Familial occurrence of epilepsy in children with newly diagnosed multiple seizures: Dutch Study of Epilepsy in Childhood

Reproduction and genetic causal attribution of epilepsy

OBJECTIVE

This study addresses the contribution of genetics-related concerns to reduced childbearing among people with epilepsy.

METHODS

Surveys were completed by 606 adult patients with epilepsy of unknown cause at our medical center. Poisson regression analysis was used to assess the relations of number of offspring to: (1) genetic attribution (GA: participants' belief that genetics was a cause of their epilepsy), assessed via a novel scale developed from four survey items (Cronbach's alpha = .89), (2) participants' estimates of epilepsy risk in the child of a parent with epilepsy (1%, 5%-10%, 25%, and 50%-100%), and (3) participants' reports of the influence on their reproductive decisions of "the chance of having a child with epilepsy" (none/weak/moderate, strong/very strong). Analyses were adjusted for age, education, race/ethnicity, religion, type of epilepsy (generalized, focal, and both/unclassifiable), and age at epilepsy onset (<10, 10-19, and ≥20 years).

RESULTS

Among participants 18-45 years of age, the number of offspring decreased significantly with increasing GA (highest vs lowest GA quartile rate ratio [RR] = .5, p < .001), and increasing estimated epilepsy risk in offspring (with 5%-10% as referent because it is closest to the true value, RR for 25%: .7, p = .05; RR for 50%-100%: .6, p = .03). Number of offspring was not related to the reported influence of "the chance of having a child with epilepsy" on reproductive decisions. Among participants >45 years of age, the number of offspring did not differ significantly according to GA quartile or estimated offspring epilepsy risk. However, those reporting a strong/very strong influence on their reproductive decisions of "the chance of having a child with epilepsy" had only 60% as many offspring as others.

SIGNIFICANCE

These findings suggest that overestimating the risk of epilepsy in offspring can have important consequences for people with epilepsy. Patient and provider education about recurrence risks and genetic testing options to clarify risks are critical, given their potential influence on reproductive decisions.

Anti-seizure medications for Lennox-Gastaut syndrome

BACKGROUND

Lennox-Gastaut syndrome (LGS) is an age-specific epilepsy syndrome characterised by multiple seizure types, including drop seizures. LGS has a characteristic electroencephalogram, an onset before age eight years and an association with drug resistance. This is an updated version of the Cochrane Review published in 2013.

OBJECTIVES

To assess the efficacy and tolerability of anti-seizure medications (ASMs) for LGS.

SEARCH METHODS

We searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 28 February 2020) on 2 March 2020. CRS Web includes randomised controlled trials (RCTs) or quasi-RCTs from the Cochrane Central Register of Controlled Trials (CENTRAL); the Specialised Registers of Cochrane Review Groups, including Cochrane Epilepsy; PubMed; Embase; ClinicalTrials.gov; and the World Health Organization's International Clinical Trials Registry Platform (ICTRP). We imposed no language restrictions. We contacted pharmaceutical companies and colleagues in the field to seek any unpublished or ongoing studies.

SELECTION CRITERIA

We considered RCTs, including cross-over trials, of ASMs for LGS in children and adults. We included studies of ASMs used as either monotherapy or as an add-on (adjunctive) therapy. We excluded studies comparing different doses of the same ASM.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures, including independent, dual assessment for risk of bias and application of the GRADE approach to rate the evidence certainty for outcomes.

MAIN RESULTS

We found no trials of ASM monotherapy. The review included 11 trials (1277 participants; approximately 11 weeks to 112 weeks follow-up after randomisation) using add-on ASMs for LGS in children, adolescents and adults. Two studies compared add-on cannabidiol (two doses) with add-on placebo in children and adolescents only. Neither study reported overall seizure cessation or reduction. We found high-certainty evidence that 72 more people per 1000 (confidence interval (CI) 4 more to 351 more) had adverse events (AE) leading to study discontinuation with add-on cannabidiol, compared to add-on placebo (two studies; 396 participants; risk ratio (RR) 4.90, 95% CI 1.21 to 19.87). One study compared add-on cinromide with add-on placebo in children and adolescents only. We found very low-certainty evidence that 35 more people per 1000 (CI 123 fewer to 434 more) had 50% or greater average reduction of overall seizures with add-on cinromide compared to add-on placebo (one study; 56 participants; RR 1.15, 95% CI 0.47 to 2.86). This study did not report participants with AE leading to study discontinuation. One study compared add-on clobazam (three doses) with add-on placebo. This study did not report overall seizure cessation or reduction. We found high-certainty evidence that 106 more people per 1000 (CI 0 more to 538 more) had AE leading to study discontinuation with add-on clobazam compared to add-on placebo (one study; 238 participants; RR 4.12, 95% CI 1.01 to 16.87). One study compared add-on felbamate with add-on placebo. No cases of seizure cessation occurred in either regimen during the treatment phase (one study; 73 participants; low-certainty evidence). There was low-certainty evidence that 53 more people per 1000 (CI 19 fewer to 716 more) with add-on felbamate were seizure-free during an EEG recording at the end of the treatment phase, compared to add-on placebo (RR 2.92, 95% CI 0.32 to 26.77). The study did not report overall seizure reduction. We found low-certainty evidence that one fewer person per 1000 (CI 26 fewer to 388 more) with add-on felbamate had AE leading to study discontinuation compared to add-on placebo (one study, 73 participants; RR 0.97, 95% CI 0.06 to 14.97). Two studies compared add-on lamotrigine with add-on placebo. Neither study reported overall seizure cessation. We found high-certainty evidence that 176 more people per 1000 (CI 30 more to 434 more) had ≥ 50% average seizure reduction with add-on lamotrigine compared to add-on placebo (one study; 167 participants; RR 2.12, 95% CI 1.19 to 3.76). We found low-certainty evidence that 40 fewer people per 1000 (CI 68 fewer to 64 more) had AE leading to study-discontinuation with add-on lamotrigine compared to add-on placebo (one study; 169 participants; RR 0.49, 95% CI 0.13 to 1.82). Two studies compared add-on rufinamide with add-on placebo. Neither study reported seizure cessation. We found high-certainty evidence that 202 more people per 1000 (CI 34 to 567 more) had ≥ 50% average seizure reduction (one study; 138 participants; RR 2.84, 95% CI 1.31 to 6.18). We found low-certainty evidence that 105 more people per 1000 (CI 17 fewer to 967 more) had AE leading to study discontinuation with add-on rufinamide compared to add-on placebo (one study; 59 participants; RR 4.14, 95% CI 0.49 to 34.86). One study compared add-on rufinamide with another add-on ASM. This study did not report overall seizure cessation or reduction. We found low-certainty evidence that three fewer people per 1000 (CI 75 fewer to 715 more) had AE leading to study discontinuation with add-on rufinamide compared to another add-on ASM (one study; 37 participants; RR 0.96, 95% CI 0.10 to 9.57). One study compared add-on topiramate with add-on placebo. This study did not report overall seizure cessation. We found low-certainty evidence for ≥ 75% average seizure reduction with add-on topiramate (one study; 98 participants; Peto odds ratio (Peto OR) 8.22, 99% CI 0.60 to 112.62) and little or no difference to AE leading to study discontinuation compared to add-on placebo; no participants experienced AE leading to study discontinuation (one study; 98 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

RCTs of monotherapy and head-to-head comparison of add-on ASMs are currently lacking. However, we found high-certainty evidence for overall seizure reduction with add-on lamotrigine and rufinamide, with low-certainty evidence for AE leading to study discontinuation compared with add-on placebo or another add-on ASM. The evidence for other add-on ASMs for overall seizure cessation or reduction was low to very low with high- to low-certainty evidence for AE leading to study discontinuation. Future research should consider outcome reporting of overall seizure reduction (applying automated seizure detection devices), impact on development, cognition and behaviour; future research should also investigate age-specific efficacy of ASMs and target underlying aetiologies.

