Attention-based deep convolutional neural network for classification of generalized and focal epileptic seizures.

Epilepsy affects over 50 million people globally. Electroencephalography is critical for epilepsy diagnosis, but manual seizure classification is time-consuming and requires extensive expertise. This paper presents an automated multi-class seizure classification model using EEG signals from the Temple University Hospital Seizure Corpus ver. 1.5.2. 11 features including time-based correlation, time-based eigenvalues, power spectral density, frequency-based correlation, frequency-based eigenvalues, sample entropy, spectral entropy, logarithmic sum, standard deviation, absolute mean, and ratio of Daubechies D4 wavelet transformed coefficients were extracted from 10-second sliding windows across channels. The model combines multi-head self-attention mechanism with a deep convolutional neural network (CNN) to classify seven subtypes of generalized and focal epileptic seizures. The model achieved 0.921 weighted accuracy and 0.902 weighted F1 score in classifying focal onset non-motor, generalized onset non-motor, simple partial, complex partial, absence, tonic, and tonic-clonic seizures. In comparison, a CNN model without multi-head attention achieved 0.767 weighted accuracy. Ablation studies were conducted to validate the importance of transformer encoders and attention. The promising classification results demonstrate the potential of deep learning for handling EEG complexity and improving epilepsy diagnosis. This seizure classification model could enable timely interventions when translated into clinical practice.

Modeling seizures in the Human Phenotype Ontology according to contemporary ILAE concepts makes big phenotypic data tractable.

OBJECTIVE: The clinical features of epilepsy determine how it is defined, which in turn guides management. Therefore, consideration of the fundamental clinical entities that comprise an epilepsy is essential in the study of causes, trajectories, and treatment responses. The Human Phenotype Ontology (HPO) is used widely in clinical and research genetics for concise communication and modeling of clinical features, allowing extracted data to be harmonized using logical inference. We sought to redesign the HPO seizure subontology to improve its consistency with current epileptological concepts, supporting the use of large clinical data sets in high-throughput clinical and research genomics. METHODS: We created a new HPO seizure subontology based on the 2017 International League Against Epilepsy (ILAE) Operational Classification of Seizure Types, and integrated concepts of status epilepticus, febrile, reflex, and neonatal seizures at different levels of detail. We compared the HPO seizure subontology prior to, and following, our revision, according to the information that could be inferred about the seizures of 791 individuals from three independent cohorts: 2 previously published and 150 newly recruited individuals. Each cohort's data were provided in a different format and harmonized using the two versions of the HPO. RESULTS: The new seizure subontology increased the number of descriptive concepts for seizures 5-fold. The number of seizure descriptors that could be annotated to the cohort increased by 40% and the total amount of information about individuals' seizures increased by 38%. The most important qualitative difference was the relationship of focal to bilateral tonic-clonic seizure to generalized-onset and focal-onset seizures. SIGNIFICANCE: We have generated a detailed contemporary conceptual map for harmonization of clinical seizure data, implemented in the official 2020-12-07 HPO release and freely available at hpo.jax.org. This will help to overcome the phenotypic bottleneck in genomics, facilitate reuse of valuable data, and ultimately improve diagnostics and precision treatment of the epilepsies.

Implementation of the new ILAE classification of epilepsies into clinical practice - A cohort study.

