Unprovoked seizures after complex febrile convulsions

Febrile Seizures: An Updated Narrative Review for Pediatric Ambulatory Care Providers

BACKGROUND

While generally self-limited, febrile seizures result in significant familial distress. Ambulatory pediatric care providers must be prepared to counsel families on the causes, risk factors, management principles, and prognosis of children with febrile seizures.

OBJECTIVE

To provide an updated, evidence-based review of febrile seizures focused on the needs of an ambulatory pediatric care provider.

METHODS

A narrative review of the literature prioritizing landmark articles, metanalyses, longitudinal population longitudinal cohort studies and national level guidelines.

RESULTS

Febrile seizures are aberrant physiological responses to fever in children caused by complex interactions of cytokine mediated neuroinflammation, environmental triggers, and genetic predisposition. Other than investigations to determine fever etiology, routine bloodwork, lumbar punctures, neuroimaging and electroencephalograms are low yield. The general prognosis is excellent, however, clinicians should be aware of long-term outcomes including: cognitive impairment with non-simple febrile seizures; neuropsychiatric associations; recurrent febrile seizure and epilepsy risk factors; and the association between complex febrile seizures and sudden unexpected death. Children with a high risk of recurrence, complex febrile seizures, limited access to care, or extreme parental anxiety may benefit from intermittent oral diazepam prophylaxis.

CONCLUSION

Clinicians should consider four management priorities: 1) terminating the seizure; 2) excluding critical differential diagnoses; 3) investigating fever etiology; and 4) providing adequate counselling to families. The clinical approach and prognosis of febrile seizure can be based on subtype. Children with non-simple (i.e. complex or febrile status epilepticus) febrile seizures require closer care than the vast majority of children with simple febrile seizures, who have excellent outcomes.

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.

MRI Abnormalities of the Brain After Complex Febrile Seizures in Children

Background Though simple febrile seizures do not cause significant and lasting neurological deficits, complex febrile seizures (CFS) can result in neurologic sequelae. Because CFS causes cortical focal injuries and other brain lesions, it needs to be evaluated. Objective The objective of this study was to evaluate the MRI brain changes in CFS, the incidence of seizures in children aged six months to five years, and their severity in relation to MRI findings of the brain. Methods In this observational study, 36 children aged six months to five years, having fever with seizure, and fulfilling the criteria of CFS were enrolled within 48 hours of the episode. Detailed clinical and neurological examinations were performed with MRI scans to find out the probable CNS lesions of CFS. Two radiologists separately evaluated all MRI brains. Results MRI lesions of the brain were found in 11 (30.56%) CFS patients. Generalized tonic-clonic seizures (GTCS) (n=31, 86.11%) were the most common type of seizure among CFS cases. Cortical focal hyperintensity (CFH) (42.1%) was the most common MRI presentation. Positive MRI findings were significantly associated with focal convulsions (n=5, 100%) as compared to GTCS cases (n=6, 19%) (p=0.001). Conclusions CFH is the most common abnormality in the MRI brain among CFS cases. CFS patients with focal seizures or prolonged seizures in 24 hours have higher abnormal neuroimaging findings. MRI should be considered a preferred investigatory tool for detecting CNS pathology in CFS cases. Follow-up studies are needed to determine the long-term outcomes of CNS lesions in children with CFS.

Risk factors of epilepsy in children with complex febrile seizures: A retrospective cohort study

BACKGROUND

Febrile seizures are the most common seizures in children. Children with complex febrile seizures have a higher risk of subsequent epilepsy compared with children with simple febrile seizures. Multiple risks factors for epilepsy, including focal status epilepticus, family history of epilepsy, neurodevelopmental abnormalities and abnormal electroencephalogram findings, have been found with inconsistent results. The aim of this study is to identify risk factors for developing epilepsy in children with complex febrile seizures.

METHODS

The study included 248 children aged 3-72-months, diagnosed with complex febrile seizures at Chiang Mai University Hospital. Demographic data, seizure characteristics, electroencephalogram and neuroimaging findings were identified, and assessed to establish whether they were risk factors for subsequent epilepsy.

RESULTS

Fifty-five patients (22.1%) had subsequent epilepsy. Using Cox regression-survival analysis, factors associated with epilepsy were prolonged seizures >15 min (P = 0.006; Hazard Ratio (HR): 2.475; 95% Confidence Interval (CI): 1.294-4.735), developmental delay (P = 0.019; HR: 4.476; 95% CI: 2.280-15.646), epileptiform discharges on electroencephalogram (P = 0.023; HR: 1.391; 95%CI: 1.174-1.876), and abnormal neuroimaging (computed tomography or magnetic resonance imaging; P = 0.028; HR: 1.355; 95% CI: 1.034-1.776). Age at onset, peak febrile temperature, duration between the onset of fever and the occurrence of seizure, recurrent seizures within 24 h, focal seizures, abnormal neurological exams and family history of febrile seizure or epilepsy were not associated with increased risk of subsequent epilepsy in this study.

