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Sitnikova E. Behavioral and Cognitive Comorbidities in Genetic Rat Models of Absence Epilepsy (Focusing on GAERS and WAG/Rij Rats). Biomedicines 2024; 12:122. [PMID: 38255227 PMCID: PMC10812980 DOI: 10.3390/biomedicines12010122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/24/2024] Open
Abstract
Absence epilepsy is a non-convulsive type of epilepsy characterized by the sudden loss of awareness. It is associated with thalamo-cortical impairment, which may cause neuropsychiatric and neurocognitive problems. Rats with spontaneous absence-like seizures are widely used as in vivo genetic models for absence epilepsy; they display behavioral and cognitive problems similar to epilepsy in humans, such as genetic absence epilepsy rats from Strasbourg (GAERS) and Wistar Albino rats from Rijswijk (WAG/Rij). Depression- and anxiety-like behaviors were apparent in GAERS, but no anxiety and depression-like symptoms were found in WAG/Rij rats. Deficits in executive functions and memory impairment in WAG/Rij rats, i.e., cognitive comorbidities, were linked to the severity of epilepsy. Wistar rats can develop spontaneous seizures in adulthood, so caution is advised when using them as a control epileptic strain. This review discusses challenges in the field, such as putative high emotionality in genetically prone rats, sex differences in the expression of cognitive comorbidities, and predictors of cognitive problems or biomarkers of cognitive comorbidities in absence epilepsy, as well as the concept of "the cognitive thalamus". The current knowledge of behavioral and cognitive comorbidities in drug-naive rats with spontaneous absence epilepsy is beneficial for understanding the pathophysiology of absence epilepsy, and for finding new treatment strategies.
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Affiliation(s)
- Evgenia Sitnikova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5A Butlerova St., Moscow 117485, Russia
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Yavuz M, İyiköşker P, Mutlu N, Kiliçparlar S, Şalci ÖH, Dolu G, Kaymakçilar EN, Akkol S, Onat F. Dexmedetomidine, an alpha 2A receptor agonist, triggers seizures unilaterally in GAERS during the pre-epileptic phase: does the onset of spike-and-wave discharges occur in a focal manner? Front Neurol 2023; 14:1231736. [PMID: 38146441 PMCID: PMC10749324 DOI: 10.3389/fneur.2023.1231736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 11/13/2023] [Indexed: 12/27/2023] Open
Abstract
Introduction The genetic absence epilepsy rat from Strasbourg (GAERS) is a rat model for infantile absence epilepsy with spike-and-wave discharges (SWDs). This study aimed to investigate the potential of alpha 2A agonism to induce seizures during the pre-epileptic period in GAERS rats. Methods Stereotaxic surgery was performed on male pups and adult GAERS rats to implant recording electrodes in the frontoparietal cortices (right/left) under anesthesia (PN23-26). Following the recovery period, pup GAERS rats were subjected to electroencephalography (EEG) recordings for 2 h. Before the injections, pup epileptiform activity was examined using baseline EEG data. Dexmedetomidine was acutely administered at 0.6 mg/kg to pup GAERS rats 2-3 days after the surgery and once during the post-natal (PN) days 25-29. Epileptiform activities before injections triggered unilateral SWDs and induced sleep durations, and power spectral density was evaluated based on EEG traces. Results The most prominent finding of this study is that unilateral SWD-like activities were induced in 47% of the animals with the intraperitoneal dexmedetomidine injection. The baseline EEGs of pup GAERS rats had no SWDs as expected since they are in the pre-epileptic period but showed low-amplitude non-rhythmic epileptiform activity. There was no difference in the duration of epileptiform activities between the basal EEG groups and DEX-injected unilateral SWD-like-exhibiting and non-SWD-like activities groups; however, the sleep duration of the unilateral SWD-like-exhibiting group was shorter. Power spectrum density (PSD) results revealed that the 1.75-Hz power in the left hemisphere peaks significantly higher than in the right. Discussion As anticipated, pup GAERS rats in the pre-epileptic stage showed no SWDs. Nevertheless, they exhibited sporadic epileptiform activities. Specifically, dexmedetomidine induced SWD-like activities solely within the left hemisphere. These observations imply that absence seizures might originate unilaterally in the left cortex due to α2AAR agonism. Additional research is necessary to explore the precise cortical focal point of this activity.
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Affiliation(s)
- Melis Yavuz
- Department of Pharmacology, Faculty of Pharmacy, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Pelin İyiköşker
- Faculty of Pharmacy, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Nursima Mutlu
- Department of Biotechnology and Genetics, Institute of Science, Istanbul University, Istanbul, Türkiye
| | - Serra Kiliçparlar
- Faculty of Pharmacy, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Öykü Hazal Şalci
- Faculty of Pharmacy, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | - Gökçen Dolu
- Faculty of Pharmacy, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
| | | | - Serdar Akkol
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Filiz Onat
- Department of Medical Pharmacology, School of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
- Institute of Neurosciences, Acibadem Mehmet Ali Aydinlar University, Istanbul, Türkiye
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Jayaram S, Alkhaldi M, Shahid A. The Role and Controversies of Electroencephalogram in Focal versus Generalized Epilepsy. JOURNAL OF PEDIATRIC EPILEPSY 2021. [DOI: 10.1055/s-0041-1722869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractAs early in 1935, Gibbs et al described electroencephalogram (EEG) features of large slow waves seen in “petit mal” seizures and change in background rhythm to a higher frequency, greater amplitude pattern in “grand mal” seizures. Studies have shown many typical EEG features in focal onset as well as generalized epilepsies.2
3 It is usually easy to delineate focal epilepsy cases when EEG onset of seizures is clear as seen in Benign focal epileptiform discharges of childhood.4 However, it is not uncommon to see cases where epileptiform discharges are not very clear. For example, there can be secondary bilateral synchrony or generalized onset of epileptiform discharges in some cases of focal epilepsy5 and nongeneralized EEG features is cases of generalized epilepsy like absence seizures.6
The awareness of occurrence of focal clinical and EEG features in generalized epilepsy is particularly important to help to select appropriate AEDs and also to avoid inappropriate consideration for epilepsy surgery.7 Lüders et al8 have shown that multiple factors like electroclinical seizure evolution, neuroimaging (both functional and anatomical) have to be analyzed in depth before defining an epileptic syndrome. Here, we are providing few examples of different situations where it is still mysterious to figure out focal onset seizures with secondary generalization versus primary generalized epilepsy.
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Affiliation(s)
- Shoba Jayaram
- Neurosciences Institute, Atrium Health, Charlotte, North Carolina, United States
- Department of Epilepsy, University Hospitals, Cleveland Medical Center, Cleveland, Ohio, United States
| | - Modhi Alkhaldi
- Department of Neurology, King Fahad University Hospital, Imam Abdulrhman Bin Faisal University, Khobar, Saudi Arabia
| | - Asim Shahid
- Department of Epilepsy, University Hospitals, Cleveland Medical Center, Cleveland, Ohio, United States
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Al-Asmi A, Poothrikovil RP, Nandhagopal R, Al-Zakwani I, Al-Futaisi A, Al-Abri M, Gujjar AR. Clinico-electrographic characteristics and classification of genetic generalized epilepsy in Oman. Epilepsy Res 2020; 166:106380. [PMID: 32590287 DOI: 10.1016/j.eplepsyres.2020.106380] [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: 05/01/2020] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE There is a lack of information on the annual incidence of genetic generalized epilepsy (GGE) in the Arab countries, especially Oman. Ascertaining the true burden of illness has crucial implications for health policies and priorities. We aim to study the clinico-electrographic characteristics, classification, and annual incidence of GGE in Oman. METHOD Using the cross-sectional data of EEGs obtained from all patients with GGE who presented to Sultan Qaboos University hospital (major referral center for epilepsy in Oman) from January 2007 to June 2014. Analyses were performed using univariate statistics. RESULTS Approximately 10,423 patients had EEG studies during the study period of which 376 patients (3.6 %) had EEG abnormalities suggestive of GGE. Forty two percent of the 376 GGE patients were male with ages ranging from 3 to 58 years. We were able to classify 273 patients to one of the GGE syndromes. Forty-three percent of 130 patients had a positive family history of epilepsy in their first or second-degree relatives. The generalized tonic-clonic seizure was the most common seizure type observed in 242 patients (64 %; 95 %CI: 59.2 %-68.9 %). Juvenile myoclonic epilepsy was the most common epilepsy syndrome (41 % of the total GGE patients) encountered in our region. A significant female predominance (9.7 % vs 2.5 %; p = 0.016) was observed in juvenile absence epilepsy. Certain interictal focal EEG abnormalities did not exclude a diagnosis of GGE. An average annual GGE incidence of 2.9 % (95 % CI: 2.6 %-3.2 %) was observed during the study period. CONCLUSION This hospital-based study is the first of its kind in the Arabian Gulf region, classifying the different subcategories of GGE. Our results indicate that GGE is a common epilepsy subtype in Oman. A prospective population-based epidemiological study is required to estimate the precise frequency of GGE in Oman.
