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Yayıcı Köken Ö, Şekeroğlu B, Şanlıdağ B, Sarı Yanartaş M, Yılmaz A. Focality in childhood absence epilepsy. Neurol Res 2024; 46:626-633. [PMID: 38643974 DOI: 10.1080/01616412.2024.2339114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 03/31/2024] [Indexed: 04/23/2024]
Abstract
BACKGROUND AND PURPOSE Childhood absence epilepsy (CAE) has a typical electroencephalography (EEG) pattern of generalized 3 Hz spike and wave discharges (SWD). Focal interictal discharges were also documented in a small number of documents. The aim was to investigate the amplitudes of interictal 3 Hz SWD within the 1st second in drug-naïve CAE patients. In this way, areas with maximal electronegativity at the beginning of clinically generalized discharges will be documented. METHODS The EEG records of children with drug-naïve CAE were evaluated retrospectively by two child neurologists first for 3 Hz SWD. Then, a machine-learning model evaluated the amplitudes of 3 Hz in the 1st second of SWD. Maximum electronegativity areas were documented and classified as focal, bilateral, and generalized. RESULTS One hundred and twelve 3 Hz SWD were evaluated in 11 patients. Among discharges within the 1st second, maximum electronegativity areas were documented as focal for 44 (39.2%), bilateral for 8 (7.1%), generalized for 60 (53.5%). Among focal electronegativity areas, mostly right central, left occipital and midline parietal areas were documented in 12 (10.7%), 7 (6.2%), and 6 (5.3%), respectively. Eight (7.1%) of the maximum electronegativity areas were detected bilaterally, of which 7 (6.2%) originated from the frontopolar areas. CONCLUSIONS Focal maximal electronegativity areas were frequently observed in drug-naïve CAE patients, comprising approximately half of non-generalized discharges. Focal discharges might be misleading in diagnosis. Focal areas within the brain may be responsible for and contribute to absence seizures that appear bilaterally symmetrical and generalized clinically. Although its clinical implication is unknown, this warrants further study.
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Affiliation(s)
- Özlem Yayıcı Köken
- Faculty of Medicine, Department of Pediatric Neurology, Akdeniz University, Antalya, Turkey
| | - Boran Şekeroğlu
- Artificial Intelligence Engineering, Near East University, Nicosia, Cyprus
- DESAM Institute, Near East University, Nicosia, Cyprus
| | - Burçin Şanlıdağ
- Faculty of Medicine, Department of Pediatric Neurology, Near East University, Nicosia, Cyprus
| | - Mehpare Sarı Yanartaş
- Faculty of Medicine, Department of Pediatric Neurology, Akdeniz University, Antalya, Turkey
| | - Arzu Yılmaz
- Ministry of Health, Ankara Research and Training Hospital, Department of Pediatric Neurology, Ankara, Turkey
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Koren J, Lang C, Gritsch G, Mayer L, Hartmann M, Hafner S, Kluge T, Baumgartner C. Idiopathic generalized epilepsies in the epilepsy monitoring unit: Systematic quantification of focal EEG and semiological signs. Clin Neurophysiol 2024; 162:82-90. [PMID: 38603948 DOI: 10.1016/j.clinph.2024.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/04/2024] [Accepted: 03/23/2024] [Indexed: 04/13/2024]
Abstract
OBJECTIVE Focal seizure symptoms (FSS) and focal interictal epileptiform discharges (IEDs) are common in patients with idiopathic generalized epilepsies (IGEs), but dedicated studies systematically quantifying them both are lacking. We used automatic IED detection and localization algorithms and correlated these EEG findings with clinical FSS for the first time in IGE patients. METHODS 32 patients with IGEs undergoing long-term video EEG monitoring were systematically analyzed regarding focal vs. generalized IEDs using automatic IED detection and localization algorithms. Quantitative EEG findings were correlated with FSS. RESULTS We observed FSS in 75% of patients, without significant differences between IGE subgroups. Mostly varying/shifting lateralizations of FSS across successive recorded seizures were seen. We detected a total of 81,949 IEDs, whereof 19,513 IEDs were focal (23.8%). Focal IEDs occurred in all patients (median 13% focal IEDs per patient, range 1.1 - 51.1%). Focal IED lateralization and localization predominance had no significant effect on FSS. CONCLUSIONS All included patients with IGE showed focal IEDs and three-quarter had focal seizure symptoms irrespective of the specific IGE subgroup. Focal IED localization had no significant effect on lateralization and localization of FSS. SIGNIFICANCE Our findings may facilitate diagnostic and treatment decisions in patients with suspected IGE and focal signs.
