Martha Feucht

15q13.3 microdeletions increase risk of idiopathic generalized epilepsy

We identified 15q13.3 microdeletions encompassing the CHRNA7 gene in 12 of 1,223 individuals with idiopathic generalized epilepsy (IGE), which were not detected in 3,699 controls (joint P = 5.32 × 10−8). Most deletion carriers showed common IGE syndromes without other features previously associated with 15q13.3 microdeletions, such as intellectual disability, autism or schizophrenia. Our results indicate that 15q13.3 microdeletions constitute the most prevalent risk factor for common epilepsies identified to date.

Recurrent microdeletions at 15q11.2 and 16p13.11 predispose to idiopathic generalized epilepsies

Idiopathic generalized epilepsies account for 30% of all epilepsies. Despite a predominant genetic aetiology, the genetic factors predisposing to idiopathic generalized epilepsies remain elusive. Studies of structural genomic variations have revealed a significant excess of recurrent microdeletions at 1q21.1, 15q11.2, 15q13.3, 16p11.2, 16p13.11 and 22q11.2 in various neuropsychiatric disorders including autism, intellectual disability and schizophrenia. Microdeletions at 15q13.3 have recently been shown to constitute a strong genetic risk factor for common idiopathic generalized epilepsy syndromes, implicating that other recurrent microdeletions may also be involved in epileptogenesis. This study aimed to investigate the impact of five microdeletions at the genomic hotspot regions 1q21.1, 15q11.2, 16p11.2, 16p13.11 and 22q11.2 on the genetic risk to common idiopathic generalized epilepsy syndromes. The candidate microdeletions were assessed by high-density single nucleotide polymorphism arrays in 1234 patients with idiopathic generalized epilepsy from North-western Europe and 3022 controls from the German population. Microdeletions were validated by quantitative polymerase chain reaction and their breakpoints refined by array comparative genomic hybridization. In total, 22 patients with idiopathic generalized epilepsy (1.8%) carried one of the five novel microdeletions compared with nine controls (0.3%) (odds ratio = 6.1; 95% confidence interval 2.8-13.2; chi(2) = 26.7; 1 degree of freedom; P = 2.4 x 10(-7)). Microdeletions were observed at 1q21.1 [Idiopathic generalized epilepsy (IGE)/control: 1/1], 15q11.2 (IGE/control: 12/6), 16p11.2 IGE/control: 1/0, 16p13.11 (IGE/control: 6/2) and 22q11.2 (IGE/control: 2/0). Significant associations with IGEs were found for the microdeletions at 15q11.2 (odds ratio = 4.9; 95% confidence interval 1.8-13.2; P = 4.2 x 10(-4)) and 16p13.11 (odds ratio = 7.4; 95% confidence interval 1.3-74.7; P = 0.009). Including nine patients with idiopathic generalized epilepsy in this cohort with known 15q13.3 microdeletions (IGE/control: 9/0), parental transmission could be examined in 14 families. While 10 microdeletions were inherited (seven maternal and three paternal transmissions), four microdeletions occurred de novo at 15q13.3 (n = 1), 16p13.11 (n = 2) and 22q11.2 (n = 1). Eight of the transmitting parents were clinically unaffected, suggesting that the microdeletion itself is not sufficient to cause the epilepsy phenotype. Although the microdeletions investigated are individually rare (<1%) in patients with idiopathic generalized epilepsy, they collectively seem to account for a significant fraction of the genetic variance in common idiopathic generalized epilepsy syndromes. The present results indicate an involvement of microdeletions at 15q11.2 and 16p13.11 in epileptogenesis and strengthen the evidence that recurrent microdeletions at 15q11.2, 15q13.3 and 16p13.11 confer a pleiotropic susceptibility effect to a broad range of neuropsychiatric disorders.