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Affiliation(s)
- Abdullah Al-Asmi
- Neurology Unit, Department of Medicine, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.
| | | | - Ramachandiran Nandhagopal
- Neurology Unit, Department of Medicine, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Ibrahim Al-Zakwani
- Department of Pharmacology and Clinical Pharmacy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Amna Al-Futaisi
- Department of Child Health, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Mohammed Al-Abri
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
| | - Arunodaya R Gujjar
- Neurology Unit, Department of Medicine, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman
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Tatum W, Rubboli G, Kaplan P, Mirsatari S, Radhakrishnan K, Gloss D, Caboclo L, Drislane F, Koutroumanidis M, Schomer D, Kasteleijn-Nolst Trenite D, Cook M, Beniczky S. Clinical utility of EEG in diagnosing and monitoring epilepsy in adults. Clin Neurophysiol 2018; 129:1056-1082. [DOI: 10.1016/j.clinph.2018.01.019] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 12/28/2017] [Accepted: 01/09/2018] [Indexed: 12/20/2022]
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Salvati KA, Beenhakker MP. Out of thin air: Hyperventilation-triggered seizures. Brain Res 2017; 1703:41-52. [PMID: 29288644 DOI: 10.1016/j.brainres.2017.12.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/29/2017] [Accepted: 12/27/2017] [Indexed: 12/11/2022]
Abstract
Voluntary hyperventilation triggers seizures in the vast majority of people with absence epilepsy. The mechanisms that underlie this phenomenon remain unknown. Herein, we review observations - many made long ago - that provide insight into the relationship between breathing and absence seizures.
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Affiliation(s)
- Kathryn A Salvati
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22903, United States
| | - Mark P Beenhakker
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22903, United States.
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Gesche J, Khanevski M, Solberg C, Beier CP. Resistance to valproic acid as predictor of treatment resistance in genetic generalized epilepsies. Epilepsia 2017; 58:e64-e69. [DOI: 10.1111/epi.13702] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/17/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Joanna Gesche
- Department of Neurology; University Hospital of Odense; Odense Denmark
| | - Marina Khanevski
- Department of Neurology; University Hospital of Odense; Odense Denmark
| | - Carl Solberg
- Department of Neurology; University Hospital of Odense; Odense Denmark
| | - Christoph Patrick Beier
- Department of Neurology; University Hospital of Odense; Odense Denmark
- Department for Clinical Research; University of Southern Denmark; Odense Denmark
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Kirazlı Ö, Çavdar S, Yıldızel S, Onat F, Kaptanoğlu E. A developmental study of glutamatergic neuron populations in the ventrobasal and the lateral geniculate nucleus of the thalamus: Comparing Genetic Absence Rats from Strasbourg (GAERS) and normal control wistar rats. Int J Dev Neurosci 2016; 56:35-41. [PMID: 27939427 DOI: 10.1016/j.ijdevneu.2016.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/04/2016] [Indexed: 11/28/2022] Open
Abstract
An imbalance of GABAergic inhibition and glutamatergic excitation is suspected to be the cause of absence epileptic seizures. Absence seizures are known to be generated in thalamocortical circuitry. In the present study we used light microscopy immunohistochemistry to quantify the density of glutamate+ve neurons at two developmental stages (P10 and P60) in two thalamic nuclei, the ventrobasal (VB) and lateral geniculate nucleus (LGN) in Wistar rats and compared the results with similar data obtained from genetic absence epilepsy rats from Strasbourg (GAERS). Rats were perfused transcardially with glutaraldehyde and paraformaldehyde fixative, then samples from VB and LGN were removed from each animal and sectioned. The glutamatergic neurons were labelled using light-microscopic glutamate immunohistochemistry. The disector method was used to quantify the glutamate+ve neurons in VB and LGN of GAERS and Wistar rats. The data were statistically analyzed. The distribution of the glutamate+ve neurons in the VB thalamic nucleus showed a significant reduction in the neuronal profiles per unit thalamic area from P10 to P60 in both Wistar and GAERS. The decrease was greater in the GAERS compared to the Wistar animals. However, in the LGN no reduction was observed either in the Wistar or in the GAERS. Comparing the density of glutamate+ve neurons in the VB thalamic nucleus of P10 of Wistar animals with of P10 GAERS showed statistically significant greater densities of these neurons in GAERS than in the Wistar rats. However no significant difference was present at P60 between the Wistar and GAERS animals. The disproportional decrease in GAERS may be related to the onset of absence seizures or may be related to neurogenesis of absence epilepsy.
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Affiliation(s)
- Özlem Kirazlı
- Department of Anatomy, School of Medicine, Marmara University, Istanbul, Turkey
| | - Safiye Çavdar
- Department of Anatomy, School of Medicine, Koç University, Rumelifeneri Yolu Sarıyer, Istanbul, Turkey.
| | - Sercan Yıldızel
- Department of Anatomy, School of Medicine, Marmara University, Istanbul, Turkey
| | - Filiz Onat
- Department of Pharmacology, School of Medicine, Marmara University, Istanbul, Turkey
| | - Erkan Kaptanoğlu
- Department of Neurosurgery, Marmara University, School of Medicine, Institute of Neurological Sciences, Istanbul, Turkey
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Increased inhibitory synaptic activity in the hippocampus (CA1) of genetic absence epilepsy rats: Relevance of kindling resistance. Epilepsy Res 2016; 126:70-7. [PMID: 27434859 DOI: 10.1016/j.eplepsyres.2016.06.013] [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: 03/08/2016] [Revised: 05/31/2016] [Accepted: 06/25/2016] [Indexed: 11/21/2022]
Abstract
PURPOSE Genetic absence epilepsy rats from Strasbourg (GAERS), a well-validated genetic rat model for typical absence epilepsy, are known to manifest a resistance to secondary generalization of abnormal focal electrical activity evoked by kindling. The mechanism of this resistance is still unclear. In order to understand the possible mechanism of kindling resistance, we investigated for the first time, the differences of short-term synaptic plasticity by using a paired-pulse paradigm as an indicator of GABAergic activity in CA1 region of hippocampus in GAERS and non-epileptic Wistar rats in-vivo. METHODS Rats were subjected to kindling process, basolateral amygdala was stimulated twice a day, with a supra-threshold current, until they displayed limbic or convulsive seizures. One hour after the last kindling stimulation, evoked field potentials from CA1 pyramidal layer of hippocampus were recorded in-vivo under urethane anesthesia. RESULTS In response to supra-threshold kindling stimulations GAERS showed a significantly delayed kindling progression and displayed a significant increase in hippocampal excitability at early stages of kindling that is the critical for the development of convulsive seizures. In control rats that were not received kindling stimulation, paired-pulse depression (PPD) was significantly pronounced in GAERS with respect to the Wistar group. During the kindling course, PPD was gradually reduced in the Wistar rats as kindling progression was advanced. However in GAERS, PPD ratios were not significantly changed at early stages of kindling. When GAERS reached convulsive stage, their PPD ratios became similar to that of Wistar rats. DISCUSSION The increased inhibition in paired-pulse responses at early stages of kindling in GAERS suggests the role of augmented GABAergic activity as one of the underlying mechanisms of kindling resistance observed in genetic rat models of absence epilepsy.