CONCLUSIONS

Risk factors associated with increased risk of epilepsy in children with complex febrile seizures are prolonged seizures or febrile status epilepticus, developmental delay, electroencephalogram epileptiform discharges, and abnormal neuroimaging. Their presence would merit close clinical monitoring.

Clinical Predictive Factors of Pathological EEG in Children with Febrile Seizures and Their Association with Subsequent Epileptic Seizures

The objective of this study was to identify clinical parameters predicting either a pathological EEG or a subsequent epileptic seizure (SES), based on the relation between paroxysmal EEG abnormalities and clinical features in children who presented at least one febrile seizure (FS). We collected data of children who presented to our department during the period 2013 to 2018 for EEG recording as part of their febrile seizure assessment. Only children aged between 1 month to 5 years were included. Both the clinical and EEG data were retrospectively collected and statistically studied. We performed a detailed analysis of the EEG recordings. SES was identified for patients with sufficient follow-up. A total of 120 children were included in the study, of whom 48% had EEG abnormalities. Psychomotor retardation (p = 0.002), completion of an EEG within 7 days of the last FS (p = 0.046), and late age (> 3 years) of the first FS onset (p = 0.021) were significantly associated with a pathological EEG. In multivariate analysis, performing early EEG (< 7 days from the last FS) (odds ratio [OR]: 2.35; p = 0.043; confidence interval [CI]: 1.028–5.375) and psychomotor retardation (OR: 4.19; p = 0.008; CI: 1.46–12) were independent predictors of a pathological EEG. Of 120 patients, 45 had a follow-up. However, only 10 (22.22%) had SES. Children with SES tended more to have a psychomotor delay, compared with children without SES (50% vs. 14.28%, p = 0.029). Moreover, the percentage of initial abnormal EEG in patients with SES was significantly higher than those without SES (70% vs. 34.28%, p = 0.05). Even though some FS characteristics predict EEG abnormalities, they are not always associated with SES. We highlight the importance of performing an EEG in the group of children who had both FS and psychomotor retardation. This is most likely the group at the highest risk of developing epilepsy.

Basics of modern epilepsy classification and terminology

BACKGROUND

The terminology and classification of seizures and epilepsy has undergone multiple revisions in the last several decades, which can lead to confusion and miscommunication amongst physicians and researchers. In 2017, the International League Against Epilepsy (ILAE) revised the classification of both seizures and epilepsy types in an effort to use less ambiguous terminology. Over time, definitions for status epilepticus, febrile seizures, and neonatal seizures have also evolved, as has the delineation of various epilepsy syndromes by age.

METHODS

Review of the literature for old and new terminology and various epilepsy syndromes was accomplished using the PubMed database system.

RESULTS

In the following article, we review old terminology for classifying seizures and epilepsy as compared to the new (2017) ILAE guidelines. We discuss neonatal seizures, status epilepticus, febrile seizures, autoimmune epilepsy and various epilepsy syndromes by age of onset.

CONCLUSION

Adopting a classification system that uses plain language allows for more effective and efficient communication between individuals and across specialties. Definitions of various syndromes and seizure types have evolved over time and are reviewed.

Severe Factor X Deficiency Presenting as Febrile Seizure in an Infant

Factor X deficiency is a severe inherited coagulation disorder, which is characterized by severe systemic bleeding manifestations in affected individuals. It is a rare disorder with a frequency of around 1:1,000,000 in the general population. We present the case of an infant with factor X deficiency who presented with complex febrile seizure. Although febrile seizures are very common in children, a closer scrutiny leads to neuroimaging and finding of intracranial bleed. Hematologic and genetic investigations confirmed the diagnosis. A high index of suspicion should be maintained to diagnose uncommon bleeding disorders in children.

Predictors of Outcome in Juvenile Myoclonic Epilepsy

Background

Juvenile myoclonic epilepsy (JME) is the most common idiopathic generalized epilepsy syndrome, accounting for 10% of all epilepsy. However, there is limited information regarding the predictors of seizure outcome. The aim of this study was to determine the predictors of seizure outcome in JME patients.

Methods

A population-based retrospective study of JME patients who were treated at the Department of Neurology of affiliated Zhongshan Hospital, Xiamen University from 2008 to 2013.

