French, Jacqueline A.

AbstractEpilepsy syndromes have been recognized for >50 years, as distinct electroclinical phenotypes with therapeutic and prognostic implications. Nonetheless, no formally accepted International League Against Epilepsy (ILAE) classification of epilepsy syndromes has existed. The ILAE Task Force on Nosology and Definitions was established to reach consensus regarding which entities fulfilled criteria for an epilepsy syndrome and to provide definitions for each syndrome. We defined an epilepsy syndrome as “a characteristic cluster of clinical and electroencephalographic features, often supported by specific etiological findings (structural, genetic, metabolic, immune, and infectious).” The diagnosis of a syndrome in an individual with epilepsy frequently carries prognostic and treatment implications. Syndromes often have age‐dependent presentations and a range of specific comorbidities. This paper describes the guiding principles and process for syndrome identification in both children and adults, and the template of clinical data included for each syndrome. We divided syndromes into typical age at onset, and further characterized them based on seizure and epilepsy types and association with developmental and/or epileptic encephalopathy or progressive neurological deterioration. Definitions for each specific syndrome are contained within the corresponding position papers.

AbstractThe goal of this paper is to provide updated diagnostic criteria for the epilepsy syndromes that have a variable age of onset, based on expert consensus of the International League Against Epilepsy Nosology and Definitions Taskforce (2017–2021). We use language consistent with current accepted epilepsy and seizure classifications and incorporate knowledge from advances in genetics, electroencephalography, and imaging. Our aim in delineating the epilepsy syndromes that present at a variable age is to aid diagnosis and to guide investigations for etiology and treatments for these patients.

Abstract In 2017, the International League Against Epilepsy (ILAE) Classification of Epilepsies described the “genetic generalized epilepsies” (GGEs), which contained the “idiopathic generalized epilepsies” (IGEs). The goal of this paper is to delineate the four syndromes comprising the IGEs, namely childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic–clonic seizures alone. We provide updated diagnostic criteria for these IGE syndromes determined by the expert consensus opinion of the ILAE’s Task Force on Nosology and Definitions (2017–2021) and international external experts outside our Task Force. We incorporate current knowledge from recent advances in genetic, imaging, and electroencephalographic studies, together with current terminology and classification of seizures and epilepsies. Patients that do not fulfill criteria for one of these syndromes, but that have one, or a combination, of the following generalized seizure types: absence, myoclonic, tonic‐clonic and myoclonic‐tonic‐clonic seizures, with 2.5–5.5 Hz generalized spike‐wave should be classified as having GGE. Recognizing these four IGE syndromes as a special grouping among the GGEs is helpful, as they carry prognostic and therapeutic implications.

Summary Objective A prospective multicenter phase III trial was undertaken to evaluate the performance and tolerability in the epilepsy monitoring unit ( EMU ) of an investigational wearable surface electromyographic ( sEMG ) monitoring system for the detection of generalized tonic–clonic seizures ( GTCSs ). Methods One hundred ninety‐nine patients with a history of GTCSs who were admitted to the EMU in 11 level IV epilepsy centers for clinically indicated video‐electroencephalographic monitoring also received sEMG monitoring with a wearable device that was worn on the arm over the biceps muscle. All recorded sEMG data were processed at a central site using a previously developed detection algorithm. Detected GTCSs were compared to events verified by a majority of three expert reviewers. Results For all subjects, the detection algorithm detected 35 of 46 (76%, 95% confidence interval [CI] = 0.61–0.87) of the GTCSs, with a positive predictive value ( PPV ) of 0.03 and a mean false alarm rate ( FAR ) of 2.52 per 24 h. For data recorded while the device was placed over the midline of the biceps muscle, the system detected 29 of 29 GTCSs (100%, 95% CI = 0.88–1.00), with a detection delay averaging 7.70 s, a PPV of 6.2%, and a mean FAR of 1.44 per 24 h. Mild to moderate adverse events were reported in 28% (55 of 199) of subjects and led to study withdrawal in 9% (17 of 199). These adverse events consisted mostly of skin irritation caused by the electrode patch that resolved without treatment. No serious adverse events were reported. Significance Detection of GTCSs using an sEMG monitoring device on the biceps is feasible. Proper positioning of this device is important for accuracy, and for some patients, minimizing the number of false positives may be challenging.

Summary Objective Epilepsy surgery is the most effective treatment for select patients with drug‐resistant epilepsy. In this article, we aim to provide an accurate understanding of the current epidemiologic characteristics of this intervention, as this knowledge is critical for guiding educational, academic, and resource priorities. Methods We profile the practice of epilepsy surgery between 1991 and 2011 in nine major epilepsy surgery centers in the United States, Germany, and Australia. Clinical, imaging, surgical, and histopathologic data were derived from the surgical databases at various centers. Results Although five of the centers performed their highest number of surgeries for mesial temporal sclerosis ( MTS ) in 1991, and three had their highest number of MTS surgeries in 2001, only one center achieved its peak number of MTS surgeries in 2011. The most productive year for MTS surgeries varied then by center; overall, the nine centers surveyed performed 48% (95% confidence interval [CI] −27.3% to −67.4%) fewer such surgeries in 2011 compared to either 1991 or 2001, whichever was higher. There was a parallel increase in the performance of surgery for nonlesional epilepsy. Further analysis of 5/9 centers showed a yearly increase of 0.6 ± 0.07% in the performance of invasive electroencephalography ( EEG ) without subsequent resections. Overall, although MTS was the main surgical substrate in 1991 and 2001 (proportion of total surgeries in study centers ranging from 33.3% to 70.2%); it occupied only 33.6% of all resections in 2011 in the context of an overall stable total surgical volume. Significance These findings highlight the major aspects of the evolution of epilepsy surgery across the past two decades in a sample of well‐established epilepsy surgery centers, and the critical current challenges of this treatment option in addressing complex epilepsy cases requiring detailed evaluations. Possible causes and implications of these findings are discussed.

SummaryObjectiveTo better understand the relationship between efficacy and perampanel dose, integrated actual (last) dose data from three phase III trials and an extension study (blinded Conversion Period; open‐label Maintenance Period) were analyzed.MethodsSeizure frequency data were analyzed in patients who were randomized to and completed the 13‐week Maintenance Period of the phase III studies on perampanel 8 mg, and who received an actual (last) dose of 12 mg during (1) the extension 16‐week blinded Conversion Period or (2) weeks 1–13 of the extension Maintenance Period. Due to a treatment‐by‐region interaction (p = 0.042), analyses excluded patients from the Latin America region (n = 162/1,480; 10.9% of the treated cohort).ResultsOf 372 patients randomized to 8 mg in the phase III studies, 273 completed the Maintenance Period at 8 mg and 267 entered the extension study. In patients who then had an actual (last) dose of 12 mg during the extension blinded Conversion Period (n = 217), median percent change in seizure frequency per 28 days improved from −32.4% (8 mg, phase III Maintenance Period) to −44.2% (12 mg, extension blinded Conversion Period); 50% responder rates increased slightly from 37.3% to 42.9%. In patients who completed the phase III studies on 8 mg and had an actual (last) dose of 12 mg during weeks 1–13 of the extension Maintenance Period (n = 181), median percent change in seizure frequency per 28 days improved from −34.1% (phase III Maintenance Period) to −46.0% (weeks 1–13 extension Maintenance Period); 50% responder rates were 39.2% and 46.4%. Seizure control remained substantially unchanged in patients who completed the phase III studies at 12 mg and continued on that dose during the extension.SignificanceIncreasing perampanel dose from 8 to 12 mg can produce additional benefits in seizure control in at least some patients who tolerate the higher dose.