Evaluation of psychiatric comorbidity in attention-deficit hyperactivity disorder with epilepsy: A case-control study

OBJECTIVE

Attention deficit/hyperactivity disorder (ADHD) is a developmental disorder caused by structural and functional brain abnormalities as well as genetic and environmental factors. ADHD symptoms are commonly observed in individuals with epilepsy. A few studies have reported a pattern of behavioral problems in children with combined epilepsy and ADHD. We aimed to evaluate comorbid behavioral problems and mental health concerns among children with epilepsy with ADHD and without ADHD including autism spectrum disorder, anxiety, depression, somatic problems, oppositional defiant disorder, and conduct disorder.

METHODS

A total of 100 children aged between 6 and 11 years were recruited and categorized into 1 of 5 groups (20 child/group): (1) epilepsy, (2) epilepsy with ADHD, (3) ADHD with electroencephalogram (EEG) changes, (4) ADHD without EEG changes, and (5) healthy control. The scales used in our study included the Childhood Autism Spectrum Test (CAST) to screen autism spectrum conditions and related social and communication conditions, Conners' Parent Rating Scale (CPRS) to assess ADHD and other comorbid behavioral and social-emotional difficulties, and Children Behavior Checklist (CBCL) to evaluate behavior problems.

RESULTS

The CAST scale score showed no significant difference among the studied groups. Regarding the Conners-3 scale, the combined type of ADHD was predominant in the ADHD with EEG changes group and the ADHD with epilepsy group, while hyperactive ADHD was predominant in the ADHD without EEG changes group. The ADHD with EEG changes group and the ADHD with epilepsy group had equally high clinical rating scores for CBCL in internalizing and externalizing problems. There was a significant difference in the profile of all Diagnostic and Statistical Manual of Mental Disorders (DSM-5) scales of CBCL among the studied groups.

CONCLUSION

This is the first study to use EEG in patients with ADHD in comparison with epilepsy. ADHD with epilepsy is closely related to ADHD with EEG changes regarding psychiatric comorbidity in terms of anxiety, depression, somatic problems, oppositional defiance problems, and conduct problems.

Evaluation of pediatric patients in new-onset seizure clinic (NOSc)

AIM

We evaluated the clinical and demographic features of children presenting with unprovoked seizures at a regional new-onset seizure clinic (NOSc).

METHODS

We retrospectively reviewed charts of 492 consecutive patients evaluated in the NOSc at the Childrne's Healthcare of Atlanta RESULTS: Nonepileptic events (NEE) were diagnosed in 102 (24%) and epileptic seizures in the remaining 326 (76%). Patients with NEE were younger than patients with epileptic seizure (5.0 vs. 7.4 years). Except for headache which occurred more frequently in NEE (14% vs. 6%), frequencies of comorbidities were similar in groups with NEE and epileptic seizure. Electroencephalogram (EEG) was performed in 98%, and finding was abnormal in 51%. Brain magnetic resonance imaging (MRI) was performed in 55%, and finding was abnormal in 15%. An electroclinical epilepsy syndrome was diagnosed in 42%. Antiseizure medication was started in 25% with first seizure and in 77% with recurrent seizures.

INTERPRETATION

For children with newly-presenting seizures, a regional NOSc provided efficient, timely diagnosis and appropriate evaluations and treatment. Timely recognition of NEE resulted in fewer unnecessary evaluations and treatment for a quarter of referred patients whereas identification of the specific types of seizures and epilepsy allowed appropriate use, including deferral, of neuroimaging and guided treatment selection.

Sociodemographic, Electrophysiological, and Biochemical Profiles in Children with Attention Deficit Hyperactivity Disorder and/or Epilepsy

Attention deficit hyperactivity disorder (ADHD) is among the most prevalent neurobehavioral disorders affecting children worldwide. The prevalence of ADHD is higher in children with epilepsy. Despite the plethora of conducted work, the precise cause of ADHD is not identified yet. We studied here the sociodemographic, clinical, electrophysiological, and biochemical profiles of children with ADHD, epilepsy, and ADHD with epilepsy. Subjects were divided into 4 groups (25 child/group): I—control, II—ADHD, III—epilepsy, and IV—ADHD with epilepsy. Male to female ratio was significantly (p < 0.05) higher in the ADHD (3.1) and ADHD with epilepsy (2.1) groups when compared to the control (1.08) or epilepsy (1.08) groups. Positive family history was significantly evident in patients with epilepsy and ADHD with epilepsy, but not in the control or ADHD groups. Speech development was significantly delayed in the ADHD and ADHD with epilepsy groups. EEG abnormalities were detected in patients with ADHD (12%) and ADHD with epilepsy (68%). Focal frontal activities were significantly detectable in the ADHD (100%) and ADHD with epilepsy (77.8%) groups, whereas focal temporal activity was significantly present in the epilepsy (83.3%) group. Serum ferritin was significantly lower in the ADHD group (110.27 ± 6.64 ηg/ml) when compared to the control (134.23 ± 14.82 ηg/ml), epilepsy (159.66 ± 33.17 ηg/ml), and ADHD with epilepsy (203.04 ± 50.64 ηg/ml) groups. Serum zinc was significantly higher in the ADHD, epilepsy, and ADHD with epilepsy groups (236.63 ± 20.89, 286.74 ± 43.84, and 229.95 ± 67.34 μg/dl, respectively), when compared to the control group (144.21 ± 17.40 μg/dl). Serum adenosine deaminase was insignificantly different among the groups. Our results indicate that gender and family history are significant moderators in the aetiology of ADHD and epilepsy or their comorbidity. We also demonstrated that EEG could be central in the assessment of ADHD with epilepsy cases. Serum ferritin and zinc alteration may contribute significantly in ADHD and epilepsy pathophysiology.

Incidence of Childhood Epilepsy in Estonia

The aim of this prospective epidemiological study was to establish the incidence rate of childhood epilepsy in Estonia, to describe the clinical spectrum and to identify etiology of childhood epilepsy. The overall incidence rate was 86.3/100 000. The incidence rate was the highest (141.9/100 000) in the age group from 5 to 9 years. Specific electroclinical syndromes were identified in 22.8% of cases. Structural or metabolic etiology was identified in 20.0% of cases, presumed genetic origin was identified in 33.9% of cases, and in 46.1% of cases the cause of epilepsy remained unknown. The incidence rate of childhood epilepsy in Estonia (86.3/100 000) is similar to the other European countries. In comparison with the results of the first epidemiological study of childhood epilepsy in Estonia (incidence rate 45/100 000; Beilmann et al), the incidence rate in this study is almost 2 times higher, what can be explained with better case collection and improved diagnostic modalities in Estonia.

Seizures, syndromes, and etiologies in childhood epilepsy: The International League Against Epilepsy 1981, 1989, and 2017 classifications used in a population-based cohort

OBJECTIVE

The study provides updated information about the distribution of seizures, epilepsies, and etiologies of epilepsy in the general child population, and compares the old and new classification systems from the International League Against Epilepsy (ILAE).

METHODS

The study platform was the Norwegian Mother and Child Cohort Study. Cases of epilepsy were identified through registry linkages and sequential parental questionnaires. Epilepsy diagnoses were validated using a standardized protocol, and seizures, epilepsies, and etiologies were classified according to the old (ILAE 1981/1989) and new (ILAE 2017) classifications. Information was collected through medical record reviews and/or parental telephone interviews.