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Dugan P, Carlson C, Bluvstein J, Chong DJ, Friedman D, Kirsch HE. Auras in generalized epilepsy. Neurology 2014; 83:1444-9. [PMID: 25230998 DOI: 10.1212/wnl.0000000000000877] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE We studied the frequency of auras in generalized epilepsy (GE) using a detailed semistructured diagnostic interview. METHODS In this cross-sectional study, participants with GE were drawn from the Epilepsy Phenome/Genome Project (EPGP). Responses to the standardized diagnostic interview regarding tonic-clonic (grand mal) seizures were then examined. This questionnaire initially required participants to provide their own description of any subjective phenomena before their "grand mal seizures." Participants who provided answers to these questions were considered to have an aura. All participants were then systematically queried regarding a list of specific symptoms occurring before grand mal seizures, using structured (closed-ended) questions. RESULTS Seven hundred ninety-eight participants with GE were identified, of whom 530 reported grand mal seizures. Of these, 112 (21.3%) reported auras in response to the open-ended question. Analysis of responses to the closed-ended questions suggested that 341 participants (64.3%) experienced at least one form of aura. CONCLUSIONS Auras typically associated with focal epilepsy were reported by a substantial proportion of EPGP subjects with GE. This finding may support existing theories of cortical and subcortical generators of GE with variable spread patterns. Differences between responses to the open-ended question and closed-ended questions may also reflect clinically relevant variation in patient responses to history-taking and surveys. Open-ended questions may underestimate the prevalence of specific types of auras and may be in part responsible for the underrecognition of auras in GE. In addition, structured questions may influence participants, possibly leading to a greater representation of symptoms.
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Affiliation(s)
- Patricia Dugan
- From the Department of Neurology (P.D., J.B., D.J.C., D.F.), New York University Langone Medical Center, New York; Department of Neurology (C.C.), Medical College of Wisconsin, Milwaukee; and Department of Neurology (H.E.K.), University of California, San Francisco.
| | - Chad Carlson
- From the Department of Neurology (P.D., J.B., D.J.C., D.F.), New York University Langone Medical Center, New York; Department of Neurology (C.C.), Medical College of Wisconsin, Milwaukee; and Department of Neurology (H.E.K.), University of California, San Francisco
| | - Judith Bluvstein
- From the Department of Neurology (P.D., J.B., D.J.C., D.F.), New York University Langone Medical Center, New York; Department of Neurology (C.C.), Medical College of Wisconsin, Milwaukee; and Department of Neurology (H.E.K.), University of California, San Francisco
| | - Derek J Chong
- From the Department of Neurology (P.D., J.B., D.J.C., D.F.), New York University Langone Medical Center, New York; Department of Neurology (C.C.), Medical College of Wisconsin, Milwaukee; and Department of Neurology (H.E.K.), University of California, San Francisco
| | - Daniel Friedman
- From the Department of Neurology (P.D., J.B., D.J.C., D.F.), New York University Langone Medical Center, New York; Department of Neurology (C.C.), Medical College of Wisconsin, Milwaukee; and Department of Neurology (H.E.K.), University of California, San Francisco
| | - Heidi E Kirsch
- From the Department of Neurology (P.D., J.B., D.J.C., D.F.), New York University Langone Medical Center, New York; Department of Neurology (C.C.), Medical College of Wisconsin, Milwaukee; and Department of Neurology (H.E.K.), University of California, San Francisco
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Long-term follow-up of adult patients with genetic generalized epilepsy with typical absence seizures and generalized paroxysmal fast activity in their EEG. Seizure 2014; 23:607-15. [DOI: 10.1016/j.seizure.2014.04.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 04/28/2014] [Accepted: 04/30/2014] [Indexed: 11/19/2022] Open
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Outcome of pediatric epilepsies in adulthood. HANDBOOK OF CLINICAL NEUROLOGY 2014. [PMID: 23622229 DOI: 10.1016/b978-0-444-52891-9.00084-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
A good understanding of the long-term outcome of epileptic disorders that have begun in infancy or childhood allows the practitioner to choose the best medical management and to adjust it throughout the life of the patient. The identification of risk factors of poor outcome is crucial, the issue being to prevent or minimize their impacts by appropriate interventions. However, knowledge on the natural course and long-term outcome of pediatric epilepsies is fragmentary for a lot of them for reasons that the authors discuss in this chapter. After reviewing general considerations on outcome for the epilepsies persisting throughout life, the authors will discuss the present state of knowledge on specific aspects concerning some pediatric epilepsy syndromes. These disorders have been chosen because they are representative of the wide range of potential outcomes that can be observed in adults.
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Neuroimaging of epilepsy: lesions, networks, oscillations. Clin Neuroradiol 2014; 24:5-15. [PMID: 24424576 DOI: 10.1007/s00062-014-0284-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 01/03/2014] [Indexed: 10/25/2022]
Abstract
While analysis and interpretation of structural epileptogenic lesion is an essential task for the neuroradiologist in clinical practice, a substantial body of epilepsy research has shown that focal lesions influence brain areas beyond the epileptogenic lesion, across ensembles of functionally and anatomically connected brain areas. In this review article, we aim to provide an overview about altered network compositions in epilepsy, as measured with current advanced neuroimaging techniques to characterize the initiation and spread of epileptic activity in the brain with multimodal noninvasive imaging techniques. We focus on resting-state functional magnetic resonance imaging (MRI) and simultaneous electroencephalography/fMRI, and oppose the findings in idiopathic generalized versus focal epilepsies. These data indicate that circumscribed epileptogenic lesions can have extended effects on many brain systems. Although epileptic seizures may involve various brain areas, seizure activity does not spread diffusely throughout the brain but propagates along specific anatomic pathways that characterize the underlying epilepsy syndrome. Such a functionally oriented approach may help to better understand a range of clinical phenomena such as the type of cognitive impairment, the development of pharmacoresistance, the propagation pathways of seizures, or the success of epilepsy surgery.
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Tsiptsios DI, Howard RS, Koutroumanidis MA. Electroencephalographic assessment of patients with epileptic seizures. Expert Rev Neurother 2014; 10:1869-86. [DOI: 10.1586/ern.10.175] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pugnaghi M, Carmichael DW, Vaudano AE, Chaudhary UJ, Benuzzi F, Di Bonaventura C, Giallonardo AT, Rodionov R, Walker MC, Duncan JS, Meletti S, Lemieux L. Generalized spike and waves: effect of discharge duration on brain networks as revealed by BOLD fMRI. Brain Topogr 2013; 27:123-37. [PMID: 23990340 DOI: 10.1007/s10548-013-0311-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 08/14/2013] [Indexed: 11/28/2022]
Abstract
In the past decade, the possibility of combining recordings of EEG and functional MRI (EEG-fMRI), has brought a new insight into the brain network underlying generalized spike wave discharges (GSWD). Nevertheless, how GSWD duration influences this network is not fully understood. In this study we aim to investigate whether GSWD duration had a threshold (non-linear) and/or a linear effect on the amplitude of the associated BOLD changes in any brain regions. This could help in elucidating if there is an hemodynamic background supporting the differentiation between interictal and ictal events. We studied a population of 42 patients with idiopathic generalized epilepsies (IGE) who underwent resting-state EEG-fMRI recordings in three centres (London, UK; Modena, Italy; Rome, Italy), applying a parametric analysis of the GSWD duration. Patients were classified as having Childhood Absence epilepsy, Juvenile Absence Epilepsy, or Juvenile Myoclonic Epilepsy. At the population level linear GSWD duration-related BOLD signal changes were found in a network of brain regions: mainly BOLD increase in thalami and cerebral ventricles, and BOLD decrease in posterior cingulate, precuneus and bilateral parietal regions. No region of significant BOLD change was found in the group analysis for the non-linear effect of GSWD duration. To explore the possible effect of both the different IGE sub-syndromes and the different protocols and scanning equipment used in the study, a full-factorial ANOVA design was performed revealing no significant differences. These findings support the idea that the amplitude of the BOLD changes is linearly related to the GSWD duration with no universal threshold effect of spike and wave duration on the brain network supporting this activity.