Results

Sixty-three patients (30 women and 33 men) were enrolled in this study. The median age at seizure onset was 14 years old, and the average duration of epilepsy was 5 years. The onset of JME at age <16 years was found in 63.5% of patients. The epileptiform runs ≥3 s were observed in 35.8% patients. Febrile seizure was noted in 28.9% of patients. Among 63 patients, 40 patients (63.5%) had remission. Multivariate analysis identified the following factors as significant predictors of seizure outcome: the onset of JME at age <16 years, epileptiform runs ≥3 s runs, and febrile seizure.

Conclusion

The onset of JME at age <16 years, febrile seizures and epileptiform runs ≥3 s might be associated with poor long-term seizure outcome in patients with JME.

Myelin water fraction changes in febrile seizures

OBJECTIVE

The objective of this feasibility study was to investigate whether myelin water fraction (MWF) patterns can differentiate children presenting with febrile seizures who will go on to develop nonfebrile epilepsy from those who will not.

PATIENTS AND METHODS

As part of a prospective study of myelination patterns in pediatric epilepsy, seven subjects with febrile seizures underwent magnetic resonance imaging (MRI) including the following standard sequences-T1-weighted, T2-weighted, fluid-attenuated inversion recovery (FLAIR)-and an additional experimental sequence, multicomponent-derived equilibrium single-pulse observation of T1 and T2 (mcDESPOT) to quantify MWF. For each of these subjects, MWF maps were derived and compared with an age-matched population-averaged MWF atlas.

RESULTS

All seven subjects (<5 years old) initially presented with febrile seizures. Of the seven, four had complex seizures and three had simple seizures. All of the children with simple febrile seizures had higher MWF compared with model-derived controls and did not develop epilepsy. All of the children with complex febrile seizures had lower MWF than their model-derived control, and two of these subjects later developed epilepsy.

CONCLUSION

This is the first study in which MWF maps were used to study children with febrile *seizures. This data suggests that relatively higher or stable MWF compared with normative data indicates a lower risk of nonfebrile epilepsy while relatively lower MWF may indicate a pathological condition that could lead to nonfebrile epilepsy.

Metabolic profile of oxidative stress and trace elements in febrile seizures among children

Febrile seizures (FS) are frequent convulsive disorders, occurring in infants and young children. The present study aims to assess and compare the serum levels of oxidative stress markers and some essential trace minerals in FS with normal or abnormal EEG and evaluate the effect of antioxidant therapy on the clinical outcome. This study has been carried out on 80 children with FS (40 with simple FS and 40 with complex FS) and 40 febrile children without seizures. Clinical and EEG findings were recorded for the included patients. Biochemical assays of serum nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), copper (Cu), zinc (Zn) and selenium (Se), using colorimetric methods, were measured in the studied groups. The overall results showed an increased values of NO, MDA and Cu with decreased values of SOD, Zn and Se in patients with FS (simple and complex) in comparison with febrile children without seizures (p < 0.05 for all). Additionally, NO and MDA was increased in complex FS patients with EEG abnormalities in comparison with complex FS with normal EEG findings (p < 0.05); NO and MDA were also significantly decreased after valproate therapy in complex FS patients (p < 0.05 for all). In conclusions, oxidative stress, decreased Zn and Se with increased Cu may play a role in FS. Valproate improves the oxidative stress status in complex FS.

The risk of subsequent epilepsy in children with febrile seizure after 5 years of age

PURPOSE

Despite their age-dependent definition, febrile seizures (FS) may be observed in people of almost any age. The risk of developing unprovoked seizures after an FS is well defined. However, there are limited data about FS starting or persisting after 5 years of age. In the present study, we evaluated patients who developed FS after 5 years of age.

METHOD

Between 2010 and 2014, we prospectively enrolled all patients with FS. We collected demographic and clinical features, radiologic images, electroencephalograms (EEGs), and results of psychomotor development tests and treatment data of the patients. The patients were grouped into two groups. Group 1 consisted of patients who had the first FS after 5 years of age, and group 2 consisted of patients in whom FS persisted after 5 years of age. Fisher's exact test and Pearson's chi-square test were used to analyse the study data and derive conclusions.

RESULTS

Sixty-four patients were enrolled, and afebrile seizure was observed in 12 (18.8%) of them. Nine (14%) patients were diagnosed to have epilepsy in their follow-up examination. Subsequent epilepsy occurrence was independent of gender, mean age, medical history of the patient, family history of epilepsy, presence of afebrile seizure, type of seizure, type of FS, duration of seizure, semiology of seizure, peak fever and EEG and magnetic resonance imaging (MRI) findings in our total cohort. There were no statistical differences between the groups with regard to the occurrence of subsequent afebrile seizure or epilepsy (p>0.5).