RESULTS

The study population included 112,744 children aged 3-13 years at the end of follow-up on December 31, 2012. Of these, there were 606 children with epilepsy (CWE). Distribution of seizure types varied by age of onset. Multiple seizure types were common with early onset. Focal epilepsies were the most common, occurring in 317 per 100,000 children in the study population and in 59% of CWE. Generalized epilepsies were found in 190 per 100,000 (35% of CWE). CWE with onset during the first 2 years of life had an even distribution of focal and generalized epilepsies, whereas focal epilepsies became dominant at later ages of onset. A definite cause of epilepsy had been demonstrated in 33% of CWE. The ILAE 1989 classification allowed for a broad syndrome category in 93% of CWE and a defined epileptic syndrome in 37%. With the ILAE 2017 classification, 41% of CWE had a defined epileptic syndrome and 63% had either a defined syndrome or structural-metabolic etiology.

SIGNIFICANCE

The distribution of seizures and epilepsies is strongly dependent on age of onset. Despite diagnostic advances, the causes of epilepsy are still unknown in two-thirds of CWE. The ILAE 2017 classifications allow for a higher precision of diagnoses, but at the expense of leaving more epilepsies classifiable only at the mode of onset level.

A critical evaluation of the gamma-hydroxybutyrate (GHB) model of absence seizures

Typical absence seizures (ASs) are nonconvulsive epileptic events which are commonly observed in pediatric and juvenile epilepsies and may be present in adults suffering from other idiopathic generalized epilepsies. Our understanding of the pathophysiological mechanisms of ASs has been greatly advanced by the availability of genetic and pharmacological models, in particular the γ-hydroxybutyrate (GHB) model which, in recent years, has been extensively used in studies in transgenic mice. GHB is an endogenous brain molecule that upon administration to various species, including humans, induces not only ASs but also a state of sedation/hypnosis. Analysis of the available data clearly indicates that only in the rat does there exist a set of GHB-elicited behavioral and EEG events that can be confidently classified as ASs. Other GHB activities, particularly in mice, appear to be mostly of a sedative/hypnotic nature: thus, their relevance to ASs requires further investigation. At the molecular level, GHB acts as a weak GABA-B agonist, while the existence of a GHB receptor remains elusive. The pre- and postsynaptic actions underlying GHB-elicited ASs have been thoroughly elucidated in thalamus, but little is known about the cellular/network effects of GHB in neocortex, the other brain region involved in the generation of ASs.

Current advances in childhood absence epilepsy

BACKGROUND

Childhood absence epilepsy is an age-dependent, idiopathic, generalized epilepsy with a characteristic seizure appearance. The disorder is likely to be multifactorial, resulting from interactions between genetic and acquired factors, but the debate is still open. We review recent studies on different aspects of childhood absence epilepsy and also to describe new concepts.

METHODS

Data for this review were identified using Medline and PubMed survey to locate studies dealing with childhood absence epilepsy. Searches included articles published between 1924 and 2013.

RESULTS

The diagnosis comprises predominant and associated seizure types associated with other clinical and electroencephalographic characteristics. Many studies have challenged the prevailing concepts, particularly with respect to the pathophysiological mechanisms underlying the electroencephalographic seizure discharges. Childhood absence epilepsy fits the definition of system epilepsy as a condition resulting from the persisting susceptibility of the thalamocortical system as a whole to generate seizures. This syndrome, if properly defined using strict diagnostic criteria, has a good prognosis. In some cases, it may affect multiple cognitive functions determining risk for academic and functional difficulties; the detection of children at risk allows tailored interventions. Childhood absence epilepsy is usually treated with ethosuximide, valproate, lamotrigine, or levetiracetam, but the most efficacious and tolerable initial empirical treatment has not been well defined.

CONCLUSIONS

We review recent studies and new concepts on the electroclinical features and pathophysiological findings of childhood absence epilepsy in order to highlight areas of consensus as well as areas of uncertainty that indicate directions for future research.

Long-term seizure remission in childhood absence epilepsy: might initial treatment matter?

OBJECTIVE

Examine the possible association between long-term seizure outcome in childhood absence epilepsy (CAE) and the initial treatment choice.

METHODS

Children with CAE were prospectively recruited at initial diagnosis and followed in a community-based cohort study. Children presenting with convulsive seizures, significant imaging abnormalities, or who were followed <5 years were excluded. Early outcomes included success of initial medication, early remission, and pharmacoresistance. The primary long-term outcome was complete remission: ≥5 years both seizure free and medication free. Survival methods were used for analyses.

RESULTS

The first medication was ethosuximde (ESM) in 41 (69%) and valproic acid (VPA) in 18 (31%). Initial success rates were 59% (ESM) and 56% (VPA). Early remission and pharmacoresistance were similar in each group. Apart from atypical electroencephalography (EEG) features (61% [VPA], 17% [ESM]), no clinical features varied substantially between the treatment groups. Complete remission occurred in 31 children (76%) treated with ESM and 7 (39%) who received VPA (p = 0.007). Children with versus without atypical EEG features were less likely to enter complete remission (50% vs. 71%, p = 0.03). In a Cox regression, ESM was associated with a higher rate of complete remission than VPA (hazards ratio [HR] 2.5, 95% confidence interval [CI] 1.1-6.0; p = 0.03). Atypical EEG features did not independently predict outcome (p = 0.15). Five-year and 10-year remission, regardless of continued treatment, occurred more often in children initially treated with ESM versus VPA.

SIGNIFICANCE

These findings are congruent with results of studies in genetic absence models in rats and provide preliminary evidence motivating a hypothesis regarding potential disease-modifying effects of ESM in CAE. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

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.

A neurodevelopmental basis for BECTS: evidence from structural MRI

PURPOSE

BECTS (benign epilepsy with centro-temporal spikes) is one of the most common childhood-onset epilepsy syndromes. We investigated quantitative evidence for brain morphological variation associated with BECTS to provide insights into the neuroanatomical basis of this disorder.

METHODS

Three independent BECTS groups were imaged at different stages: (a) near onset (n=16, mean age 9.3±1.6 years), (b) ~9 years after onset (n=9, mean age 15.8±2.3 years), and (c) ~15 years after onset (n=10, mean age 22.7±2.7 years). Age-matched controls were imaged with each group. Whole brain T1-weighted MRI was acquired. Voxel-based morphometry (groups a-c) and cortical thickness analyses (groups b and c) were undertaken within each group and for the groups combined. The relationship between cortical morphology and age was investigated.

KEY FINDINGS

The voxel-based morphometry analysis indicated increased bilateral grey matter volume in the superior frontal gyrus, insula and right inferior frontal gyrus regions in BECTS. The magnitude of the increase lessened with age of the cases. Cortical thickness analysis revealed thicker cortex in BECTS along middle and inferior frontal gyri bilaterally, left insula and bilateral supramarginal gyrus in the 9-year-after-onset group, that normalised with age. The rate of cortical thickness changes with age were greater in BECTS cases than in controls.

SIGNIFICANCE

Increased cortical gray matter associated with BECTS was found. The decreasing magnitude of the effect with increasing age parallels the natural history of the disorder. The areas affected are consistent with neurocognitive dysfunction in BECTS.

