GRIN2A-related disorders: genotype and functional consequence predict phenotype.

Alterations of the N-methyl-d-aspartate receptor (NMDAR) subunit GluN2A, encoded by GRIN2A, have been associated with a spectrum of neurodevelopmental disorders with prominent speech-related features, and epilepsy. We performed a comprehensive assessment of phenotypes with a standardized questionnaire in 92 previously unreported individuals with GRIN2A-related disorders. Applying the criteria of the American College of Medical Genetics and Genomics to all published variants yielded 156 additional cases with pathogenic or likely pathogenic variants in GRIN2A, resulting in a total of 248 individuals. The phenotypic spectrum ranged from normal or near-normal development with mild epilepsy and speech delay/apraxia to severe developmental and epileptic encephalopathy, often within the epilepsy-aphasia spectrum. We found that pathogenic missense variants in transmembrane and linker domains (misTMD+Linker) were associated with severe developmental phenotypes, whereas missense variants within amino terminal or ligand-binding domains (misATD+LBD) and null variants led to less severe developmental phenotypes, which we confirmed in a discovery (P = 10-6) as well as validation cohort (P = 0.0003). Other phenotypes such as MRI abnormalities and epilepsy types were also significantly different between the two groups. Notably, this was paralleled by electrophysiology data, where misTMD+Linker predominantly led to NMDAR gain-of-function, while misATD+LBD exclusively caused NMDAR loss-of-function. With respect to null variants, we show that Grin2a+/- cortical rat neurons also had reduced NMDAR function and there was no evidence of previously postulated compensatory overexpression of GluN2B. We demonstrate that null variants and misATD+LBD of GRIN2A do not only share the same clinical spectrum (i.e. milder phenotypes), but also result in similar electrophysiological consequences (loss-of-function) opposing those of misTMD+Linker (severe phenotypes; predominantly gain-of-function). This new pathomechanistic model may ultimately help in predicting phenotype severity as well as eligibility for potential precision medicine approaches in GRIN2A-related disorders.

Contextual Structured Reporting in Radiology: Implementation and Long-Term Evaluation in Improving the Communication of Critical Findings.

Structured reporting contributes to the completeness of radiology reports and improves quality. Both the content and the structure are essential for successful implementation of structured reporting. Contextual structured reporting is tailored to a specific scenario and can contain information retrieved from the context. Critical findings detected by imaging need urgent communication to the referring physician. According to guidelines, the occurrence of this communication should be documented in the radiology reports and should contain when, to whom and how was communicated. In free-text reporting, one or more of these required items might be omitted. We developed a contextual structured reporting template to ensure complete documentation of the communication of critical findings. The WHEN and HOW items were included automatically, and the insertion of the WHO-item was facilitated by the template. A pre- and post-implementation study demonstrated a substantial improvement in guideline adherence. The template usage improved in the long-term post-implementation study compared with the short-term results. The two most often occurring categories of critical findings are "infection / inflammation" and "oncology", corresponding to the a large part of urgency level 2 (to be reported within 6 h) and level 3 (to be reported within 6 days), respectively. We conclude that contextual structured reporting is feasible for required elements in radiology reporting and for automated insertion of context-dependent data. Contextual structured reporting improves guideline adherence for communication of critical findings.

Changes in empowerment and anxiety of patients and parents during genetic counselling for epilepsy.

