Methodology for classification and definition of epilepsy syndromes with list of syndromes: Report of the ILAE Task Force on Nosology and Definitions.

Epilepsy 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.

ILAE definition of the Idiopathic Generalized Epilepsy Syndromes: Position statement by the ILAE Task Force on Nosology and Definitions.

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.

International League Against Epilepsy classification and definition of epilepsy syndromes with onset at a variable age: position statement by the ILAE Task Force on Nosology and Definitions.

The 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.

Telemedicine in epilepsy: How can we improve care, teaching, and awareness?

Telemedicine (TM) is the use of telecommunications' technologies to provide medical information and services. Telehealth (TH) permits broader and psychosocial support for patients and their families. We aimed to highlight the importance of the use of TH for all aspects of epilepsy, either for the scientific aspects (e.g., research, education, care, management, etc.) or for the social matters (e.g., education, sensitization, association support, etc.). There is a deep gap in knowledge and use of TH in the developing and developed countries. Epilepsy is a condition responsible for 1% of the global burden of disease. More than 50 million people have epilepsy, and barriers to care include shortage of human resources, medical facilities, and resources. Eighty (80) percent of people with epilepsy (PWE) live in low- and middle-income countries. Telehealth has the potential of addressing limited resources and improving access to PWE across the globe.

Olfactory stimulation induces delayed responses in epilepsy.

Precipitation and inhibition of seizures and epileptic discharges by sensory stimuli are receiving increasing attention because they provide insight into natural seizure generation in human epilepsies and can identify potential nonpharmacological therapies. We aimed to investigate modulation (provocation or inhibition) of epileptiform discharges (EDs) in mesial temporal lobe epilepsy (MTLE) versus idiopathic generalized epilepsy (IGE) by olfactory stimulation (OS) compared with standard provocation methods. The underlying hypothesis was that any response would be more likely to occur in MTLE, considering the anatomical connections of the temporal lobe to the olfactory system. This multicenter, international study recruited patients with either MTLE or IGE who were systematically compared for responses to OS using an EEG/video-EEG protocol including a 30-min baseline, twice 3-min olfactory stimulation with ylang-ylang, hyperventilation, and intermittent photic stimulation. The 95% confidence interval (CI) for the baseline EDs in each patient was calculated, and modulation was assumed when the number of EDs during any 3-min test period was outside this CI. A total of 134 subjects (55 with MTLE, 53 with IGE, and 26 healthy controls) were included. Epileptiform discharges were inhibited during OS in about half the patients with both MTLE and IGE, whereas following OS, provocation was seen in 29.1% of patients with MTLE and inhibition in 28.3% of patients with IGE. Olfactory stimulation was less provocative than standard activation methods. The frequent subclinical modulation of epileptic activity in both MTLE and IGE is in striking contrast with the rarity of reports of olfactory seizure precipitation and arrest. Inhibition during OS can be explained by nonspecific arousal. The delayed responses seem to be related to processing of olfactory stimuli in the temporal lobe, thalamus, and frontal cortex.

ILAE official report: a practical clinical definition of epilepsy.

Epilepsy was defined conceptually in 2005 as a disorder of the brain characterized by an enduring predisposition to generate epileptic seizures. This definition is usually practically applied as having two unprovoked seizures >24 h apart. The International League Against Epilepsy (ILAE) accepted recommendations of a task force altering the practical definition for special circumstances that do not meet the two unprovoked seizures criteria. The task force proposed that epilepsy be considered to be a disease of the brain defined by any of the following conditions: (1) At least two unprovoked (or reflex) seizures occurring >24 h apart; (2) one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years; (3) diagnosis of an epilepsy syndrome. Epilepsy is considered to be resolved for individuals who either had an age-dependent epilepsy syndrome but are now past the applicable age or who have remained seizure-free for the last 10 years and off antiseizure medicines for at least the last 5 years. "Resolved" is not necessarily identical to the conventional view of "remission or "cure." Different practical definitions may be formed and used for various specific purposes. This revised definition of epilepsy brings the term in concordance with common use. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

Cognitive tasks as provocation methods in routine EEG: a multicentre field study.