Omega-3 Fatty Acids Supplementation in Children with Autism: A Double-blind Randomized, Placebo-controlled Pilot Study

BACKGROUND There is increasing evidence that fatty acid deficiencies or imbalances may contribute to childhood neurodevelopmental disorders. METHODS We conducted a randomized, double-blind, placebo-controlled 6-week pilot trial investigating the effects of 1.5 g/d of omega-3 fatty acids (.84 g/d eicosapentaenoic acid, .7 g/d docosahexaenoic acid) supplementation in 13 children (aged 5 to 17 years) with autistic disorders accompanied by severe tantrums, aggression, or self-injurious behavior. The outcome measure was the Aberrant Behavior Checklist (ABC) at 6 weeks. RESULTS We observed an advantage of omega-3 fatty acids compared with placebo for hyperactivity and stereotypy, each with a large effect size. Repeated-measures ANOVA indicated a trend toward superiority of omega-3 fatty acids over placebo for hyperactivity. No clinically relevant adverse effects were elicited in either group. CONCLUSIONS The results of this study provide preliminary evidence that omega-3 fatty acids may be an effective treatment for children with autism.

Lennox-Gastaut syndrome: a consensus approach on diagnosis, assessment, management, and trial methodology

Lennox-Gastaut syndrome is one of the most severe epileptic encephalopathies of childhood onset. The cause of this syndrome can be symptomatic (ie, secondary to an underlying brain disorder) or cryptogenic (ie, has no known cause). Although Lennox-Gastaut syndrome is commonly characterised by a triad of signs, which include multiple seizure types, slow spike-wave complexes on electroencephalographic (EEG) recordings, and impairment of cognitive function, there is debate with regard to the precise limits, cause, and diagnosis of the syndrome. Tonic seizures, which are thought to be a characteristic sign of Lennox-Gastaut syndrome, are not present at onset and the EEG features are not pathognomonic of the disorder. There are few effective treatment options for the multiple seizures and comorbidities, and the long-term outlook is poor for most patients. Probably as a result of the complexity of the disorder, only a few randomised trials have studied Lennox-Gastaut syndrome, and thus many of the drugs that are more commonly used have little or no supporting evidence base from controlled trials. In this Review, we discuss the main issues with regard to the diagnosis and treatment options available. We also suggest key considerations for future trials and highlight the importance of a comprehensive approach to the assessment and management of this syndrome.

Mutations in GRIN2A cause idiopathic focal epilepsy with rolandic spikes

Idiopathic focal epilepsy (IFE) with rolandic spikes is the most common childhood epilepsy, comprising a phenotypic spectrum from rolandic epilepsy (also benign epilepsy with centrotemporal spikes, BECTS) to atypical benign partial epilepsy (ABPE), Landau-Kleffner syndrome (LKS) and epileptic encephalopathy with continuous spike and waves during slow-wave sleep (CSWS). The genetic basis is largely unknown. We detected new heterozygous mutations in GRIN2A in 27 of 359 affected individuals from 2 independent cohorts with IFE (7.5%; P = 4.83 × 10−18, Fishers exact test). Mutations occurred significantly more frequently in the more severe phenotypes, with mutation detection rates ranging from 12/245 (4.9%) in individuals with BECTS to 9/51 (17.6%) in individuals with CSWS (P = 0.009, Cochran-Armitage test for trend). In addition, exon-disrupting microdeletions were found in 3 of 286 individuals (1.0%; P = 0.004, Fishers exact test). These results establish alterations of the gene encoding the NMDA receptor NR2A subunit as a major genetic risk factor for IFE.

The Original Gerstmann-Sträussler-Scheinker Family of Austria: Divergent Clinicopathological Phenotypes but Constant PrP Genotype

We present new data on the original Austrian kindred with Gerstmann‐Sträussler‐Scheinker disease (GSS) which encompasses currently 221 members in 9 generations. The mode of inheritance is autosomal dominant. Predominant clinical features are slowly progressive ataxia and late impairment of higher cerebral functins. In contrast, a recent case with proven P102L mutation of the PRNP gene had rapidly developing dementia and severe cortical damage indistinguishable from the clinicopathological phenotype of Creutzfeldt‐Jakob disease (CJD). PRNP codon 129 was homozygous for methionine in both the historic and recent cases. Neuropathology confirms spongiosis of variable degree and numerous protease resistant / prion protein (PrP) amyloid plaques scattered throughout most of the brain as constant features in this family. Some amyloid deposits are surrounded by dystrophic neurites with accumulation of phosphorylated neurofilaments and abnormal organelles, reminiscent of Alzheimer‐type plaques. Severe telencephalic damage and a synaptic‐type fine granular immunoreactivity in laminar distribution in the cortex with anti‐PrP after hydrated autoclaving of sections were seen only in the recent patient. In conclusion, factors in addition to the PRNP genotype at codons 102 and 129 must play a role in determining clinicopathological characteristics of this inherited brain amyloidosis.

