The past decade has yielded a host of important conceptual advances in epilepsy, along with some promising findings related to diagnostics and therapeutics. We are on an upswing where precise identification of the cause of a patient’s seizure disorder can be matched to therapy that has a high likelihood of success.

Purpose of review

We aim to review the most recent advances in the field of epilepsy genetics with particular focus on the progress in gene discovery in monogenic epilepsies, identification of risk genes in complex genetic epilepsies and recent findings in the field of epilepsy pharmacogenomics.

Recent findings

During the last 12 months, the use of massive parallel sequencing technologies has allowed for the discovery of several genes for monogenic epilepsies. Most importantly, PRRT2 was identified as the long-sought gene for benign familial infantile seizures. Mutations in KCNT1 were found in two seemingly unrelated monogenic epilepsies including malignant migrating partial seizures of infancy and severe autosomal dominant nocturnal frontal lobe epilepsy. A genome-wide association study in idiopathic generalized epilepsy revealed the first common risk variants for human seizure disorders including variants in VRK2, PNPO and SCN1A. Furthermore, a landmark study provided evidence that screening for the HLA-B1502 variant may prevent carbamazepine CBZ-induced side effects in the Taiwanese population. Also, HLA-A3101 variants were identified as a risk factor for carbamazepine side effects in Europeans.

Summary

Novel technologies and an unprecedented level of international collaboration have resulted in identification of novel genes for monogenic and complex genetic epilepsies as well as risk factors for side effects of antiepileptic drugs. This review provides an overview of the most relevant studies in the last year and highlights the future direction of the field.

Ms. Q, a 29-year-old woman, began to behave strangely, claiming to see and hear imaginary people. The following day, she was confused and somnolent in the morning. In the late morning, she had a generalized tonic-clonic seizure and was transported to the hospital. Her past medical and developmental histories were unremarkable. She took a daily oral contraceptive and had no drug allergies. She worked as a teacher and had been married for one year. On initial examination, blood pressure was 129/82, pulse 88, respiratory rate 16, temperature 37.5 °C. She was stuporous, moving her arms appropriately in response to a painful stimulus. Pupils were 2 mm and reactive. There was no gaze preference, and the rest of the examination was nonfocal. About 30 minutes after her first seizure, she had a second GTCS and was given 4 mg lorazepam intravenously. She had a third GTCS 6 min after her second seizure and received a second dose of lorazepam. Initial blood tests-including complete blood count, comprehensive metabolic panel, urinalysis, and toxic screen-were normal. Head CT was normal. She remained stuporous. EEG demonstrated waxing and waning electrographic ictal activity, and she was loaded with fosphenytoin. Intermittent electrographic seizure activity persisted, and a continuous infusion of intravenous propofol was administered. After 24 hr, propofol was weaned, but electrographic seizures recurred and it was restarted.

Psychogenic nonepileptic seizures (PNES) are relatively common, accounting for 5-40% of visits to tertiary epilepsy centers. Inpatient video-electroencephalogram (vEEG) monitoring is the gold standard for diagnosis, but additional positive predictive tools are necessary given vEEG's relatively scarce availability. In this study, we investigated if the number of patient-reported allergies distinguishes between PNES and epilepsy. Excessive allergy-reporting, like PNES, may reflect somatization. Using electronic medical records, ICD-9 codes, and text-identification algorithms to search EEG reports, we identified 905 cases of confirmed PNES and 5187 controls with epilepsy but no PNES. Patients with PNES averaged more self-reported allergies than patients with epilepsy alone (1.93 vs. 1.00, p<0.001). Compared to those with no allergies, each additional allergy linearly increased the percentage of patients with PNES by 2.98% (R(2)=0.71) such that with ≥12 allergies, 12/28 patients (42.8%) had PNES compared to 349/3368 (11.6%) of the population with no allergies (odds ratio=6.49). This relationship remained unchanged with logistic regression analysis. We conclude that long allergy lists may help identify patients with PNES. We hypothesize that a tendency to inaccurately self-report allergies reflects a maladaptive externalization of psychologic distress and that a similar mechanism may be responsible for PNES in some patients with somatic symptom disorder.

This survey study explores whether leading US medical schools have policies about dependent care travel costs.

Objective

To determine incidence rates and predictors of epilepsy after childhood stroke and compare these to published estimates of 3 to 5% cumulative epilepsy incidence by 5 years poststroke in adults.

