Incidence of epileptic syndromes in Rochester, Minnesota: 1980-1984

Somatic mosaicism in focal epilepsies

PURPOSE OF REVIEW

Over the past decade, it has become clear that brain somatic mosaicism is an important contributor to many focal epilepsies. The number of cases and the range of underlying pathologies with somatic mosaicism are rapidly increasing. This growth in somatic variant discovery is revealing dysfunction in distinct molecular pathways in different focal epilepsies.

RECENT FINDINGS

We briefly summarize the current diagnostic yield of pathogenic somatic variants across all types of focal epilepsy where somatic mosaicism has been implicated and outline the specific molecular pathways affected by these variants. We will highlight the recent findings that have increased diagnostic yields such as the discovery of pathogenic somatic variants in novel genes, and new techniques that allow the discovery of somatic variants at much lower variant allele fractions.

SUMMARY

A major focus will be on the emerging evidence that somatic mosaicism may contribute to some of the more common focal epilepsies such as temporal lobe epilepsy with hippocampal sclerosis, which could lead to it being re-conceptualized as a genetic disorder.

Functional brain connectivity in children with focal epilepsy: A systematic review of functional MRI studies

Epilepsy is increasingly recognised as a brain network disorder and many studies have investigated functional connectivity (FC) in children with epilepsy using functional MRI (fMRI). This systematic review of fMRI studies, published up to November 2023, investigated profiles of FC changes and their clinical relevance in children with focal epilepsy compared to healthy controls. A literature search in PubMed and Web of Science yielded 62 articles. We categorised the results into three groups: 1) differences in correlation-based FC between patients and controls; 2) differences in other FC measures between patients and controls; and 3) associations between FC and disease variables (for example, age of onset), cognitive and seizure outcomes. Studies revealed either increased or decreased FC across multiple brain regions in children with focal epilepsy. However, findings lacked consistency: conflicting FC alterations (decreased and increased FC) co-existed within or between brain regions across all focal epilepsy groups. The studies demonstrated overall that 1) interhemispheric connections often displayed abnormal connectivity and 2) connectivity within and between canonical functional networks was decreased, particularly for the default mode network. Focal epilepsy disrupted FC in children both locally (e.g., seizure-onset zones, or within-brain subnetworks) and globally (e.g., whole-brain network architecture). The wide variety of FC study methodologies limits clinical application of the results. Future research should employ longitudinal designs to understand the evolution of brain networks during the disease course and explore the potential of FC biomarkers for predicting cognitive and postsurgical seizure outcomes.

Nonconvulsive Status Epilepticus: Clinical Findings, EEG Features, and Prognosis in a Developing Country, Mexico

PURPOSE

There is a lack of clinical and epidemiological knowledge about nonconvulsive status epilepticus (NCSE) in developing countries including Mexico, which has the highest prevalence of epilepsy in the Americas. Our aim was to describe the clinical findings, EEG features, and outcomes of NCSE in a tertiary center in Mexico.

METHODS

We conducted a retrospective case series study (2010-2020) including patients (≥15 years old) with NCSE according to the modified Salzburg NCSE criteria 2015 with at least 6 months of follow-up. We extracted the clinical data (age, sex, history of epilepsy, antiseizure medications, clinical manifestations, triggers, and etiology), EEG patterns of NCSE, and outcome. Descriptive statistics and multinomial logistic regression were used.

RESULTS

One hundred thirty-four patients were analyzed; 74 (54.8%) women, the total mean age was 39.5 (15-85) years, and 71% had a history of epilepsy. Altered state of consciousness was found in 82% (including 27.7% in coma). A generalized NCSE pattern was the most common (32.1%). The NCSE etiology was mainly idiopathic (56%), and previous uncontrolled epilepsy was the trigger in 48% of patients. The clinical outcome was remission with clinical improvement in 54.5%. Multinomial logistic regression showed that the patient's age (P = 0.04), absence of comorbidities (P = 0.04), history of perinatal hypoxia (P = 0.04), absence of clinical manifestations (P = 0.01), and coma (P = 0.03) were negatively correlated with the outcome and only the absence of generalized slowing in the EEG (P = 0.001) had a significant positive effect on the prognosis.

CONCLUSIONS

Age, history of perinatal hypoxia, coma, and focal ictal EEG pattern influence negatively the prognosis of NCSE.

Familial Mesial Temporal Lobe Epilepsy: Clinical Spectrum and Genetic Evidence for a Polygenic Architecture

OBJECTIVE

Familial mesial temporal lobe epilepsy (FMTLE) is an important focal epilepsy syndrome; its molecular genetic basis is unknown. Clinical descriptions of FMTLE vary between a mild syndrome with prominent déjà vu to a more severe phenotype with febrile seizures and hippocampal sclerosis. We aimed to refine the phenotype of FMTLE by analyzing a large cohort of patients and asked whether common risk variants for focal epilepsy and/or febrile seizures, measured by polygenic risk scores (PRS), are enriched in individuals with FMTLE.

METHODS

We studied 134 families with ≥ 2 first or second-degree relatives with temporal lobe epilepsy, with clear mesial ictal semiology required in at least one individual. PRS were calculated for 227 FMTLE cases, 124 unaffected relatives, and 16,077 population controls.

RESULTS

The age of patients with FMTLE onset ranged from 2.5 to 70 years (median = 18, interquartile range = 13-28 years). The most common focal seizure symptom was déjà vu (62% of cases), followed by epigastric rising sensation (34%), and fear or anxiety (22%). The clinical spectrum included rare cases with drug-resistance and/or hippocampal sclerosis. FMTLE cases had a higher mean focal epilepsy PRS than population controls (odds ratio = 1.24, 95% confidence interval = 1.06, 1.46, p = 0.007); in contrast, no enrichment for the febrile seizure PRS was observed.

INTERPRETATION

FMTLE is a generally mild drug-responsive syndrome with déjà vu being the commonest symptom. In contrast to dominant monogenic focal epilepsy syndromes, our molecular data support a polygenic basis for FMTLE. Furthermore, the PRS data suggest that sub-genome-wide significant focal epilepsy genome-wide association study single nucleotide polymorphisms are important risk variants for FMTLE. ANN NEUROL 2023;94:825-835.

Text mining of electronic health records can validate a register-based diagnosis of epilepsy and subgroup into focal and generalized epilepsy

OBJECTIVE

Combining population-based health registries and electronic health records offers the opportunity to create large, phenotypically detailed patient cohorts of high quality. In this study, we used text mining of clinical notes to confirm International Classification of Diseases, 10th Revision (ICD-10)-registered epilepsy diagnoses and classify patients according to focal and generalized epilepsy types.

METHODS

Using the Danish National Patient Registry, we identified patients who between 2006 and 2016 received an ICD-10 diagnosis of epilepsy. To validate the epilepsy diagnosis and stratify patients into focal and generalized epilepsy types, we constructed dictionaries for text mining-based extraction of clinical notes. Two physicians manually reviewed the clinical notes for a total of 527 patients and assigned epilepsy diagnoses, which were compared with the text-mined diagnoses.