PURPOSE: Appropriate management of patients with epilepsy requires precise classification of their disease. Implementation of the recent International League Against Epilepsy (ILAE) classification of seizures and epilepsies may affect data on the relative proportions of specific types of seizures or epilepsies and should be tested in everyday practice. The aim of the study was to determine the prevalence of specific epilepsy types, syndromes, and etiologies, as defined by the new ILAE classification, in a large cohort of adult patients with epilepsy. MATERIAL AND METHODS: The single-center cohort study involved consecutive adult patients with epilepsy seen at the university epilepsy clinic. Information about medical history, neurological examination, neuroimaging, electroencephalography (EEG), genetic tests, epilepsy treatment, and other investigations was collected from medical records and prospectively updated if necessary. Epilepsy types and etiology, as well as epileptic syndromes, were classified according to the new ILAE classifications. RESULTS: We studied 653 patients (mean age: 37.2 years, 59.9% were women). Epilepsy was classified as focal in 458 cases (70.2%), generalized in 155 subjects (23.7%), or as combined focal and generalized in 11 patients (1.7%). The epilepsy type was labeled as unknown in 29 (4.4%) patients. A definite cause of epilepsy was identified in 59.4% of the cases, with a structural etiology (n = 179, 27.4%) and genetic or presumed genetic etiology (n = 169, 25.9%) being the most common. In 167 (25.5%) patients, specific epilepsy syndromes, mostly genetic generalized epilepsy syndromes, were diagnosed. CONCLUSION: The use of the recent ILAE classification of seizures and epilepsies in the cohort of patients with epilepsy seen in single epilepsy center enabled unequivocal characterization of epilepsy type in >95% of patients. A definite etiology of epilepsy could be established in about 60% of patients.

Genomic DNA methylation distinguishes subtypes of human focal cortical dysplasia.

OBJECTIVES: Focal cortical dysplasia (FCD) is a major cause of drug-resistant focal epilepsy in children, and the clinicopathological classification remains a challenging issue in daily practice. With the recent progress in DNA methylation-based classification of human brain tumors we examined whether genomic DNA methylation and gene expression analysis can be used to also distinguish human FCD subtypes. METHODS: DNA methylomes and transcriptomes were generated from massive parallel sequencing in 15 surgical FCD specimens, matched with 5 epilepsy and 6 nonepilepsy controls. RESULTS: Differential hierarchical cluster analysis of DNA methylation distinguished major FCD subtypes (ie, Ia, IIa, and IIb) from patients with temporal lobe epilepsy patients and nonepileptic controls. Targeted panel sequencing identified a novel likely pathogenic variant in DEPDC5 in a patient with FCD type IIa. However, no enrichment of differential DNA methylation or gene expression was observed in mechanistic target of rapamycin (mTOR) pathway-related genes. SIGNIFICANCE: Our studies extend the evidence for disease-specific methylation signatures toward focal epilepsies in favor of an integrated clinicopathologic and molecular classification system of FCD subtypes incorporating genomic methylation.

Effective clinical classification of chronic epilepsy into focal and generalized: A cross sectional study.

PURPOSE: Investigations such as EEG and brain imaging are often difficult to obtain in primary care settings of resource-limited regions impacting millions of epilepsy patients. We wanted to test the hypothesis that classification of chronic epilepsy into focal and generalized based on clinical history and examination alone would be comparable to making such a classification with additional inputs from EEG and brain imaging. METHODS: Two investigators independently classified consecutive chronic epilepsy patients into focal, generalized and unclassified epilepsy. Investigator 1 made this determination using clinical history and examination alone whereas Investigator II additionally used EEG and brain imaging too. We calculated inter observer agreement between the two investigators and also looked at the predictors of focal and generalized epilepsy. RESULTS: Five hundred and twelve patients were recruited. Inter observer agreement between the two investigators in making the focal versus generalized classification was 96.8%, kappa 0.91 (p<0.0001). When EEG and neuroimaging findings were added to clinical information, there was a change in classification in 3.2% patients. Several predictors of focal and generalized epilepsy were identified. CONCLUSIONS: Classification of chronic epilepsy into focal and generalized can be done reliably in most patients using clinical information alone. Investigating chronic epilepsy patients with EEG and brain imaging may not be necessary in every patient. The results of our study are especially significant for epilepsy patients living in resource-limited regions where such investigations may not always be available.

New classification of epilepsy-related neoplasms: The clinical perspective.

