4,212 results match your criteria Epileptiform Discharges


Epilepsy With Eyelid Myoclonia (Jeavons Syndrome).

Pediatr Neurol 2020 Dec 1;121:75-80. Epub 2020 Dec 1.

Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland Ohio.

The purpose of this review is to provide a comprehensive update and highlight the distinct electroclinical features and discuss recent advances in the etiology, pathophysiology, and management strategies of epilepsy with eyelid myoclonia. Recent studies indicate that variations of certain genes including CHD2 (chromodomain helicase DNA-binding protein 2), KCNB1, KIAA2022, and NAA10 may occur in these patients. It has been postulated that the occipital cortex may play a role in the pathophysiology. Read More

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December 2020

A deep learning framework with multi-perspective fusion for interictal epileptiform discharges detection in scalp electroencephalogram.

J Neural Eng 2021 Jun 22. Epub 2021 Jun 22.

BeiHang University School of Biological Science and Medical Engineering, No. 37 Xueyuan Road, Haidian District, Beijing, Beijing, 100191, CHINA.

Objective: Interictal epileptiform discharges (IEDs) are an important and widely accepted biomarker used in the diagnosis of epilepsy based on scalp electroencephalography (EEG). Because the visual detection of IEDs has various limitations, including high time consumption and high subjectivity, a faster, more robust, and automated IED detector is strongly in demand.

Approach: Based on deep learning, we proposed an end-to-end framework with multi-scale morphologic features in the time domain and correlation in sensor space to recognize IEDs from raw scalp EEG. Read More

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Do Triphasic Waves and Nonconvulsive Status Epilepticus Arise From Similar Mechanisms? A Computational Model.

J Clin Neurophysiol 2021 Jun 18. Epub 2021 Jun 18.

Department of Technical Medicine, University of Twente, Enschede, the Netherlands; Department of Applied Mathematics, University of Twente, Enschede, the Netherlands; Northwest University, Xi'an, China; and Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.

Purpose: Triphasic waves arising in patients with toxic metabolic encephalopathy (TME) are often considered different from generalized periodic discharges (GPDs) in patients with generalized nonconvulsive status epilepticus (GNCSE). The primary objective of this study was to investigate whether a common mechanism can explain key aspects of both triphasic waves in TME and GPDs in GNCSE.

Method: A neural mass model was used for the simulation of EEG patterns in patients with acute hepatic encephalopathy, a common etiology of TME. Read More

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Triphasic Waves: Historical Overview of an Unresolved Mystery.

J Clin Neurophysiol 2021 Jun 18. Epub 2021 Jun 18.

Clinical Neurophysiology Department, Marqués de Valdecilla University Hospital, Santander, Cantabria, Spain; Biomedical Research Institute (IDIVAL), Santander, Cantabria, Spain; and Department of Neurology, Johns Hopkins Bayview Medical Center, Baltimore, Maryland, U.S.A.

Summary: Triphasic waves are a fascinating and mysterious EEG feature. We now have to accept that, at times, epileptiform discharges may have a blunted "triphasic morphology," and that there may be great difficulty in distinguishing between these often similar forms. The aim of this review was to describe the evolution in our understanding of triphasic waves that has occurred regarding the pathophysiology of triphasic waves, their most frequent causes, and the diagnostic difficulties involved in interpretation and differentiation from nonconvulsive status epilepticus. Read More

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fMRI-Based Effective Connectivity in Surgical Remediable Epilepsies: A Pilot Study.

Brain Topogr 2021 Jun 21. Epub 2021 Jun 21.

Neurology Unit, OCB Hospital, Azienda Ospedaliero-Universitaria of Modena, Via Giardini 1355, 41100, Modena, Italy.

Simultaneous EEG-fMRI can contribute to identify the epileptogenic zone (EZ) in focal epilepsies. However, fMRI maps related to Interictal Epileptiform Discharges (IED) commonly show multiple regions of signal change rather than focal ones. Dynamic causal modeling (DCM) can estimate effective connectivity, i. Read More

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Interictal Epileptiform Discharge Dynamics in Peri-sylvian Polymicrogyria Using EEG-fMRI.

Front Neurol 2021 3;12:658239. Epub 2021 Jun 3.

Sagol Brain Institute, Wohl Institute for Advanced Imaging, Sourasky Medical Center, Tel Aviv, Israel.

Polymicrogyria (PMG) is a common malformation of cortical development associated with a higher susceptibility to epileptic seizures. Seizures secondary to PMG are characterized by difficult-to-localize cerebral sources due to the complex and widespread lesion structure. Tracing the dynamics of interictal epileptiform discharges (IEDs) in patients with epilepsy has been shown to reveal the location of epileptic activity sources, crucial for successful treatment in cases of focal drug-resistant epilepsy. Read More

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Indications for Inpatient Magnetoencephalography in Children - An Institution's Experience.