RESULTS

We identified 23 632 patients with an ICD-10 diagnosis of epilepsy, of whom 50% were registered with an unspecified epilepsy diagnosis. In total, 11 211 patients were considered likely to have epilepsy by text mining, with an F1 measure ranging from 82% to 90%. Manual review of the electronic health records for 310 patients revealed a false discovery rate of 29%. This rate was decreased to 4% by the text mining algorithm. The weighted average F1 measure for text mining-assigned epilepsy types was 79% (82% for focal and 76% for generalized epilepsy). Text mining successfully assigned a focal or generalized epilepsy type to 92% of the text mining-eligible patients registered with unspecified epilepsy.

SIGNIFICANCE

Text mining of electronic health records can be used to establish a patient cohort with much higher likelihood of having a diagnosis of epilepsy and a focal or generalized epilepsy type compared to the cohort created from ICD-10 epilepsy codes alone. We believe the concept will be essential for future genome-wide and phenome-wide association studies and subsequently the development of precision medicine for epilepsy patients.

Brain magnetic resonance imaging findings and brain volumetric differences in a large series of benign rolandic epilepsy

BACKGROUND

Several studies with a small sample size have investigated the relationship between structural and functional changes on MRI and the clinical and natural history of BRE. We aim to assess the frequency of incidental epileptogenic lesions on brain MRI in a large cohort of patients diagnosed with BRE and to assess the difference in volumetric brain measurements in BRE patients compared to healthy controls.

METHODS

The case-control study includes 214 typical BRE cases and 197 control children with non-epileptic spells. Brain MRIs were evaluated for abnormalities which were classified into normal and abnormal with or without epileptogenic lesions with categorization of epileptogenic lesions. Brain segmentation was also performed for a smaller group of BRE patients and another healthy control group. Pearson's chi-squared test and two-tailed independent samples t-test were used.

RESULTS

In patients with BRE, 7% had an epileptogenic lesion on their MRI. The frequency of epileptogenic lesion in the control group was 10.2% and not significantly different from those with BRE (p= 0.2). Significantly higher intracranial and white matter volumes were found in BRE patients compared to the healthy group while lower gray matter volume was found in BRE patients. Cortical and subcortical regions showed either higher or lower volumes with BRE. Interestingly, altered subcallosal cortex development which has a known association with depression was also found in BRE.

CONCLUSIONS

Our findings confirm the absence of any association between specific brain MRI abnormalities and BRE. However, the altered cortical and subcortical development in BRE patients suggests a microstructural-functional correlation.

Lamotrigine versus levetiracetam or zonisamide for focal epilepsy and valproate versus levetiracetam for generalised and unclassified epilepsy: two SANAD II non-inferiority RCTs

BACKGROUND

Levetiracetam (Keppra^®, UCB Pharma Ltd, Slough, UK) and zonisamide (Zonegran^®, Eisai Co. Ltd, Tokyo, Japan) are licensed as monotherapy for focal epilepsy, and levetiracetam is increasingly used as a first-line treatment for generalised epilepsy, particularly for women of childbearing age. However, there is uncertainty as to whether or not they should be recommended as first-line treatments owing to a lack of evidence of clinical effectiveness and cost-effectiveness.

OBJECTIVES

To compare the clinical effectiveness and cost-effectiveness of lamotrigine (Lamictal^®, GlaxoSmithKline plc, Brentford, UK) (standard treatment) with levetiracetam and zonisamide (new treatments) for focal epilepsy, and to compare valproate (Epilim^®, Sanofi SA, Paris, France) (standard treatment) with levetiracetam (new treatment) for generalised and unclassified epilepsy.

DESIGN

Two pragmatic randomised unblinded non-inferiority trials run in parallel.

SETTING

Outpatient services in NHS hospitals throughout the UK.

PARTICIPANTS

Those aged ≥ 5 years with two or more spontaneous seizures that require anti-seizure medication.

INTERVENTIONS

Participants with focal epilepsy were randomised to receive lamotrigine, levetiracetam or zonisamide. Participants with generalised or unclassifiable epilepsy were randomised to receive valproate or levetiracetam. The randomisation method was minimisation using a web-based program.

MAIN OUTCOME MEASURES

The primary outcome was time to 12-month remission from seizures. For this outcome, and all other time-to-event outcomes, we report hazard ratios for the standard treatment compared with the new treatment. For the focal epilepsy trial, the non-inferiority limit (lamotrigine vs. new treatments) was 1.329. For the generalised and unclassified epilepsy trial, the non-inferiority limit (valproate vs. new treatments) was 1.314. Secondary outcomes included time to treatment failure, time to first seizure, time to 24-month remission, adverse reactions, quality of life and cost-effectiveness.

RESULTS

Focal epilepsy. A total of 990 participants were recruited, of whom 330 were randomised to receive lamotrigine, 332 were randomised to receive levetiracetam and 328 were randomised to receive zonisamide. Levetiracetam did not meet the criteria for non-inferiority (hazard ratio 1.329) in the primary intention-to-treat analysis of time to 12-month remission (hazard ratio vs. lamotrigine 1.18, 97.5% confidence interval 0.95 to 1.47), but zonisamide did meet the criteria (hazard ratio vs. lamotrigine 1.03, 97.5% confidence interval 0.83 to 1.28). In the per-protocol analysis, lamotrigine was superior to both levetiracetam (hazard ratio 1.32, 95% confidence interval 1.05 to 1.66) and zonisamide (hazard ratio 1.37, 95% confidence interval 1.08 to 1.73). For time to treatment failure, lamotrigine was superior to levetiracetam (hazard ratio 0.60, 95% confidence interval 0.46 to 0.77) and zonisamide (hazard ratio 0.46, 95% confidence interval 0.36 to 0.60). Adverse reactions were reported by 33% of participants starting lamotrigine, 44% starting levetiracetam and 45% starting zonisamide. In the economic analysis, both levetiracetam and zonisamide were more costly and less effective than lamotrigine and were therefore dominated. Generalised and unclassifiable epilepsy. Of 520 patients recruited, 260 were randomised to receive valproate and 260 were randomised to receive to levetiracetam. A total of 397 patients had generalised epilepsy and 123 had unclassified epilepsy. Levetiracetam did not meet the criteria for non-inferiority in the primary intention-to-treat analysis of time to 12-month remission (hazard ratio 1.19, 95% confidence interval 0.96 to 1.47; non-inferiority margin 1.314). In the per-protocol analysis of time to 12-month remission, valproate was superior to levetiracetam (hazard ratio 1.68, 95% confidence interval 1.30 to 2.15). Valproate was superior to levetiracetam for time to treatment failure (hazard ratio 0.65, 95% confidence interval 0.50 to 0.83). Adverse reactions were reported by 37.4% of participants receiving valproate and 41.5% of those receiving levetiracetam. Levetiracetam was both more costly (incremental cost of £104, 95% central range -£587 to £1234) and less effective (incremental quality-adjusted life-year of -0.035, 95% central range -0.137 to 0.032) than valproate, and was therefore dominated. At a cost-effectiveness threshold of £20,000 per quality-adjusted life-year, levetiracetam was associated with a probability of 0.17 of being cost-effective.

LIMITATIONS

The SANAD II trial was unblinded, which could have biased results by influencing decisions about dosing, treatment failure and the attribution of adverse reactions.

FUTURE WORK

SANAD II data could now be included in an individual participant meta-analysis of similar trials, and future similar trials are required to assess the clinical effectiveness and cost-effectiveness of other new treatments, including lacosamide and perampanel.