Clinical characteristics and use of antiepileptic drugs among adolescents with uncomplicated epilepsy at a referral center in Novi Sad, Serbia

The study aimed to investigate the type and etiology of epileptic seizures and the use of antiepileptic drugs for the treatment of various forms of epileptic seizures among adolescents with active but uncomplicated epilepsy at a tertiary referral center in Novi Sad, Serbia. The study design was cross sectional. Data were obtained from patients and medical records. A total of 103 adolescents (39 males and 64 females) with active but uncomplicated epilepsy were included. Patients with primary generalized seizures had significantly better control of epilepsy than those with partial seizures with or without secondary generalization. A total of 80 (77.7%) adolescents had no known underlying etiology based on initial diagnosis and evaluation. All adolescents were classified into known idiopathic syndromes (54.4%), non-classifiable cryptogenic etiology (23.3%), and secondary epilepsy attributed to MRI-identified lesions (22.3%). Eighty-eight percent of adolescents were taking monotherapy and 64.8% of these were taking valproate. New antiepileptic drugs (AEDs), topiramate and lamotrigine, the only drugs available free of charge at the Serbian market, were used in 19.4% of patients. A total of 57.3% adolescents were seizure-free, 24.2% had occasional seizures, and 18.5% had seizures despite AED treatment.

Two epileptic syndromes, one brain: childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes

Childhood absence epilepsy (CAE) and benign childhood epilepsy with centrotemporal spikes (BCECTS), or benign rolandic epilepsy (BRE), are the most common forms of childhood epilepsy. CAE and BCECTS are well-known and clearly defined syndromes; although they are strongly dissimilar in terms of their pathophysiology, these functional epileptic disturbances share many features such as similar age at onset, overall good prognosis, and inheritance factors. Few reports are available on the concomitance of CAE and BCECTS in the same patients or the later occurrence of generalized epilepsy in patients with a history of partial epilepsy. In most cases described in the literature, absence seizures always started after the onset of benign focal epilepsy but the contrary has never occurred yet. We describe two patients affected by idiopathic generalized epileptic syndrome with typical absences, who experienced BCECTS after remission of seizures and normalization of EEG recordings. While the coexistence of different seizure types within an epileptic syndrome is not uncommon, the occurrence of childhood absence and BCECTS in the same child appears to be extremely rare, and this extraordinary event supports the hypothesis that CAE and BCECTS are two distinct epileptic conditions. However, recent interesting observations in animal models suggest that BCECTS and CAE could be pathophysiologically related and that genetic links could play a large role.

Hippocampal size anomalies in a community-based cohort with childhood-onset epilepsy

OBJECTIVES

Epidemiologic evidence suggests the natural history of refractory mesial temporal lobe epilepsy is complicated, yet little is known about the hippocampus from the nontertiary center perspective.

METHODS

In a community-based cohort, individuals with nonsyndromic focal epilepsy with onset <16 years and controls had research MRI scans. Hippocampal (HC) volumes were manually measured, corrected for total brain volume, and converted to Z scores (Z(HC)) based on the controls' values. Volumes in cases and controls were compared.

RESULTS

Average volumes were not significantly different in cases with unknown cause (n = 117) relative to controls (n = 63). The group with structural and other conditions (n = 23) had significantly smaller volumes. Asymmetry (larger/smaller HC) did not vary among the 3 groups. Hippocampal variances were significantly larger in each epilepsy group relative to controls. In the unknown cause group, 25 (21%) had extreme() values: 15 (13%) with Z(HC) >1.96; 10 (9%) with Z(HC) <-1.96. By contrast, 2/63 (3%) controls had extreme values (p = 0.001). Within the unknown cause group, temporal lobe epilepsy (TLE) cases were more likely to have extreme hippocampal volumes than non-TLE (31% vs 15%, p = 0.03). Extreme volumes were generally interpreted as normal visually. These anomalies were not associated with seizure remission or pharmacoresistance.

CONCLUSIONS

Classic mesial TLE with hippocampal sclerosis is an uncommon finding in the general population. Volume anomalies, both large and small, are often bilateral. The significance of these findings is unclear; however, speculations regarding preexisting hippocampal pathology (e.g., dysplasia) as a factor in TLE and other neocortical epilepsies have been made by others.

Childhood absence epilepsy: Elctroclinical features and diagnostic criteria

OBJECTIVE

To analyze the electroclinical features of children with childhood absence epilepsy (CAE) and discuss the diagnostic criteria for CAE.

METHODS

The video-electroencephalogram (VEEG) database in our hospital was searched using "absence seizures" and "3-Hz generalized spike and waves (GSW)" as key-words. Other epileptic syndromes with typical absence seizures were carefully excluded. Children meeting the CAE diagnostic criteria of the International League Against Epilepsy (ILAE) in 1989 were further evaluated with the diagnostic criteria proposed by Panayiotopoulos in 2005.

RESULTS

Totally 37 children met the 1989 ILAE criteria of CAE. The onset age of absence seizures ranged from 3 to 11 years. All patients had frequent absence seizures (5-60 times per day). Two patients (5.4%) had generalized tonic-clonic seizures. Hyperventilation induced absences in all patients. VEEG confirmed that 7 patients (18.9%) had only simple absences, 25 patients (67.6%) had only complex absences, and 5 patients (13.5%) had both simple and complex absences. Ictal EEG showed 3Hz GSW discharges in all patients. The seizure duration ranged from 3 to 40s. Four patients (10.8%) had two spikes per wave in ictal EEG. GSW fragments were found in 29 patients (78.4%) during sleep. Interictal polyspikes and waves were present in 17 patients (45.9%). Focal discharges predominantly in the anterior regions, were found in 22 patients (56.8%). Only 7 patients (18.9%) met the diagnostic criteria proposed by Panayiotopoulos in 2005.

CONCLUSIONS

Few patients meeting the 1989 ILAE diagnostic criteria for CAE meet the new diagnostic criteria proposed by Panayiotopoulos in 2005. The new criteria for CAE are too strict to appropriately classify some patients.

A pilot study of topiramate in childhood absence epilepsy

OBJECTIVE

Evaluate the antiepileptic effect of topiramate monotherapy in childhood absence epilepsy (CAE).

MATERIALS AND METHODS

Childhood absence epilepsy patients aged 4-9 years were initiated with topiramate 15 or 25 mg/day, which was titrated upwards until patients were free of absence seizures. The primary efficacy outcome was seizure-free rates after a 12-week maintenance period.

RESULTS

The study was terminated early due to lack of efficacy after enrollment of 12 patients. Four patients completed the study; two became clinically seizure-free, but without a significant reduction in the number of electrographic seizures. Six patients discontinued for lack of efficacy, none due to adverse events (AEs). Mean reduction in seizure count was seen on Days 22 (P = 0.0391) and 36 (P = 0.0156) and percentage of days with seizures decreased from baseline. Most AEs were mild.

CONCLUSIONS

Although well-tolerated, this pilot study did not demonstrate an antiepileptic effect of topiramate monotherapy for treatment of CAE.

Identification of pharmacoresistant epilepsy

There is no single definition of pharmacoresistant (intractable, refractory) epilepsy. Prospective identification of pharmacoresistance is complicated by the variability of its appearance across different types of epilepsy and the variability of seizure control within a given patient over time. Failure of informative trials of two appropriate antiepileptic drugs has been recommended as a threshold that should trigger referral for evaluation at a comprehensive epilepsy center. Maximizing seizure control is imperative for reducing the risks and consequences of epilepsy, including the cognitive and psychiatric comorbidities and even sudden death.