Front Hum Neurosci 2021 4;15:667777. Epub 2021 Jun 4.

Division of Child Neurology, Department of Pediatrics, McGovern Medical School, Houston, TX, United States.

Magnetoencephalography (MEG) is recognized as a valuable non-invasive clinical method for localization of the epileptogenic zone and critical functional areas, as part of a pre-surgical evaluation for patients with pharmaco-resistant epilepsy. MEG is also useful in localizing functional areas as part of pre-surgical planning for tumor resection. MEG is usually performed in an outpatient setting, as one part of an evaluation that can include a variety of other testing modalities including 3-Tesla MRI and inpatient video-electroencephalography monitoring. Read More

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Age-related evolution of EEG in Dravet syndrome: Meta-analysis of 155 patients.

Seizure 2021 Jun 11;91:108-111. Epub 2021 Jun 11.

Research Institute of the McGill University Medical Centre, 1001 Décarie Blvd, Montreal, Quebec, H4A 3J1, Canada; Division of Neurology, Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre, 1001 Décarie Blvd, Montreal, Quebec, H4A 3J1, Canada; Department of Neurology and Neurosurgery, Montreal Children's Hospital, McGill University Health Centre, 1001 Décarie Blvd, Montreal, Quebec, H4A 3J1, Canada. Electronic address:

Purpose: Dravet syndrome is an early-onset developmental and epileptic encephalopathy caused by pathogenic SCN1A variants in 80-90% of patients. EEG is initially normal, but abnormalities, both generalized and focal, may develop later. There is a limited understanding of typical EEG evolution in Dravet syndrome. Read More

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Sporadic and Periodic Interictal Discharges in Critically Ill Children: Seizure Associations and Time to Seizure Identification.

J Clin Neurophysiol 2021 May 5. Epub 2021 May 5.

Division of Epilepsy and Neurophysiology, Boston Children's Hospital, Boston, Massachusetts, U.S.A.; Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, U.S.A.; and Department of Critical Care Medicine and Anesthesiology, Boston Children's Hospital, Boston, Massachusetts, U.S.A.

Purpose: We evaluated interictal discharges (IEDs) as a biomarker for the time to development of electrographic seizures (ES).

Methods: Prospective observational study of 254 critically ill children who underwent continuous electroencephalography (cEEG) monitoring. We excluded neonates and patients with known epilepsy or the sole cEEG indication to characterize events. Read More

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Magnetoencephalography to confirm epileptiform discharges mimicking small sharp spikes in temporal lobe epilepsy.

Clin Neurophysiol 2021 May 8;132(8):1785-1789. Epub 2021 May 8.

Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan; Department of Collaborative Laboratory of Electromagnetic Neurophysiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.

Objective: To determine whether magnetoencephalography (MEG) can identify epileptiform discharges mimicking small sharp spikes (SSSs) on scalp electroencephalography (EEG) in patients with temporal lobe epilepsy (TLE).

Methods: We retrospectively reviewed simultaneous scalp EEG and MEG recordings of 83 consecutive patients with TLE and 49 with extra-TLE (ETLE).

Results: SSSs in scalp EEG were detected in 15 (18. Read More

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Recommendations for Preclinical Testing of Treatments Against Alzheimer's Disease-Related Epileptiform Spikes in Transgenic Rodent Models.

J Alzheimers Dis 2021 May 29. Epub 2021 May 29.

A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.

Recent evidence suggests that about 30%of patients with mild to moderate Alzheimer's disease (AD) without a known diagnosis of epilepsy may display epileptiform spikes during electroencephalographic (EEG) recordings. These abnormal discharges occur predominantly during sleep and may be associated with accelerated disease progression. Subclinical spikes may represent a relevant target for clinical drug interventions, and there is a clear unmet need for preclinical testing of novel disease modifying agents in suitable animal models. Read More

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Transient incubation of cultured hippocampal neurons in the absence of magnesium induces rhythmic and synchronized epileptiform-like activity.

Sci Rep 2021 May 31;11(1):11374. Epub 2021 May 31.

CNC-Center for Neuroscience and Cell Biology, Faculty of Medicine, University of Coimbra, Rua Larga, 3004-504, Coimbra, Portugal.

