this disorder would be of great benefit to primary care providers and child neurologists.

Genetic generalized epilepsies

In the International League Against Epilepsy's most recent revision of classification and terminology, the term idiopathic epilepsy, previously used to describe those epilepsies whose cause was unknown, but presumed genetic, has been removed. It has been replaced by the term genetic epilepsy, only to be used to describe epilepsy in which the etiology has a known or presumed genetic defect in which seizures are the core symptom of the disorder. The purpose of this article was to review the electroclinical spectrum of those epilepsies that would fall under this new designation of genetic epilepsies in the context of specific generalized epilepsy syndromes providing an update in the clinical, electroencephalographic, and genetic findings in these syndromes.

Fever and fever-related epilepsies

Febrile seizures are a common emergency faced by general pediatricians. They are mostly self-limiting, isolated events with no sequelae in later life. A minority are more complex. In the acute stage, there are a small number of underlying etiologies that are important to recognize in order to determine the prognosis accurately and to optimize management. There has been a long-standing debate about the relationship of early febrile seizures to the later development of epilepsy. It is now clear that this risk differs for simple and complex febrile seizures: complex febrile seizures may herald the presentation of a number of epilepsy syndromes of which febrile and illness-related seizures are part of the phenotype. This review examines the existing knowledge on febrile seizures and the various clinical phenotypes to which they are linked.

In search of epilepsy biomarkers in the immature brain: goals, challenges and strategies

Epilepsy and seizures are very common in the early years of life and are often associated with significant morbidity and mortality. Identification of biomarkers for the early detection of epileptogenicity, epileptogenesis, comorbidities, disease progression and treatment implementation will be very important in implementing more effective therapies. This article summarizes the current needs in the search for new early life epilepsy-related biomarkers and discusses the candidate biomarkers that are under investigation, as well as the challenges associated with the identification and validation of these biomarkers.

Developmental outcome after a single episode of status epilepticus

Consequences of status epilepticus (SE) on psychomotor development and the specific impact of the convulsive event on emerging executive functions remain controversial. Infants treated for a single episode of SE, those treated for a single febrile seizure, and healthy infants were tested with respect to motor development, language, personal, and social skills and self-regulation. The children were divided into two age groups to investigate the impact of the convulsive event at different windows of brain maturation. We found that infants who had had SE were inferior to healthy controls on the development scales. Age differentiated SE impact on visuomotor development versus sociolinguistic development. Children who had been treated for SE had significantly more difficulties delaying a response to an attractive stimulus in one of the long-delay conditions. A single episode of SE can interfere with psychomotor and cognitive development in children without previous developmental delay, and it seems that the functions that are emerging at the time of insult are most vulnerable.