CONCLUSIONS

Focal epilepsy - The SANAD II findings do not support the use of levetiracetam or zonisamide as first-line treatments in focal epilepsy. Generalised and unclassifiable epilepsy - The SANAD II findings do not support the use of levetiracetam as a first-line treatment for newly diagnosed generalised epilepsy. For women of childbearing potential, these results inform discussions about the benefit (lower teratogenicity) and harm (worse seizure outcomes and higher treatment failure rate) of levetiracetam compared with valproate.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN30294119 and EudraCT 2012-001884-64.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 75. See the NIHR Journals Library website for further project information.

The SANAD II study of the effectiveness and cost-effectiveness of valproate versus levetiracetam for newly diagnosed generalised and unclassifiable epilepsy: an open-label, non-inferiority, multicentre, phase 4, randomised controlled trial

BACKGROUND

Valproate is a first-line treatment for patients with newly diagnosed idiopathic generalised or difficult to classify epilepsy, but not for women of child-bearing potential because of teratogenicity. Levetiracetam is increasingly prescribed for these patient populations despite scarcity of evidence of clinical effectiveness or cost-effectiveness. We aimed to compare the long-term clinical effectiveness and cost-effectiveness of levetiracetam compared with valproate in participants with newly diagnosed generalised or unclassifiable epilepsy.

METHODS

We did an open-label, randomised controlled trial to compare levetiracetam with valproate as first-line treatment for patients with generalised or unclassified epilepsy. Adult and paediatric neurology services (69 centres overall) across the UK recruited participants aged 5 years or older (with no upper age limit) with two or more unprovoked generalised or unclassifiable seizures. Participants were randomly allocated (1:1) to receive either levetiracetam or valproate, using a minimisation programme with a random element utilising factors. Participants and investigators were aware of treatment allocation. For participants aged 12 years or older, the initial advised maintenance doses were 500 mg twice per day for levetiracetam and valproate, and for children aged 5-12 years, the initial daily maintenance doses advised were 25 mg/kg for valproate and 40 mg/kg for levetiracetam. All drugs were administered orally. SANAD II was designed to assess the non-inferiority of levetiracetam compared with valproate for the primary outcome time to 12-month remission. The non-inferiority limit was a hazard ratio (HR) of 1·314, which equates to an absolute difference of 10%. A HR greater than 1 indicated that an event was more likely on valproate. All participants were included in the intention-to-treat (ITT) analysis. Per-protocol (PP) analyses excluded participants with major protocol deviations and those who were subsequently diagnosed as not having epilepsy. Safety analyses included all participants who received one dose of any study drug. This trial is registered with the ISRCTN registry, 30294119 (EudraCt number: 2012-001884-64).

FINDINGS

520 participants were recruited between April 30, 2013, and Aug 2, 2016, and followed up for a further 2 years. 260 participants were randomly allocated to receive levetiracetam and 260 participants to receive valproate. The ITT analysis included all participants and the PP analysis included 255 participants randomly allocated to valproate and 254 randomly allocated to levetiracetam. Median age of participants was 13·9 years (range 5·0-94·4), 65% were male and 35% were female, 397 participants had generalised epilepsy, and 123 unclassified epilepsy. Levetiracetam did not meet the criteria for non-inferiority in the ITT analysis of time to 12-month remission (HR 1·19 [95% CI 0·96-1·47]); non-inferiority margin 1·314. The PP analysis showed that the 12-month remission was superior with valproate than with levetiracetam. There were two deaths, one in each group, that were unrelated to trial treatments. Adverse reactions were reported by 96 (37%) participants randomly assigned to valproate and 107 (42%) participants randomly assigned to levetiracetam. Levetiracetam was dominated by valproate in the cost-utility analysis, with a negative incremental net health benefit of -0·040 (95% central range -0·175 to 0·037) and a probability of 0·17 of being cost-effectiveness at a threshold of £20 000 per quality-adjusted life-year. Cost-effectiveness was based on differences between treatment groups in costs and quality-adjusted life-years.

INTERPRETATION

Compared with valproate, levetiracetam was found to be neither clinically effective nor cost-effective. For girls and women of child-bearing potential, these results inform discussions about benefit and harm of avoiding valproate.

FUNDING

National Institute for Health Research Health Technology Assessment Programme.

Ambulatory care for epilepsy via telemedicine during the COVID-19 pandemic

OBJECTIVE

To assess feasibility, patient satisfaction, and financial advantages of telemedicine for epilepsy ambulatory care during the current COVID-19 pandemic.

METHODS

The demographic and clinical characteristics of all consecutive patients evaluated via telemedicine at a level 4 epilepsy center between March 20 and April 20, 2020 were obtained retrospectively from electronic medical records. A telephone survey to assess patient satisfaction and preferences was conducted within one month following the initial visit.

RESULTS

Among 223 telehealth patients, 85.7% used both synchronous audio and video technology. During the visits, 39% of patients had their anticonvulsants adjusted while 18.8% and 11.2% were referred to laboratory/diagnostic testing and specialty consults, respectively. In a post-visit survey, the highest degree of satisfaction with care was expressed by 76.9% of patients. The degree of satisfaction tended to increase the further a patient lived from the clinic (p = 0.05). Beyond the pandemic, 89% of patients reported a preference for continuing telemedicine if their epilepsy symptoms remained stable, while only 44.4% chose telemedicine should their symptoms worsen. Inclement weather and lack of transportation were factors favoring continued use of telemedicine. An estimated cost saving to patient attributed to telemedicine was $30.20 ± 3.8 per visit.

SIGNIFICANCE

Our findings suggest that epilepsy care via telemedicine provided high satisfaction and economic benefit, without compromising patients' quality of care, thereby supporting the use of virtual care during current and future epidemiological fallouts. Beyond the current pandemic, patients with stable seizure symptoms may prefer to use telemedicine for their epilepsy care.

Activation of Peripheral and Central Trigeminovascular Neurons by Seizure: Implications for Ictal and Postictal Headache

An epileptic seizure can trigger a headache during (ictal) or after (postictal) the termination of the event. Little is known about the pathophysiology of seizure-induced headaches. In the current study, we determined whether a seizure can activate nociceptive pathways that carry pain signals from the meninges to the spinal cord, and if so, to what extent and through which classes of peripheral and central neurons. To achieve these goals, we used single-unit recording techniques and an established animal model of seizure (picrotoxin) to determine the effects of epileptic seizure on the activity of trigeminovascular Aδ-, C-, wide-dynamic range, and high-threshold neurons in male and female rats. Occurrence of seizure activated 54%, 50%, 68%, and 39% of the Aδ-, C-, wide-dynamic range, and high-threshold neurons, respectively. Regardless of their class, activated neurons exhibited a twofold to fourfold increase in their firing, which started immediately (1 min) or up to 90 min after seizure initiation, and lasted as short as 10 min or as long as 120 min. Administration of lidocaine to the dura prevented activation of all neuronal classes but not the initiation or maintenance of the seizure. These findings suggest that all neuronal classes may be involved in the initiation and maintenance of seizure-induced headache, and that their activation patterns can provide a neural substrate for explaining the timing and duration of ictal and possibly postictal headaches. By using seizure, which is evident in humans, this study bypasses controversies associated with cortical spreading depression, which is less readily observed in humans.SIGNIFICANCE STATEMENT This preclinical study provides a neural substrate for ictal and postictal headache. By studying seizure effects on the activity of peripheral (C and Aδ) and central (wide dynamic range and high-threshold) trigeminovascular neurons in intact and anesthetized dura, the findings help resolve two outstanding questions about the pathophysiology of headaches of intracranial origin. The first is that abnormal brain activity (i.e., seizure) that is evident in human (unlike cortical spreading depression) gives rise to specific and selective activation of the different components of the trigeminovascular system, and the second is that the activation of all components of the trigeminovascular pathway (i.e., peripheral and central neurons) depends on activation of the meningeal nociceptors from their receptors in the dura.