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Affiliation(s)
- Matteo Pugnaghi
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
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Abstract
UNLABELLED Polyspike ictal-onset absence seizures may predict an unfavorable response to treatment in patients with epilepsy. The authors assessed absences in adults with idiopathic generalized epilepsy (IGE) associated with polyspike onset before classic 3-Hz generalized spike-and-waves (GSW). Seven adults with absences undergoing video EEG were accompanied by 3-Hz GSW, preceded by polyspike-ictal onset by >1 second in two or more seizures. The clinical profile, interictal, and ictal EEG noted had at least 1-year follow-up. A total of 1,164 patients underwent video EEG, with 58 (5%) receiving a diagnosis of IGE or subsyndrome. All seven patients with absence seizures had an ictal EEG pattern of polyspike onset prior to 3-Hz GSW. Four female and three male adults (mean age, 28.9 years) had absence as their primary seizure type. All but one had seizure onset between 4 and 20 years and failed at least two broad-spectrum antiepileptic drug trials. Typical features of IGE were normal neurologic examination, brain MRI, and 3- to 3.5-Hz GSW and generalized polyspike-and-waves on interictal EEG. Atypical features included learning disability (2 of 7), absence status (1 of 7), and paroxysmal fast activity during nonrapid eye movement sleep (3 of 7). CONCLUSIONS Polyspikes are common during video EEG in adults with IGE. Absence seizures with polyspike onset 3-Hz GSW suggest an intermediary form of IGE that may be drug resistant.
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Szaflarski JP, DiFrancesco M, Hirschauer T, Banks C, Privitera MD, Gotman J, Holland SK. Cortical and subcortical contributions to absence seizure onset examined with EEG/fMRI. Epilepsy Behav 2010; 18:404-13. [PMID: 20580319 PMCID: PMC2922486 DOI: 10.1016/j.yebeh.2010.05.009] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2009] [Revised: 05/10/2010] [Accepted: 05/13/2010] [Indexed: 10/19/2022]
Abstract
In patients with idiopathic generalized epilepsies (IGEs), bursts of generalized spike and wave discharges (GSWDs) lasting > or =2 seconds are considered absence seizures. The location of the absence seizures generators in IGEs is thought to involve interplay between various components of thalamocortical circuits; we have recently postulated that medication resistance may, in part, be related to the location of the GSWD generators [Szaflarski JP, Lindsell CJ, Zakaria T, Banks C, Privitera MD. Epilepsy Behav. 2010;17:525-30]. In the present study we hypothesized that patients with medication-refractory IGE (R-IGE) and continued absence seizures may have GSWD generators in locations other than the thalamus, as typically seen in patients with IGE. Hence, the objective of this study was to determine the location of the GSWD generators in patients with R-IGE using EEG/fMRI. Eighty-three patients with IGE received concurrent EEG/fMRI at 4 T. Nine of them (aged 15-55) experienced absence seizures during EEG/fMRI and were included; all were diagnosed with R-IGE. Subjects participated in up to three 20-minute EEG/fMRI sessions (400 volumes, TR=3 seconds) performed at 4 T. After removal of fMRI and ballistocardiographic artifacts, 36 absence seizures were identified. Statistical parametric maps were generated for each of these sessions correlating seizures to BOLD response. Timing differences between brain regions were tested using statistical parametric maps generated by modeling seizures with onset times shifted relative to the GSWD onsets. Although thalamic BOLD responses peaked approximately 6 seconds after the onset of absence seizures, other areas including the prefrontal and dorsolateral cortices showed brief and nonsustained peaks occurring approximately 2 seconds prior to the maximum of the thalamic peak. Temporal lobe peaks occurred at the same time as the thalamic peak, with a cerebellar peak occurring approximately 1 second later. Confirmatory analysis averaging cross-correlation between cortical and thalamic regions of interest across seizures corroborated these findings. Finally, Granger causality analysis showed effective connectivity directed from frontal lobe to thalamus, supporting the notion of earlier frontal than thalamic involvement. The results of this study support our original hypothesis and indicate that in the patients with R-IGE studied, absence seizures may be initiated by widespread cortical (frontal and parietal) areas and sustained in subcortical (thalamic) regions, suggesting that the examined patients have cortical onset epilepsy with propagation to thalamus.
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Affiliation(s)
- Jerzy P. Szaflarski
- Department of Neurology, University of Cincinnati Medical Center, Cincinnati, OH, USA, Department of Neuroscience, University of Cincinnati Medical Center, Cincinnati, OH, USA, Center for Imaging Research at the University of Cincinnati Medical Center, Cincinnati, OH, USA, Imaging Research Center at the Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA,Address for Correspondence: Jerzy P. Szaflarski, MD, PhD, Department of Neurology, University of Cincinnati College of Medicine, 260 Stetson Street, Cincinnati, OH 45267-0525, Phone: 513.558.5440,
| | - Mark DiFrancesco
- Imaging Research Center at the Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA, Department of Radiology, University of Cincinnati Medical Center, Cincinnati, OH, USA
| | - Thomas Hirschauer
- Imaging Research Center at the Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Christi Banks
- Department of Neurology, University of Cincinnati Medical Center, Cincinnati, OH, USA
| | - Michael D. Privitera
- Department of Neurology, University of Cincinnati Medical Center, Cincinnati, OH, USA
| | - Jean Gotman
- Montreal Neurological Institute at the McGill University, Montreal, CA
| | - Scott K. Holland
- Department of Neuroscience, University of Cincinnati Medical Center, Cincinnati, OH, USA, Imaging Research Center at the Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA, Department of Pediatrics, University of Cincinnati Medical Center, Cincinnati, OH, USA, Department of Radiology, University of Cincinnati Medical Center, Cincinnati, OH, USA
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Szaflarski JP, Lindsell CJ, Zakaria T, Banks C, Privitera MD. Seizure control in patients with idiopathic generalized epilepsies: EEG determinants of medication response. Epilepsy Behav 2010; 17:525-30. [PMID: 20227351 PMCID: PMC2923211 DOI: 10.1016/j.yebeh.2010.02.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 02/10/2010] [Accepted: 02/12/2010] [Indexed: 10/19/2022]
Abstract
In a minority of patients with idiopathic generalized epilepsies (IGEs), seizures continue despite appropriate treatment. We sought to determine the clinical and EEG factors associated with medication response in these patients. All patients with IGEs evaluated by epilepsy specialists between 17 November 2008 and 16 November 2009 were included. We collected information on seizure freedom (dependent variable), EEG asymmetries, response to valproic acid (VPA), MRI characteristics, medication use, demographics, and seizure history (predictors). We identified 322 patients with IGEs; 45 (14%) were excluded from analyses because they had always had a normal EEG (N=26), there were no EEG data (N=3), or they were non-compliant with medication (N=26). Patients with juvenile myoclonic epilepsy were more likely to respond to VPA than were patients with other IGEs, and VPA response was associated with seizure freedom. When EEG characteristics were considered, presence of any focal EEG abnormalities (focal slowing, focal epileptiform discharges, or both) was associated with decreased odds of seizure freedom. These findings suggest that patients with IGEs with poor seizure control may have atypical IGEs with possibly focal, for example, frontal, rather than thalamic onset.
