The concept of epilepsy syndromes, introduced in 1989, was defined as “clusters of signs and symptoms customarily occurring together”. Definition of epilepsy syndromes based on electro‐clinical features facilitated clinical practice and, whenever possible, clinical research in homogeneous groups of patients with epilepsies. Progress in the fields of neuroimaging and genetics made it rapidly clear that, although crucial, the electro‐clinical description of epilepsy syndromes was not sufficient to allow much needed development of targeted therapies and a better understanding of the underlying pathophysiological mechanisms of seizures. The 2017 ILAE position paper on Classification of the Epilepsies recognized that “as a critical tool for the practicing clinician, epilepsy classification must be relevant and dynamic to changes in thinking”. The concept of “epilepsy syndromes” evolved, incorporating issues related to aetiologies and comorbidities. A comprehensive update (and revision where necessary) of the EEG diagnostic criteria in the light of the 2017 revised terminology and concepts was deemed necessary. Part 2 covers the neonatal and paediatric syndromes in accordance with the age of onset. [Published with educational EEG plates at http://www.epilepticdisorders.com].

Rational. The concept of epilepsy syndromes, introduced in 1989, was defined as "clusters of signs and symptoms customarily occurring together". Definition of epilepsy syndromes based on electro-clinical features facilitated clinical practice and, whenever possible, clinical research in homogeneous groups of patients with epilepsies. Progress in the fields of neuroimaging and genetics made it rapidly clear that, although crucial, * M. Koutroumanidis, et al. the electro-clinical description of epilepsy syndromes was not sufficient to allow much needed development of targeted therapies and a better understanding of the underlying pathophysiological mechanisms of seizures. The 2017 ILAE position paper on Classification of the Epilepsies recognized that "as a critical tool for the practicing clinician, epilepsy classification must be relevant and dynamic to changes in thinking". The concept of "epilepsy syndromes" evolved, incorporating issues related to aetiologies and comorbidities. A comprehensive update (and revision where necessary) of the EEG diagnostic criteria in the light of the 2017 revised terminology and concepts was deemed necessary. Methods. The work was commissioned by the Neurophysiology Task Force of the ILAE Committee on the Diagnostic Methods. Diagnostic criteria and recording procedures were developed by group consensus, reached through an "informal", internal decision-making process. Each working group member was allocated a number of syndromes, and a standard structured template was used. International literature was extensively reviewed. Results. We developed a simple diagnostic system that is applicable to all epilepsy syndromes which allows the physician (i) to rate the strength of EEG diagnosis (degree of diagnostic certainty) by weighting EEG findings in relation to the available clinical information or the specific clinical question, and ii) to suggest further EEG diagnostics where conclusive diagnostic evidence is lacking. We also propose a system of syndrome-specific recording protocols that, used with the relevant clinical presentation or specific clinical question, may maximize activation of epileptic discharges and ultimately help with standardization of EEG recording across departments, worldwide. Because recording methodology also depends on available resources, a two-tier system was developed to embrace clinical EEG services in resourcelimited and industrialized countries. A clinical practice statement for each of the epilepsy syndromes discussed underscores the crucial role of the clinical information with regards to both the optimization of the EEG recording and mainly its meaningful interpretation. Part I covers Genetic (Idiopathic) generalized epilepsies and syndromes, Reflex epilepsies, structural and genetic focal (lobar) syndromes and Progressive Myoclonus Epilepsies [Published with educational EEG plates on www.epilepticdisorders.com].

Since it was originally described nearly 70 years ago, insular epilepsy has been increasingly recognized and may explain failures after apparently well-planned operations. We review the history of awareness of the phenomenon, techniques for its assessment, and its surgical management. Insular epilepsy can mimic features of frontal, parietal, or temporal seizures. It should be considered when a combination of somatosensory, visceral, and motor symptoms is observed early in a seizure. Extraoperative intracranial recordings are required to accurately diagnose insular seizures. Stereo-electroencephalography (EEG) or craniotomy with implantation of surface and depth electrodes have been used successfully to identify insular onset of seizures. Surgical resection of an insular focus may be performed with good success and acceptable risk.

Background: Interictal ¹⁸F-fluorodeoxyglucose-positron emission topography (FDG-PET) hypometabolism is routinely used in the presurgical workup of children with medically intractable epilepsy (MIE). FDG-PET hypermetabolism, however, is rarely seen, and the significance of this finding in the epilepsy workup is not well established. Methods: We performed a retrospective study of patients who underwent FDG-PET during the presurgical workup of MIE over a 4-year period, between 1 January 2010 and 31 December 2013, at the Children’s Hospital Colorado, CO, USA. Results: Focal FDG-PET hypermetabolism was identified in 7 (2.2%) of 317 patients. The median age was 124 months, all cases with catastrophic epilepsy. Surface electroencephalography (EEG) performed concomitantly with FDG injections revealed ictal EEG discharges in 2 patients, frequent interictal epileptiform discharges (IEDs) in 3, occasional IEDs in 1, and no IEDs in 1. All 7 patients underwent functional hemispherectomies. Histopathology revealed type 1 focal cortical dysplasia in all patients. Six (86%) were completely seizure-free (Engel class I) and 1 had extremely infrequent seizures (Engel class II) (mean follow-up, 47.4 months). Conclusion: While a rare finding, interictal PET hypermetabolism does occur, may help identify epileptogenic zones, and assessment to reveal it should be made by concomitant use of surface EEG during PET scans.