Novel study design to assess the efficacy and tolerability of antiseizure medications for focal-onset seizures in infants and young children: A consensus document from the regulatory task force and the pediatric commission of the International League against Epilepsy (ILAE), in collaboration with the Pediatric Epilepsy Research Consortium (PERC)

High-quality placebo-controlled drug trials for focal-onset seizures in infants and children younger than 4 years have become increasingly difficult to perform because of eligibility constraints and onerous study designs. Traditional designs used in these populations require a high baseline seizure frequency, two hospitalizations for video-electroencephalography (video-EEG) monitoring, and willingness to accept potential exposure to placebo when the drugs to be tested are usually already available for off-label prescription. To address these constraints, the International League Against Epilepsy (ILAE) regulatory taskforce and the ILAE pediatric commission, in collaboration with the Pediatric Epilepsy Research Consortium (PERC), propose a novel trial design which involves seizure counting by caregivers based on previous video-EEG/video validation of specific seizure semiologies. We present a novel randomized placebo-controlled trial design intended to be used for studying new antiseizure medications (ASMs) for focal-onset seizures (FOS) in children aged one month to four years. This design uses "time to Nth seizure" as the primary outcome and incorporates a new element of variable baseline duration. This approach permits enrollment of infants with lower seizure burden, who might not have video-EEG-recorded seizures within 2-3 days of monitoring. Repeated hospitalizations for video-EEG recordings are avoided, and duration of baseline and exposure to placebo or ineffective treatment(s) are minimized. By broadening eligibility criteria, reducing risks from prolonged placebo exposure, and relying on validated recording of seizure counting by caregivers, clinical trials will be likely to be completed more efficiently than in the recent past.

Latitudinal differences on the global epidemiology of infantile spasms: systematic review and meta-analysis

BACKGROUND

Infantile spasms represent the catastrophic, age-specific seizure type associated with acute and long-term neurological morbidity. However, due to rarity and heterogenous determination, there is persistent uncertainty of its pathophysiological and epidemiological characteristics. The purpose of the current study was to address a historically suspected latitudinal basis of infantile spasms incidence, and to interrogate a geographical basis of epidemiology, including the roles of latitude and other environmental factors, using meta-analytic and -regression methods.

METHODS

A systematic search was performed in Ovid MEDLINE and Embase for primary reports on infantile spasms incidence and prevalence epidemiology.

RESULTS

One thousand fifteen studies were screened to yield 54 eligible publications, from which 39 incidence figures and 18 prevalence figures were extracted. The pooled incidence was 0.249 cases/1000 live births. The pooled prevalence was 0.015 cases/1000 population. Univariate meta-regression determined a continental effect, with Europe demonstrating the highest onset compared from Asia (OR = 0.51, p = 0.004) and from North America (OR = 0.50, p = 0.004). Latitude was also positively correlated with incidence globally (OR = 1.02, p < 0.001). Sub-analyses determined a particularly elevated Scandinavian incidence compared to the rest of world (OR = 1.88, p < 0.001), and lack of latitudinal effect with Scandinavian exclusion (p = 0.10). Metrics of healthcare quality did not predict incidence. Multiple meta-regression determined that latitude was the key predictor of incidence (OR = 1.02, p = 0.001).

CONCLUSIONS

This is the first systematic epidemiological study of infantile spasms. Limitations included lack of Southern hemispheric representation, insufficient study selection and size to support some sub-continental analyses, and lack of accessible ethnic and healthcare quality data. Meta-analyses determined a novel, true geographical difference in incidence which is consistent with a latitudinal and/or ethnic contribution to epileptogenesis. These findings justify the establishment of a global registry of infantile spasms epidemiology to promote future systematic studies, clarify risk factors, and expand understanding of the pathophysiology.

Incidence of childhood epilepsy: A population-based study in rural Japan

INTRODUCTION

Epilepsy is a common childhood neurological condition and a major public health concern worldwide. A higher incidence of epilepsy is reported in low- and middle-income countries, particularly in rural areas. However, no Japanese reports on the incidence of childhood epilepsy have been published in the past 25 years. We estimated the annual incidence of epilepsy in children aged 1-14 years in Uwajima, a city in a rural, relatively isolated area of Japan.

METHODS

Candidates were extracted from Japan's public insurance database following the International Classification of Diseases code for epilepsy. Epilepsy was defined as two or more unprovoked seizures more than 24 hours apart, as per the International League Against Epilepsy definition. The study sample was divided into three cohorts based on age at diagnosis: 1-4, 5-9, and 10-14 years. The incidence of epilepsy was calculated as the number of children with epilepsy divided by the person-years in each cohort.

RESULTS

The annual incidence rate of epilepsy in children aged 1-14 years was 70.4/100,000 children (95% confidence interval, 44.8-96.0). There was no significant difference in incidence between boys and girls. This rate was similar to those reported in other countries, although the incidence in children aged 1-4 years was slightly higher in our study than in other countries.

CONCLUSION

The annual incidence of childhood epilepsy in rural areas of Japan is generally comparable with rates of childhood epilepsy reported in other countries.

Spectral bandwidth of interictal fast epileptic activity characterizes the seizure onset zone

The foremost aim of presurgical epilepsy evaluation is the delineation of the seizure onset zone (SOZ). There is increasing evidence that fast epileptic activity (FEA, 14–250 Hz) occurring interictally, i.e. between seizures, is predominantly localized within the SOZ. Currently it is unknown, which frequency band of FEA performs best in identifying the SOZ, although prior studies suggest highest concordance of spectral changes with the SOZ for high frequency changes. We suspected that FEA reflects dampened oscillations in local cortical excitatory-inhibitory neural networks, and that interictal FEA in the SOZ is a consequence of reduced oscillatory damping. We therefore predict a narrowing of the spectral bandwidth alongside increased amplitudes of spectral peaks during interictal FEA events. To test this hypothesis, we evaluated spectral changes during interictal FEA in invasive EEG (iEEG) recordings of 13 patients with focal epilepsy. In relative spectra of beta and gamma band changes (14–250 Hz) during FEA, we found that spectral peaks within the SOZ indeed were significantly more narrow-banded and their power changes were significantly higher than outside the SOZ. In contrast, the peak frequency did not differ within and outside the SOZ. Our results show that bandwidth and power changes of spectral modulations during FEA both help localizing the SOZ. We propose the spectral bandwidth as new source of information for the evaluation of EEG data.

•

Invasive EEG spectral bandwidth changes differ in and outside seizure onset zone.

•

Peak frequency of invasive EEG spectral changes was not informative.

•

Model of dampened oscillator explains the observed spectral bandwidth changes.