Methods

In a retrospective population-based study of children with stroke (29 days-19 years) in an integrated health care system (1993-2007), poststroke seizures were identified through electronic searches and confirmed by chart review. Stroke and seizure characteristics were abstracted from medical records. Survival analysis was used to determine rates and predictors of remote seizures and active epilepsy (anticonvulsant treatment for remote seizure within prior 6 months) at last follow-up.

Results

From a population of 2.5 million children, we identified 305 stroke cases. Over a median follow-up of 4.1 years (interquartile range = 1.8-6.8), 49 children had a first unprovoked remote seizure. The average annual incidence rate of first remote seizure was 4.4% (95% confidence interval [CI] = 3.3-5.8) with a cumulative risk of 16% (95% CI = 12-21) at 5 years and 33% (95% CI = 23-46) at 10 years poststroke. The cumulative risk of active epilepsy was 13% (95% CI = 9-18) at 5 years and 30% (95% CI = 20-44) at 10 years. Acute seizures at the time of stroke predicted development of active epilepsy (hazard ratio = 4.2, 95% CI = 2.2-8.1). At last follow-up, ⅓ of the children with active epilepsy had a recent breakthrough seizure despite anticonvulsant usage.

Interpretation

Unlike adults, children are uniquely vulnerable to epilepsy after stroke. Children with acute seizures at the time of stroke are at particularly high risk.

There is urgent need for clinical trials of novel interventions to reduce the burden of acute ischemic stroke. A key impediment to such trials is slow recruitment. Since obtaining written informed consent in the setting of acute stroke is especially challenging, some experts have endorsed relaxing the requirement for informed consent by permitting verbal consent or waivers to facilitate recruitment. This systematic review of 36 randomized controlled trials of acute interventions for ischemic stroke assesses whether alternatives to written informed consent are associated with increased recruitment rates. After the exclusion of 2 outlier trials that differed from other trials in conduct and interventions studied, no association was observed on univariable analysis (8.9 participants/month in trials requiring written consent vs 6.1 participants/month in trials with alternatives, p = 0.43) or multivariable analysis (when adjusting for the number of centers, number of countries, and exclusions based on modified Rankin Scale scores). Alternatives to written informed consent in acute stroke trials may enable trial designs that would not be feasible otherwise. However, we did not find evidence that, within traditional trial designs, such alternatives are associated with faster recruitment.

Genomic findings are emerging rapidly in 2 large, closely related epilepsy research consortia: the Epilepsy Phenome/Genome Project and Epi4K. Disclosure of individual results to participants in genomic research is increasingly viewed as an ethical obligation, but strategies for return of results were not included in the design of these consortia, raising complexities in establishing criteria for which results to offer, determining participant preferences, managing the large number of sites involved, and covering associated costs. Here, we describe the challenges faced, alternative approaches considered, and progress to date. Experience from these 2 consortia illustrates the importance, for genomic research in epilepsy and other disorders, of including a specific plan for return of results in the study design, with financial support for obtaining clinical confirmation and providing ongoing support for participants. Participant preferences for return of results should be established at the time of enrollment, and methods for allowing future contacts with participants should be included. In addition, methods should be developed for summarizing meaningful, comprehensible information about findings in the aggregate that participants can access in an ongoing way.

Objective

To examine the effectiveness of intramuscular (IM) midazolam versus intravenous (IV) lorazepam for the treatment of pediatric patients with status epilepticus (SE) in the prehospital care setting.

Methods

This multicenter clinical trial randomized patients diagnosed with SE to receive either IM midazolam or IV lorazepam administered by paramedics in the prehospital care setting. Included in this secondary analysis were only patients younger than 18 years of age. Evaluated were the associations of the treatment group (IM vs. IV) with the primary outcome, defined as seizure cessation prior to emergency department (ED) arrival, and with patient characteristics, time to important events, and adverse events. Descriptive statistics and 99% confidence intervals (CIs) were used for the analysis.

Results

Of 893 primary study subjects, 120 met criteria for this study (60 in each treatment group). There were no differences in important baseline characteristics or seizure etiologies between groups. The primary outcome was met in 41 (68.3%) and 43 (71.7%) of subjects in the IM and IV groups, respectively (risk difference [RD] -3.3%, 99% CI -24.9% to 18.2%). Similar results were noted for those younger than 11 years (RD -1.3%, 99% CI -25.7% to 23.1%). Time from initiating the treatment protocol was shorter for children who received IM midazolam, mainly due to the shorter time to administer the active treatment. Safety profiles were similar.

Significance

IM midazolam can be rapidly administered and appears to be safe and effective for the management of children with SE treated in the prehospital setting. The results must be interpreted in the context of the secondary analysis design and sample size of the study.