Wirrell, Elaine

Abstract Dravet syndrome is a severe developmental and epileptic encephalopathy caused by heterozygous, loss‐of‐function, pathogenic variants in the SCN1A gene. It is characterized by frequent, often prolonged convulsive seizures. Dravet syndrome is associated with diverse comorbid conditions, including developmental impairment, intellectual disability, and behavioral disturbances, in addition to high mortality rates. Prompt diagnosis and treatment initiation are essential to reduce seizure frequency, status epilepticus, and potentially improve neurodevelopmental outcomes. Currently available therapies such as fenfluramine, stiripentol, and cannabidiol have demonstrated significant reduction in convulsive seizure frequency, based on randomized controlled trials and real‐world studies; however, they have not markedly affected non‐seizure symptoms. Emerging therapies such as genetic modulation are promising given their potential for disease modification, seizure frequency reduction, and improvement of non‐seizure outcomes. This review of observational studies and randomized clinical trials provides an overview of the natural history of Dravet syndrome, current treatment guidelines with recently approved medications, addressing both safety and efficacy, and new therapeutic approaches, including disease‐modifying therapies. The therapeutic landscape in Dravet syndrome is evolving, with the use of new antiseizure agents and precision therapies that target the SCN1A variant. Goals of treatment include improvement of seizure burden, neurodevelopment, comorbidities, and quality of life in individuals with Dravet syndrome.

Abstract The accurate interpretation of scalp EEG remains an instrumental diagnostic component of epilepsy care. Knowledge of what constitutes normal EEG findings, non‐epileptiform abnormalities, and epileptiform patterns—both ictal and interictal—is essential for appropriate patient management. The International League Against Epilepsy (ILAE) has developed an educational curriculum containing learning objectives necessary to accurately diagnose and manage people with epilepsy. In this Seminar in Epileptology, we address the learning objectives related to assessment and interpretation of EEG background activity, normal sleep patterns, provocation methods, interictal abnormalities, and ictal patterns, as well as a brief discussion on relevant advances in scalp EEG analysis and future perspectives on this topic.

Abstract Objective To assess the localization and lateralization values of ictal emotional features and ictal defensive behaviors in pediatric and young adult patients with frontal lobe epilepsy (FLE). Methods Children and young adults with FLE were identified from a single institution's epilepsy surgery database. Two epileptologists determined by consensus the presence of ictal emotional features (positive‐ smile, laughter, humming, singing; negative‐ fear, crying, anger, disgust, contempt, sadness) and ictal defensive behaviors (freezing with a fearful facial expression, shielding the face with hands, burying the face in a pillow, or exhibiting hyperkinetic motor behaviors like attempting to escape from bed or resisting restraint) in each patient's first video EEG (vEEG). Historic seizure semiology and vEEG reports were compared with the consensus vEEG analysis. Longitudinal changes in ictal emotional features were defined by the emergence or resolution of ictal emotional features between historic seizure semiology and re‐review of presurgical vEEG analysis. Subgroup analyses were conducted according to the seizure lateralization (left vs. right) and sublobar localization (precentral, medial, lateral, extensive) based on surgical extent. Results Twenty‐three FLE patients were included (female 39%; mean age at vEEG analysis: 11.28 years, range 1.75–20.17). The inter‐rater reliability was very good for both ictal emotional features ( κ = 0.81, 95% CI: 0.59–1) and ictal defensive behaviors ( κ = 0.91, 95% CI: 0.79–1). Ictal emotional features were observed in 10 patients (43.4%), with negative emotions present in 70% (7/10) of these cases. vEEG reports lacked documentation of ictal emotional features in two patients. Although ictal emotional features showed no statistical correlation by sublobar regions, ictal defensive behaviors were consistently seen in medial compared to lateral FLE (100% vs. 16.6%; p = 0.004). Longitudinal changes in ictal emotional features were observed in 8 (34.7%) patients. Significance Ictal emotional features were common in pediatric and young adult FLE patients and were mainly negative. Ictal defensive behaviors were more likely associated with medial FLE. Longitudinal changes in ictal emotional features occurred in about a third of pediatric and young adult patients with FLE. Plain Language Summary This study examined emotional features and defensive behaviors during seizures in children and young adults with FLE. Negative emotions were commonly seen during seizures. Ictal defensive behaviors were more frequently observed in patients with medial FLE, and recognizing these signs could help clinicians localize the seizures. Changes in emotional features were seen over time in about one‐third of children and young adult patients.