Neoplastic CNS lesions are a common cause of focal epilepsy refractory to anticonvulsant treatment, i.e. long-term epilepsy-associated tumors (LEATs). Epileptogenic tumors encompass a variety of intriguing lesions, e.g. dysembryoplastic neuroepithelial tumors or gangliogliomas, which differ from more common CNS neoplasms in their clinical context as well as on histopathology. Long-term epilepsy-associated tumor classification is a rapidly evolving issue in surgical neuropathology, with new entities still being elucidated. One major issue to be resolved is the inconsistent tissue criteria applied to LEAT accounting for high diagnostic variability between individual centers and studies, a problem recently leading to a proposal for a new histopathological classification by Blümcke et al. in Acta Neuropathol. 2014; 128: 39-54. While a new approach to tissue diagnosis is appreciated and needed, histomorphological criteria alone will not suffice and we here approach the situation of encountering a neoplastic lesion in an epilepsy patient from a clinical perspective. Clinical scenarios to be supported by an advanced LEAT classification will be illustrated and discussed.

The new approach to classification of focal epilepsies: Epileptic discharge and disconnectivity in relation to cognition.

The new classification of epilepsy stratifies the disease into an acute level, based on seizures, and an overarching chronic level of epileptic syndromes (Berg et al., 2010). In this new approach, seizures are considered either to originate and evolve in unilateral networks or to rapidly encompass both hemispheres. This concept extends the former vision of focal and generalized epilepsies to a genuine pathology of underlying networks. These key aspects of the new classification can be linked to the concept of cognitive curtailing in focal epilepsy. The present review will discuss the conceptual implications for acute and chronic cognitive deficits with special emphasis on transient and structural disconnectivity. Acute transient disruption of brain function is the hallmark of focal seizures. Beyond seizures, however, interictal epileptic discharges (IEDs) are increasingly recognized to interfere with physiological brain circuitry. Both concomitant EEG and high-precision neuropsychological testing are necessary to detect these subtle effects, which may concern task-specific or default-mode networks. More recent data suggest that longstanding IEDs may affect brain maturation and eventually be considered as a biomarker of pathological wiring. This brings us to the overarching level of chronic cognitive and behavioral comorbidity. We will discuss alterations in structural connectivity measured with diffusion-weighted imaging and tractography. Among focal epilepsies, much of our current insights are derived from temporal lobe epilepsy and its impact on neuropsychological and psychiatric functioning. Structural disconnectivity is maximal in the temporal lobe but also concerns widespread language circuitry. Eventually, pathological wiring may contribute to the clinical picture of cognitive dysfunction. We conclude with the extrapolation of these concepts to current research topics and to the necessity of establishing individual patient profiles of network pathology with EEG, high-precision neuropsychological testing, and state-of-the-art neuroimaging. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

Epilepsy classification and additional definitions in occipital lobe epilepsy.

AIM: To evaluate epileptic children with occipital lobe epilepsy (OLE) in the light of the characteristics of Panayiotopoulos syndrome and late-onset occipital lobe epilepsy of Gastaut (OLE-G). METHODS: Patients were categorized into six groups: primary OLE with autonomic symptoms (Panayiotopoulos syndrome), primary OLE with visual symptoms (OLE-G), secondary OLE with autonomic symptoms (P-type sOLE), secondary OLE with visual symptoms (G-type sOLE), and non-categorized primary OLE and non-categorized secondary OLE according to characteristic ictal symptoms of both Panayiotopoulos syndrome and OLE-G, as well as aetiology (primary or secondary). Patients were compared with regards to seizure symptoms, aetiology, cranial imaging, EEG, treatment and outcome. RESULTS: Of 108 patients with OLE (6.4±3.9 years of age), 60 patients constituted primary groups (32 with Panayiotopoulos syndrome, 11 with OLE-G, and 17 with non-categorized primary OLE); the other 48 patients constituted secondary groups (eight with P-type sOLE, three with G-type sOLE, and 37 with non-categorized sOLE). Epileptiform activity was restricted to the occipital area in half of the patients. Generalized epileptiform activity was observed in three patients, including a patient with Panayiotopoulos syndrome (PS). Only one patient had refractory epilepsy in the primary groups while such patients made up 29% in the secondary groups. CONCLUSION: In OLE, typical autonomic or visual ictal symptoms of Panayiotopoulos syndrome and OLE-G do not necessarily indicate primary (i.e. genetic or idiopathic) aetiology. Moreover, primary OLE may not present with these symptoms. Since there are many patients with OLE who do not exhibit the characteristics of Panayiotopoulos syndrome or OLE-G, additional definitions and terminology appear to be necessary to differentiate between such patients in both clinical practice and studies.