Genetic testing and counselling are increasingly important in epilepsy care, aiming at finding a diagnosis, understanding aetiology and improving treatment and outcome. The psychological impact of genetic counselling from patients' or parents' perspectives is, however, unknown. We studied the counselee-reported outcome of genetic counselling before and after genetic testing for epilepsy by evaluating empowerment - a key outcome goal of counselling reflecting cognitive, decisional and behavioural control, emotional regulation and hope - and anxiety. We asked patients or their parents (for those <16 years or intellectually disabled) referred for genetic testing for epilepsy in two university hospitals between June 2014 and 2017 to complete the same two questionnaires at three timepoints: before and after pre-test counselling and after post-test counselling. Empowerment was measured with the Genetic Counselling Outcome Scale (GCOS-18); anxiety with the short State Trait Anxiety Inventory (STAI-6). A total of 63 participants (55 parents with the age of 29-66 years; 8 patients with the age of 21-42 years) were included in our study. Empowerment significantly increased during the genetic counselling trajectory with a medium effect size (p < 0.001, d = 0.57). A small but significant increase in empowerment was already seen after pre-test counselling (p = 0.038, d = 0.29). Anxiety did not change significantly during the counselling trajectory (p = 0.223, d = -0.24). Our study highlights that patients with epilepsy or their parents show a clinically relevant increase in empowerment after genetic counselling. Empowerment was already increased after pre-test counselling, suggesting the importance of counselling before initiating genetic testing for epilepsy. However, individual differences in changes in empowerment and anxiety were seen, suggesting that counselling could be further improved, based on individual needs.

Prevalence of sleep disturbances in people with epilepsy and the impact on quality of life: a survey in secondary care.

PURPOSE: Studies in adults with epilepsy, mainly in specialized epilepsy clinics, have shown that sleep disturbances were twice as prevalent in people with epilepsy as in healthy controls. Our aim was to determine the prevalence of sleep disturbances in people with epilepsy treated in district hospitals, as well as the impact of it on Quality of Life. METHOD: Adults with epilepsy, attending outpatient clinics in three district hospitals were invited to participate. Those who accepted (N = 122) provided their own controls matched for age and sex. Both groups completed four questionnaires (Groningen Sleep Quality Scale (GSQ), Medical Outcomes Study-Sleep scale (MOSS), Sleep Diagnosis List (SDL) and Epworth Sleepiness Scale) to measure their sleep over different periods and the 36-Item Short Form Health Survey (SF-36) to measure Quality of Life (QoL). The prevalence of sleep disturbances and scores on QoL were compared between both groups. RESULTS: Sleep quality, measured by the SDL, was in the pathological range 50% more often in the epilepsy group than in controls. This was confirmed by the MOSSINDEX and GSQ. People with epilepsy experienced excessive daytime sleepiness more often than controls. The lowest scores on nearly all domains of the SF-36 were seen in people with epilepsy and associated sleep disturbances. CONCLUSION: We confirmed the higher prevalence of sleep disturbances in people with epilepsy compared to controls as previously reported from specialized settings. The (co-morbid) sleep disturbances result in lower QoL scores, in both people with epilepsy and in controls, but more in people with epilepsy.

PRRT2-related phenotypes in patients with a 16p11.2 deletion.

We studied the presence of benign infantile epilepsy (BIE), paroxysmal kinesigenic dyskinesia (PKD), and PKD with infantile convulsions (PKD/IC) in patients with a 16p11.2 deletion including PRRT2 or with a PRRT2 loss-of-function sequence variant. Index patients were recruited from seven Dutch university hospitals. The presence of BIE, PKD and PKD/IC was retrospectively evaluated using questionnaires and medical records. We included 33 patients with a 16p11.2 deletion: three (9%) had BIE, none had PKD or PKD/IC. Twelve patients had a PRRT2 sequence variant: BIE was present in four (p = 0.069), PKD in six (p < 0.001) and PKD/IC in two (p = 0.067). Most patients with a deletion had undergone genetic testing because of developmental problems (87%), whereas all patients with a sequence variant were tested because of a movement disorder (55%) or epilepsy (45%). BIE, PKD and PKD/IC clearly showed incomplete penetrance in patients with 16p11.2 deletions, but were found in all and 95% of patients with a PRRT2 sequence variant in our study and a large literature cohort, respectively. Deletions and sequence variants have the same underlying loss-of-function disease mechanism. Thus, differences in ascertainment have led to overestimating the frequency of BIE, PKD and PKD/IC in patients with a PRRT2 sequence variant. This has important implications for counseling if genome-wide sequencing shows such variants in patients not presenting the PRRT2-related phenotypes.