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Affiliation(s)
- Jerzy P. Szaflarski
- Department of Neurology, University of Cincinnati, Cincinnati, OH
,Department of Psychiatry, University of Cincinnati, Cincinnati, OH
,Department of Psychology, University of Cincinnati, Cincinnati, OH
,Department of Neuroscience, University of Cincinnati, Cincinnati, OH
,Cincinnati Epilepsy Center, University of Cincinnati, Cincinnati, OH
,Address for Correspondence University of Cincinnati Department of Neurology 260 Stetson Street, Rm. 2350 Cincinnati, OH 45267-0525 Phone: (513) 558.5440
| | | | - Tarek Zakaria
- Department of Neurology, University of Cincinnati, Cincinnati, OH
| | - Christi Banks
- Department of Neurology, University of Cincinnati, Cincinnati, OH
| | - Michael D. Privitera
- Department of Neurology, University of Cincinnati, Cincinnati, OH
,Cincinnati Epilepsy Center, University of Cincinnati, Cincinnati, OH
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Epstein D, Diu E, Abeysekera T, Kam D, Chan Y. Review of non-convulsive status epilepticus and an illustrative case history manifesting as delirium. Australas J Ageing 2009; 28:110-5. [DOI: 10.1111/j.1741-6612.2009.00365.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sadleir LG, Scheffer IE, Smith S, Carstensen B, Farrell K, Connolly MB. EEG features of absence seizures in idiopathic generalized epilepsy: Impact of syndrome, age, and state. Epilepsia 2009; 50:1572-8. [DOI: 10.1111/j.1528-1167.2008.02001.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Park KI, Lee SK, Chu K, Lee JJ, Kim DW, Nam H. The value of video-EEG monitoring to diagnose juvenile myoclonic epilepsy. Seizure 2009; 18:94-9. [DOI: 10.1016/j.seizure.2008.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2008] [Revised: 06/16/2008] [Accepted: 07/04/2008] [Indexed: 11/26/2022] Open
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Matur Z, Baykan B, Bebek N, Gürses C, Altindağ E, Gökyiğit A. The evaluation of interictal focal EEG findings in adult patients with absence seizures. Seizure 2009; 18:352-8. [PMID: 19213578 DOI: 10.1016/j.seizure.2009.01.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2008] [Revised: 01/05/2009] [Accepted: 01/08/2009] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To investigate the focal interictal EEG abnormalities in adult patients with absence seizures (ASs) and to identify their clinical, EEG and semiological correlates. METHODS Fifty patients older than 18 years, diagnosed as having IGE with AS documented with ictal recordings. Interictal focal sharp or spike-waves and strictly focal paroxysmal slow activity were considered as focal EEG features. The patients having focal EEG features were classified as "Group I", whereas the remaining of them was classified as "Group II". RESULTS We observed focal findings in 34% of the patients, mainly in frontotemporal (41%), and frontal (29%) regions. There were no significant differences with respect to the clinical parameters such as sex, epilepsy duration, positive family history and the age of the onset between the groups. Psychiatric co-morbidities were significantly higher in Group I when compared to Group II (P=0.00). Accompanying automatisms were higher in Group I, whereas eye deviation during absences was higher in Group II. In Group I, the asymmetry of the ictal discharges was more frequently observed. Focal EEG features were more frequently seen in juvenile absence epilepsy syndrome, without reaching a significance level. CONCLUSION The focal findings in adult absence epilepsy patients could have some unknown etio-pathogenetic and prognostic implications. We emphasize the cautious interpretation of isolated interictal focal EEG abnormalities to prevent a wrong diagnosis of focal epilepsy in patients who may indeed suffer from generalized epilepsy.
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Affiliation(s)
- Zeliha Matur
- Istanbul University, Istanbul Faculty of Medicine, Department of Neurology, 34390 Istanbul, Turkey.
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Koutroumanidis M, Aggelakis K, Panayiotopoulos CP. Idiopathic epilepsy with generalized tonic-clonic seizures only versus idiopathic epilepsy with phantom absences and generalized tonic-clonic seizures: One or two syndromes? Epilepsia 2008; 49:2050-62. [DOI: 10.1111/j.1528-1167.2008.01702.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sadleir LG, Scheffer IE, Smith S, Carstensen B, Carlin J, Connolly MB, Farrell K. Factors influencing clinical features of absence seizures. Epilepsia 2008; 49:2100-7. [PMID: 18616552 DOI: 10.1111/j.1528-1167.2008.01708.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The clinical features of absence seizures in idiopathic generalized epilepsy have been held to be syndrome-specific. This hypothesis is central to many aspects of epilepsy research yet has not been critically assessed. We examined whether specific factors such as epilepsy syndrome, age, and state determine the features of absence seizures. METHODS Children with newly presenting absence seizures were studied using video electroencephalography (EEG) recording. We analyzed whether a child's epilepsy syndrome, age, state of arousal, and provocation influenced specific clinical features of their absence seizures: duration, eyelid movements, eye opening, and level of awareness during the seizure. RESULTS Seizures (509) were evaluated in 70 children with the following syndromes: Childhood absence epilepsy (CAE), 37; CAE plus photoparoxysmal response (PPR), 10; juvenile absence epilepsy (JAE), 8; juvenile myoclonic epilepsy (JME), 6; unclassified, 9. Seizure duration was associated with epilepsy syndrome as children with JME had shorter seizures than in other syndromes, independent of age. Age independently influences level of awareness and eye opening. Arousal or provocation affected all features except level of awareness. Specific factors unique to the child independently influenced all features; the nature of these factors has not been identified. DISCUSSION The view that the clinical features of absence seizures have syndrome-specific patterns is not supported by critical analysis. We show that confounding variables profoundly affect clinical features and that syndromes also show marked variation. Variation in clinical features of absence seizures results from a complex interaction of many factors that are likely to be genetically and environmentally determined.
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Affiliation(s)
- Lynette G Sadleir
- Department of Pediatrics, Wellington School of Medicine, University of Otago, Wellington, New Zealand.
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Genton P, Ferlazzo E, Thomas P. Absence status epilepsy: Delineation of a distinct idiopathic generalized epilepsy syndrome. Epilepsia 2008; 49:642-9. [DOI: 10.1111/j.1528-1167.2007.01467.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Koutroumanidis M, Bourvari G, Tan SV. Idiopathic generalized epilepsies: clinical and electroencephalogram diagnosis and treatment. Expert Rev Neurother 2006; 5:753-67. [PMID: 16274333 DOI: 10.1586/14737175.5.6.753] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This review concentrates on the principles of the clinical and electroencephalogram diagnosis of idiopathic generalized epilepsies and their treatment. The electroclinical variability of the main seizure types is detailed and particular emphasis is placed on the differential diagnosis from other seizures and nonepileptic conditions that is essential for the optimal management of these patients. The authors review the various idiopathic generalized epilepsy subsyndromes and conditions that are included in both the 1989 International League Against Epilepsy classification system and the recently proposed International League Against Epilepsy scheme, but also syndromes and forms that have not been formally recognized. Finally, the authors describe the principles of antiepileptic drug treatment with the old and newer drugs, and their specific indications and contraindications in the various syndromes and seizure types.
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Affiliation(s)
- Michael Koutroumanidis
- Department of Clinical Neurophysiology and Epilepsies, Lambeth Wing, 3rd Floor, St Thomas' Hospital, London SE1 7EH, UK.