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Affiliation(s)
- Johannes Koren
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Vienna, Austria; Department of Neurology, Clinic Hietzing, Vienna, Austria.
| | - Clemens Lang
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Vienna, Austria; Department of Neurology, Clinic Hietzing, Vienna, Austria
| | - Gerhard Gritsch
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | - Lisa Mayer
- Department of Neurology, Clinic Hietzing, Vienna, Austria
| | - Manfred Hartmann
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | | | - Tilmann Kluge
- Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | - Christoph Baumgartner
- Karl Landsteiner Institute for Clinical Epilepsy Research and Cognitive Neurology, Vienna, Austria; Department of Neurology, Clinic Hietzing, Vienna, Austria; Medical Faculty, Sigmund Freud University, Vienna, Austria
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Vlachou M, Ryvlin P, Armand Larsen S, Beniczky S. Focal electroclinical features in generalized tonic-clonic seizures: Decision flowchart for a diagnostic challenge. Epilepsia 2024; 65:725-738. [PMID: 38279904 DOI: 10.1111/epi.17895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 01/29/2024]
Abstract
OBJECTIVE Bilateral tonic-clonic seizures with focal semiology or focal interictal electroencephalography (EEG) can occur in both focal and generalized epilepsy types, leading to diagnostic errors and inappropriate therapy. We investigated the prevalence and prognostic values of focal features in patients with idiopathic generalized epilepsy (IGE), and we propose a decision flowchart to distinguish between focal and generalized epilepsy in patients with bilateral tonic-clonic seizures and focal EEG or semiology. METHODS We retrospectively analyzed video-EEG recordings of 101 bilateral tonic-clonic seizures from 60 patients (18 with IGE, 42 with focal epilepsy). Diagnosis and therapeutic response were extracted after ≥1-year follow-up. The decision flowchart was based on previous observations and assessed concordance between interictal and ictal EEG. RESULTS Focal semiology in IGE was observed in 75% of seizures and 77.8% of patients, most often corresponding to forced head version (66.7%). In patients with multiple seizures, direction of head version was consistent across seizures. Focal interictal epileptiform discharges (IEDs) were observed in 61.1% of patients with IGE, whereas focal ictal EEG onset only occurred in 13% of seizures and 16.7% of patients. However, later during the seizures, a reproducible pattern of 7-Hz lateralized ictal rhythm was observed in 56% of seizures, associated with contralateral head version. We did not find correlation between presence of focal features and therapeutic response in IGE patients. Our decision flowchart distinguished between focal and generalized epilepsy in patients with bilateral tonic-clonic seizures and focal features with an accuracy of 96.6%. SIGNIFICANCE Focal semiology associated with bilateral tonic-clonic seizures and focal IEDs are common features in patients with IGE, but focal ictal EEG onset is rare. None of these focal findings appears to influence therapeutic response. By assessing the concordance between interictal and ictal EEG findings, one can accurately distinguish between focal and generalized epilepsies.
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Affiliation(s)
- Maria Vlachou
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Philippe Ryvlin
- Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland
| | - Sidsel Armand Larsen
- Department of Clinical Neurophysiology, Danish Epilepsy Center, Dianalund, Denmark
| | - Sándor Beniczky
- Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Clinical Neurophysiology, Danish Epilepsy Center, Dianalund, Denmark
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Datta AN, Crawford J, Wallbank L, Wong PKH. Outcome of Absence Epilepsy With Onset at 8-11 Years of Age: Watershed Ages When Syndromes Overlap. J Child Neurol 2023; 38:505-512. [PMID: 37461321 PMCID: PMC10493039 DOI: 10.1177/08830738231188397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 06/19/2023] [Accepted: 06/30/2023] [Indexed: 09/10/2023]
Abstract
Introduction: Absence seizures occur in various epilepsy syndromes, including childhood and juvenile absence epilepsy and juvenile myoclonic epilepsy. When children present with absence seizures at ages when syndromes overlap, initial syndrome designation is not always possible, making early prognostication challenging. For these children, the study objective is to determine clinical and initial electroencephalograph (EEG) findings to predict the development of generalized tonic-clonic seizures, which is a factor that affects outcome. Methods: Children with new-onset absence seizures between 8 and 11 years of age with at least 5 years of follow-up data were studied through the review of medical records and initial EEG tracings. Results: Ninety-eight patients were included in the study. The median age of absence seizure onset was 9 years (interquartile range [IQR] = 8.00, 10.00) and follow-up was 15 years (IQR = 13.00, 18.00). Forty-six percent developed generalized tonic-clonic seizures and 20% developed myoclonic seizures. On multiple regression analysis, a history of myoclonic seizures, anxiety, as well as bifrontal slowing and mild background slowing on initial EEG (P < .05) were associated with generalized tonic-clonic seizures. Although not statistically significant, a shorter duration of shortest EEG burst on baseline EEG was also associated with generalized tonic-clonic seizures. Conclusion: On initial EEG, bifrontal and background slowing and myoclonic seizures and anxiety are associated with developing generalized tonic-clonic seizures, which is of prognostic significance when early syndrome designation is difficult.