Add-on levetiracetam in children and adolescents with refractory epilepsy: results of an open-label multi-centre study.

PURPOSE: To study the efficacy and tolerability of add-on levetiracetam in children and adolescents with refractory epilepsy. METHODS: In this prospective multi-centre, open-label, add-on study, 33 children aged 4-16 years (median 8.5 years) with epilepsy refractory to at least two antiepileptic drugs were treated with levetiracetam in addition to their present treatment regimen with a follow-up of 26 weeks. The starting dose of 10 mg/kg/day was increased with 2-week steps of 10 mg/kg/day, if necessary, up to a maximum dose of 60 mg/kg/day. RESULTS: Retention rate was 69.7% after 26 weeks on a median levetiracetam dosage of 22 mg/kg/day. Four children dropped-out because levetiracetam was ineffective, four because seizure frequency increased and/or seizures became more severe, and two because they developed aggressive behaviour. Compared to their baseline seizure frequency, 13 children (39.4%) had a >50% seizure reduction 12 weeks after initiation of levetiracetam, and 17 children (51.5%) at 26 weeks. At 26 weeks, nine children (27.3%) had been seizure-free for at least the last 4 weeks, terminal remission ranged from 0 to 187 days (mean 46 days). Levetiracetam was effective in both partial and primary generalized seizures, but had most effect in partial seizures. Most reported side effects were hyperactivity (48.5%), somnolence (36.4%), irritability (33.3%) and aggressive behaviour (27.3%). Severity of most side effects was mild. Five children had a serious adverse event, which all concerned hospital admissions that were not related to levetiracetam use. CONCLUSION: Levetiracetam proved to be an effective and well-tolerated add-on treatment in this group of children with refractory epilepsy.

Antiepileptic drug prescription in Dutch children from 2006-2014 using pharmacy-dispensing data.

OBJECTIVE: In the last two decades several new antiepileptic drugs (AEDs) have become available. The aim of our study was to analyse whether and how AED prescribing patterns in Dutch children have changed during the last decade and whether these changes were supported by guidelines and results from recently available trials. METHODS: From a large community pharmacy-dispensing database in the Netherlands, we identified children aged 0-19 years who received at least one prescription for an AED between 2006 and 2014. Children who also received prescriptions for migraine or psychiatric disorders were excluded. We calculated year-prevalences and -incidences of AED use with emphasis on old versus new AEDs, and individual AEDs. We evaluated these results, including the course of AED prescribing. RESULTS: During the study period, the prescribing prevalence of old AEDs decreased from 1.61 per 1000 (95% C.I. 1.40-1.82) to 1.39 per 1000 (95% C.I. 1.18-1.60); for new AEDs it increased from 0.58 per 1000 (95% C.I. 0.45-0.71) to 1.35 per 1000 (95% C.I. 1.14-1.56). Valproic acid was the most frequently initiated AED in 2006. From 2010, prescribing of old and new AEDs became equal with levetiracetam as the most often initiated AED since 2012. This drug was recommended for all seizure types in the 2013 Dutch national epilepsy guideline. Only 5.5% of the children used AED combination therapy. Of those on monotherapy, 85.7% remained on the first prescribed AED. CONCLUSIONS: In the last 10 years, prescribing of new AEDs increased at the expense of old AEDs. Levetiracetam has replaced valproic acid as the most frequently prescribed first line antiepileptic drug in children since 2012, which is in line with national guidelines.

Ketogenic Diet in Refractory Childhood Epilepsy: Starting With a Liquid Formulation in an Outpatient Setting.