This study aimed to analyse the effect of neuropsychological activation methods on interictal epileptiform discharges, compared to standard activation methods, for both focal and generalized epilepsies. This was a multicentre, prospective study including 429 consecutive EEG recordings of individuals with confirmed or suspected diagnosis of epilepsy. Neuropsychological activation included reading aloud in foreign and native language, praxis and a letter cancelation task (each with a duration of three minutes). After counting interictal discharges in three-minute time windows, activation and inhibition were assessed for each procedure, accounting for spontaneous fluctuations (95% CI) and compared to the baseline condition with eyes closed. Differences between generalized and focal epilepsies were explored. Interictal epileptiform discharges were present in 59.4% of the recordings. Activation was seen during hyperventilation in 31%, in at least one neuropsychological activation method in 15.4%), during intermittent photic simulation in 13.1% and in the resting condition with eyes open in 9.9%. The most frequent single cognitive task eliciting activation was praxis (10.3%). Lasting activation responses were found in 18-25%. Significant inhibition was found in 88/98 patients with baseline interictal epileptiform discharges, and was not task-specific. Adding a brief neuropsychological activation protocol to the standard EEG slightly increased its sensitivity in patients with either focal or generalized epilepsy. However, in unselected epilepsy patients, this effect seems only exceptionally to result in ultimate diagnostic gain, compared to standard procedures. From a diagnostic perspective, cognitive tasks should be reserved for patients with a suspicion of cognitive reflex epilepsy/seizures and probably require longer exposure times. Further research is needed to explore potential therapeutic applications of the observed inhibition of interictal epileptiform discharges by cognitive tasks in some patients.

Prodromal symptoms in epileptic patients: clinical characterization of the pre-ictal phase.

Although recent advances in seizure anticipation have been achieved with the development of several biomathematical electroencephalographic (EEG) methods, pre-ictal clinical phenomena have not been extensively investigated. The aim of the study was to thoroughly analyze premonitory or prodromal symptoms (PS) in a randomly selected sample of 100 adult epileptic patients. A semi-structured protocol was used for in-person interviews to both patients and observers. PS were found in 39% of patients, the most frequent ones being behavioral, cognitive and mood changes. Both patients with focal and generalized epilepsies reported prodromes, although they were more frequently found in the former group. PS were mostly perceived preceding complex partial and generalized tonic-clonic seizures. Prodromal symptoms were reported to have an insidious onset and their duration ranged from 30min to several hours. The potential value of prodromes in seizure anticipation would allow the use of preventive and therapeutic measures, including drugs, neurostimulation procedures and behavioral intervention.

Applicability and contribution of the new ILAE 2017 classification of epileptic seizures and epilepsies.

The aim of the study was to evaluate the clinical applicability of the 2017 ILAE classification of seizures and epilepsies through the analysis of a sample of 100 outpatients with a diagnosis of epilepsy. All clinical charts were reviewed applying both the 1981/1989 and 2017 classifications of seizures and epilepsies, respectively. For most focal seizures, descriptors were required to include all the relevant clinical information. The reclassification of complex partial seizures into focal seizures with impaired awareness with a motor / non-motor onset allowed the inclusion of features of topographic value, although the chronological sequence of awareness impairment was lacking. The use of the term "focal to bilateral tonic-clonic" reduced the number of seizures classified as generalized tonic-clonic seizures (GTCS) by 19%. A subset of GTCS (35%) and absence seizures (12.5%) were reclassified as seizures of unknown onset. Most focal symptomatic epilepsies (92%) were reclassified as focal structural epilepsies, while 27% of idiopathic generalized and 7% of focal cryptogenic epilepsies merged into the category of "epilepsies of unknown type". Major strengths of the new classification are simplicity and the role of the category "unknown onset" to avoid forced categorization. A section assigned to uncertainty reinforces the need for further ancillary studies and periodic diagnostic re-evaluation.

Epilepsy for primary health care: a cost-effective Latin American E-learning initiative.

A lack of neurologists in Latin America forces primary health care providers to manage epilepsy. With the main goal of improving diagnostic and therapeutic management of patients with epilepsy through training of physicians in the primary health care level, the International League Against Epilepsy Education Commission (2013-2017) created a low-cost, regional, virtual course. The course, set-up in Moodle platform, was structured in eight modules, each lasting for a week. Teaching was based on written didactic material, videos, and interactive discussions, both in Spanish and Portuguese. Topics included epidemiology, diagnosis, classification, treatment, prognosis, social issues, and epilepsy policies. Each course was limited to 50 participants and priority was given to general practitioners. Certification was given to those approving the final examination. Since 2015, five courses have been developed, involving 143 participants from 17 countries and 21 tutors. Of the participants, 61% worked in primary health care services. A total of 129 participants (90%) completed the course, and 110 submitted the final examination with an approval rate of 95%. From 85 participants completing the course evaluation, 98% would recommend the course to other colleagues, and 99% showed interest in taking other similar courses. High self-confidence for the management of patients with epilepsy increased from 21% at baseline to 73% after the course. The online course on epilepsy for primary care physicians in Latin America was shown to be a cost-effective course, with good retention and excellent approval rates. Our current challenges include periodic updating, complete self-sustainability, and exploring different strategies to reach our target audience more effectively.