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Affiliation(s)
- Anita N. Datta
- Department of Pediatrics, Division of Neurology, BC Children's Hospital, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Department of Diagnostic Neurophysiology, BC Children's Hospital, Vancouver, BC, Canada
| | - Jacqueline Crawford
- Department of Diagnostic Neurophysiology, BC Children's Hospital, Vancouver, BC, Canada
| | - Laura Wallbank
- Department of Diagnostic Neurophysiology, BC Children's Hospital, Vancouver, BC, Canada
| | - Peter K. H. Wong
- Department of Pediatrics, Division of Neurology, BC Children's Hospital, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- Department of Diagnostic Neurophysiology, BC Children's Hospital, Vancouver, BC, Canada
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Evaluation of patients with epileptiform activities in the posterior temporal-parietal-occipital regions. Neurol Sci 2021; 42:4607-4613. [PMID: 33661483 DOI: 10.1007/s10072-021-05154-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 02/23/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The aim of this study was to determine the type, etiology and the rates of epilepsy and to identify accompanying cognitive and behavioral problems in patients with epileptiform abnormalities in the posterior cerebral localization. METHODS In this study, 3500 patients with at least one EEG record at the EEG Laboratory of Clinical Child Neurology Department of Cerrahpaşa Medical Faculty of Istanbul University were evaluated in 2014-2015. Three hundred forty-six patients were included in the study. RESULTS Of the 346 patients included in the study, 42.4% were female and 57.5% were male. The age range of the cases was 1-21 (mean: 8.7) years. Epileptiform activities were observed in post TPO region isolatedly in 58,95% (n = 204), post-TPO epileptiform focus with focal epileptiform focus in different localizations in 31.21% (n = 108), generalized epileptiform activity with more than one epileptiform focus in 9.8% (n= 34). In the period of EEG examinations 250 (72.25%) patients had a history of epileptic seizures and / or epilepsy, while 96 (27.74%) had non-epileptic clinical conditions such as behavioral disorder and autism. CONCLUSION In the EEG recordings we examined, sharp and spike wave activities were frequently observed in the post TPO region isolatedly. We believe that this study, which investigated the relationship between focal epilptiform activity in post TPO region and different clinical conditions, will serve as an example for other studies.
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Atalar AÇ, Vanlı-Yavuz EN, Yılmaz E, Bebek N, Baykan B. Investigation of Generalized EEG Paroxysms Accompanying Focal Epilepsies. Clin EEG Neurosci 2019; 50:413-422. [PMID: 31248273 DOI: 10.1177/1550059419841837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Interictal focal EEG features were frequently observed in generalized, epilepsies, but there is limited information about interictal, epileptiform/nonepileptiform generalized paroxysms in focal epilepsies. We aimed to report the frequency and associated factors of generalized EEG discharges in focal epilepsy with unknown cause (FEUC) and mesial, temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). A total of 200 patients (FEUC in 90 patients; MTLE-HS in 110 patients) were included. Generalized epileptiform (spike/sharp waves simultaneously in all regions) and nonspecific generalized discharges (paroxysmal slow waves) were investigated. All clinical and laboratory findings of 2 groups were compared with each other and with remaining control group, without generalized paroxysms, statistically. Generalized EEG features were present in 22 (11%; 4 males) patients; 9 in the FEUC group (10%; 2) and 13 in the MTLE-HS group (11.8%). Female gender (P < .021), febrile seizure (P < .034), precipitant factors (P < .025), and parental consanguinity (P < .033) were significantly higher in the group with generalized EEG findings. Monotherapy rates were lower in the MTLE-HS group (P < .05). The relationship of generalized EEG features with female gender and parental consanguinity may point out to a genetic property among focal epilepsies, while the relationship with febrile seizures and precipitant factors may be a clue about mechanisms with more extensive involvement of the neuronal networks.