Cell culture models are important tools to study epileptogenesis mechanisms. The aim of this work was to characterize the spontaneous and synchronized rhythmic activity developed by cultured hippocampal neurons after transient incubation in zero Mg to model Status Epilepticus. Cultured hippocampal neurons were transiently incubated with a Mg-free solution and the activity of neuronal networks was evaluated using single cell calcium imaging and whole-cell current clamp recordings. Read More

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Antiepileptic Efficacy and Network Connectivity Modulation of Repetitive Transcranial Magnetic Stimulation by Vertex Suppression.

Front Hum Neurosci 2021 13;15:667619. Epub 2021 May 13.

Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China.

A core feature of drug-resistant epilepsy is hyperexcitability in the motor cortex, and low-frequency repetitive transcranial magnetic stimulation (rTMS) is a suitable treatment for seizures. However, the antiepileptic effect causing network reorganization has rarely been studied. Here, we assessed the impact of rTMS on functional network connectivity (FNC) in resting functional networks (RSNs) and their relation to treatment response. Read More

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Risk factors affecting seizure recurrence in childhood epilepsy during short-term follow-up.

Childs Nerv Syst 2021 May 28. Epub 2021 May 28.

Department of Pediatrics, Faculty of Medicine, Training and Research Hospital, Bolu Abant Izzet Baysal University, Bolu, Turkey.

Purpose: The aim of this study is to examine the factors affecting seizure recurrence in pediatric patients diagnosed with epilepsy.

Methods: Three hundred patients presenting to the pediatric neurology clinic between 2015 and 2018 and diagnosed with epilepsy and treated with single antiseizure drug were included in the study. Medical histories and clinical and laboratory findings were retrieved retrospectively from the hospital data system. Read More

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Heritability of Magnetoencephalography Phenotypes Among Patients With Genetic Generalized Epilepsy and Their Siblings.

Neurology 2021 May 27. Epub 2021 May 27.

Clinic of Clinical Neurophysiology, Georg-August University Göttingen

ObjectiveTo assess whether neuronal signals in patients with genetic generalized epilepsy (GGE) are heritable, we examined magnetoencephalography (MEG) resting-state recordings in patients and their healthy siblings.MethodsIn a prospective, cross-sectional design, we investigated source-reconstructed power and functional connectivity in patients, siblings and controls. We analyzed 5 minutes of cleaned and awake data without epileptiform discharges in six frequency bands (1-40 Hz). Read More

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Risk Factors for Intraoperative Seizures in Glioma Surgery: Electrocorticography Matters.

J Clin Neurophysiol 2021 Apr 30. Epub 2021 Apr 30.

Neurology and Clinical Neurophysiology Unit, "S. Maria della Misericordia" University-Hospital, Udine, Italy; Neurosurgery Unit, "S. Maria della Misericordia" University-Hospital, Udine, Italy; Department of Medicine (DAME), University of Udine, Italy; Clinical Neurology Unit, "S. Maria della Misericordia" University-Hospital, Udine, Italy; and Department of Mathematics, Informatics and Physics (DMIF), University of Udine, Italy.

Purpose: Few and contradictory data are available regarding intraoperative seizures during surgery for low-grade gliomas. Aim of this study was to evaluate possible risk factors for the occurrence of IOS.

Methods: The authors performed a retrospective analysis of 155 patients affected by low-grade gliomas and tumor-related epilepsy, who underwent surgery in our Department, between 2007 and 2018. Read More

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Subclinical epileptiform activity accelerates the progression of Alzheimer's disease: A long-term EEG study.

Clin Neurophysiol 2021 May 8. Epub 2021 May 8.

National Institute of Clinical Neurosciences, Department of Neurology Budapest, Hungary; Semmelweis University Department of Neurology, Budapest, Hungary.

Objective: While many studies suggest that patients with Alzheimer's disease have a higher chance for developing epileptic seizures, only a few studies are available examining independent epileptic discharges. The major aims of our study was to determine the prevalence of subclinical epileptiform activity (SEA) in AD compared to healthy elderly controls with the hypothesis that SEA is more frequent in AD than in cognitively normal individuals. Another aim was to analyze the effect of baseline SEA captured with electroencephalography on the progression of the disease with longitudinal cognitive testing. Read More

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Exploring the Inhibitory Effect of Low-frequency Magnetic Fields on Epileptiform Discharges in Juvenile Rat Hippocampus.

Neuroscience 2021 May 24;467:1-15. Epub 2021 May 24.

School of Life Sciences, Tiangong University, Tianjin 300387, China. Electronic address:

Stimulation with a low frequency electromagnetic field (LF-EMF) has proven to represent a powerful method for the suppression of seizures, as demonstrated in select clinical and laboratory studies. However, the mechanism by which LF-EMF suppresses seizures remains unclear. The purpose of the present study was to explore the modulatory effect of LF-EMF on epileptiform discharges (EDs) using rat hippocampal slices and investigate the underlying mechanisms that mediate these effects. Read More

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Hyperventilation maneuver during EEG in children with epilepsy after the COVID-19 pandemic. Is a routine procedure necessary?