Epileptic spasms without hypsarrhythmia in infancy and childhood: tonic spasms as a seizure type.

Epileptic spasms were defined by the International League Against Epilepsy Task Force on Classification and Terminology in 2001 as a specific seizure type. Epileptic spasms without hypsarrhythmia have been described in some series of patients, occurring either in infancy or childhood. More prolonged epileptic spasms without hypsarrhythmia were previously defined as a different seizure type, and referred to as "tonic spasm seizures". Here, we present a 5-year-old boy who started having epileptic spasms without hypsarrhythmia at 8 months of age, effectively treated with oxcarbazepine. With the withdrawal of medication, epileptic spasms returned. Video-EEG monitoring revealed high-voltage slow waves superimposed by low-voltage fast activity, followed by an electrodecremental phase and a burst of asymmetric fast activity, time-locked to clinical tonic spasm seizures. Brain MRI showed left temporal atrophy with temporal pole grey/white matter junction blurring and ictal PET-CT showed left basal frontal hypermetabolism. Seizures were refractory to several AEDs and vigabatrin was introduced with seizure cessation. Despite efforts to classify epileptic spasms, these are still considered as part of the group of unknown seizure types. In some cases, a focal origin has been suggested, leading to the term "periodic spasms" and "focal spasms". In this case, epileptic spasms without hypsarrhythmia, associated with tonic spasms, may be a variant of focal spasms and might be considered as an epileptic syndrome. [Published with video sequence].

Efficacy of lacosamide by focal seizure subtype.

The purpose of this post hoc exploratory analysis was to determine the effects of the antiepileptic drug, lacosamide, on focal (partial-onset) seizure subtypes. Patient data from the three lacosamide pivotal trials were grouped and pooled by focal seizure subtype at Baseline: simple partial seizures (SPS), complex partial seizures (CPS), and secondarily generalized partial seizures (SGPS). Both efficacy outcomes (median percent change from Baseline to Maintenance Phase in seizure frequency per 28 days and the proportion of patients experiencing at least a 50% reduction in seizures) were evaluated by lacosamide dose (200, 400, or 600 mg/day) compared to placebo for each seizure subtype. An additional analysis was performed to determine whether a shift from more severe focal seizure subtypes to less severe occurred upon treatment with lacosamide. In patients with CPS or SGPS at Baseline, lacosamide 400 mg/day (maximum recommended daily dose) and 600 mg/day reduced the frequency of CPS and SGPS compared to placebo. Likewise, a proportion of patients with CPS and SGPS at Baseline experienced at least a 50% reduction in the frequency of CPS and SGPS (≥50% responder rate) in the lacosamide 400 and 600 mg/day groups compared with placebo. For both outcomes, numerically greatest responses were observed in the lacosamide 600 mg/day group among patients with SGPS at Baseline. In patients with SPS at Baseline, no difference between placebo and lacosamide was observed for either efficacy outcome. An additional exploratory analysis suggests that in patients with SPS at Baseline, CPS and SGPS may have been shifted to less severe SPS upon treatment with lacosamide. The results of these exploratory analyses revealed reductions in CPS and SGPS frequency with adjunctive lacosamide. Reduction in CPS and SGPS may confound assessment of SPS since the CPS or SGPS may possibly change to SPS by effective treatment.

Classification of EEG abnormalities in partial epilepsy with simultaneous EEG-fMRI recordings.