BACKGROUND: Ketogenic diet in children with epilepsy has a considerable impact on daily life and is usually adopted for at least 3 months. Our aim was to evaluate whether the introduction of an all-liquid ketogenic diet in an outpatient setting is feasible, and if an earlier assessment of its efficacy can be achieved. METHODS: The authors conducted a prospective, observational study in a consecutive group of children with refractory epilepsy aged 2 to 14 years indicated for ketogenic diet. Ketogenic diet was started as an all-liquid formulation of the classical ketogenic diet, KetoCal 4:1 LQ, taken orally or by tube. After 6 weeks, the liquid diet was converted into solid meals. The primary outcome parameter was time-to-response (>50% seizure reduction). Secondary outcome parameters were time to achieve stable ketosis, the number of children showing a positive response, and the retention rate at 26 weeks. RESULTS: Sixteen children were included. Four of them responded well with respect to seizure frequency, the median time-to-response was 14 days (range 7-28 days). The mean time to achieve stable ketosis was 7 days. The retention rate at 26 weeks was 50%. Of the 8 children who started this protocol orally fed, 6 completed it without requiring a nasogastric tube. CONCLUSIONS: Introduction of ketogenic diet with a liquid formulation can be accomplished in orally fed children without major complications. It allowed for fast and stable ketosis.

Sumatriptan nasal spray in the acute treatment of migraine in adolescents and children.

About 4-10% of children and adolescents suffer from migraine. In the last few years, several studies have been performed to assess the efficacy and safety of triptans for the acute treatment of migraine in children and adolescents. Only sumatriptan nasal spray has been approved for the treatment of acute migraine with or without aura in adolescents aged 12-17 years in Europe. This review describes the results of the studies with sumatriptan nasal spray that have been performed in children and adolescents, including a study performed in the Netherlands.

Investigator-initiated randomized controlled trials in children with epilepsy: Mission impossible?

OBJECTIVE: In children many antiepileptic drugs (AEDs) are prescribed off-label due to a lack of well-designed randomized controlled trials (RCTs). We conducted a multicenter RCT in the Netherlands to compare levetiracetam and valproic acid as monotherapy in children with newly diagnosed epilepsy. After 2 years, we had to stop this investigator-initiated trial prematurely because the inclusion rate was too low. We analyzed the reasons for this failure, assessed the various issues involved in performing RCTs in children, and now give recommendations for future studies. METHODS: A questionnaire was completed by all investigators involved in the study. It included questions about the motivation to participate and the perceived reasons for recruitment failure. We also studied literature about financial, logistic, legal, and ethical aspects of RCTs in children. RESULTS: Main reasons for recruitment failure were overestimation of the number of eligible AED-naive children referred by general pediatricians; personal preferences of investigators for specific antiepileptic drugs; and the extensive administrative load due to extra regulations and guidelines for children. Fundraising for investigator-initiated trials is difficult and the majority of RCTs concerning AEDs are sponsored by pharmaceutical companies. Involving children requires balancing between protection and participation; the randomization procedure and obtaining informed consent are complex for both children and parents. SIGNIFICANCE: Performing RCTs with AEDs in children is important but complicated by logistic, regulatory, legal, and ethical restrictions. Based on our recent experience, our advice to colleagues who are planning a similar trial would be to perform a feasibility pilot study; to set up intensive collaboration with referring pediatricians; to arrange support of a clinical trials unit and a local research nurse during the complete trial period; and to incorporate the possibility of extending the recruitment period. Major investments, both financially from governmental organizations and in time, are imperative for independent RCTs in children.

Copy number variation in a hospital-based cohort of children with epilepsy.