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Affiliation(s)
- Arife Çimen Atalar
- 1 Istanbul University, Istanbul, Turkey.,2 Istanbul Education and Research Hospital, Istanbul, Turkey
| | - Ebru Nur Vanlı-Yavuz
- 1 Istanbul University, Istanbul, Turkey.,3 Koç University Hospital, Istanbul, Turkey
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Yu YL, Shi MT, Lu HJ. Case of Childhood Absence Epilepsy with Focal Spikes. World Neurosurg 2019; 126:601-604. [DOI: 10.1016/j.wneu.2019.02.225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 10/27/2022]
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Ninni S, Kouakam C, Szurhaj W, Baille G, Klug D, Lacroix D, Derambure P. Usefulness of head-up tilt test combined with video electroencephalogram to investigate recurrent unexplained atypical transient loss of consciousness. Arch Cardiovasc Dis 2019; 112:82-94. [PMID: 30600217 DOI: 10.1016/j.acvd.2018.08.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 08/17/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Convulsive syncope and epileptic seizure share many similar clinical features. Early diagnosis is critical for choosing the appropriate management strategy. AIM Our aim was to evaluate the diagnostic yield of an innovative diagnostic strategy - combined head-up tilt test (HUT)/video electroencephalogram (EEG) monitoring - in patients with unexplained seizure-like transient loss of consciousness (T-LOC). METHODS Combined HUT/video EEG was performed in patients with unexplained atypical T-LOC with both syncope and seizure characteristics remaining undiagnosed after a first-line investigation. T-LOC diagnosis was achieved in case of reproduction of usual symptoms. Events were classified as vasovagal, psychogenic or epilepsy. The link between EEG abnormalities and T-LOC was determined by an epilepsy specialist. Clinical follow-up was performed to assess T-LOC recurrence. RESULTS Hundred and one consecutive patients were prospectively enrolled (median age 26 [19; 46] years; 72% female) and underwent combined HUT/video EEG between 2007 and 2015. Antiepileptic drugs were being prescribed in 42% of patients. Combined HUT/video EEG was diagnostic in 67% of patients, leading to diagnosis of vasovagal syncope in 59 patients and psychogenic pseudosyncope in nine cases. Antiepileptic drugs were discontinued in 18 patients without epilepsy. Independent predictors of a definitive diagnosis were the presence of prodromal symptoms (odds ratio 5.97, 95% confidence interval 1.37-26; P=0.017) and a history of myoclonic jerks during T-LOC (odds ratio 4.36, 95% confidence interval 1.71-11.15; P=0.002). CONCLUSIONS Combined HUT/video EEG is useful for investigating recurrent unexplained atypical seizure-like T-LOC, especially in patients with a history of myoclonic jerks or with documented interictal non-specific EEG abnormalities.
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Affiliation(s)
- Sandro Ninni
- Clinique cardiologique, Institut Cœur-Poumon, CHRU de Lille, boulevard du Professeur-Jules-Leclercq, 59037 Lille, France.