•

Spectral bandwidth changes are a novel diagnostic feature.

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.

Psychological features and quality of life in 50 adult patients with epilepsy and their caregivers from the Lecco epilepsy center, Italy

Epilepsy is one of the most common neurological disorders. To the best of our knowledge, in Italy, the relationship between patients' and caregivers' psychological state has rarely been analyzed. Thus, we sought to evaluate both the psychological state of patients with epilepsy and that of their caregivers and the interrelationship between them. We also assessed the existing relation between psychological features and some clinical and demographic information, such as number of antiepileptic drugs (AEDs), epilepsy duration and education level of patients and their caregivers. We enrolled in the study 50 consecutive adult patients attending the epilepsy clinic of "A. Manzoni" Hospital and their caregivers. Both patients and their caregivers were administered Hospital Anxiety and Depression Scale (HADS) and 36-item Short-Form Health Survey (SF-36). Anxiety, depression and quality of life values of both patients and their caregivers did not differ significantly from the normative samples. No statistically significant correlation between epilepsy duration and patients' and caregivers' psychological features was found. Patients which took more than one AED reported lower values of "Vitality" (p <.05) and "Social Functioning" (p <.05) than their own caregivers. Caregivers with higher education level presented lower "Vitality" values than caregivers with lower education level (p <.05). Patients with pharmacoresistant seizures reported lower values of "Mental Health" than patients with non-pharmacoresistant seizures (p <.05). In this context, the role of coping mechanisms by patients and caregivers may explain apparently unexpected findings and suggests that strategies aimed at reinforcing them may be effective in selected cases. Therefore, while the severity of epilepsy may have an impact on the psychological state of adult patients with epilepsy and their caregivers, our results highlight the role of multidimensional determinants, including stigma. Further studies are needed to identify the factors related to epilepsy, patients, caregivers, treatments, and the environment that may be modifiable in order to improve self-perceived QoL.

Evaluation of GLUT1 variation in non-acquired focal epilepsy

Brain glucose transport is dependent on glucose transporter 1 (GLUT1), encoded by the solute carrier family 2 member 1 (SLC2A1) gene. Mutations in SLC2A1 cause GLUT1 deficiency which is characterized by a broad spectrum of neurological phenotypes including generalized epilepsy, motor disorders, developmental delay and microcephaly. Recent case reports suggest SLC2A1 mutations can contribute to non-acquired focal epilepsy (NAFE) but interrogation of a large patient cohort has not been reported. We studied 200 patients with NAFE (126 with temporal lobe epilepsy) comprising 104 females and 96 males with a mean age of onset of 18 years. Polymerase chain reaction (PCR) and Sanger sequencing was performed to detect variants in all 10 coding exons and splice site regions of the SLC2A1 gene. We did not detect any pathogenic mutations in SLC2A1 in this cohort. Our data suggests that the frequency of GLUT1 mutations in NAFE is low. Limitations of this study include the mean age of onset and cohort size. Future research should focus on subpopulations of focal epilepsy with lower age of seizure onset particularly with co-existent movement disorders in which GLUT1 mutations may play a more important role.

A targeted resequencing gene panel for focal epilepsy

OBJECTIVES

We report development of a targeted resequencing gene panel for focal epilepsy, the most prevalent phenotypic group of the epilepsies.

METHODS

The targeted resequencing gene panel was designed using molecular inversion probe (MIP) capture technology and sequenced using massively parallel Illumina sequencing.

RESULTS

We demonstrated proof of principle that mutations can be detected in 4 previously genotyped focal epilepsy cases. We searched for both germline and somatic mutations in 251 patients with unsolved sporadic or familial focal epilepsy and identified 11 novel or very rare missense variants in 5 different genes: CHRNA4, GRIN2B, KCNT1, PCDH19, and SCN1A. Of these, 2 were predicted to be pathogenic or likely pathogenic, explaining ∼0.8% of the cohort, and 8 were of uncertain significance based on available data.

CONCLUSIONS

We have developed and validated a targeted resequencing panel for focal epilepsies, the most important clinical class of epilepsies, accounting for about 60% of all cases. Our application of MIP technology is an innovative approach that will be advantageous in the clinical setting because it is highly sensitive, efficient, and cost-effective for screening large patient cohorts. Our findings indicate that mutations in known genes likely explain only a small proportion of focal epilepsy cases. This is not surprising given the established clinical and genetic heterogeneity of these disorders and underscores the importance of further gene discovery studies in this complex syndrome.

Non-pharmacological interventions for people with epilepsy and intellectual disabilities

BACKGROUND

Approximately 30% of patients with epilepsy remain refractory to drug treatment and continue to experience seizures whilst taking one or more antiepileptic drugs (AEDs). Several non-pharmacological interventions that may be used in conjunction with or as an alternative to AEDs are available for refractory patients. In view of the fact that seizures in people with intellectual disabilities are often complex and refractory to pharmacological interventions, it is evident that good quality randomised controlled trials (RCTs) are needed to assess the efficacy of alternatives or adjuncts to pharmacological interventions.This is an updated version of the original Cochrane review (Beavis 2007) published in The Cochrane Library (2007, Issue 4).

OBJECTIVES

To assess data derived from randomised controlled trials of non-pharmacological interventions for people with epilepsy and intellectual disabilities.Non-pharmacological interventions include, but are not limited to, the following.• Surgical procedures.• Specialised diets, for example, the ketogenic diet, or vitamin and folic acid supplementation.• Psychological interventions for patients or for patients and carers/parents, for example, cognitive-behavioural therapy (CBT), electroencephalographic (EEG) biofeedback and educational intervention.• Yoga.• Acupuncture.• Relaxation therapy (e.g. music therapy).

SEARCH METHODS

For the latest update of this review, we searched the Cochrane Epilepsy Group Specialised Register (19 August 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) via CRSO (19 August 2014), MEDLINE (Ovid, 1946 to 19 August 2014) and PsycINFO (EBSCOhost, 1887 to 19 August 2014).

SELECTION CRITERIA

Randomised controlled trials of non-pharmacological interventions for people with epilepsy and intellectual disabilities.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria and extracted study data.

MAIN RESULTS

One study is included in this review. When two surgical procedures were compared, results indicated that corpus callosotomy with anterior temporal lobectomy was more effective than anterior temporal lobectomy alone in improving quality of life and performance on IQ tests among people with epilepsy and intellectual disabilities. No evidence was found to support superior benefit in seizure control for either intervention. This is the only study of its kind and was rated as having an overall unclear risk of bias. The previous update (December 2010) identified one RCT in progress. The study authors have confirmed that they are aiming to publish by the end of 2015; therefore this study (Bjurulf 2008) has not been included in the current review.

AUTHORS' CONCLUSIONS

This review highlights the need for well-designed randomised controlled trials conducted to assess the effects of non-pharmacological interventions on seizure and behavioural outcomes in people with intellectual disabilities and epilepsy.