Abstract Objective This study was undertaken to evaluate the response to second treatments for infantile epileptic spasms syndrome (IESS). Methods Infants aged 2–24 months with IESS were prospectively enrolled in the National Infantile Spasms Cohort study at 21 pediatric epilepsy centers in the United States from 2012 to 2018. We analyzed data from infants who initially received standard treatment (hormonal therapy [adrenocorticotropic hormone, high‐dose prednisolone] or vigabatrin), had continued or recurring epileptic spasms, and received a second treatment. We excluded those with tuberous sclerosis. Treatment groups included hormonal therapy followed by vigabatrin (reference), hormonal‐to‐hormonal, hormonal‐to‐nonstandard, vigabatrin‐to‐hormonal, and vigabatrin‐to‐nonstandard. Nonstandard treatments included other antiseizure medications and dietary therapy. Treatment groups were tested for differences in 3‐month clinical remission using a binary logistic regression to estimate odds ratios (ORs). Results There were 153 infants with IESS who received second treatments. The highest rates of 3‐month remission were among infants in the hormonal‐to‐vigabatrin (22/65, 34%) and vigabatrin‐to‐hormonal (9/26, 35%) groups, followed by vigabatrin‐to‐nonstandard (3/10, 30%), hormonal‐to‐hormonal (4/22, 18%), and hormonal‐to‐nonstandard (1/30, 3.3%). Compared to the hormonal‐to‐vigabatrin group (reference), fewer infants had remission in the hormonal‐to‐nonstandard group (OR = .07, 95% confidence interval [CI] = .01–.53), and there was a trend toward fewer infants in the hormonal‐to‐hormonal group (OR = .43, 95% CI = .13–1.4, p = .17). Following initial hormonal treatment, the number needed to treat was three infants for one additional infant to have remission when treated with vigabatrin compared to nonstandard therapy as the second treatment. Significance This updated analysis with an expanded sample size provided power for additional subgroup analysis. Overall response rates were low, and at best only one third had remission after second treatment. Results support a clinical strategy of switching mechanism of action when selecting a second medication for epileptic spasms (i.e., use vigabatrin after hormonal therapy, or hormonal therapy after vigabatrin). Our findings also support the use of standard over nonstandard therapies.

Abstract The International League Against Epilepsy (ILAE) has updated the operational classification of epileptic seizures, building upon the framework established in 2017. This revision, informed by the implementation experience, involved a working group appointed by the ILAE Executive Committee. Comprising 37 members from all ILAE regions, the group utilized a modified Delphi process, requiring a consensus threshold of more than two thirds for any proposal. Following public comments, the Executive Committee appointed seven additional experts to the revision task force to address and incorporate the issues raised, as appropriate. The updated classification maintains four main seizure classes: Focal, Generalized, Unknown (whether focal or generalized), and Unclassified. Taxonomic rules distinguish classifiers, which are considered to reflect biological classes and directly impact clinical management, from descriptors, which indicate other important seizure characteristics. Focal seizures and those of unknown origin are further classified by the patient's state of consciousness (impaired or preserved) during the seizure, defined operationally through clinical assessment of awareness and responsiveness. If the state of consciousness is undetermined, the seizure is classified under the parent term, that is, the main seizure class (focal seizure or seizure of unknown origin). Generalized seizures are grouped into absence seizures, generalized tonic–clonic seizures, and other generalized seizures, now including recognition of negative myoclonus as a seizure type. Seizures are described in the basic version as with or without observable manifestations, whereas an expanded version utilizes the chronological sequence of seizure semiology. This updated classification comprises four main classes and 21 seizure types. Special emphasis was placed on ensuring translatability into languages beyond English. Its aim is to establish a common language for all health care professionals involved in epilepsy care, from resource‐limited areas to highly specialized centers, and to provide accessible terms for patients and caregivers.