Scalp EEG recordings and the classification of interictal epileptiform discharges (IED) in patients with epilepsy provide valuable information about the epileptogenic network, particularly by defining the boundaries of the "irritative zone" (IZ), and hence are helpful during pre-surgical evaluation of patients with severe refractory epilepsies. The current detection and classification of epileptiform signals essentially rely on expert observers. This is a very time-consuming procedure, which also leads to inter-observer variability. Here, we propose a novel approach to automatically classify epileptic activity and show how this method provides critical and reliable information related to the IZ localization beyond the one provided by previous approaches. We applied Wave_clus, an automatic spike sorting algorithm, for the classification of IED visually identified from pre-surgical simultaneous Electroencephalogram-functional Magnetic Resonance Imagining (EEG-fMRI) recordings in 8 patients affected by refractory partial epilepsy candidate for surgery. For each patient, two fMRI analyses were performed: one based on the visual classification and one based on the algorithmic sorting. This novel approach successfully identified a total of 29 IED classes (compared to 26 for visual identification). The general concordance between methods was good, providing a full match of EEG patterns in 2 cases, additional EEG information in 2 other cases and, in general, covering EEG patterns of the same areas as expert classification in 7 of the 8 cases. Most notably, evaluation of the method with EEG-fMRI data analysis showed hemodynamic maps related to the majority of IED classes representing improved performance than the visual IED classification-based analysis (72% versus 50%). Furthermore, the IED-related BOLD changes revealed by using the algorithm were localized within the presumed IZ for a larger number of IED classes (9) in a greater number of patients than the expert classification (7 and 5, respectively). In contrast, in only one case presented the new algorithm resulted in fewer classes and activation areas. We propose that the use of automated spike sorting algorithms to classify IED provides an efficient tool for mapping IED-related fMRI changes and increases the EEG-fMRI clinical value for the pre-surgical assessment of patients with severe epilepsy.

Early classification of childhood focal idiopathic epilepsies: is it possible at the first seizure?

PURPOSES: To evaluate the possibility of early syndrome classification of idiopathic partial epilepsies in children at the first seizure. PATIENTS AND METHODS: In this observational study we prospectively evaluated 298 patients, aged between 1 month and 17 years and consecutively referred for the first unprovoked focal seizure. The whole cohort included 133 patients; the final analysis was carried out on 107 (59 males) individuals. Age at the first seizure ranged between 2.3 and 13.0 years. Clinical and EEG data of all patients were independently reviewed by two medical doctors. Patients were followed-up for at least 5 years, with a mean period of follow-up of 6.9 years. RESULTS: After the first seizure, a specific syndrome could be diagnosed in eighty (74.7%) children. In particular, Childhood Epilepsy with Centro-Temporal Spikes (CECTS) 42.9% of cases, Panayiotopoulos Syndrome (PS) 28.9%, idiopathic childhood occipital epilepsy of Gastaut (ICOE-G) 2.8%. Unclassified cases were 25.4%. At the end of the follow-up, the diagnosis was confirmed in 72 of 80 children (90%): BCECTS 89% of patients, PS 90% and ICOE-G 100%: among the unclassified cases, in 11 patients (40.7%) the diagnosis did not change, whereas 16 patients (59.3%) evolved into other syndromes or into atypical forms. CONCLUSIONS: At the onset an initial diagnosis is possible in the majority of cases; epilepsy syndromes can be identified at the time of the initial diagnosis and at follow up this diagnosis has not to be revised in 90% of the cases.

Clinical factors associated with postictal headache in Chinese patients with partial epilepsy.

PURPOSE: To investigate the incidence of postictal headache (PIH) and the factors potentially related to the occurrence of PIH in a Chinese epileptic center. METHODS: Consecutive adult patients with epilepsy, referred to the outpatient clinic of the Epilepsy Center of the PLA General Hospital between February 01, 2012, and May 10, 2013, were recruited to this study. 854 patients with partial epilepsy completed a questionnaire regarding headache, 466 patients with temporal lobe epilepsy (TLE), 82 patients with occipital lobe epilepsy (OLE) and 306 patients with frontal lobe epilepsy (FLE). A semi-structured interview was performed in those who confirmed headache. RESULTS: PIH occurred in 328 (38.41%) of the subjects. By type of epilepsy, PIH was found in 164 (35.19%) of the patients with TLE, 46 (56.01%) of the patients with OLE, and 118 (38.56%) of the patients with FLE. The incidence of PIH in OLE was significantly higher than in TLE and FLE (P<0.05). It occurs more frequently after generalized tonic-clonic seizures than other seizure types. Logistic regression analysis revealed that age at onset, type of seizure and classification of epilepsy were each significantly related to the occurrence of PIH. CONCLUSION: The results of our study revealed possible relationships between PIH and the region of epileptic focus and area of spread of epileptic discharges.