Partial seizures and atypical absence seizures as a single ictal event in a patient with Lennox-Gastaut syndrome

The authors report a patient with Lennox-Gastaut syndrome who was a fraternal twin. The twins encountered myoclonic seizures at the age of 4 years, but the seizures in the other patient were controlled very quickly without intellectual development damage. With the disease evolving, other characteristic seizures of Lennox-Gastaut syndrome appeared and failed to be controlled by multiple antiepileptic drugs, so levetiracetam was added on. At this time, frequent partial seizures from the left occipital and posterior temporal regions occurred, which always intermixed with atypical absence seizures in a single ictal event. To control the status epilepticus, levetiracetam was withdrawn immediately, and clonazepam, midazolam, and corticotropin in turn were used. The partial seizures were gradually alleviated. The results obtained in this study suggest that there might be some correlative mechanisms between partial seizures and atypical absence seizures in a single event. There is a temporal relationship between the occurrence of partial seizures and the introduction of levetiracetam.

Hyperglycosylation and reduced GABA currents of mutated GABRB3 polypeptide in remitting childhood absence epilepsy

Childhood absence epilepsy (CAE) accounts for 10% to 12% of epilepsy in children under 16 years of age. We screened for mutations in the GABA(A) receptor (GABAR) beta 3 subunit gene (GABRB3) in 48 probands and families with remitting CAE. We found that four out of 48 families (8%) had mutations in GABRB3. One heterozygous missense mutation (P11S) in exon 1a segregated with four CAE-affected persons in one multiplex, two-generation Mexican family. P11S was also found in a singleton from Mexico. Another heterozygous missense mutation (S15F) was present in a singleton from Honduras. An exon 2 heterozygous missense mutation (G32R) was present in two CAE-affected persons and two persons affected with EEG-recorded spike and/or sharp wave in a two-generation Honduran family. All mutations were absent in 630 controls. We studied functions and possible pathogenicity by expressing mutations in HeLa cells with the use of Western blots and an in vitro translation and translocation system. Expression levels did not differ from those of controls, but all mutations showed hyperglycosylation in the in vitro translation and translocation system with canine microsomes. Functional analysis of human GABA(A) receptors (alpha 1 beta 3-v2 gamma 2S, alpha 1 beta 3-v2[P11S]gamma 2S, alpha 1 beta 3-v2[S15F]gamma 2S, and alpha 1 beta 3-v2[G32R]gamma 2S) transiently expressed in HEK293T cells with the use of rapid agonist application showed that each amino acid transversion in the beta 3-v2 subunit (P11S, S15F, and G32R) reduced GABA-evoked current density from whole cells. Mutated beta 3 subunit protein could thus cause absence seizures through a gain in glycosylation of mutated exon 1a and exon 2, affecting maturation and trafficking of GABAR from endoplasmic reticulum to cell surface and resulting in reduced GABA-evoked currents.

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.

Pharmacological treatment of childhood absence epilepsy

This review discusses current pharmacological treatment of childhood absence epilepsy (CAE). The key to successful treatment is the correct diagnosis of the epileptic syndrome, hence the initial part of the paper discusses the definition, diagnostic criteria and epidemiology. This is followed by a detailed analysis of pharmacological agents used in the treatment of CAE. The characteristics of old and new anticonvulsants used in the treatment of CAE are also reviewed. For each of the drugs, the mechanism of action, usual dose, common side effects and recommendations for treatment are also discussed. A separate section focuses on instances when anticonvulsants may exacerbate seizures. Particular emphasis is given to the evidence currently available, on which clinical practice needs to be based.

Phenotype definition in epilepsy

Phenotype definition consists of the use of epidemiologic, biological, molecular, or computational methods to systematically select features of a disorder that might result from distinct genetic influences. By carefully defining the target phenotype, or dividing the sample by phenotypic characteristics, we can hope to narrow the range of genes that influence risk for the trait in the study population, thereby increasing the likelihood of finding them. In this article, fundamental issues that arise in phenotyping in epilepsy and other disorders are reviewed, and factors complicating genotype-phenotype correlation are discussed. Methods of data collection, analysis, and interpretation are addressed, focusing on epidemiologic studies. With this foundation in place, the epilepsy subtypes and clinical features that appear to have a genetic basis are described, and the epidemiologic studies that have provided evidence for the heritability of these phenotypic characteristics, supporting their use in future genetic investigations, are reviewed. Finally, several molecular approaches to phenotype definition are discussed, in which the molecular defect, rather than the clinical phenotype, is used as a starting point.

Idiopathic generalized epilepsies: clinical and electroencephalogram diagnosis and treatment

This review concentrates on the principles of the clinical and electroencephalogram diagnosis of idiopathic generalized epilepsies and their treatment. The electroclinical variability of the main seizure types is detailed and particular emphasis is placed on the differential diagnosis from other seizures and nonepileptic conditions that is essential for the optimal management of these patients. The authors review the various idiopathic generalized epilepsy subsyndromes and conditions that are included in both the 1989 International League Against Epilepsy classification system and the recently proposed International League Against Epilepsy scheme, but also syndromes and forms that have not been formally recognized. Finally, the authors describe the principles of antiepileptic drug treatment with the old and newer drugs, and their specific indications and contraindications in the various syndromes and seizure types.

[Typical absence seizure: epidemiological and clinical characteristics and outcome]

OBJECTIVE

To analyze the epidemiological and clinical characteristics and outcome of absence epilepsy in the pediatric age group with the aim of facilitating its diagnosis in clinical practice.

PATIENTS AND METHODS

Information on epidemiological and clinical characteristics, complementary investigations, and outcome was collected from the medical records of 51 children with absence epilepsy. The criteria defined by the International League Against Epilepsy (ILAE) were used in the diagnosis.

RESULTS

Fifty-one percent of the patients had simple absence seizures and 49% had complex absence seizures. A total of 70.6% of the patients were school-aged children and the prevalence was greater among girls (72.5%). The mean age at onset was 7.5 +/- 2.7 years. In 80%, there were multiple seizures per day with a mean duration of 12 seconds. School performance was impaired in 19.6%. Ictal electroencephalogram showed generalized 3 Hz spike and slow wave complexes in 84.3%. Hyperventilation was positive in 98%, and intermittent photic stimulation was positive in 15.7%. The seizures were controlled by sodium valproate (mean dosage: 26 mg/kg/day) in 84.3% of the patients. In 43 patients antiepileptic drugs were withdrawn (mean duration: 3.3 +/- 0.6 years) but 3 patients relapsed.

CONCLUSIONS

Typical absences are a common type of epilepsy in the pediatric age group and generally begin in school-aged children. Absences may be difficult to detect and can impair learning. Treatment response is excellent. Nevertheless, because absences may be the first manifestation of severe forms of epilepsy syndromes, strict follow-up of these patients is essential.

Risk factors for childhood epilepsy: a case-control study

BACKGROUND

Risk factors for epilepsy are conditions associated with an increased frequency of epilepsy, and those for childhood epilepsy are different from those for epilepsy occurring later in life. In the present matched case-control study, we attempted to identify some possible risk factors for childhood epilepsy.

METHODS

All children with epilepsy who attended the clinic of Motahary in Shiraz, Iran during a 6-month period were included in the study. Neurologically normal children, matched for age and sex, visiting the same clinic were considered as controls. The data on patients and controls were obtained from answers to a questionnaire obtained through personal interviews. Details on the patient, family history, parental smoking, breast versus formula feeding, and parental age at the time of childbirth were included. Medical records were then reviewed.

RESULTS

In total, 142 patients and 138 controls participated. Positive family history of epilepsy increased the risk of developing epilepsy by 3.34-fold. A higher risk of epilepsy was observed in patients living in rural areas (OR = 2.44).

CONCLUSIONS

Positive family history of epilepsy and residence in rural areas were the two major risk factors associated with epilepsy in this study; neonatal jaundice, parental age, and passive smoke exposure added no risk. Breast-feeding was not shown to have a protective effect against development of epilepsy.