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28
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Durón RM, Medina MT, Martínez-Juárez IE, Bailey JN, Perez-Gosiengfiao KT, Ramos-Ramírez R, López-Ruiz M, Alonso ME, Ortega RHC, Pascual-Castroviejo I, Machado-Salas J, Mija L, Delgado-Escueta AV. Seizures of idiopathic generalized epilepsies. Epilepsia 2005; 46 Suppl 9:34-47. [PMID: 16302874 DOI: 10.1111/j.1528-1167.2005.00312.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Idiopathic generalized epilepsies (IGEs) comprise at least 40% of epilepsies in the United States, 20% in Mexico, and 8% in Central America. Here, we review seizure phenotypes across IGE syndromes, their response to treatment and advances in molecular genetics that influence nosology. Our review included the Medline database from 1945 to 2005 and our prospectively collected Genetic Epilepsy Studies (GENESS) Consortium database. Generalized seizures occur with different and similar semiologies, frequencies, and patterns, ages at onset, and outcomes in different IGEs, suggesting common neuroanatomical pathways for seizure phenotypes. However, the same seizure phenotypes respond differently to the same treatments in different IGEs, suggesting different molecular defects across syndromes. De novo mutations in SCN1A in sporadic Dravet syndrome and germline mutations in SCN1A, SCN1B, and SCN2A in generalized epilepsies with febrile seizures plus have unraveled the heterogenous myoclonic epilepsies of infancy and early childhood. Mutations in GABRA1, GABRG2, and GABRB3 are associated with absence seizures, while mutations in CLCN2 and myoclonin/EFHC1 substantiate juvenile myoclonic epilepsy as a clinical entity. Refined understanding of seizure phenotypes, their semiology, frequencies, and patterns together with the identification of molecular lesions in IGEs continue to accelerate the development of molecular epileptology.
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Affiliation(s)
- Reyna M Durón
- California Comprehensive Epilepsy Program, David Geffen School of Medicine at UCLA, Los Angeles, CA 90073, USA
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Panayiotopoulos CP. Syndromes of idiopathic generalized epilepsies not recognized by the International League Against Epilepsy. Epilepsia 2005; 46 Suppl 9:57-66. [PMID: 16302876 DOI: 10.1111/j.1528-1167.2005.00314.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This chapter assesses probable epileptic syndromes within the idiopathic generalized epilepsies (IGE) that have not yet been recognized by the International League Against Epilepsy (ILAE). Jeavons syndrome, a purely reflex IGE that predominantly manifests with eyelid myoclonia and electroencephalogram (EEG) abnormalities on eye closure, is the most distinct and undisputed of the syndromes. Another is autosomal-dominant cortical tremor, myoclonus, and epilepsy, a purely monogenic disorder that has been documented in numerous reports, mainly from Japan and Italy. Perioral myclonia with absences is certainly a seizure type that may constitute an IGE syndrome when it is associated with a number of other clinical and EEG manifestations. Similarly, many patients suffer for years from phantom absences, a type of mild absence, before a first generalized tonic-clonic seizure that usually occurs in adulthood. Both perioral myoclonia with absences and phantom absences are clinically significant because they are probably lifelong and are associated with a very high incidence (around 50%) of absence status epilepticus that may escape diagnosis and appropriate treatment. The position of early childhood IGE, which manifests mainly with typical absence seizures that are distinctly different from childhood absence epilepsy and other recognized IGE syndromes, is less clear. The prevalence of these syndromes is significant. Their identification allows better clinical management and is important for genetic research and counselling. In addition, their recognition permits application of exclusion criteria for a more purified definition and a better understanding of the true boundaries of the other IGE syndromes already accepted by the ILAE.
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Abstract
Classification of epileptic seizures and epilepsy syndromes as either focal or generalized is a fundamental and early part in the diagnostic process and is generally fairly easily accomplished. However, in patients with idiopathic generalized epilepsies, seizure and EEG features may suggest, particularly to the unwary, the occurrence of focal rather than generalized seizures. Misinterpretation of typical absence seizures as focal seizures, especially as temporal lobe seizures and of myoclonic seizures as focal clonic seizures, is a relatively common error and focal features during generalized tonic-clonic seizures may also be quite common. Sequences of seizures in idiopathic generalized epilepsies (such as absences or jerks followed by generalized tonic-clonic seizures) may also cause confusion. Versive and circling seizures are seizure types whose ictal semiology is clearly focal; nevertheless such seizures are described in idiopathic generalized epilepsies accompanied by generalized EEG discharges. The occurrence of focal EEG abnormalities in certain idiopathic generalized epilepsy syndromes is common. This is best known in juvenile myoclonic epilepsy.
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Affiliation(s)
- Colin D Ferrie
- Department of Paediatric Neurology, Clarendon Wing Leeds General Infirmary, Leeds, United Kingdom.
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Abstract
From a phenomenological point of view, absence seizures refer to any type of epileptic event characterized by loss of awareness and responsiveness. However, a phenomenological definition of absence seizures is hampered by difficulties in conceptualizing consciousness and needs to take into account the electroclinical features and anatomical basis of seizures. Sensu stricto, absence seizures are defined as an electroclinical pattern of generalized 3/s spike-wave activity accompanied by loss of awareness and responsiveness. Although there is general belief that absences are most often encountered in childhood or early adolescence, a considerable number of patients suffer from absences late into adulthood, which are often refractory to antiepileptic drugs. These patients generally fall into one of two groups. The first group consists of those who have more or less typical absences in childhood or adolescence which continue into adulthood, and may be accompanied by other generalized seizures or neurological impairment. Few data are available addressing whether the seizure semiology of the absences in these patients changes over time or not. The second class of patients corresponds to those in whom absences emerge for the first time in adulthood or even in the senium. These need to be carefully distinguished from later aggravation or semiological transformation of undiagnosed childhood epilepsies and from certain complex focal seizures originating from the frontal or temporal lobe. A wide range of aetiologically and anatomically diverse processes may lead to the appearance of epileptic absences. It is important to note that absences also vary in their intensity, their impact on the ability of the subject to respond and react, and in particular in their natural history and their response to antiepileptic medication.
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Affiliation(s)
- E Trinka
- Universitätsklinik für Neurologie, Medizinische Universität Innsbruck, Innsbruck, Austria.
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Koutroumanidis M, Smith S. Use and Abuse of EEG in the Diagnosis of Idiopathic Generalized Epilepsies. Epilepsia 2005; 46 Suppl 9:96-107. [PMID: 16302882 DOI: 10.1111/j.1528-1167.2005.00320.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This article concentrates on the role of electroencephalograms (EEGs) in the diagnosis and management of patients with idiopathic generalized epilepsies (IGEs). We review the morphologic and behavioral characteristics of the interictal and ictal EEG markers of IGE that should guide recording strategies to augment its diagnostic yield, and we attempt to delineate those particular features that may be relevant to different IGE syndromes. We also explore the electrographic boundaries between IGEs and cryptogenic/symptomatic generalized and focal epilepsies, and focal/secondary generalized epilepsies, with particular relevance to the phenomena of focal abnormalities and secondary bilateral synchrony, commenting on possible diagnostic pitfalls and areas of uncertainty.
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Affiliation(s)
- Michael Koutroumanidis
- Department of Clinical Neurophysiology and Epilepsies, St Thomas' Hospital, London, United Kingdom.
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Affiliation(s)
- Masao Adachi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
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Blumenfeld H. Consciousness and epilepsy: why are patients with absence seizures absent? PROGRESS IN BRAIN RESEARCH 2005; 150:271-86. [PMID: 16186030 PMCID: PMC3153469 DOI: 10.1016/s0079-6123(05)50020-7] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Epileptic seizures cause dynamic, reversible changes in brain function and are often associated with loss of consciousness. Of all seizure types, absence seizures lead to the most selective deficits in consciousness, with relatively little motor or other manifestations. Impaired consciousness in absence seizures is not monolithic, but varies in severity between patients and even between episodes in the same patient. In addition, some aspects of consciousness may be more severely involved than other aspects. The mechanisms for this variability are not known. Here we review the literature on human absence seizures and discuss a hypothesis for why effects on consciousness may be variable. Based on behavioral studies, electrophysiology, and recent neuroimaging and molecular investigations, we propose absence seizures impair focal, not generalized brain functions. Impaired consciousness in absence seizures may be caused by focal disruption of information processing in specific corticothalamic networks, while other networks are spared. Deficits in selective and varying cognitive functions may lead to impairment in different aspects of consciousness. Further investigations of the relationship between behavior and altered network function in absence seizures may improve our understanding of both normal and impaired consciousness.