[Epilepsy surgery in children with focal cortical dysplasias]. / Cirugía de la epilepsia en niños con displasias corticalesfocales.

INTRODUCTION: Focal cortical dysplasias (FCD) are the first cause of surgery in paediatric epilepsy surgery. The pre-surgical assessment in FCD is often complex, since they are lesions that can be highly epileptogenic and at the same time can preserve neurological functioning and may not be displayed in magnetic resonance imaging. The success of the operation largely depends on the proper identification of the lesion and the possibility of performing a complete resection of the dysplastic tissue. In this work we review the literature related with this topic, in relation to the authors' experience. DEVELOPMENT: The study reviews some of the advances made as regards the pre-surgical assessment and the neurosurgical management of epilepsy in children with FCD; results from the surgical series regarding the classifications of FCD and the post-surgical prognostic factors are commented on; some anatomo-clinical phenotypes that are distinctive in children with FCD and their surgical management are described; and current challenges and the future of the surgical treatment of epilepsy in FCD are also briefly discussed. CONCLUSIONS: The advances being made in the methods of pre-surgical diagnosis and surgical procedures are making it possible to offer successful treatment at earlier ages in patients with FCD who were previously considered 'non-lesional' and in patients with localised lesions in the 'eloquent cortex'. The identification of anatomo-electro-clinical phenotypes of FCD makes it possible to establish surgical approaches and post-surgical prognostic expectations that are well suited to each situation, which are better in the transmantle-type FCD IIb and in bottom-of-sulcus dysplasias than in multilobe FCD, which are mostly FCD I.

TITLE: Cirugia de la epilepsia en niños con displasias corticales focales.Introduccion. Las displasias corticales focales (DCF) son la primera etiologia de cirugia de la epilepsia pediatrica. La evaluacion prequirurgica en DCF a menudo es compleja, ya que son lesiones que pueden ser altamente epileptogenas y, a la vez, conservar funcion neurologica, y no visualizarse en la resonancia magnetica. El exito de la cirugia depende, en gran medida, de la adecuada identificacion de la lesion y de la posibilidad de realizar una reseccion completa del tejido displasico. En este trabajo se revisa la bibliografia relacionada con el tema, en relacion con la experiencia de los autores. Desarrollo. Se revisan algunos avances relacionados con la evaluacion prequirurgica y el abordaje neuroquirurgico de la epilepsia en niños con DCF; se comentan los resultados de las series quirurgicas en relacion con las clasificaciones de DCF y los factores de pronostico posquirurgico; se describen algunos fenotipos anatomoelectroclinicos distintivos en niños con DCF y su abordaje quirurgico; y se comentan brevemente los actuales retos y el futuro del tratamiento quirurgico de la epilepsia en DCF. Conclusiones. El avance los metodos de diagnostico prequirurgico y de procedimientos quirurgicos esta permitiendo ofrecer un tratamiento exitoso en edades tempranas a pacientes con DCF previamente considerados 'no lesionales' y a pacientes con lesiones localizadas en la 'corteza elocuente'. La identificacion de fenotipos anatomoelectroclinicos de DCF permite establecer abordajes quirurgicos y expectativas de pronostico posquirurgico adecuadas a cada situacion, mejor en las DCF IIb transmantle y en las displasias de fondo de surco que en las DCF multilobares, en su mayoria DCF I.

Should consciousness be included in the classification of focal (partial) seizures?