Objective: To evaluate the diagnostic yield of microarray analysis in a hospital-based cohort of children with seizures and to identify novel candidate genes and susceptibility loci for epilepsy. Methods: Of all children who presented with their first seizure in the University Medical Center Groningen (January 2000 through May 2013) (n = 1,368), we included 226 (17%) children who underwent microarray analysis before June 2014. All 226 children had a definite diagnosis of epilepsy. All their copy number variants (CNVs) on chromosomes 1-22 and X that contain protein-coding genes and have a prevalence of <1% in healthy controls were evaluated for their pathogenicity. Results: Children selected for microarray analysis more often had developmental problems (82% vs. 25%, p < 0.001), facial dysmorphisms (49% vs. 8%, p < 0.001), or behavioral problems (41% vs. 13%, p < 0.001) than children who were not selected. We found known clinically relevant CNVs for epilepsy in 24 of the 226 children (11%). Seventeen of these 24 children had been diagnosed with symptomatic focal epilepsy not otherwise specified (71%) and five with West syndrome (21%). Of these 24 children, many had developmental problems (100%), behavioral problems (54%) or facial dysmorphisms (46%). We further identified five novel CNVs comprising four potential candidate genes for epilepsy: MYT1L, UNC5D, SCN4B, and NRXN3. Significance: The 11% yield in our hospital-based cohort underscores the importance of microarray analysis in diagnostic evaluation of children with epilepsy.

δ-Catenin (CTNND2) missense mutation in familial cortical myoclonic tremor and epilepsy.

OBJECTIVE: To identify the causative gene in a large Dutch family with familial cortical myoclonic tremor and epilepsy (FCMTE). METHODS: We performed exome sequencing for 3 patients of our FCMTE family. Next, we performed knock-down (shRNA) and rescue experiments by overexpressing wild-type and mutant human δ-catenin (CTNND2) proteins in cortical mouse neurons and compared the results with morphologic abnormalities in the postmortem FCMTE brain. RESULTS: We identified a missense mutation, p.Glu1044Lys, in the CTNND2 gene that cosegregated with the FCMTE phenotype. The knock-down of Ctnnd2 in cultured cortical mouse neurons revealed increased neurite outgrowth that was rescued by overexpression of wild-type, but not mutant, CTNND2 and was reminiscent of the morphologic abnormalities observed in cerebellar Purkinje cells from patients with FCMTE. CONCLUSIONS: We propose CTNND2 as the causal gene in FCMTE3. Functional testing of the mutant protein revealed abnormal neuronal sprouting, consistent with the abnormal cerebellar Purkinje cell morphology in patients with FCMTE.

Haploinsufficiency of the STX1B gene is associated with myoclonic astatic epilepsy.

We describe an 18-year-old male patient with myoclonic astatic epilepsy (MAE), moderate to severe intellectual disability, behavioural problems, several dysmorphisms and a 1.2-Mb de novo deletion on chromosome 16p11.2. This deletion results in haploinsufficiency of STX1B and other genes. Recently, variants in the STX1B gene have been associated with a wide spectrum of fever-related epilepsies ranging from single febrile seizures to severe epileptic encephalopathies. Two previously reported patients with a STX1B missense variant or deletion were diagnosed with MAE. Our observation of a STX1B deletion in a third patient with MAE therefore supports that STX1B gene variants or deletions can be involved in the aetiology of MAE. Furthermore, STX1B encodes for syntaxin-1B, of which interaction with the protein encoded by the STXBP1 gene is essential for the regulation of the synaptic transmission of neurotransmitters. STXBP1 gene variants have been identified in patients with many different types of epilepsy, including Dravet syndrome and epileptic encephalopathies, suggesting STX1B plays a similar role. We recommend that analysis of STX1B should be considered in the diagnostic work-up of individuals with MAE.

Clinical and genetic aspects of idiopathic epilepsies in childhood.