Genetic liability to epilepsy in Kerala State, India

BACKGROUND

Familial clustering is common in epilepsies, but pedigree patterns suggest a multi-factorial inheritance. Genetic liability for multi-factorial inheritance is population specific and such data are not available for the population of Kerala or other states in south India.

OBJECTIVES

In this study, we have attempted to determine the genetic liability to epilepsy based on an adult population of this state.

MATERIAL AND METHODS

Pedigrees were recorded for probands who reported to the Kerala Registry of Epilepsy and Pregnancy. In order to obtain a genetically matched sample for comparison and estimation of empiric risks, we have used the family history of the spouse except when the spouse was proband's relative. The ILAE criteria were followed for diagnosis and classification of epilepsy.

RESULTS

Data were collected on 18,419 family members of 505 probands with epilepsy (82 men and 423 women) and 10,231 family members of spouses (control). The frequency of epilepsy in first and second-degree relatives of the spouses was comparable to the population frequency (0.5%), justifying the use of this sample as control. Positive family history was observed in 22.2% of probands and 8.24% of controls (Odd's Ratio 3.2, 95% Confidence Interval 2.12-4.73). An affected first-degree relative was observed in 7.5% of probands. The corresponding figure for GE, LRE and other epileptic syndromes were 10.2%, 5.8% and 5.12%, respectively. The segregation ratio for Juvenile Myoclonic Epilepsy (JME) (1:19) was higher than that for other types of Generalized Epilepsy (GE) (1:24) and Localization Related Epilepsy (LRE) (1:52). Prevalence of epilepsy among the first-degree relatives (1.96%) was greater than the square root of the population frequency (0.51%) and was higher than that for second-degree (1.24%) and third-degree (0.64%) relatives for the probands. Probands had higher parental consanguinity (13.07%) compared to controls (6.64%). The above factors support a complex inheritance. Genetic liability to epilepsy (heritability) is greater for GE (0.6) and significantly higher for JME (0.7) compared to LRE (0.4). A limitation of this study is that the inferences are based on a predominantly adult female proband sample but no gender specific differences were identified.

CONCLUSIONS

The observations of this study indicate complex inheritance and the liability values are useful for genetic counseling in the local population. Further studies involving more individuals from younger age group and male gender are envisaged.

Fever, genes, and epilepsy

About 13% of patients with epilepsy have a history of febrile seizures (FS). Studies of familial forms suggest a genetic component to the epidemiological link. Indeed, in certain monogenic forms of FS, for which several loci have been reported, some patients develop epilepsy with a higher risk than in the general population. Patients with generalised epilepsy with febrile seizures plus (GEFS+) can have typical and isolated FS, FS lasting more beyond age 6 years, and subsequent afebrile (typically generalised) seizures. Mutations associated with GEFS+ were identified in genes for subunits of the voltage-gated sodium channel and the gamma2 subunit of the ligand-gated GABAA receptor. Screening for these genes in patients with severe myoclonic epilepsy in infancy showed de novo mutations of the alpha1 subunit of the voltage-gated sodium channel. Antecedent FS are commonly observed in temporal-lobe epilepsy (TLE). In sporadic mesial TLE-characterised by the sequence of complex FS in childhood, hippocampal sclerosis, and refractory temporal-lobe seizures-association studies suggested the role of several susceptibility genes. Work on some large pedigrees also suggests that FS and temporal-lobe seizures may have a common genetic basis, whether hippocampus sclerosis is present or not. The molecular defects identified in the genetic associations of FS and epileptic seizures are very attractive models to aid our understanding of epileptogenesis and susceptibility to seizure-provoking factors, especially fever.

Modeling remission and relapse in pediatric epilepsy: application of a Markov process

Seizure outcome is frequently described in terms of patients ever attaining remission or being in terminal remission. Outcomes are more complicated and, over many years, repeated remission and relapses may occur. These are difficult to quantify with standard survival techniques used in analysis of remission and relapse. The Markov process, which allows one to track a patient's state (remission or not) over time, provides a suitable approach for studying repeated remission and relapse. In a prospective community-based study of children followed from the point of the initial diagnosis of epilepsy, we examined the probability of repeated remission and relapse over up to three different remission episodes (minimum 1 year each) per patient. The role of epilepsy syndrome was the main determinant of remission-relapse patterns considered in the analysis. Two different Markov models were used, one involving three states and the other seven states. Of 613 children initially recruited into the study, 602 were followed at least 1 year and thus eligible for the analysis. Almost 90% of the cohort experienced a remission; however, almost half then relapsed. Second remissions occurred in 81% of those who relapsed of whom 38% relapsed again. A third remission occurred in 82% of those after a second relapse of whom 58% relapsed yet again. After the first 2 years, approximately 70% of the cohort was in remission, 20% was no longer in remission having relapsed, and 10% had never been in remission. Significant differences were seen by underlying epilepsy syndrome. Children with one of the epileptic encephalopathies were least likely of all syndrome groups ever to remit. Those with symptomatic partial epilepsies were less likely to remit than children with any of the other syndromes, idiopathic partial or generalized, cryptogenic partial, and unclassified. Differences between these last groups became apparent when considering their subsequent remission and relapse histories. These differences were best seen in the seven-state model. For example, idiopathic partial epilepsies were most likely to enter remission and never relapse. By contrast, idiopathic generalized and cryptogenic partial epilepsies were more likely to remit and relapse repeatedly. The Markov approach provides an alternative to standard survival techniques for understanding remission and relapse outcomes in epilepsy. Its advantage is that it allows one to track the individuals' outcome over time even as the condition fluctuates. The technique would also be applicable in virtually any remitting-relapsing disorder.

Prevalence of epilepsy in Turkish children between the ages of 0 and 16 years

The aim of this cross-sectional study was to determine the prevalence of epilepsy in Turkey among children between the ages of 0 and 16 years. The study population consisted of 24,773,569 children living in Turkey. Because the prevalence of childhood epilepsy is reported to be 0.001 to 1% in the literature, the sample size was determined as 48,260, with 0.05 error type I and 0.10 error type 2 (power 0.90), and the effect size was 2. With the cluster sampling method, samples were selected from cities, towns, districts, and villages, and 46,813 (97%) children were reached. The study questionnaire contained sections with individual informational questions and questions for the selection of suspected epilepsy cases and physical examination results. The epilepsy classification was designed according to the classification of the International League Against Epilepsy (ILAE). The prevalence of epilepsy was determined as 0.8%; 55.2% of the subjects with epilepsy were grouped as generalized, 39% as partial, and 5.8% as unidentified. Age, place of residence, route of delivery, place of delivery, and social and economic status had no statistically significant effect on the development of epilepsy. Male gender, preterm, and post-term delivery increased the risk of developing epilepsy. Early diagnosis and treatment of epilepsy, as well as the education of health workers and families, are very important.

Specific Epileptic Syndromes Are Rare Even in Tertiary Epilepsy Centers: A Patient‐oriented Approach to Epilepsy Classification

PURPOSE

To assess the practicability and reliability of a five-dimensional patient-oriented epilepsy classification and to compare it with the International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The dimensions consist of the epileptogenic zone, semiologic seizure type(s), etiology, related medical conditions, and seizure frequency.

METHODS

The 185 epilepsy patients (94 adults, 91 children, aged 18 years or younger) were randomly selected from the database of a tertiary epilepsy center and the general neurological department of a metropolitan hospital (28 adults). The charts were reviewed independently by two investigators and classified according to both the ILAE and the patient-oriented classification. Interrater reliability was assessed, and a final consensus among all investigators was established.