Genome-wide association analysis of genetic generalized epilepsies implicates susceptibility loci at 1q43, 2p16.1, 2q22.3 and 17q21.32

Genetic generalized epilepsies (GGEs) have a lifetime prevalence of 0.3% and account for 20-30% of all epilepsies. Despite their high heritability of 80%, the genetic factors predisposing to GGEs remain elusive. To identify susceptibility variants shared across common GGE syndromes, we carried out a two-stage genome-wide association study (GWAS) including 3020 patients with GGEs and 3954 controls of European ancestry. To dissect out syndrome-related variants, we also explored two distinct GGE subgroups comprising 1434 patients with genetic absence epilepsies (GAEs) and 1134 patients with juvenile myoclonic epilepsy (JME). Joint Stage-1 and 2 analyses revealed genome-wide significant associations for GGEs at 2p16.1 (rs13026414, P(meta) = 2.5 × 10(-9), OR[T] = 0.81) and 17q21.32 (rs72823592, P(meta) = 9.3 × 10(-9), OR[A] = 0.77). The search for syndrome-related susceptibility alleles identified significant associations for GAEs at 2q22.3 (rs10496964, P(meta) = 9.1 × 10(-9), OR[T] = 0.68) and at 1q43 for JME (rs12059546, P(meta) = 4.1 × 10(-8), OR[G] = 1.42). Suggestive evidence for an association with GGEs was found in the region 2q24.3 (rs11890028, P(meta) = 4.0 × 10(-6)) nearby the SCN1A gene, which is currently the gene with the largest number of known epilepsy-related mutations. The associated regions harbor high-ranking candidate genes: CHRM3 at 1q43, VRK2 at 2p16.1, ZEB2 at 2q22.3, SCN1A at 2q24.3 and PNPO at 17q21.32. Further replication efforts are necessary to elucidate whether these positional candidate genes contribute to the heritability of the common GGE syndromes.

Predictors for Negative Attitudes toward Subjects with Epilepsy: A Representative Survey in the General Public in Austria

Summary:  Purpose: To assess knowledge of and attitudes toward epilepsy in the Austrian general public and to identify independent predictors of negative attitudes.

EKG abnormalities in children and adolescents with symptomatic temporal lobe epilepsy

Background: Changes in cardiac rate and rhythm are often found in adult patients with temporal lobe epilepsy (TLE) and could be involved in the pathogenesis of sudden unexplained death (SUDEP). However, little is known about heart rate (HR) variability in pediatric patients with TLE. Objectives: To investigate ictal and peri-ictal HR abnormalities in children and adolescents with medically refractory symptomatic TLE and to determine the influence of focus localization and laterality. Methods: Patients younger than 18 years, with drug-resistant unilateral symptomatic TLE and presenting with at least one habitual complex partial seizure (CPS) during presurgical noninvasive video-EEG monitoring, were enrolled. Synchronous single-channel EKG recordings were analyzed during the preictal, ictal, and postictal stages. Results: Twenty patients fulfilled the inclusion criteria. Seventy-two temporal lobe seizures (TLSs) were analyzed. Ictal tachycardia was found in 71 TLSs (98%), whereas ictal bradycardia was not observed. During preictal stages, tachycardia occurred in 20 seizures and mild bradycardia in 3. In 44 seizures (62%), tachycardia was still present >60 seconds after EEG seizure termination. Cluster analysis revealed significant differences in HR evolution depending on location and side of seizure onset: Early and high HR increase was primarily associated with right mesial TLSs. Conclusions: Cardiovascular dysregulation is common during temporal lobe CPSs in children. These results confirm a right hemispheric lateralization of sympathetic cardiac control.

Vagus nerve stimulation for drug-resistant epilepsy: A European long-term study up to 24 months in 347 children

To gain insight into the long‐term impact of vagus nerve stimulation (with VNS Therapy) in children with drug‐resistant epilepsy, we conducted the largest retrospective multicenter study to date over an extended follow‐up period of up to 24 months.