Slow Spatial Recruitment of Neocortex during Secondarily Generalized Seizures and Its Relation to Surgical Outcome

Understanding the spatiotemporal dynamics of brain activity is crucial for inferring the underlying synaptic and nonsynaptic mechanisms of brain dysfunction. Focal seizures with secondary generalization are traditionally considered to begin in a limited spatial region and spread to connected areas, which can include both pathological and normal brain tissue. The mechanisms underlying this spread are important to our understanding of seizures and to improve therapies for surgical intervention. Here we study the properties of seizure recruitment-how electrical brain activity transitions to large voltage fluctuations characteristic of spike-and-wave seizures. We do so using invasive subdural electrode arrays from a population of 16 patients with pharmacoresistant epilepsy. We find an average delay of ∼30 s for a broad area of cortex (8 × 8 cm) to be recruited into the seizure, at an estimated speed of ∼4 mm/s. The spatiotemporal characteristics of recruitment reveal two categories of patients: one in which seizure recruitment of neighboring cortical regions follows a spatially organized pattern consistent from seizure to seizure, and a second group without consistent spatial organization of activity during recruitment. The consistent, organized recruitment correlates with a more regular, compared with small-world, connectivity pattern in simulation and successful surgical treatment of epilepsy. We propose that an improved understanding of how the seizure recruits brain regions into large amplitude voltage fluctuations provides novel information to improve surgical treatment of epilepsy and highlights the slow spread of massive local activity across a vast extent of cortex during seizure.

Developmental stage affects cognition in children with recently-diagnosed symptomatic focal epilepsy

This study explored the impact of developmental stage on cognitive function in children with recently-diagnosed epilepsy. In keeping with a neurodevelopmental framework, skills in a critical developmental period were expected to be more vulnerable than those stable at the time of seizure onset. We studied children with early-onset (EO) symptomatic focal epilepsy (onset: 3-5 years; n=18) and compared their performance with that of the group with late-onset (LO) epilepsy (onset: 6-8 years performance of; n=8) on a range of cognitive tasks. Performance of both groups was compared with normative standards. 'Critical' and 'stable' classifications were based on developmental research. Nonparametric analyses revealed that skills in a critical developmental period for the group with EO epilepsy fell below normative standards (Phonological Processing: p=.007, Design Copying: p=.01, Visuomotor Precision:, p=.02) and fell below the performance of the group with LO epilepsy (Design Copying: p=.03, Visuomotor Precision: p=.03). There were no differences between the group with EO epilepsy and the group with LO epilepsy on measures of receptive vocabulary and memory, which were proposed to be in a stable developmental period across both groups. Auditory span, as measured by Word Order, was reduced for both the group with EO epilepsy (p=.02) and the group with LO epilepsy (p=.02) relative to normative standards, but the groups did not differ from each other. These results are consistent with a prolonged period of critical development for this skill. These findings support the notion that skills in a critical phase of development are particularly vulnerable following the onset of symptomatic focal epilepsy in childhood.

Optogenetic delay of status epilepticus onset in an in vivo rodent epilepsy model

Epilepsy is a devastating disease, currently treated with medications, surgery or electrical stimulation. None of these approaches is totally effective and our ability to control seizures remains limited and complicated by frequent side effects. The emerging revolutionary technique of optogenetics enables manipulation of the activity of specific neuronal populations in vivo with exquisite spatiotemporal resolution using light. We used optogenetic approaches to test the role of hippocampal excitatory neurons in the lithium-pilocarpine model of acute elicited seizures in awake behaving rats. Hippocampal pyramidal neurons were transduced in vivo with a virus carrying an enhanced halorhodopsin (eNpHR), a yellow light activated chloride pump, and acute seizure progression was then monitored behaviorally and electrophysiologically in the presence and absence of illumination delivered via an optical fiber. Inhibition of those neurons with illumination prior to seizure onset significantly delayed electrographic and behavioral initiation of status epilepticus, and altered the dynamics of ictal activity development. These results reveal an essential role of hippocampal excitatory neurons in this model of ictogenesis and illustrate the power of optogenetic approaches for elucidation of seizure mechanisms. This early success in controlling seizures also suggests future therapeutic avenues.

The prognosis of idiopathic generalized epilepsy

Prognosis describes the trajectory and long-term outcome of a condition. Most studies indicate a better prognosis in idiopathic generalized epilepsy (IGE) in comparison with other epilepsy syndromes. Studies looking at the long-term outcome of different IGE syndromes are relatively scant. Childhood absence epilepsy appears to have a higher rate of remission compared to juvenile absence epilepsy. In absence epilepsies, development of myoclonus and generalized tonic-clonic seizures predicts lower likelihood of remission. Although most patients with juvenile myoclonic epilepsy (JME) achieve remission on antiepileptic drug therapy, <20% appear to remain in remission without treatment. Data on the prognosis of other IGE syndromes are scarce. There are contradictory findings reported on the value of electroencephalography as a predictor of prognosis. Comparisons are made difficult by study heterogeneity, particularly in methodology and diagnostic criteria.

Inferring evoked brain connectivity through adaptive perturbation

Inference of functional networks-representing the statistical associations between time series recorded from multiple sensors-has found important applications in neuroscience. However, networksexhibiting time-locked activity between physically independent elements can bias functional connectivity estimates employing passive measurements. Here, a perturbative and adaptive method of inferring network connectivity based on measurement and stimulation-so called "evoked network connectivity" is introduced. This procedure, employing a recursive Bayesian update scheme, allows principled network stimulation given a current network estimate inferred from all previous stimulations and recordings. The method decouples stimulus and detector design from network inference and can be suitably applied to a wide range of clinical and basic neuroscience related problems. The proposed method demonstrates improved accuracy compared to network inference based on passive observation of node dynamics and an increased rate of convergence relative to network estimation employing a naïve stimulation strategy.

Primary headache and epilepsy: a multicenter cross-sectional study

The prevalence and characteristics of interictal headache, epilepsy and headache/epilepsy comorbidity were assessed in 858 women and 309 men aged 18-81 years from headache and epilepsy centers in Italy. The research hypothesis was that comorbidity among patients with either disorder would be expected to be higher than in the general population. Interictal headache was diagnosed in 675 cases (migraine 482; tension-type headache 168; other types 25), epilepsy in 336 (partial 171; generalized 165) and comorbidity in 156 (1.6% from headache centers; 30.0% from epilepsy centers). Patients with epilepsy, headache and comorbidity differed in a number of demographic and clinical aspects. However, for both headache and epilepsy, a family history of the same clinical condition was equally prevalent in patients with and without comorbidity. These findings do not support the purported association between headache and epilepsy.

Magnetic resonance imaging abnormalities in children with epilepsy

BACKGROUND AND PURPOSE

The aim of this study is to analyze the proportional distribution of epilepsy and epileptic syndromes in children and to describe the magnetic resonance imaging (MRI) abnormalities found in these patients.

METHODS

Data from 457 children aged 1 month to 15 years at the time of diagnosis of epilepsy were recorded. A routine MRI has been requested in all patients with epilepsy at diagnosis according to a standardized pediatric seizure protocol. Abnormalities on MRI were classified as either significant or non-significant (standardized scoring system). International League Against Epilepsy criteria were used for diagnoses.

RESULTS

The prevalence of significant MRI abnormalities was 21.9% (in infants 42.3%, in childhood 18.2%, and in adolescents 15.9%). The most common abnormalities included white-matter lesions (27.6%), volume loss (19.6%), gray-matter lesions (19.6%), and ventricular enlargement (12%).