RESULTS

Only four (4%) adults and 19 (21%) children were diagnosed with a specific epilepsy syndrome of the ILAE classification. All other patients were in unspecific categories. The patient-oriented classification revealed that 64 adults and 56 children had focal epilepsy. In an additional 34 adults and 45 children, the epileptogenic zone could be localized to a certain brain region, and in 14 adults and five children, the epileptogenic zone could be lateralized. Fourteen adults and 21 children had generalized epilepsy. In 16 adults and 14 children, it remained unclear whether the epilepsy was focal or generalized. Generalized simple motor seizures were found in 66 adults and 52 children, representing the most frequent seizure type. Etiology could be determined in 40 adults and 45 children. Hippocampal sclerosis was the most frequent etiology in adults (10%), and cortical dysplasia (9%), in children. Seven adults and 31 children had at least daily seizures. Seventeen adults and 26 children had rare or no seizures at their last documented contact. The most frequent related medical conditions were psychiatric disorders and mental retardation. Interrater agreement was high (kappa values of 0.8 to 0.9) for both the patient-oriented and the ILAE classification.

CONCLUSIONS

Specific epilepsy syndromes included in the current ILAE classification are rare even in a tertiary epilepsy center. Most patients are included in unspecific categories that provide only incomplete information. In contrast, all of the patients could be classified by the five-dimensional patient-oriented classification, providing all essential information for the management of the patients with a high degree of interrater reliability.

Evidence for distinct genetic influences on generalized and localization-related epilepsy

PURPOSE

Determining the existence of syndrome-specific genetic factors in epilepsy is essential for phenotype definition in genetic linkage studies, and informs research on basic mechanisms. Analysis of concordance of epilepsy syndromes in families has been used to assess shared versus distinct genetic influences on generalized epilepsy (GE) and localization-related epilepsy (LRE). However, it is unclear how the results should be interpreted in relation to specific genetic hypotheses.

METHODS

To assess evidence for distinct genetic influences on GE and LRE, we examined concordance of GE and LRE in 63 families containing multiple individuals with idiopathic or cryptogenic epilepsy, drawn from the Epilepsy Family Study of Columbia University. To control for the number of concordant families expected by chance, we used a permutation test to compare the observed number with the number expected from the distribution of individuals with GE and LRE in the study families.

RESULTS

Of the families, 62% were concordant for epilepsy type, and 38% were discordant. In all analyses, the proportion of concordant families was significantly greater than expected.

CONCLUSIONS

This suggests that some genetic influences predispose specifically to either GE or LRE. Because of the ascertainment bias resulting from the selection of families containing multiple individuals with epilepsy, we could not test whether there are also shared genetic influences on these two epilepsy subtypes. Population-based studies will be needed to explore these results further.

Family study of epilepsy in first degree relatives: data from the Italian Episcreen Study

OBJECTIVE

To evaluate the family history of epilepsy in first degree relatives of probands with epilepsy.

METHODS

A sample of 10787 patients with epilepsy with complete information about first degree relatives (parents, siblings and offspring) was selected from the database of the Episcreen Project, the largest Italian observational study on epilepsy. Family history was assessed by: (1) prevalence estimates of epilepsy among proband's relatives, (2) modified cumulative risks (MCR), adjusted using proband's age as censoring time in life tables, (3) standardised morbidity ratios (SMR), using a sub-group of symptomatic epilepsies as control group.

RESULTS

Patients (9.1%) had a family history of epilepsy. The overall prevalence of epilepsy among first degree relatives was 2.6%. Idiopathic generalised epilepsies had the highest prevalence (5.3%). Cryptogenetic epilepsies had a lower prevalence (2.1%) than idiopathic epilepsies, but higher then symptomatic epilepsies (1.5%), both in generalised and focal forms (3.8% vs. 2.0% and 1.8% vs. 1.3%). A similar tendency was detected using MCR and SMR, with the higher values of risks/ratios for idiopathic and generalised epilepsies. Probands with idiopathic generalised epilepsies were highly concordant with respect to their relatives' type of epilepsy. Considering other strata factors, risks were higher in proband's epilepsies with an onset less then 14 years of age, while sex played no definite role in differentiating the family history.

CONCLUSIONS

The Episcreen model permits a variety of stratification factors to measure family risk, including age at onset, epilepsy localisation and aetiology with a large sample of more than 10,000 probands and 1065/40,544 relatives affected and classified.

Status epilepticus in a population-based cohort with childhood-onset epilepsy in Finland

Little is known about the time course over which status epilepticus occurs in childhood-onset epilepsy and its impact on long-term prognosis. A population-based cohort of 150 children younger than age 16 years with new onset epilepsy between 1961 and 1964 residing in the catchment area of Turku University Hospital was observed prospectively until 1997. The occurrence of status epilepticus and recurrent status epilepticus, risk factors for status epilepticus, and the impact of status epilepticus on prognosis were examined. Of the 150 cases, 41 patients (27%) experienced an episode of status epilepticus of whom 22 patients (56%) had two or more episodes. The risk of status epilepticus was highest at the onset of the disorder with 30 (73%) cases occurring before (n = 12) or at (n = 18) onset and 37 (90%) cases within 2 years of onset. On multivariable analysis, risk factors for status epilepticus included remote symptomatic cause, age of onset 6 years or younger, and partial seizures. Specific epilepsy syndromes also were associated with a differential risk of status epilepticus. The occurrence of status epilepticus did not alter the mortality rates and had only a modest impact on the probability of attaining remission. In subjects with no other neurological handicap, social and educational outcomes were similar in those with status epilepticus and those with no history of status epilepticus. We conclude that status epilepticus is a common occurrence in childhood-onset epilepsy. When it does occur, it occurs early in the course of the disorder. The occurrence of status epilepticus does not appear to have significant adverse impact on long-term prognosis of childhood-onset epilepsy.

Concordance of disease form in kindreds ascertained through affected individuals

When designing or conducting genetic epidemiological studies of a disease with several distinct forms, it is useful to know whether susceptibilities to the different forms are conferred by different genes or whether there are genes that confer susceptibility to multiple forms. A natural approach to exploring these issues is to examine how the disease forms cluster in kindreds. When inclusion in the study is based on the affection status of multiple relatives, however, distorted patterns of familial clustering of disease form can be evident. The purpose here is to present statistical methods for adjusting for this distortion. In particular, approaches to testing two null hypotheses are presented: a null hypothesis that corresponds to all genes acting in the same way on the relative risk of the different disease forms, and a null hypothesis that corresponds to each gene conferring susceptibility to distinct disease forms. The approaches are illustrated through an application to the generalized and localization-related forms of epilepsy.

Nonsymptomatic generalized epilepsy in children younger than six years: excellent prognosis, but classification should be reconsidered after follow-up: the Dutch Study of Epilepsy in Childhood

PURPOSE

To assess the prognosis and the accuracy of the epilepsy classification in young children with nonsymptomatic generalized epilepsy.

METHODS

Of the cohort of the Dutch Study of Epilepsy in Childhood (n = 466), all children younger than 6 years with a diagnosis of idiopathic (IGE) or cryptogenic (CGE) generalized epilepsy either at intake (n = 108) and/or after 2 years of follow-up (n = 102) were included. The number of reclassifications after 2 years was determined, and the reasons for reclassification were analyzed. All children receiving a diagnosis of IGE or CGE at 2 years were followed up for 5 years to study their outcome in terms of terminal remission (TR). Data on their level of intellectual functioning were collected at the start of this analysis.