| | - Claude Kouakam
- Clinique cardiologique, Institut Cœur-Poumon, CHRU de Lille, boulevard du Professeur-Jules-Leclercq, 59037 Lille, France
| | - William Szurhaj
- Service de neurophysiologie clinique, hôpital Roger-Salengro, CHRU de Lille, avenue du Professeur-Emile-Laine, 59037 Lille, France
| | - Guillaume Baille
- Service de neurophysiologie clinique, hôpital Roger-Salengro, CHRU de Lille, avenue du Professeur-Emile-Laine, 59037 Lille, France
| | - Didier Klug
- Clinique cardiologique, Institut Cœur-Poumon, CHRU de Lille, boulevard du Professeur-Jules-Leclercq, 59037 Lille, France
| | - Dominique Lacroix
- Clinique cardiologique, Institut Cœur-Poumon, CHRU de Lille, boulevard du Professeur-Jules-Leclercq, 59037 Lille, France
| | - Philippe Derambure
- Service de neurophysiologie clinique, hôpital Roger-Salengro, CHRU de Lille, avenue du Professeur-Emile-Laine, 59037 Lille, France
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Dinopoulos A, Tsirouda MA, Bonakis A, Pons R, Pavlopoulou ID, Tsoumakas K. Sleep architecture and epileptic characteristics of drug naïve patients in childhood absence epilepsy spectrum. A prospective study. Seizure 2018; 59:99-107. [DOI: 10.1016/j.seizure.2018.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 03/07/2018] [Accepted: 04/26/2018] [Indexed: 11/25/2022] Open
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Seneviratne U, Cook MJ, D'Souza WJ. Electroencephalography in the Diagnosis of Genetic Generalized Epilepsy Syndromes. Front Neurol 2017; 8:499. [PMID: 28993753 PMCID: PMC5622315 DOI: 10.3389/fneur.2017.00499] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/07/2017] [Indexed: 01/05/2023] Open
Abstract
Genetic generalized epilepsy (GGE) consists of several syndromes diagnosed and classified on the basis of clinical features and electroencephalographic (EEG) abnormalities. The main EEG feature of GGE is bilateral, synchronous, symmetric, and generalized spike-wave complex. Other classic EEG abnormalities are polyspikes, epileptiform K-complexes and sleep spindles, polyspike-wave discharges, occipital intermittent rhythmic delta activity, eye-closure sensitivity, fixation-off sensitivity, and photoparoxysmal response. However, admixed with typical changes, atypical epileptiform discharges are also commonly seen in GGE. There are circadian variations of generalized epileptiform discharges. Sleep, sleep deprivation, hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are often used as activation techniques to increase the diagnostic yield of EEG recordings. Reflex seizure-related EEG abnormalities can be elicited by the use of triggers such as cognitive tasks and pattern stimulation during the EEG recording in selected patients. Distinct electrographic abnormalities to help classification can be identified among different electroclinical syndromes.
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Affiliation(s)
- Udaya Seneviratne
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC, Australia.,Department of Neuroscience, Monash Medical Centre, Melbourne, VIC, Australia
| | - Mark J Cook
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC, Australia
| | - Wendyl Jude D'Souza
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC, Australia
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Sahin D, Yilmaz CU, Orhan N, Arican N, Kaya M, Gürses C, Ates N, Ahishali B. Changes in electroencephalographic characteristics and blood-brain barrier permeability in WAG/Rij rats with cortical dysplasia. Epilepsy Behav 2017; 67:70-76. [PMID: 28088684 DOI: 10.1016/j.yebeh.2016.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/06/2016] [Accepted: 11/03/2016] [Indexed: 12/13/2022]
Abstract
PURPOSE This study investigated the effects of cortical dysplasia (CD) on electrophysiology and blood-brain barrier (BBB) permeability in WAG/Rij rats with genetic absence epilepsy. METHODS Pregnant WAG/Rij rats were exposed to 145cGy of gamma-irradiation on embryonic day 17 to induce CD. An electroencephalogram was recorded from cortices subdurally in the offspring of the pregnant animals. Horseradish peroxidase (HRP) was used as determinant of BBB permeability. RESULTS A massive tissue loss in the cerebral cortex was seen in WAG/Rij rats with CD (p<0.05). There was a significant decrease in the number and duration of spike-and-wave discharges (SWDs) and an increase in the frequency of SWDs in the WAG/Rij rats with CD when compared with the properties of SWDs in intact WAG/Rij rats (p<0.01). Ultrastructurally, the accumulation of HRP reaction products in the cerebral cortex and thalamus of WAG/Rij rats was significantly higher than that of control values (p<0.01). The accumulation of HRP reaction products in the cerebral cortex and thalamus regions of WAG/Rij rats with CD increased and was higher than that of the control and WAG/Rij animals (p<0.01). CONCLUSION In our study, we showed that number and duration of SWDs decreased and SWD frequency increased in WAG/Rij rats with CD, suggesting a shift in seizure pattern. The association of these alterations with significant loss of cortical thickness and increased BBB permeability to HRP tracer may represent a causal relation of the EEG abnormalities with cerebral structural changes in these animals.