CONCLUSIONS

The use of MRI and a reliable standardized scoring system at diagnosis of epilepsy in children identified a high rate of significant abnormalities findings. This may have important implications for practice guidelines in this population.

High incidence of pediatric idiopathic epilepsy is associated with familial and autosomal dominant disease in Eastern Newfoundland

PURPOSE

To describe the incidence and epidemiology of pediatric idiopathic epilepsy (IE) in Newfoundland and Labrador.

METHODS

All children in Newfoundland and Labrador aged 0-15 years with IE were ascertained through the provincial neurology clinic at the Janeway Child Health Centre. Family history, medical history and blood samples were obtained from probands and relatives. Two genes, SCN1A and KCNQ2, were screened for mutations by direct sequencing.

RESULTS

The mean annual incidence of IE for the population of children living in the Avalon region of Newfoundland from 2000 to 2004 was 107 per 100,000. This rate is approximately three-fold greater than rates reported in other developed countries. Of 117 families with IE eligible for study, 86 (74%) provided detailed pedigree data. Multiple different epilepsy phenotypes were identified. Fifty-five families (64%) had a positive family history. Eight of these had family histories compatible with autosomal dominant (AD) inheritance and these families lived in five different geographic isolates. DNA was obtained from 21 families (79 individuals). The two previously identified mutations in Newfoundland families with epilepsy were sequenced and excluded as pathogenic sites in all but one family which had a mutation in SCN1A.

CONCLUSION

The incidence of IE is high in the Avalon Peninsula of Newfoundland and the rate of familial disease is high throughout the province of Newfoundland and Labrador. The distribution of familial and AD IE in different geographic isolates, together with the clinical heterogeneity of disease suggests substantial genetic heterogeneity. It is likely that other novel mutations will be identified in this population.

Behavioral changes in dogs associated with the development of idiopathic epilepsy

OBJECTIVES

The aim of the study was to demonstrate behavioral changes with the development of epilepsy in dogs, a species proposed as a naturally occurring animal model for human epilepsy.

METHODS

Owners of dogs diagnosed with idiopathic epilepsy (n=80) completed a modified, previously-validated behavioral and seizure questionnaire. Principal axis factor analysis identified behavioral factors, the scores for which were compared before and after the development of epilepsy.

RESULTS

Drug-naïve dogs showed an increase in the behavior factors Fear/Anxiety, Defensive Aggression, and Abnormal Perception. In dogs receiving antiepileptic medication, there were still increases in Fear/Anxiety and Abnormal Perception, but no longer in Defensive Aggression. Additional increases were observed in Abnormal Reactivity, Attachment Disorder, Demented Behavior, and Apathetic Behavior. Pharmacoresistant dogs had larger increases in Controlling Aggression, Abnormal Perception, and Demented Behavior than drug responders.

CONCLUSION

Our data suggest that dogs, like humans and rodents, exhibit neurobehavioral comorbidities with the development of epilepsy.

Incidence and classification of new-onset epilepsy and epilepsy syndromes in children in Olmsted County, Minnesota from 1980 to 2004: a population-based study

PURPOSE

To determine the incidence and classification of new-onset epilepsy, as well as the distribution of epilepsy syndromes in a population-based group of children, using the newly proposed Report of the ILAE Commission on Classification and Terminology 2005-2009.

METHODS

We identified all children residing in Olmsted County, MN, 1 month through 17 years with newly diagnosed epilepsy from 1980 to 2004. For each patient, epilepsy was classified into mode of onset, etiology, and syndrome or constellation (if present). Incidence rates were calculated overall and also separately for categories of mode of onset and etiology.

RESULTS

The adjusted incidence rate of new-onset epilepsy in children was 44.5 cases per 100,000 persons per year. Incidence rates were highest in the first year of life and diminished with age. Mode of onset was focal in 68%, generalized/bilateral in 23%, spasms in 3% and unknown in 5%. Approximately half of children had an unknown etiology for their epilepsy, and of the remainder, 78 (22%) were genetic and 101 (28%) were structural/metabolic. A specific epilepsy syndrome could be defined at initial diagnosis in 99/359 (28%) children, but only 9/359 (3%) had a defined constellation.

CONCLUSION

Nearly half of childhood epilepsy is of "unknown" etiology. While a small proportion of this group met criteria for a known epilepsy syndrome, 41% of all childhood epilepsy is of "unknown" cause with no clear syndrome identified. Further work is needed to define more specific etiologies for this group.

Multicultural challenges in epilepsy

Epilepsy is a common neurological condition throughout the world. Its care involves medical expertise, but may also bring different cultural challenges. We discuss clinical, social and psychological outcomes in different cultural settings. We point out differences and similarities in epilepsy epidemiology (etiology and risk factors, prognosis, and natural history), disparities in care and health services, and cultural influences and traditional beliefs, with special respect to practical issues and possible transcultural misunderstandings. We also discuss the relevance of multicultural issues to clinicians working in developed countries.

Profile of ezogabine (retigabine) and its potential as an adjunctive treatment for patients with partial-onset seizures

Epilepsy is a common disease with significant morbidity and mortality. Approximately one-third of patients with epilepsy are refractory to available seizure medications, emphasizing the need to develop better drugs with novel mechanisms of action. Ezogabine, also known as retigabine, is a new potential adjunctive treatment for adults with intractable partial seizures. Ezogabine has a unique mechanism of action consisting of activating KCNQ2/3 (Kv7) potassium channels. Ezogabine has undergone a number of Phase II and III trials demonstrating efficacy at 600,900 and 1200 mg/day in a dose-dependent fashion. The most common adverse events with ezogabine are central nervous system effects, particularly dizziness and somnolence. Urologic symptoms, particularly urinary retention, represent a rare but unique side effect of ezogabine. Ezogabine is predominantly metabolized via glucuronidation. Its half-life is 8 hours, suggesting a need for three-times-a-day administration. Ezogabine exhibits minimal interactions with other seizure medications, except possibly lamotrigine. Ezogabine has potential for clinical applications in other medical conditions beyond epilepsy, such as neuropathic pain, neuromyotonia, and bipolar disease, but these are based primarily on experimental models.

Prognostic significance of interictal epileptiform discharges in newly diagnosed seizure disorders

EEGs performed for new-onset seizures show epileptiform discharge in approximately 18% to 56% of children and 12% to 50% of adults. An EEG after sleep deprivation improves detection of epileptiform abnormalities, showing discharge in 13% to 35% of patients whose standard EEG findings were normal. Some studies have also shown a higher yield with EEG performed within 24 hours after the seizure. The EEG is a useful diagnostic study in this clinical setting for a number of reasons. First, specific EEG abnormalities help characterize the seizure type and epilepsy syndrome, which allows more informed decisions regarding therapy and more accurate prediction of seizure control and ultimate remission. Second, in certain cases, the EEG may detect more subtle seizures, including absence, myoclonic, or partial seizures. Third, specific EEG patterns may alert the clinician to the presence of a focal cerebral lesion. Fourth, most studies have shown that an epileptiform discharge is predictive of seizure recurrence, particularly in patients with idiopathic epilepsy. In the presence of epileptiform discharge, the recurrence risk is approximately double what would be predicted after a normal EEG. The predictive value of nonepileptiform abnormalities is not clearly established.