RESULTS

The epilepsy syndrome was reclassified in 17 children. In 14 of them, the seizure type also was reclassified, and in three, the course of the epilepsy determined the new epilepsy type. Two other children had a reclassification of their seizure types without a change of the epilepsy type. Many children were categorized as having IGE not otherwise specified. In all probability, this is a heterogeneous group, containing patients with various epilepsy syndromes, with generalized tonic-clonic seizures as a common hallmark. Of the 102 children with IGE or CGE at 2 years of follow-up, 75% had a TR of >6 months after 2 years, and 85% a TR of >or=1 year after 5 years.

CONCLUSIONS

In a fair proportion of children with nonsymptomatic generalized epilepsy in this age group, it is not possible to classify firmly the epilepsy and/or the seizures immediately after the intake. Instead, they are reclassified during the course of the disease. This and the apparent heterogeneity of the category IGE not otherwise specified point to inherent drawbacks of the current International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The prognosis of IGE at this young age is generally excellent.

Epilepsy genetics

BACKGROUND

Epilepsy genetics is a complex and rapidly expanding field that involves the contributions and collaborative efforts of geneticists, molecular biologists, epidemiologists, and clinicians.

REVIEW SUMMARY

This article first provides a background review of basic terminology and contributions from the fields of epilepsy, genetics, and genetic epidemiology. It further describes the evidence for the genetic basis of epilepsy and enumerates the linkage findings and epilepsy susceptibility genes reported to date. It then addresses existing knowledge about the genetics of electroencephalogram abnormalities and their relationship to clinical epilepsy. Finally, it gives guidelines for genetic counseling, with attention to patients' frequently asked questions.

CONCLUSIONS

This review provides a framework for understanding current and future investigations in the field of epilepsy genetics and a way to assist and educate individuals and families living with epilepsy.

Update on the epidemiology and prognosis of pediatric epilepsy

Epilepsy is among the most common serious neurologic disorders in childhood. Epidemiologic studies over the past few decades have greatly increased current knowledge of the incidence and prognosis of seizures. Newer epidemiologic studies have used population- or community-based cohorts, and careful attention has been given to etiology and specific epilepsy syndromes, the two most important factors affecting prognosis. Risk of epilepsy is highest in patients with an associated serious neurologic abnormality, such as mental retardation or cerebral palsy. More than two thirds of patients with childhood-onset epilepsy ultimately achieve remission. Of those attaining remission on medications, approximately 70% remain seizure free when medications are discontinued. Mortality is increased in patients with epilepsy, but the increased mortality risk in childhood-onset epilepsy is primarily seen in patients with neurologic abnormalities or intractable epilepsy. Although long-term seizure outcomes are generally favorable, childhood-onset epilepsy is associated with adverse long-term psychosocial outcomes, even in patients attaining remission. This review summarizes recent data on the epidemiology and prognosis of pediatric epilepsy.

Treatment of typical absence seizures and related epileptic syndromes

Typical absences are brief (seconds) generalised seizures of sudden onset and termination. They have 2 essential components: clinically, the impairment of consciousness (absence) and, generalised 3 to 4Hz spike/polyspike and slow wave discharges on electroencephalogram (EEG). They differ fundamentally from other seizures and are pharmacologically unique. Their clinical and EEG manifestations are syndrome-related. Impairment of consciousness may be severe, moderate, mild or inconspicuous. This is often associated with motor manifestations, automatisms and autonomic disturbances. Clonic, tonic and atonic components alone or in combination are motor symptoms; myoclonia, mainly of facial muscles, is the most common. The ictal EEG discharge may be consistently brief (2 to 5 seconds) or long (15 to 30 seconds), continuous or fragmented, with single or multiple spikes associated with the slow wave. The intradischarge frequency may be constant or may vary (2.5 to 5Hz). Typical absences are easily precipitated by hyperventilation in about 90% of untreated patients. They are usually spontaneous, but can be triggered by photic, pattern, video games stimuli, and mental or emotional factors. Typical absences usually start in childhood or adolescence. They occur in around 10 to 15% of adults with epilepsies, often combined with other generalised seizures. They may remit with age or be lifelong. Syndromic diagnosis is important for treatment strategies and prognosis. Absences may be severe and the only seizure type, as in childhood absence epilepsy. They may predominate in other syndromes or be mild and nonpredominant in syndromes such as juvenile myoclonic epilepsy where myoclonic jerks and generalised tonic clonic seizures are the main concern. Typical absence status epilepticus occurs in about 30% of patients and is more common in certain syndromes, e.g. idiopathic generalised epilepsy with perioral myoclonia or phantom absences. Typical absence seizures are often easy to diagnose and treat. Valproic acid, ethosuximide and lamotrigine, alone or in combination, are first-line therapy. Valproic acid controls absences in 75% of patients and also GTCS (70%) and myoclonic jerks (75%); however, it may be undesirable for some women. Similarly, lamotrigine may control absences and GTCS in possibly 50 to 60% of patients, but may worsen myoclonic jerks; skin rashes are common. Ethosuximide controls 70% of absences, but it is unsuitable as monotherapy if other generalised seizures coexist. A combination of any of these 3 drugs may be needed for resistant cases. Low dosages of lamotrigine added to valproic acid may have a dramatic beneficial effect. Clonazepam, particularly in absences with myoclonic components, and acetazolamide may be useful adjunctive drugs.

A cross-sectional study which measures the prevalence and characteristics of prisoners who report a family history of epilepsy

Epilepsy is often a familial disorder, although it is not known if relatives of an epileptic proband suffer from any psychological disorders, even without a clinical manifestation of epilepsy. The present study considers this concept in the setting of the largest male prison in Europe, HMP Liverpool. The study formed part of the National Prison Needs Assessment Survey, and consisted of a cross-sectional, questionnaire study. There was a high response rate, and the results indicate that prisoners have a high prevalence of a family history of epilepsy. The study also showed that prisoners who report such a history have significantly more psychological symptoms than those prisoners without such a family history. The conclusion is that the psychological health of relatives of those with epilepsy requires further investigation because the morbidity is higher than expected and may be associated with offending behaviour.

Incidence of epilepsies and epileptic syndromes in children and adolescents: a population-based prospective study in Germany

PURPOSE

To estimate the incidence rate of epilepsies and epileptic syndromes in German children and adolescents aged 1 month to <15 years, and to provide data on their classification.

METHODS

A population-based prospective study was performed between July 1, 1999, and June 30, 2000. All children aged 1 month to <15 years with a newly diagnosed epilepsy or epileptic syndrome were recorded by private pediatricians, EEG laboratories, and the two University Children's Hospitals in the neighboring cities of Heidelberg and Mannheim. The diagnoses were classified according to the International Classification of Epilepsies and Epileptic Syndromes of the International League Against Epilepsy (ILAE).

RESULTS

The total age-adjusted annual incidence rate was 60/100,000 (95% confidence interval, 42-84), with the highest incidence in the first year of life (146/100,000). Focal epilepsies or epileptic syndromes (58%; incidence rate, 35/100,000) were more common than were generalized ones (39%; incidence rate, 24/100,000), and 3% (incidence rate, 2/100,000) of the epilepsies or epileptic syndromes were undetermined. The rate of idiopathic (47%; incidence rate, 29/100,000) and symptomatic or cryptogenic epilepsies (50%; incidence rate, 30/100,000) was equal. No significant difference in incidence between boys and girls was found.

CONCLUSIONS

Incidence rates for epilepsy in German children aged 1 month to <15 years are about equal to those of other countries in Europe and North America. In accordance with studies from the United States and from many European countries, incidence was highest in the first year of life, and no difference in the incidence between girls and boys was found. In Germany as throughout Europe, idiopathic generalized epileptic syndromes are more often diagnosed than in the United States.