The identification of the first genes associated with idiopathic epilepsy has been an important breakthrough in the field of epilepsy research. In almost all cases these genes were found to encode components of voltage- or ligand-gated ion channels or functionally related structures. For many other idiopathic syndromes, there is linkage evidence to one or more chromosomes, but the genes have not yet been identified. Identification of the responsible genes and their gene products will further increase the knowledge of the pathogenic mechanisms involved in epilepsy, and will hopefully facilitate the development of drug targets for the effective treatment of epilepsy. This review gives an overview of the clinical characteristics and an update of genetic research of those idiopathic childhood epilepsies for which genes have been identified and the monogenic idiopathic childhood epilepsies for which mapping data are available.

Levetiracetam Monotherapy in Children with Epilepsy: A Systematic Review.

BACKGROUND: Levetiracetam, a second-generation anti-epileptic drug (AED) with a good efficacy and safety profile, is licensed as monotherapy for adults and children older than 16 years with focal seizures with or without secondary generalization. However, it is increasingly being used off-label in younger children. OBJECTIVES: We critically reviewed the available evidence and discuss the present status of levetiracetam monotherapy in children 0-16 years old. DATA SOURCES: We systematically searched the literature using PubMed, Web of Science and Embase up to August 2014 for articles on levetiracetam monotherapy in children. Keywords were levetiracetam, monotherapy and child*. The titles and abstracts of 532 articles were evaluated by AW, of which 480 were excluded. The full texts of the other 52 articles were assessed for relevance. RESULTS: We covered one review, one opinion statement and 32 studies in this review, including four randomized controlled trials, ten open-label prospective studies, eight retrospective studies, and ten case reports. The formal evidence for levetiracetam monotherapy in children is minimal: it is potentially efficacious or effective as initial monotherapy in children with benign epilepsy with centrotemporal spikes. In all of the published studies, however, efficacy and tolerability of levetiracetam seemed to be good and comparable to other AEDs. CONCLUSION: The data of 32 studies on levetiracetam monotherapy in children were insufficient to confirm that levetiracetam is effective as initial monotherapy for different types of seizures and/or epilepsy syndromes. There is still an urgent need for well designed trials to justify the widespread use of levetiracetam monotherapy in children of all ages.

A Dutch family with 'familial cortical tremor with epilepsy'. Clinical characteristics and exclusion of linkage to chromosome 8q23.3-q24.1.

OBJECTIVES: To describe the clinical characteristics of a large Dutch family with cortical tremor with epilepsy (FCTE) and to test for genetic linkage of FCTE to chromosome 8q23.3-q24.1. BACKGROUND: FCTE is an idiopathic generalised epilepsy of adult onset with autosomal dominant inheritance. It is characterised by kinesiogenic tremor and myoclonus of the limbs, generalised seizures, and electrophysiological findings consistent with cortical reflex myoclonus. Genetic analysis has been performed in five Japanese families. In all families, linkage was shown to chromosome 8q23.3-q24.1. METHODS: Clinical and electrophysiological data of a four-generation family, suspected of autosomal dominant inherited FCTE, were collected and linkage analysis was performed. Results Clinical and electrophysiological findings were consistent with a diagnosis of FCTE. Of 41 relatives examined, 13 subjects were considered to be definitely affected, three were probably affected and ten were unaffected. In 15 relatives, the diagnosis could not be established. Linkage to chromosome 8q23.3-q24.1 was excluded. CONCLUSIONS: In this family with autosomal dominant FCTE, specific clinical and electrophysiological features were identified. Exclusion of linkage to chromosome 8q23.3-q24.1 indicates that genetic heterogeneity exists for FCTE.

Benign familial infantile convulsions: a clinical study of seven Dutch families.