Pediatric epilepsy and first afebrile seizure in Singapore: epidemiology and investigation yield at presentation

The authors studied pediatric epilepsy and first afebrile seizure at presentation in Singapore. A total of 211 participants aged 1 month to 15 years with first presentation for afebrile seizures were recruited from November 2002 to May 2004; 108 with ≥2 prior afebrile seizures (newly diagnosed epilepsy) and 103 with first afebrile seizures. A χ(2) analysis of demographics, risk factors, examination, and investigation findings showed significant differences in development (normal in 87% [newly diagnosed epilepsy] and 93% [first afebrile seizure], P = .046), neurological examination (normal in 92% [newly diagnosed epilepsy] and 98% [first afebrile seizure], P = .016), and electroencephalogram findings (abnormal in 75% [newly diagnosed epilepsy] and 36.9% [first afebrile seizure], P < .005). Pediatric epilepsy incidence at our institution is 24 per 100 000 person-years and is highest in early childhood. Focal epilepsy is more common than generalized epilepsy. Patients with first afebrile seizure and abnormal development, neurological examination, and electroencephalogram findings should be monitored for future development of epilepsy. Population-based studies are recommended.

Familial mesial temporal lobe epilepsy: a benign epilepsy syndrome showing complex inheritance

Temporal lobe epilepsy is the commonest partial epilepsy of adulthood. Although generally perceived as an acquired disorder, several forms of familial temporal lobe epilepsy, with mesial or lateral seizure semiology, have been described. Descriptions of familial mesial temporal lobe epilepsy have varied widely from a benign epilepsy syndrome with prominent déjà vu and without antecedent febrile seizures or magnetic resonance imaging abnormalities, to heterogeneous, but generally more refractory epilepsies, often with a history of febrile seizures and with frequent hippocampal atrophy and high T₂ signal on magnetic resonance imaging. Compelling evidence of a genetic aetiology (rather than chance aggregation) in familial mesial temporal lobe epilepsy has come from twin studies. Dominant inheritance has been reported in two large families, though the usual mode of inheritance is not known. Here, we describe clinical and neurophysiological features of 20 new mesial temporal lobe epilepsy families including 51 affected individuals. The epilepsies in these families were generally benign, and febrile seizure history was infrequent (9.8%). No evidence of hippocampal sclerosis or dysplasia was present on brain imaging. A single individual underwent anterior temporal lobectomy, with subsequent seizure freedom and histopathological evidence of hippocampal sclerosis was not found. Inheritance patterns in probands' relatives were analysed in these families, together with 19 other temporal lobe epilepsy families previously reported by us. Observed frequencies of epilepsies in relatives were lower than predicted by dominant Mendelian models, while only a minority (8/39) of families could be compatible with recessive inheritance. These findings strongly suggest that complex inheritance, similar to that widely accepted in the idiopathic generalized epilepsies, is the usual mode of inheritance in familial mesial temporal lobe epilepsy. This disorder, which appears to be relatively common, and not typically associated with hippocampal sclerosis, is an appropriate target for contemporary approaches to complex disorders such as genome-wide association studies for common genetic variants or deep sequencing for rare variants.

Advances in the application of technology to epilepsy: the CIMIT/NIO Epilepsy Innovation Summit

In 2008, a group of clinicians, scientists, engineers, and industry representatives met to discuss advances in the application of engineering technologies to the diagnosis and treatment of patients with epilepsy. The presentations also provided a guide for further technological development, specifically in the evaluation of patients for epilepsy surgery, seizure onset detection and seizure prediction, intracranial treatment systems, and extracranial treatment systems. This article summarizes the discussions and demonstrates that cross-disciplinary interactions can catalyze collaborations between physicians and engineers to address and solve many of the pressing unmet needs in epilepsy.

Epilepsy and neurocysticercosis: an incidence study in a Peruvian rural population

BACKGROUND

Epilepsy is a serious neurological disorder and neurocysticercosis (NCC), the central nervous system infection by the larvae of Taenia solium, is the main cause of acquired epilepsy in developing countries. NCC is becoming more frequent in industrialized countries due to immigration from endemic areas. Previously reported epilepsy incidences range from 30 to 50/100,000 people in industrialized countries and 90 to 122/100,000 people in developing countries.

OBJECTIVES

To determine the incidence of epilepsy in a cysticercosis endemic area of Peru.

METHODS

A screening survey for possible seizure cases was repeated biannually in this cohort for a period of 5 years (1999-2004) using a previously validated questionnaire. All positive respondents throughout the study were examined by a trained neurologist in the field to confirm the seizure. If confirmed, they were offered treatment, serological testing, neuroimaging (CT scans and MRI) and clinical follow-up.

RESULTS

The cohort study comprised 817 individuals. The overall epilepsy incidence rate was 162.3/100,000 person-years, and for epileptic seizures, 216.6/100,000 person-years. Out of the 8 individuals who had epileptic seizures, 4 had markers for NCC (neuroimaging and/or serology).

CONCLUSION

The incidence of epilepsy in this area endemic for cysticercosis is one of the highest reported worldwide.

Epilepsy in the northern Finland birth cohort 1966 with special reference to fertility

The aim of the study was to evaluate both the prevalence of epilepsy and the reproductive history of subjects with epilepsy in a population-based cohort study. The Northern Finland Birth Cohort 1966 (NFBC 1966) comprises 12,058 subjects with 39 years of follow-up. Of these subjects, 222 were identified as having epilepsy on the basis of information obtained from mailed questionnaires, hospital discharge registers, and records for reimbursed antiepileptic medications. The information on reproductive outcome was also updated. Both men and women with epilepsy did not differ from the reference group with respect to number of children. However, subjects with active epilepsy during adulthood had fewer children than those who achieved remission before adulthood. Subjects with epilepsy who achieved remission before adulthood did not differ from control subjects with respect to number of children.

Innovation focus: the patient with arrhythmia

Great strides have been made over the last two decades in the management of patients with rhythm disorders. Despite this, however, the remaining critical problems of stroke related to atrial fibrillation or as a result of radiofrequency ablation require innovative solutions to fully realize the potential of these recent advances. Similarly, implanted cardiac devices have revolutionized the care of patients with bradyrhythmias and tachyarrhythmias. Dyssynchronus ventricular pacing associated with present devices; however, results in heart failure, tricuspid regurgitation, and inappropriate device therapy once again create a demand for creative solutions. While not technically an arrhythmia, epilepsy management today is riddled with many of the problems that plagued cardiac arrhythmia management previously, and thus an appreciation of the similarities in requirement for investigative solutions may yield groundbreaking solutions. In this paper, we describe some novel methods to reduce complications associated with rhythm disorders and their treatment and apply the lessons learned from cardiovascular arrhythmia management to the brain. These include: a method to reduce coagulum formation and thus subsequent thromboembolism with indwelling catheters specifically during radiofrequency ablation procedures; a technique to ligate the left atrial appendage through percutaneous subxiphoid pericardial access; development and testing of a novel intramyocardial pace-sense lead, particularly used in a unique anatomic location (the atrioventricular septum) to allow pacing the ventricles in a relatively synchronous manner without crossing the tricuspid valve or entering the coronary sinus; finally, novel modifications of the cardiovascular mapping and ablation techniques used for the management of the central nervous system disorders primarily via the venous drainage of the brain. Innovative and potential solutions to treat the patient with arrhythmia are presented.