CONCLUSION

Close follow-up is important in patients with FS after the age of 5 years. These seizures are generally benign, but tend to recur and increase the risk of development of epilepsy in the patient. Further studies with a larger cohort are warranted to clarify risk factors and incidence of epilepsy in these patients.

Epilepsy in children with a history of febrile seizures

PURPOSE

Febrile seizure, the most common type of pediatric convulsive disorder, is a benign seizure syndrome distinct from epilepsy. However, as epilepsy is also common during childhood, we aimed to identify the prognostic factors that can predict epilepsy in children with febrile seizures.

METHODS

The study comprised 249 children at the Korea University Ansan Hospital who presented with febrile seizures. The relationship between the subsequent occurrence of epilepsy and clinical factors including seizure and fever-related variables were analyzed by multivariate analysis.

RESULTS

Twenty-five patients (10.0%) had additional afebrile seizures later and were diagnosed with epilepsy. The subsequent occurrence of epilepsy in patients with a history of febrile seizures was associated with a seizure frequency of more than 10 times during the first 2 years after seizure onset (P<0.001). Factors that were associated with subsequent occurrence of epilepsy were developmental delay (P<0.001), preterm birth (P=0.001), multiple seizures during a febrile seizure attack (P=0.005), and epileptiform discharges on electroencephalography (EEG) (P=0.008). Other factors such as the age at onset of first seizure, seizure duration, and family history of epilepsy were not associated with subsequent occurrence of epilepsy in this study.

CONCLUSION

Febrile seizures are common and mostly benign. However, careful observation is needed, particularly for prediction of subsequent epileptic episodes in patients with frequent febrile seizures with known risk factors, such as developmental delay, history of preterm birth, several attacks during a febrile episode, and epileptiform discharges on EEG.

Predictive value of paroxysmal EEG abnormalities for future epilepsy in focal febrile seizures

PURPOSE OF THE STUDY

To reassess the predictive role of clinical parameters and epileptiform paroxysmal EEG abnormalities for subsequent epilepsy in patients with febrile seizures.

PATIENTS AND METHODS

179 patients with febrile seizures were included in a prospective study investigating the impact of some clinical parameters and EEG abnormalities that could be important for future epilepsy. EEGs were performed in afebrile patients after hospital discharge. The follow-up period from the first presentation ranged from 2.1 to 9.2 years (mean, 6.6 years). The correlation between the development of epileptic seizures and the presence of epileptiform EEG abnormalities in the two groups was evaluated with the Mann-Whitney and chi-square test. Statistical significance was set at p<0.05.

RESULTS

Febrile seizures occurred more than once in 58 (32.5%) patients, with one recurrence in 32 (17.9%) patients and multiple recurrences in 26 (14.5%) patients. The incidence of paroxysmal abnormalities was 16.8%. Of these, 15 patients (50%) showed generalized paroxysms only, while in 15 patients (50%), focal abnormalities were found. Epilepsy developed in 12 patients (6.7%). There were 27 patients with clinically focal features of the first febrile seizure, five (18.5%) of whom developed epilepsy. With focal EEG abnormalities included, the incidence of epilepsy increased to 50%.

CONCLUSION

Generalized EEG discharges in patients with febrile seizures are not predictive of later epilepsy, but focal discharges are.

Risk factors for seizure recurrence in children after first unprovoked seizure

BACKGROUND

The question of whether to treat a patient after a first unprovoked seizure is controversial. This prospective study assessed the time to recurrence and risk factors for seizure recurrence after a first unprovoked seizure in children.

METHODS

Participants were recruited between 1 July 1997, and 30 June 2009. Eligible candidates were children between 1 month and 15 years old who presented with their first unprovoked afebrile seizure. After enrollment, recurrence of seizures was investigated. All participants were followed for at least 2 years. Log-rank test was used for bivariate analysis to check associations, and hazard ratios were used to analyze variables and clinical outcome (recurrence) during follow-up.

RESULTS

Of 73 subjects, 42 (57.5%) experienced recurrence. The overall product-limit estimate of recurrence was 61.9% at 6 months, 85.7% at 1 year, and 95.2% at 2 years after seizure onset, respectively. Incidence of recurrence with partial and generalized seizures was 69.0% and 31.0%, respectively. Children with partial seizures had recurrence significantly more often than those with generalized seizures (P < 0.001). Recurrent seizures occurred after normal findings on electroencephalogram (EEG) in 21.4%, after generalized spike-and-wave complexes in 16.7%, and after focal epileptic discharge in 61.9%. Children with focal epileptic discharge had recurrence significantly more often than children with normal EEG findings (P < 0.001).