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Affiliation(s)
- Deniz Sahin
- Department of Physiology, Medical Faculty of Kocaeli University, Kocaeli, Turkey
| | - Canan Ugur Yilmaz
- Department of Laboratory Animals Science, Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Nurcan Orhan
- Department of Neuroscience, Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Nadir Arican
- Department of Forensic Medicine, Istanbul Faculty of Medicine, Istanbul University, Turkey
| | - Mehmet Kaya
- Koç University School of Medicine, Department of Physiology, Rumelifeneri Yolu, Sarıyer, 34450 Istanbul, Turkey.
| | - Candan Gürses
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey
| | - Nurbay Ates
- Department of Physiology, Medical Faculty of Kocaeli University, Kocaeli, Turkey
| | - Bulent Ahishali
- Department of Histology and Embryology, Istanbul Faculty of Medicine, Istanbul University, Turkey
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Focal interictal epileptiform discharges in idiopathic generalized epilepsy. Neurol Sci 2016; 37:1071-7. [PMID: 26956566 DOI: 10.1007/s10072-016-2538-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 02/24/2016] [Indexed: 10/22/2022]
Abstract
Are idiopathic generalized epilepsies (IGEs) truly generalized? Do IGEs represent a continuum or rather distinct syndromes? Focal changes in the electroencephalography (EEG) have been reported in IGEs. The aim of this work is to investigate focal interictal epileptiform discharges (IEDs) in IGEs, and their relation to clinical variables. Forty-one IGE patients (classified according to ILAE, 2001) were recruited from a tertiary center (age 23 ± 10.938 years). Their files were reviewed and they were subjected to clinical examination and interictal EEG. Patients with focal IEDs were compared to those without focal IEDs. Nine patients had juvenile myoclonic epilepsy (JME) and 32 had idiopathic epilepsy with generalized tonic-clonic seizures only (EGTCSA). Focal IEDs were found in 20 patients, mostly in the frontal (45.5 %) and temporal (31.8 %) distribution. Patients with focal IEDs were treated with a larger number of combined antiepileptic drugs (AEDs) (p value = 0.022). No significant difference was found between the two groups regarding age, sex, age at onset, epilepsy syndrome, seizure frequency, family history, AEDs used (sodium valproate and carbamazepine) and their doses. Seventeen EGTCSA patients had focal IEDs. They were treated with larger number of combined AEDs (p value = 0.0142). No significant difference was found between the EGTCSA patients with and those without focal IEDs regarding age, sex, age at onset, seizure frequency, family history and AEDs doses. Caution must be applied in the interpretation of interictal focal IEDs. These focal changes may be related to prognosis, however this needs further investigation.
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Japaridze G, Kasradze S, Lomidze G, Zhizhiashvili L, Kvernadze D, Geladze K, Beniczky S. Focal EEG features and therapeutic response in patients with juvenile absence and myoclonic epilepsy. Clin Neurophysiol 2016; 127:1182-1187. [DOI: 10.1016/j.clinph.2015.11.048] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Revised: 11/14/2015] [Accepted: 11/30/2015] [Indexed: 11/24/2022]
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14
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Rozendaal YJW, van Luijtelaar G, Ossenblok PPW. Spatiotemporal mapping of interictal epileptiform discharges in human absence epilepsy: A MEG study. Epilepsy Res 2015; 119:67-76. [PMID: 26681490 DOI: 10.1016/j.eplepsyres.2015.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 10/03/2015] [Accepted: 11/13/2015] [Indexed: 01/15/2023]
Abstract
PURPOSE Although absence epilepsy is considered to be a prototypic type of generalized epilepsy, it is still under debate whether generalized 3 Hz spike-and-wave discharges (SWDs) might have a cortical focal origin. Here it is investigated whether focal interictal epileptiform discharges (IEDs), which typically occur in the electro- (EEG) and magnetoencephalogram (MEG) in case of focal epilepsy, are present in the MEG of children with absence epilepsy. Next, the location of the sources of the IEDs is established, and it is investigated whether the location is concordant to the earlier established focal cortical regions involved in the generalized SWDs of these children. METHODS Whole head MEG recordings of seven children with absence epilepsy were reviewed with respect to the presence of IEDs (spikes and sharp waves). These IEDs were grouped into distinct clusters, in which each contribution to a cluster yields a comparable magnetic field distribution. Source localization was then performed onto the average signal of each cluster using an equivalent current dipole model and a realistic head model of the cortical surface. RESULTS IEDs were detected in 6 out of 7 patients. Source reconstruction indicated most often frontal, central or parietal origins of the IED in either the left and or right hemisphere. Spatiotemporal assessment of the IEDs indicated a stable location of the averages of these discharges, indicating a single underlying cortical source. DISCUSSION The outcome of this pilot study shows that MEG is well suited for the detection of IEDs and suggests that their estimated sources coincide rather well with the cortical regions involved during the spikes of the SWDs. It is discussed whether the presence of IEDs, classically seen as a marker of focal epilepsies, indicate that absence epilepsy should be considered as a focal type of epilepsy, in which changes in the network are evolving rapidly.