Epilepsia Open 2021 06 12;6(2):437-442. Epub 2021 May 12.

Clinica Integral de Epilepsia Infanto-juvenil, Santiago, Chile.

Objective: Hyperventilation (HV) is one of the main and basic activation methods during ambulatory electroencephalogram (EEG), unless medical reasons contraindicate it. During the COVID-19 pandemic, with the high risk of human-to-human infection, local guidelines and recommendations have been developed that suggest not to perform the HV maneuver routinely. Our objective was to characterize patients who present positive HV in an epilepsy center. Read More

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Activation patterns of interictal epileptiform discharges in relation to sleep and seizures: An artificial intelligence driven data analysis.

Clin Neurophysiol 2021 Jul 8;132(7):1584-1592. Epub 2021 May 8.

Department of Neurology, Clinic Hietzing, Vienna, Austria; Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Vienna, Austria; Medical Faculty, Sigmund Freud University, Vienna, Austria.

Objective: To quantify effects of sleep and seizures on the rate of interictal epileptiform discharges (IED) and to classify patients with epilepsy based on IED activation patterns.

Methods: We analyzed long-term EEGs from 76 patients with at least one recorded epileptic seizure during monitoring. IEDs were detected with an AI-based algorithm and validated by visual inspection. Read More

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The influence of the abundance and morphology of epileptiform discharges on diagnostic accuracy: How many spikes you need to spot in an EEG.

Clin Neurophysiol 2021 Jul 5;132(7):1543-1549. Epub 2021 May 5.

Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark; and Department of Clinical Medicine, Aarhus University, Denmark. Electronic address:

Objective: The operational definition of interictal epileptiform discharges (IEDs) of the International Federation of Clinical Neurophysiology (IFCN) described six morphological criteria. Our objective was to assess the impact of pattern-repetition in the EEG-recording, on the diagnostic accuracy of using the IFCN criteria. For clinical implementation, specificity over 95% was set as target. Read More

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Detrended fluctuation analysis in the presurgical evaluation of parietal lobe epilepsy patients.

Clin Neurophysiol 2021 Jul 28;132(7):1515-1525. Epub 2021 Apr 28.

Department of Neuroscience and Biomedical Engineering, Aalto University, Finland; Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, United Kingdom; Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.

Objective: To examine the usability of long-range temporal correlations (LRTCs) in non-invasive localization of the epileptogenic zone (EZ) in refractory parietal lobe epilepsy (RPLE) patients.

Methods: We analyzed 10 RPLE patients who had presurgical MEG and underwent epilepsy surgery. We quantified LRTCs with detrended fluctuation analysis (DFA) at four frequency bands for 200 cortical regions estimated using individual source models. Read More

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Mirror writing in a patient with frontal lobe epilepsy.

Clin Case Rep 2021 May 15;9(5):e04239. Epub 2021 May 15.

A.N. Murzaliev Department of Neurology and Clinical Genetics I.K. Akhunbaev Kyrgyz State Medical Academy Bishkek Kyrgyzstan.

During the postictal period, the left cerebral hemisphere was affected by the seizures, and consecutive epileptiform discharges and disinhibition of the right cerebral hemisphere could have occurred, which may explain the observed behavior. Read More

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Acute effects of spaced cathodal transcranial direct current stimulation in drug resistant focal epilepsies.

Clin Neurophysiol 2021 Jul 7;132(7):1444-1451. Epub 2021 May 7.

Epilepsy Center, Department of Neurology, University Hospital, LMU Munich, Munich, Germany.

Objective: To evaluate the safety and temporal dynamic of the antiepileptic effect of spaced transcranial direct current stimulation (tDCS) in different focal epilepsies.

Methods: Cathodal tDCS with individual electrode placement was performed in 15 adults with drug resistant focal epilepsy. An amplitude of 2 mA was applied twice for 9 minutes, with an interstimulation interval of 20 minutes. Read More

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Machine learning for detection of interictal epileptiform discharges.

Clin Neurophysiol 2021 Jul 21;132(7):1433-1443. Epub 2021 Apr 21.