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Affiliation(s)
- Hal Blumenfeld
- Department of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
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Abstract
PURPOSE To describe the characteristics of patients with typical absence seizures (TASs), consistently triggered by photosensitivity. METHODS Consecutive patients having TAS induced by intermittent photic stimulation were included in the study. All clinical parameters, EEG, and video-EEG data were assessed during the long-term follow-up. Statistical analyses were performed with SPSS 10.0 software. RESULTS Nine female and two male patients with a mean age at onset of 14 +/- 5.9 years (range, 7-27 years) and with a mean follow-up of 9 +/- 7.56 years had photosensitive TASs. They constituted 7.64% of absence epilepsies and 0.4% of all patients seen in our tertiary center. The seizures were usually subtle and had a reported frequency of 1 to 9 times daily. Seven patients were clinically photosensitive and reported that some of their TASs were induced by photic stimuli in daily life. All patients also had spontaneous TASs, and four of them had generalized tonic-clonic seizures. EEG results did not show any distinctive features when compared with those of other cases with TASs. Remission could not be achieved in five patients with antiepileptic drug treatments, and we always observed relapses after drug discontinuation or dose reduction in the remaining six cases in remission. Spontaneous remission did not occur even in the five patients older than 30 years. CONCLUSIONS TASs triggered by photosensitivity are a rare and heterogeneous clinical condition with a marked female preponderance. It is notable that TASs do not remit in these cases.
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Affiliation(s)
- Betül Baykan
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
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McLean KJ, O'Brien TJ, Cook MJ, Vajda FJE. The influence of gender on the aggravation of absence seizures by carbamazepine in the low-dose pentylenetetrazol rat model. Seizure 2004; 13:208-16. [PMID: 15121127 DOI: 10.1016/s1059-1311(03)00144-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To determine whether carbamazepine (CBZ) aggravates absence seizures in the low-dose pentylenetetrazol (PTZ) rat model in both male and female animals, and investigate for gender differences. METHODS Inbred Sprague-Dawley rats were implanted with EEG electrodes. Seven days later PTZ (20 mg/kg, i.p.) was administered following pre-treatment with vehicle or CBZ (20 mg/kg, i.p.) and the occurrence of spike-and-wave discharges (SWDs) on the EEG quantified. RESULTS The cumulative SWD for 90-minute post-PTZ was higher in the CBZ versus vehicle pre-treatment arm for both female (mean 110 seconds vs. 62 seconds; P = 0.03) and male (mean 89 seconds vs. 60 seconds; P = 0.03) rats. The increase in SWD duration in the CBZ arm was greater in female rats for the first five 15-minute intervals, but none attained statistical significance (P > 0.05). CBZ pre-treatment resulted in reductions in both SWD frequency (Hz) (male, P = 0.003; female, P < 0.0001) and latency to onset of SWD (male, P = 0.002). The frequency of SWD in CBZ pre-treated rats was lower in females (5.8 Hz vs. 6.1 Hz, P = 0.002) as was the decrease in the SWD burst duration following CBZ versus vehicle pre-treatment (-0.05 seconds vs. -0.25 seconds, P = 0.046). CONCLUSIONS CBZ consistently aggravates absence seizures in the low-dose PTZ model in both female and male rats. However, while some gender differences were found, the results failed to support the hypothesis that females are significantly more susceptible to aggravation of the number or duration of absence seizures by CBZ.
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Affiliation(s)
- Karen J McLean
- Australian Centre for Clinical Neuropharmacology, Raoul Wallenerg Centre, Melbourne, Vic., Australia
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Mory SB, Li LM, Guerreiro CAM, Cendes F. Thalamic Dysfunction in Juvenile Myoclonic Epilepsy: A Proton MRS Study. Epilepsia 2003; 44:1402-5. [PMID: 14636347 DOI: 10.1046/j.1528-1157.2003.67702.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate neuronal dysfunction in the thalami of patients with juvenile myoclonic epilepsy (JME) by using proton magnetic resonance spectroscopy (MRS). METHODS We performed single-voxel proton MRS over the right and the left thalami of 10 consecutive patients (five women) with JME (mean age, 31.6 years) and 10 age-matched healthy volunteers (five men). All patients had seizure onset in late childhood-teenage, normal neurologic examination, typical EEG of JME, and normal high-resolution MR imaging (MRI). We determined ratios of N-acetylaspartate (NAA) over creatine-phosphocreatine (Cr). Values <2 standard deviations from controls were considered abnormal. We performed analysis of variance to evaluate group differences. RESULTS Group analysis showed that thalami NAA/Cr ratios were significantly decreased in JME patients (left side, 1.58 +/- 0.26; right side, 1.5 +/- 0.15) as compared with controls (left side, 1.98 +/- 0.18; right side, 1.88 +/- 0.15; p = 0.001 and p = 0.007, respectively). Individual analysis showed that nine of the 10 patients had abnormal NAA/Cr in at least one of the thalami. CONCLUSIONS This study shows evidence of neuronal dysfunction in the thalami of patients with JME, which may have relevance for the mechanisms of seizure generation in this form of generalized epilepsy.
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Affiliation(s)
- Susana B Mory
- Department of Neurology, University of Campinas-UNICAMP, Campinas, SP, Brazil
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Guilhoto LMFF, Manreza MLG, Yacubian EMT. Syndromic classification of patients with typical absence seizures. ARQUIVOS DE NEURO-PSIQUIATRIA 2003; 61:580-7. [PMID: 14513161 DOI: 10.1590/s0004-282x2003000400010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study is to compare ILAE classification (1989) and Panayiotopoulos' criteria (1997) for absence epilepsies. We studied 455 typical absences (ILAE, 1981) by video-EEG in 43 patients with normal neurological and neuroradiological examinations and interictal EEG with spike-wave complexes higher than 2.5Hz. Syndromic diagnosis was possible in 60.5% and 67.4% of the patients using ILAE classification and Panayiotopoulos' proposal, respectively. According to ILAE criteria 19 patients had childhood absence epilepsy (CAE), five juvenile absence epilepsy (JAE), one juvenile myoclonic epilepsy (JME) and one epilepsy with specific modes of seizure precipitation. According to Panayiotopoulos' proposal, 10 had CAE, 14 JAE, one JME, three myoclonic absence epilepsy and one eyelid myoclonia with absences. We conclude that Panayiotopoulos' criteria and ILAE classification for absence epilepsies, which did not allow for the classification of 32.6% and 39.5% of cases, respectively, were still insufficient to classify all patients under specific diagnosis.
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Affiliation(s)
- Laura M F F Guilhoto
- Divisão de Clínica Neurológica, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
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Striano S, Striano P, Nocerino C, Boccella P, Bilo L, Meo R, Ruosi P. Eyelid myoclonia with absences: an overlooked epileptic syndrome? Neurophysiol Clin 2002; 32:287-96. [PMID: 12490326 DOI: 10.1016/s0987-7053(02)00343-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
AIM To identify, among patients referred to our Epilepsy Center, those fulfilling eyelid myoclonia with absences (EMA) criteria and to evaluate their semiological, electroclinical and evolutive features. In addition, to examine some possible causes of underdiagnosis and to stress the role of video-EEG (VEEG) recording. MATERIALS AND METHODS Retrospective analysis of 2780 epileptic patients. INCLUSION CRITERIA Eyelid myoclonia and brief absences, related to EEG generalized paroxysmal activity and triggered by eye closure and/or by intermittent photic stimulation. RESULTS 7.46% of our patients with idiopathic generalized epilepsy (IGE) could be classified as EMA. Female/male ratio was 1.7:1. Familial history of epilepsy was present in about half of the patients, with two pairs of identical twins in the sample. Rare generalized tonic-clonic seizures occurred in most cases. CONCLUSIONS EMA is a not infrequent condition among IGEs. It is likely to be underdiagnosed due to the subtle clinical semiology and to masking of EEG changes by the effects of age and anti-epileptic drugs. VEEG analysis is often needed for diagnosis of EMA. Most likely, only genetic research will be able to clarify whether EMA is a distinct epileptic syndrome.