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Affiliation(s)
- Yvonne J W Rozendaal
- Department Function and Medical Technology, Academic Center of Epileptology, Kempenhaeghe & Maastricht UMC+, PO Box 61, 5590AB Heeze, The Netherlands; Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600MB Eindhoven, The Netherlands.
| | - Gilles van Luijtelaar
- Donders Centre of Cognition, Radboud University, PO Box 9104, 6500HE Nijmegen, The Netherlands.
| | - Pauly P W Ossenblok
- Department Function and Medical Technology, Academic Center of Epileptology, Kempenhaeghe & Maastricht UMC+, PO Box 61, 5590AB Heeze, The Netherlands.
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Seneviratne U, Cook M, D'Souza W. Focal abnormalities in idiopathic generalized epilepsy: A critical review of the literature. Epilepsia 2014; 55:1157-69. [DOI: 10.1111/epi.12688] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/13/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Udaya Seneviratne
- Department of Medicine; St. Vincent's Hospital; University of Melbourne; Melbourne Victoria Australia
- Department of Neuroscience; Monash Medical Centre; Melbourne Victoria Australia
| | - Mark Cook
- Department of Medicine; St. Vincent's Hospital; University of Melbourne; Melbourne Victoria Australia
| | - Wendyl D'Souza
- Department of Medicine; St. Vincent's Hospital; University of Melbourne; Melbourne Victoria Australia
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Koutroumanidis M, Tsiptsios D, Kokkinos V, Kostopoulos GK. Focal and generalized EEG paroxysms in childhood absence epilepsy: topographic associations and distinctive behaviors during the first cycle of non-REM sleep. Epilepsia 2012; 53:840-9. [PMID: 22360352 DOI: 10.1111/j.1528-1167.2012.03424.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To better understand the nature of the focal spike-wave discharges (FSWDs) and focally led generalized spike-wave discharges (GSWDs) in typical childhood absence epilepsy (CAE) and by implication their nosologic and taxonomic significance. METHODS Twenty-four abnormal video-electroencephalography (EEG) studies from 13 consecutive children with CAE and good response to appropriate antiepileptic drugs (AEDs) were analyzed. We studied the association between the topography of absence onset and the ictal automatisms, and the topographic correlation between FSWDs and GSWDs and their respective behavior during hyperventilation and the different states of phasic and nonphasic non-rapid eye movement (NREM) sleep. GSWDs were considered as of "focal" onset if a lead-in could be visibly recognized at a paper speed of 60 mm/s, and were classified by their topography. KEY FINDINGS (1) Multifocal absences occurred in 10 children; anterior onset was noted in 81 absences (73.6%) from 12 children and posterior in 18 (16.4%) from 7 children; there was no association between topography of absence onset and ictal automatisms; (2) FSWDs occurred in 85% of children and were multifocal in 73% of them; 85% of FSWDs were anterior and 14% posterior; (3) there was good topographic association between FSWDs and the leading spike of GSWDs of "focal" onset in all children with FSWDs; (4) both FSWDs and GSWDs increased during hyperventilation; (5) FSWDs occurred mainly during noncyclical NREM sleep and during periods of reduced vigilance of cyclical NREM sleep, whereas GSWDs occurred during the periods of enhanced vigilance of NREM sleep; GSWDs occurred significantly more frequently than FSWDs at the transition from reduced to enhanced vigilance of NREM sleep. SIGNIFICANCE Our findings suggest that in CAE focal EEG paroxysms reflect a system of multifocal nonlocalizing electrically unstable cortical areas that under the facilitatory influence of exogenous or endogenous factors like sleep instability can foster a corticothalamic response of sufficient strength to generate 3-Hz GSWDs that are conditionally sustainable and potentially ictal. FSWDs can be viewed as incomplete forms of the GSWDs; together they define the EEG identity of idiopathic "generalized" epileptogenesis.