Department of Clinical Neurophysiology, Institute for Technical Medicine, University of Twente, Technical Medical Centre, Enschede, the Netherlands; Neurocentrum, Medisch Spectrum Twente MST, Enschede, the Netherlands. Electronic address:

The electroencephalogram (EEG) is a fundamental tool in the diagnosis and classification of epilepsy. In particular, Interictal Epileptiform Discharges (IEDs) reflect an increased likelihood of seizures and are routinely assessed by visual analysis of the EEG. Visual assessment is, however, time consuming and prone to subjectivity, leading to a high misdiagnosis rate and motivating the development of automated approaches. Read More

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Automatic detection of generalized paroxysmal fast activity in interictal EEG using time-frequency analysis.

Comput Biol Med 2021 06 3;133:104287. Epub 2021 Mar 3.

The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; Department of Neurology, Austin Health, Melbourne, Australia. Electronic address:

Objective: Markup of generalized interictal epileptiform discharges (IEDs) on EEG is an important step in the diagnosis and characterization of epilepsy. However, manual EEG markup is a time-consuming, subjective, and the specialized task where the human reviewer needs to visually inspect a large amount of data to facilitate accurate clinical decisions. In this study, we aimed to develop a framework for automated detection of generalized paroxysmal fast activity (GPFA), a generalized IED seen in scalp EEG recordings of patients with the severe epilepsy of Lennox-Gastaut syndrome (LGS). Read More

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Intra-operative electrocorticography results and postoperative pathological findings are associated with epileptic outcomes in patients with cerebral cavernous malformations presenting with epilepsy.

Epilepsy Res 2021 Aug 13;174:106672. Epub 2021 May 13.

Department of Neurosurgery, Neurosurgery Research Institute, The First Affiliated Hospital, Fujian Medical University, Fujian Province, PR China; Fujian Key Laboratory of Precision Medicine for Cancer, The First Affiliated Hospital, Fujian Medical University, Fujian Province, PR China; Key Laboratory of Radiation Biology of Fujian Higher Education Institutions, The First Affiliated Hospital, Fujian Medical University, Fujian Province, PR China. Electronic address:

Objectives: The purpose of this study was to determine whether intraoperative electrocorticography (ECoG) results and postoperative pathological findings are associated with long-term epileptic outcomes in patients with cerebral cavernous malformations (CCMs).

Methods And Materials: To identify all consecutive patients with surgically treated CCM-related epilepsy (CRE) referred to our hospital, our prospectively maintained database of patients with CCM was reviewed (NCT03467295). For these patients, an ECoG-guided extended lesionectomy was performed, in which the CCM, surrounding hemosiderin, and detected epileptic foci were removed. Read More

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Manifestation of Hippocampal Interictal Discharges on Clinical Scalp EEG Recordings.

J Clin Neurophysiol 2021 May 14. Epub 2021 May 14.

Department of Pediatrics, The University of Chicago, Chicago, Illinois, U.S.A.; Committee on Neurobiology, The University of Chicago, Chicago, Illinois, U.S.A.; Departments of Neurology and Surgery, The University of Chicago, Chicago, Illinois, U.S.A.; and Committee on Computational Neuroscience, The University of Chicago, Chicago, Illinois, U.S.A.

Purpose: Epileptiform activity limited to deep sources such as the hippocampus currently lacks reliable scalp correlates. Recent studies, however, have found that a subset of hippocampal interictal discharges may be associated with visible scalp signals, suggesting that some types of hippocampal activity may be monitored noninvasively. The purpose of this study is to characterize the relationship between these scalp waveforms and the underlying intracranial activity. Read More

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Disparate treatment outcomes according to presence of pathogenic mutations in West syndrome.

Epilepsia 2021 May 19. Epub 2021 May 19.

Division of Pediatric Neurology, Department of Pediatrics, Epilepsy Research Institute, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea.

Objective: It has been known that West syndrome (WS) patients with an unknown etiology have better clinical outcomes than patients with an identified etiology of any kind. However, after the exponential discovery of genes with mutations responsible for developmental and epileptic encephalopathy (DEE), a significant proportion of patients with a previously unknown etiology have been reclassified as having a genetic etiology, requiring reinvestigation of this concept. Therefore, this study investigated clinical outcomes of WS patients with genetic and unknown etiologies. Read More

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How cerebral cortex protects itself from interictal spikes: The alpha/beta inhibition mechanism.

Hum Brain Mapp 2021 May 18. Epub 2021 May 18.

Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.

Interactions between interictal epileptiform discharges (IEDs) and distant cortical regions subserve potential effects on cognition of patients with focal epilepsy. We hypothesize that "healthy" brain areas at a distance from the epileptic focus may respond to the interference of IEDs by generating inhibitory alpha and beta oscillations. We predict that more prominent alpha-beta oscillations can be found in patients with less impaired neurocognitive profile. Read More

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