CONCLUSION

The time to seizure recurrence after first unprovoked seizure may be within 1 year, and particularly within 6 months; and partial seizure and abnormal EEG with focal epileptic discharge may be risk factors for seizure recurrence.

Summary of recommendations for the management of infantile seizures: Task Force Report for the ILAE Commission of Pediatrics

Evidence-based guidelines, or recommendations, for the management of infants with seizures are lacking. A Task Force of the Commission of Pediatrics developed a consensus document addressing diagnostic markers, management interventions, and outcome measures for infants with seizures. Levels of evidence to support recommendations and statements were assessed using the American Academy of Neurology Guidelines and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The report contains recommendations for different levels of care, noting which would be regarded as standard care, compared to optimal care, or "state of the art" interventions. The incidence of epilepsy in the infantile period is the highest of all age groups (strong evidence), with epileptic spasms the largest single subgroup and, in the first 2 years of life, febrile seizures are the most commonly occurring seizures. Acute intervention at the time of a febrile seizure does not alter the risk for subsequent epilepsy (class 1 evidence). The use of antipyretic agents does not alter the recurrence rate (class 1 evidence), and there is no evidence to support initiation of regular antiepileptic drugs for simple febrile seizures (class 1 evidence). Infants with abnormal movements whose routine electroencephalography (EEG) study is not diagnostic, would benefit from video-EEG analysis, or home video to capture events (expert opinion, level U recommendation). Neuroimaging is recommended at all levels of care for infants presenting with epilepsy, with magnetic resonance imaging (MRI) recommended as the standard investigation at tertiary level (level A recommendation). Genetic screening should not be undertaken at primary or secondary level care (expert opinion). Standard care should permit genetic counseling by trained personal at all levels of care (expert opinion). Genetic evaluation for Dravet syndrome, and other infantile-onset epileptic encephalopathies, should be available in tertiary care (weak evidence, level C recommendation). Patients should be referred from primary or secondary to tertiary level care after failure of one antiepileptic drug (standard care) and optimal care equates to referral of all infants after presentation with a seizure (expert opinion, level U evidence). Infants with recurrent seizures warrant urgent assessment for initiation of antiepileptic drugs (expert opinion, level U recommendation). Infantile encephalopathies should have rapid introduction and increment of antiepileptic drug dosage (expert opinion, level U recommendation). There is no high level evidence to support any particular current agents for use in infants with seizures. For focal seizures, levetiracetam is effective (strong evidence); for generalized seizures, weak evidence supports levetiracetam, valproate, lamotrigine, topiramate, and clobazam; for Dravet syndrome, strong evidence supports that stiripentol is effective (in combination with valproate and clobazam), whereas weak evidence supports that topiramate, zonisamide, valproate, bromide, and the ketogenic diet are possibly effective; and for Ohtahara syndrome, there is weak evidence that most antiepileptic drugs are poorly effective. For epileptic spasms, clinical suspicion remains central to the diagnosis and is supported by EEG, which ideally is prolonged (level C recommendation). Adrenocorticotropic hormone (ACTH) is preferred for short-term control of epileptic spasms (level B recommendation), oral steroids are probably effective in short-term control of spasms (level C recommendation), and a shorter interval from the onset of spasms to treatment initiation may improve long-term neurodevelopmental outcome (level C recommendation). The ketogenic diet is the treatment of choice for epilepsy related to glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency (expert opinion, level U recommendation). The identification of patients as potential candidates for epilepsy surgery should be part of standard practice at primary and secondary level care. Tertiary care facilities with experience in epilepsy surgery should undertake the screening for epilepsy surgical candidates (level U recommendation). There is insufficient evidence to conclude if there is benefit from vagus nerve stimulation (level U recommendation). The key recommendations are summarized into an executive summary. The full report is available as Supporting Information. This report provides a comprehensive foundation of an approach to infants with seizures, while identifying where there are inadequate data to support recommended practice, and where further data collection is needed to address these deficits.

Predictors of unprovoked seizure after febrile seizure: short-term outcomes

INTRODUCTION

We performed this study to confirm the known risk factors and to identify possible new risk factors for subsequent unprovoked seizure after febrile seizure (FS) on Jeju Island, South Korea.

METHODS

A population-based retrospective study of 204 children with FS, whose first FS developed between March 2003 and August 2011, and who were seen in the Pediatric Department at the Jeju National University Hospital.