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Affiliation(s)
- Michalis Koutroumanidis
- Department of Clinical Neurophysiology and Epilepsies, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom.
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Abstract
Idiopathic generalized epilepsy (IGE) is classified into several subsyndromes based on clinical and electroencephalography (EEG) features. The EEG signature of IGE is bisynchronous, symmetric, and generalized spike-wave complex; although focal, irregular, and so called "fragments" of discharges are not uncommon. Other characteristic EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, and photoparoxysmal response. Both human and animal data suggest involvement of the thalamus and the cortex in the generation of spike-wave discharges in IGE. Circadian variations of generalized epileptiform discharges are well described, and these can be useful in diagnostic confirmation. Those discharges tend to occur more often after awakening and during cyclic alternating pattern phase-A of non-rapid eye movement sleep. Activation procedures such as hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are useful techniques to increase the yield of both interictal and ictal EEG abnormalities. Although not in routine use, specific triggers such as pattern stimulation and cognitive tasks may also be of value in eliciting rare reflex seizure-related EEG abnormalities. Variations of EEG abnormalities are evident between different electroclinical syndromes. EEG is also affected by certain external as well as internal factors, which should be borne in mind when interpreting EEG studies in IGE.
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Affiliation(s)
- Udaya Seneviratne
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, Victoria, Australia.
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Mariani E, Rossi LN, Vajani S. Interictal paroxysmal EEG abnormalities in childhood absence epilepsy. Seizure 2011; 20:299-304. [DOI: 10.1016/j.seizure.2010.12.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 12/16/2010] [Accepted: 12/27/2010] [Indexed: 11/29/2022] Open
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Viravan S, Go C, Ochi A, Akiyama T, Carter Snead O, Otsubo H. Jeavons syndrome existing as occipital cortex initiating generalized epilepsy. Epilepsia 2011; 52:1273-9. [PMID: 21729035 DOI: 10.1111/j.1528-1167.2011.03068.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Jeavons syndrome (JS) is one of the underreported epileptic syndromes characterized by eyelid myoclonia (EM), eye closure-induced seizures/electroencephalography (EEG) paroxysms, and photosensitivity. JS has been proposed as idiopathic generalized epilepsy (IGE) because of normal posterior dominant background activity and paroxysmal generalized ictal epileptiform discharges (EDs). However, we noticed subtle occipital EDs preceding EM and interictal posterior EDs using digital video-EEG. We studied clinical and EEG findings in JS to determine the specific occipital lobe relation to this "eye closure-induced" reflex IGE. METHODS We identified 12 children who met the diagnostic criteria of JS from January 2004 to April 2009 at the Hospital for Sick Children, Toronto, Canada. All patients had EM captured by video-EEG. We reviewed and described ictal EEG patterns, interictal abnormalities, and demographics, clinical, and neuroimaging findings. KEY FINDINGS All patients but one were female (92%). Age at seizure onset ranged from 1.5 to 9 years, with a mean age of 4.9 years. Six patients (50%) were previously diagnosed as having absence epilepsy and 10 patients were on antiepileptic medications. All 12 patients had normal posterior dominant alpha rhythm, reactive to eye opening and closure. Spiky posterior alpha activity was noted with sustained eye closure in six patients (50%). Interictally, there were generalized EDs found in 10 patients (83%); four of them also had focal interictal EDs over the posterior head region. Eleven patients (92%) had evidence of focal posterior ictal EDs. EM and/or paroxysmal EDs were induced by photic stimulation in 9 (75%) and hyperventilation in 7 (58%). SIGNIFICANCE We observed two neurophysiologic findings in JS: (1) focal interictal EDs from posterior head region; and (2) predominant focal posterior ictal EDs preceding generalized EDs. Further clinical observations of seizures induced by eye closure, photic stimulation, and hyperventilation along with EEG paroxysms would raise the possibility of the occipital cortex initiating generalized epilepsy network involving the brainstem, and thalamocortical and transcortical pathways in JS.
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Affiliation(s)
- Sorawit Viravan
- Division of Neurology, the Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
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