The ILAE 2010 report does not classify focal seizures and instead uses "descriptors" to distinguish focal seizures with versus without impaired consciousness. Below, we recall a recent informal conversation that took place while traveling a back road in Australia (true story), discussing problems with the old terms as well as new biological and practical evidence separating events formerly known as complex partial versus simple partial seizures. Impaired level of consciousness is a core distinguishing feature of focal seizures, which arises from established physiological mechanisms and can be readily determined based on behavior in most cases. After some debate, we arrive at succinct terms compatible with the old as well as the new ILAE classification report: Focal Impaired Consciousness Seizures (FICS), and Focal Aware Conscious Seizures (FACS). We hope that this discussion will bring impaired consciousness off the back roads of epilepsy classification, and provide useful names for these two very common seizure types.

Seizure outcome in surgically treated drug-resistant mesial temporal lobe epilepsy based on the recent histopathological classifications.

OBJECT: The study was performed to investigate the relation between seizure outcome after surgical treatment of mesial temporal lobe epilepsy (MTLE) and pathological findings, classified according to the recently proposed classifications of mesial temporal sclerosis (MTS), granule cell pathology (GCP), focal cortical dysplasia (FCD) and epilepsy-associated low-grade tumors (ELGT). METHODS: The authors analyzed data obtained in 120 consecutive cases involving patients presenting with drug-resistant MTLE, who underwent tailored anteromesial temporal lobe resection, and correlated seizure outcome with pathological findings. They identified 5 histopathological groups: Group 1-ELGT, alone or associated with other lesions (30 cases); Group 2-isolated FCD (17 cases); Group 3-MTS, with or without GCP (28 cases); Group 4-MTS associated with FCD, with or without GCP (37 cases); Group 5-other lesions (8 cases). RESULTS: Engel Class I outcome was observed in 83% of patients with ELGT (Class IA in 63%); in 59% of patients with isolated FCD, with FCD Type II showing a better prognosis than FCD Type I; in 82% of patients with isolated MTS (Class IA in 50%), with MTS Type 1a and MTS Type 1b showing a better prognosis than MTS Type 2 and patients with MTS and GCP having better postsurgical results than those with MTS without GCP. Engel Class I outcome was also achieved in 84% of patients with FCD associated with MTS (Engel Class IA in 62%); also in this group MTS 1a and MTS 1b associated with FCD showed a better prognosis than FCD associated with MTS 2. Finally, Engel Class I was also achieved in 2 patients with vascular malformation and in 1 with a temporal pole encephalocele. CONCLUSIONS: Patients with MTLE and ELGT, MTS, or MTS associated with FCD showed the best postsurgical seizure outcome (Engel Class I in more than 80% of cases), whereas only 63% of patients with isolated FCD achieved the same type of outcome. Interestingly, the analysis of seizure outcome in histopathological subtypes of FCD and of MTS showed different prognoses in the different pathological subgroups, with worse outcomes for atypical MTS, absence of GCP, and isolated FCD Type I.

Idiopathic focal epilepsies.

In this chapter we include a series of epilepsies with onset in pediatric age characterized by focal seizures, idiopathic etiology, normal psychomotor development, and a benign course related to the spontaneous remission of seizures without sequelae. These entities are age-dependent and seizures tend to disappear spontaneously. For these reasons often the drug treatment is not necessary. On the basis of genetic assessment idiopathic focal epilepsies can be divided into two groups: nonautosomal dominant and autosomal dominant. In the group of nonautosomal entities we include benign epilepsy with centro-temporal spikes, Panayiotopoulos syndrome, idiopathic childhood occipital epilepsy described by Gastaut, and benign idiopathic midline spikes epilepsy. Seizures are rare, sometimes prolonged, as autonomic status in Panayiotopoulos syndrome. A common feature is the presence of peculiar EEG interictal paroxysmal abnormalities. In the group with an autosomal dominant mode of inheritance we include benign familial infantile seizures and benign familial neonatal-infantile seizures. These entities are characterized by partial seizures in cluster, self-limited in a brief period during the first months of life. There are no typical interictal EEG abnormalities. In some families a mutation in SCN2A, the gene coding for the 2α subunit of the voltage-gated sodium channel, has been described.