RESULTS

Two hundred four children (136 boys and 68 girls) were enrolled in this study. Simple FS was found in 107 children, and complex FS was found in 97 children. The average age at the first FS was 18.9 months. The average total number of FSs was 4.3. A family history of FS or epilepsy was found in 29.4% and 7.8% of patients, respectively. Abnormal findings of EEG were observed in 35.8%. Complex features in the first FS were noted in 28.9%. Subsequent unprovoked seizures occurred in 23.0%. Univariate analysis showed that low parental educational level was one of several variables that were significantly related to unprovoked seizure. Parental educational level was not included in the multivariate model because of an insufficient sample size. Multivariate analysis identified the following factors as significant predictors of unprovoked seizure: late onset of FS at age>3 years, complex features in the first FS, family history of epilepsy, and abnormal findings on EEG, and FS developed at a body temperature of <39°C.

CONCLUSIONS

We confirmed the known risk factors for subsequent unprovoked seizure and found that low parental educational status may be a new prognostic indicator. However, further investigation using larger populations and a prospective design is needed to confirm that this is a valid prognostic factor for FS.

Prognostic factors for subsequent epilepsy in children with febrile seizures

OBJECTIVE

Epilepsy following febrile seizures (FS) has been estimated between 2% and 7%. It concerns a prospective study in a large sample of children with a long-term follow-up. The aim of this study is to identify the prognostic factors that can lead children with FS to epilepsy.

METHODS

Children with a first episode of FS were included. We gathered information about prenatal and perinatal history, family history of FS and epilepsy in first- and second degree relatives, age at the time of the initial FS, dates of FS recurrences, focality, duration of the FS and recurrent episodes within the same febrile illness, height and duration of fever prior to the seizure, cause of the fever, and frequency of febrile illnesses. Patients were seen every 4-6 months and also at each recurrence.

KEY FINDINGS

A group of 560 children with a first FS met all entry criteria. Epilepsy was recorded at 5.4%. Statistical analysis was performed between children with epilepsy and those with no afebrile seizure. We analyzed FS recurrences in accordance with the occurrence of epilepsy. From the third FS recurrence and beyond, only focality continued to have prognostic value.

SIGNIFICANCE

Main prognostic factors for the development of epilepsy after FS are: (1) complex FS that increased the risk for epilepsy 3.6 times, (2) age at onset of FS beyond the third year of life that raised the risk 3.8 times, (3) positive family history of epilepsy 7.3 times, and (4) multiple episodes of FS about 10 times. Focality at the first and the second FS recurrence increased the risk of epilepsy about 9.7 and 11.7 times, respectively. Focality was the only factor that continued to be significant in further FS recurrences. A prognostic profile of each child with FS would be very useful for the follow-up of these children.

Prevalence and risk factors of epilepsy among school children in eastern Turkey

Epilepsy is a serious chronic brain disorder of childhood. We performed a cross-sectional prevalence study, determined the prevalence of childhood epilepsy, and identified the significance of certain risk factors for epilepsy among 1625 primary-school students aged 6-14 years, living in the center of Kars province. A questionnaire was prepared according to the definitions and principles of the Commission on Epidemiology and Prognosis, International League Against Epilepsy. Twenty-two children were diagnosed as epileptic. The point prevalence of active epilepsy in males was 4.9/1000, and in females 12.4/1000, representing a total of 8.6/1000. The cumulative prevalence in males was 11.0/1000, and 16.1/1000 in females, representing a total of 13.5/1000. Febrile convulsions, family history of epilepsy, serious maternal illness during pregnancy, a history of head trauma, antenatal/postnatal problems, and a history of neonatal jaundice were statistically significantly related to the development of epilepsy.

Yield of emergent neuroimaging among children presenting with a first complex febrile seizure

OBJECTIVES

The objective of this study was to assess the risk of intracranial pathology requiring immediate intervention among children presenting with their first complex febrile seizure (CFS).

DESIGN/METHODS

This is a retrospective cohort review of patients 6 to 60 months of age evaluated in a pediatric emergency department between 1995 and 2008 for their first CFS. Cases were identified using computerized text search followed by manual chart review. We excluded patients with a prior history of a nonfebrile seizure disorder or a prior CFS, an immune-compromised state, an underlying illness associated with seizures or altered mental status, or trauma. Data extraction included age, sex, seizure features, prior simple febrile seizures, temperature, family history of seizures, vaccination status, findings on physical examination, laboratory and imaging studies, diagnosis, and disposition.

RESULTS

We identified a first CFS in 526 patients. Two hundred sixty-eight patients (50.4%) had emergent head imaging: 4 patients had a clinically significant finding: 2 had intracranial hemorrhage, 1 had acute disseminated encephalomyelitis, and 1 patient had focal cerebral edema (1.5%; 95% confidence interval, 0.5%-4.0%). Assigning low risk to patients not imaged and not returning to the emergency department within a week of the original visit, the risk of intracranial pathology in our sample was 4 (0.8%; 95% confidence interval, 0.2%-2.1%) of 526. Three of these 4 patients had other obvious findings (nystagmus, emesis, and altered mental status; persistent hemiparesis; bruises suggestive of inflicted injury).