Benign familial infantile convulsions (BFIC) is a recently identified partial epilepsy syndrome with onset between 3 and 12 months of age. We describe the clinical characteristics and outcome of 43 patients with BFIC from six Dutch families and one Dutch-Canadian family and the encountered difficulties in classifying the syndrome. Four families had a pure BFIC phenotype; in two families BFIC was accompanied by paroxysmal kinesigenic dyskinesias; in one family BFIC was associated with later onset focal epilepsy in older generations. Onset of seizures was between 6 weeks and 10 months, and seizures remitted before the age of 3 years in all patients with BFIC. In all, 29 (67%) of the 43 patients had been treated with anti-epileptic drugs for a certain period of time. BFIC is often not recognized as (hereditary) epilepsy by the treating physician. Seizures often remit shortly after the start of anti-epileptic drugs but, because of the benign course of the syndrome and the spontaneous remission of seizures, patients with low seizure frequency do not necessarily have to be treated. If prescribed, anti-epileptic drugs can probably be withdrawn after 1 or 2 years of seizure freedom.

Treatment of prolonged convulsive seizures in children; a single centre, retrospective, observational study.

OBJECTIVES: To evaluate treatment of children with Prolonged Convulsive Seizures (PCS) at the University Medical Centre Groningen (UMCG). MATERIAL AND METHODS: PCS were identified from an UMCG database of children with epilepsy aged <18 years who had their first (a)febrile seizure between 2000 and 2010. PCS were included if they lasted ≥10 min and occurred between January 2000 and October 2012 in children aged >1 month. Order, timing, and location of treatment were analysed. Treatment of PCS before and after 2005 was compared with recommendations from a Dutch 2005 treatment guideline for Convulsive Status Epilepticus (CSE) in children aged >1 month. RESULTS: 269 PCS occurring in 102 children were included (53.9% male, median age 2.8 years; range 0.1-13.7 years). Seventy episodes concerned a first PCS. Most first and subsequent PCS started outside the hospital (78.6% and 82.4%, respectively) and lasted 10-30 min (42.4% and 51.4%, respectively). Cessation occurred after two administrations of any therapy in first (median, range 0-7) and subsequent PCS (median, range 0-10). First treatment choice was rectal diazepam in first (59.6%) and subsequent (43.9%) PCS, but since 2006 a trend towards buccal midazolam was observed in subsequent PCS. Clonazepam was frequently used as second treatment choice in first (43.8%) and subsequent (27.3%) PCS, although not mentioned in the guideline. CONCLUSION: In our study cohort rectal diazepam is still first choice in the management of PCS despite proven superior efficacy of buccal midazolam. Clonazepam is frequently used although it is not formally recommended in a Dutch guideline.

Mortality risks in new-onset childhood epilepsy.

OBJECTIVES: Estimate the causes and risk of death, specifically seizure related, in children followed from onset of epilepsy and to contrast the risk of seizure-related death with other common causes of death in the population. METHODS: Mortality experiences from 4 pediatric cohorts of newly diagnosed patients were combined. Causes of death were classified as seizure related (including sudden unexpected death [SUDEP]), natural causes, nonnatural causes, and unknown. RESULTS: Of 2239 subjects followed up for >30 000 person-years, 79 died. Ten subjects with lethal neurometabolic conditions were ultimately excluded. The overall death rate (per 100 000 person-years) was 228; 743 in complicated epilepsy (with associated neurodisability or underlying brain condition) and 36 in uncomplicated epilepsy. Thirteen deaths were seizure-related (10 SUDEP, 3 other), accounting for 19% of all deaths. Seizure-related death rates were 43 overall, 122 for complicated epilepsy, and 14 for uncomplicated epilepsy. Death rates from other natural causes were 159, 561, and 9, respectively. Of 48 deaths from other natural causes, 37 were due to pneumonia or other respiratory complications. CONCLUSIONS: Most excess death in young people with epilepsy is not seizure-related. Mortality is significantly higher compared with the general population in children with complicated epilepsy but not uncomplicated epilepsy. The SUDEP rate was similar to or higher than sudden infant death syndrome rates. In uncomplicated epilepsy, sudden and seizure-related death rates were similar to or higher than rates for other common causes of death in young people (eg, accidents, suicides, homicides). Relating the risk of death in epilepsy to familiar risks may facilitate discussions of seizure-related mortality with patients and families.