CONCLUSIONS

Very few patients with CFSs have intracranial pathology in the absence of other signs or symptoms. Patients presenting with more than one seizure in 24 hours in particular are at very low risk.

The mortality and morbidity of febrile seizures

Approaches to the treatment and investigation of febrile seizures have changed since the main reference studies on outcomes were conducted in the 1960s and 1970s. We have, therefore, conducted a systematic review of literature from the past 15 years to see whether outcomes have also changed. We found that simple febrile seizures do not carry a risk of death, but there is a very small risk of death after complex febrile seizures (CFSs), particularly febrile status epilepticus. There is no evidence that SUDEP (sudden unexpected death in epilepsy) occurs in association with febrile seizures. The risk of later epilepsy after a febrile seizure lies between 2.0% and 7.5%, and the risk of developing epilepsy after CFSs is estimated at around 10-20%. There is no evidence of any risk of hippocampal or mesial temporal sclerosis (HS/MTS) in association with simple febrile seizures. Serial imaging has shown that HS/MTS develops in 0-25% of patients over time after prolonged febrile seizures; the range in prevalence reflects selection bias in different studies. The overall risk of HS/MTS associated with CFSs is around 3%. Approximately 40% of patients with medically refractory temporal lobe epilepsy and HS/MTS on neuroimaging have a history of febrile seizures.

Influenza-associated central nervous system dysfunction: a literature review

CONTEXT

Influenza is a viral pathogen that imposes an under-recognized burden of central nervous system (CNS) disease.

OBJECTIVE

To describe the epidemiology, clinical features and etiology of the CNS disease entities associated with influenza.

DATA SOURCES

English-language publications from MEDLINE.

DATA EXTRACTION

Articles were identified using "influenza, human"[Mesh] AND "nervous system diseases"[Mesh] and screened for inclusion based on relevance and scientific rigor.

RESULTS

Febrile seizure is the most frequently encountered influenza-associated CNS complication, with one in five children hospitalized with influenza experiencing one or more events. In most instances, symptoms resolve without neurological sequelae, although the risk for subsequent afebrile seizure may be increased. Influenza-associated encephalitis/encephalopathy is a less common but potentially more serious complication that is widely reported in Japanese populations, although cases from other East Asian countries, North America, and Europe have been described. Clinical manifestations are diverse, and typically involve febrile seizures and abnormal behaviors in mild cases, with rapid evolution through decreased consciousness to coma in severe forms. In cases of serious disease, the prognosis is often poor, with outcomes including death or severe neurological sequelae. Influenza is also a known trigger for a number of rarely encountered, yet often serious, CNS diseases, including the encephalopathic condition of Reye's syndrome, the peripheral neuropathy known as Guillain-Barré syndrome, and the lesser known complaints of Kleine-Levin syndrome and post-encephalitic Parkinson's disease.

CONCLUSIONS

Influenza imposes a sizeable burden of CNS disease. Increased awareness and monitoring of CNS function is indicated, especially in infants and young children.

Which factors determine febrile seizure recurrence? A prospective study

PURPOSE

Many factors have been studied as potential predictors of recurrent febrile seizures (FS), however the available data in literature are inconsistent. The aim of the present paper is to determine which factors are responsible for the first and for multiple recurrences of FS, in a large sample of children with a long-term follow up.

METHODS

Two hundred and sixty children were followed after their first FS. The inclusion criteria were: a history of a first febrile seizure; no personal history of afebrile seizures; no previous anticonvulsant medication and age between three months and six years. The median time of follow up was 4.3 years. We had a contact with the families of the children every 4-6 months and also in every recurrence.

RESULTS

Very significant prognostic markers for the first FS recurrence were low age at onset, recurrence within the same illness, frequent febrile episodes and maternal preponderance. Powerful prognostic factors that may predispose children who already have one recurrence to a second or more are low age at onset and especially positive family history of FS. Additionally, low temperature prior to the initial seizure is a powerful predictor for three or more recurrences.

CONCLUSIONS

Prognostic factors for FS recurrence are a useful tool for the clinician. It is obvious that as many powerful predictors a child has, the greater will be the risk for FS recurrence.

Prevalence of some risk factors in children with epilepsy compared to their controls

AIM

The goal of this case-control study was to identify the significance of certain risk factors for epilepsy in Turkey.

METHOD

A total of 805 cases, aged 1-16 years, followed-up for epilepsy at the Pediatric Neurology Department and a control group consisting of 846 age-matched cases without epilepsy were included in the study. The risk factors examined were gender, neurological impairment, febrile convulsion, head trauma, central nervous system infections, parental consanguinity, family history of epilepsy, prenatal and natal risk and newborn jaundice. Data regarding the investigated epilepsy risk factors were obtained through a questionnaire via personal interviews and the medical records and were assessed using univariate and multivariate analysis.

RESULT

Univariate analysis showed an increased risk for epilepsy with a history of atypical febrile seizure (21.97-fold), severe and moderate head injury (27.76- and 7.09-fold respectively), CNS infection (4.76-fold), history of epilepsy in first-, second- or third-degree relatives (6.42-, 3.09- and 2.66-fold, respectively), presence of maternal hypertension (4.31-fold), an apgar score < or =6 at any time (7.78-fold) and neonatal jaundice (3.12-fold). Abnormal neurological signs increased the epilepsy risk 5.92 times in univariate analysis and 30.26 times in multivariate analysis.

CONCLUSION

The most important risk factors for epilepsy in this study were neurological impairment, history of atypical febrile seizures, severe head injury and a low apgar score. Other important risk factors were moderate head trauma and a history of epilepsy in the family.

Febrile seizures associated with influenza A

To clarify the clinical impact of influenza A on the development of febrile seizures (FS), consecutive FS patients brought to our hospital between October 2003 and September 2004 were prospectively surveyed. Patients infected with influenza A (influenza A patients) and those uninfected with influenza (non-influenza patients) were compared with regard to clinical characteristics of FS. Influenza infection was determined by rapid antigen test and/or serologically. Associations of influenza A with atypical findings of FS, including partial seizures, prolonged seizures, multiple seizures during the same illness, and 30-min or longer prolonged postictal impairment of consciousness (PPIC), were analyzed by multiple logistic regression. A total of 215 patients (47 influenza A and 168 non-influenza patients) were enrolled in the study. Age was significantly higher in the influenza A group (39.85+/-22.16 months vs. 27.51+/-17.14 months, P<0.001). Of 42 patients aged 48 months or older, which corresponded to the 80th percentile for age, 15 (35.7%) were influenza A patients, with a significantly higher incidence of such patients than in the subgroup of patients aged 47 months or younger (32/173, 18.5%) (P=0.015). On multiple logistic regression analysis, influenza A was independently associated with PPIC (odds ratio: 4.44, 95% confidence interval: 1.52-12.95, P=0.006), but not with other atypical findings. The positive association of influenza A with PPIC suggests that influenza may affect state of consciousness at the same time that it induces seizures with fever.

Risk of intracranial pathologic conditions requiring emergency intervention after a first complex febrile seizure episode among children

OBJECTIVE

To determine the likelihood of intracranial pathologic conditions requiring emergency neurosurgical or medical intervention among children without meningitis who presented to the pediatric emergency department after a first complex febrile seizure.

METHODS

We performed a retrospective review of prospectively collected data for children in neurologically normal condition who presented to a single pediatric emergency department after a first complex febrile seizure (focal, multiple, or prolonged). The complex febrile seizure classification was determined independently by 2 epileptologists. The presence of intracranial pathologic conditions was determined through review of neuroimaging results, telephone interviews, or medical record review.

RESULTS

Data for 71 children with first complex febrile seizures were analyzed. Fifty-one (72%) had a single complex feature (20 focal, 22 multiple, and 9 prolonged), and 20 (28%) had multiple complex features. None of the 71 patients (1-sided 95% confidence interval: 4%) had intracranial pathologic conditions that required emergency neurosurgical or medical intervention.

CONCLUSIONS

For children with first complex febrile seizures, the risk of intracranial pathologic conditions that require emergency neurosurgical or medical intervention is low, which suggests that routine emergency neuroimaging for this population is unnecessary.

Do prolonged febrile seizures produce medial temporal sclerosis? Hypotheses, MRI evidence and unanswered questions

Whether or not severe febrile seizures in infancy cause hippocampal injury and subsequent medial temporal sclerosis is an often debated question in epilepsy. Recent magnetic resonance imaging (MRI) of infants suffering from febrile seizures has provided preliminary evidence that abnormally increased T2 signal intensity can be seen in the hippocampi of infants following prolonged and focal febrile seizures. Follow-up MRIs in a few of these infants have confirmed that medial temporal sclerosis can develop following these acute MRI signal changes. In this article, we review the hypotheses and MRI evidence relating to hippocampal injury during prolonged febrile seizures and the later development of medial temporal sclerosis.