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Affiliation(s)
- Salvatore Striano
- Department of Neurological Sciences, Epilepsy Center, Federico II University, Via Pansini 5, Naples, Italy.
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Mory SB, Guerreiro CA, Li LM, Teixeira RA, Costa AL, Cardoso TA, Cendes F. Epilepsias generalizadas idiopáticas diagnosticadas incorretamente como epilepsias parciais. ARQUIVOS DE NEURO-PSIQUIATRIA 2002. [DOI: 10.1590/s0004-282x2002000500020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A epilepsia generalizada idiopática (EGI) frequentemente não é diagnosticada corretamente em adultos, com sérias consequências para os pacientes. O objetivo deste estudo foi avaliar os fatores mais frequentemente associados a dificuldades no diagnóstico diferencial entre epilepsias parciais e generalizadas em adultos. Avaliamos 41 pacientes com diagnostico de crises parciais complexas com elementos de anamnese e EEG indicando um possível diagnóstico diferencial. Foi possível a mudança do diagnóstico de epilepsia parcial para EGI em 25 pacientes: 22 (88%) com EMJ; um com ausência juvenil, um com síndrome de ausências com mioclonias periorais e um com ausência com mioclonias palpebrais. Mioclonias, uma das características da EMJ e outras formas de EGI, geralmente não eram espontaneamente relatadas pelos pacientes. Abalos mioclônicos unilaterais eram confundidos com crises parciais motoras. Ausências breves e pouco frequentes e anormalidades focais no EEG contribuíram para o não reconhecimento de EGI. Todos os 25 pacientes apresentavam crises sem controle adequado antes da revisão diagnóstica. Após o diagnóstico correto e mudança para monoterapia com acido valpróico ou valproato de sódio, 19 (76%) ficaram livre de crises e seis (24%) dos 25 pacientes apresentaram melhora significativa. A associação de lamotrigina em três destes pacientes propiciou redução significativa da frequência de crises. Em conclusão, anamnese detalhada e questionamento direcionado para determinar a presença de mioclonias e crises tipo ausência e a sua interpretação no contexto clínico são fundamentais para o diagnóstico correto das EGI em adultos.
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Affiliation(s)
| | | | - Li M. Li
- Universidade Estadual de Campinas, Brasil
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42
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Abstract
Typical absences are brief (seconds) generalised seizures of sudden onset and termination. They have 2 essential components: clinically, the impairment of consciousness (absence) and, generalised 3 to 4Hz spike/polyspike and slow wave discharges on electroencephalogram (EEG). They differ fundamentally from other seizures and are pharmacologically unique. Their clinical and EEG manifestations are syndrome-related. Impairment of consciousness may be severe, moderate, mild or inconspicuous. This is often associated with motor manifestations, automatisms and autonomic disturbances. Clonic, tonic and atonic components alone or in combination are motor symptoms; myoclonia, mainly of facial muscles, is the most common. The ictal EEG discharge may be consistently brief (2 to 5 seconds) or long (15 to 30 seconds), continuous or fragmented, with single or multiple spikes associated with the slow wave. The intradischarge frequency may be constant or may vary (2.5 to 5Hz). Typical absences are easily precipitated by hyperventilation in about 90% of untreated patients. They are usually spontaneous, but can be triggered by photic, pattern, video games stimuli, and mental or emotional factors. Typical absences usually start in childhood or adolescence. They occur in around 10 to 15% of adults with epilepsies, often combined with other generalised seizures. They may remit with age or be lifelong. Syndromic diagnosis is important for treatment strategies and prognosis. Absences may be severe and the only seizure type, as in childhood absence epilepsy. They may predominate in other syndromes or be mild and nonpredominant in syndromes such as juvenile myoclonic epilepsy where myoclonic jerks and generalised tonic clonic seizures are the main concern. Typical absence status epilepticus occurs in about 30% of patients and is more common in certain syndromes, e.g. idiopathic generalised epilepsy with perioral myoclonia or phantom absences. Typical absence seizures are often easy to diagnose and treat. Valproic acid, ethosuximide and lamotrigine, alone or in combination, are first-line therapy. Valproic acid controls absences in 75% of patients and also GTCS (70%) and myoclonic jerks (75%); however, it may be undesirable for some women. Similarly, lamotrigine may control absences and GTCS in possibly 50 to 60% of patients, but may worsen myoclonic jerks; skin rashes are common. Ethosuximide controls 70% of absences, but it is unsuitable as monotherapy if other generalised seizures coexist. A combination of any of these 3 drugs may be needed for resistant cases. Low dosages of lamotrigine added to valproic acid may have a dramatic beneficial effect. Clonazepam, particularly in absences with myoclonic components, and acetazolamide may be useful adjunctive drugs.
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Affiliation(s)
- C P Panayiotopoulos
- Department of Clinical Neurophysiology and Epilepsies, St Thomas' Hospital, London, England.
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Vuilleumier P, Assal F, Blanke O, Jallon P. Distinct behavioral and EEG topographic correlates of loss of consciousness in absences. Epilepsia 2000; 41:687-93. [PMID: 10840400 DOI: 10.1111/j.1528-1157.2000.tb00229.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To describe the behavioral and EEG topographic correlates of absences with 3-Hz generalized spike-waves and partitioned impairment of consciousness. METHODS Two adult women had so-called "phantom" absences, characterized by brief and mild impairments of consciousness that were previously inconspicuous to both patient and physician. Neuropsychological examination was performed under video-EEG monitoring during absence status. EEG topographic mapping of spike-wave discharges was obtained in the two cases. RESULTS Only mild attentional and executive disturbances were observed during absence status despite prolonged discharges. Spike-wave bursts were associated with selective impairment in the initiation of response and self-generated action, whereas short-term storage of external information during discharges was fully preserved. This is consistent with a predominant involvement of frontomesial cortex demonstrated by topographic mapping of spike-wave discharges in the two cases. By contrast, in two other patients with typical absences and a complete lack of retention for information given during the discharges, topographic mapping found a more lateral frontal involvement by spike-wave activity. CONCLUSIONS Different types of absence seizures may impair distinct components of conscious behavior. A predominant involvement of frontomesial thalamocortical circuitry may underlie an "inconspicuous" disorder of consciousness as seen in phantom absences with selective loss of initiation and goal-oriented behavior, whereas involvement of more lateral frontal areas in typical absences may additionally disrupt working memory processes.
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Affiliation(s)
- P Vuilleumier
- Department of Neurology, EEG and Clinical Epileptology Unit, and Brain Mapping Laboratory, University Hospital of Geneva, Switzerland.
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Oguni H, Hayashi K, Imai K, Hirano Y, Mutoh A, Osawa M. Study on the early-onset variant of benign childhood epilepsy with occipital paroxysms otherwise described as early-onset benign occipital seizure susceptibility syndrome. Epilepsia 1999; 40:1020-30. [PMID: 10403229 DOI: 10.1111/j.1528-1157.1999.tb00812.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE We studied the early-onset variant of benign childhood epilepsy with occipital paroxysms (EVBCEOP) proposed by Panayiotopoulos, to confirm whether his five criteria are sufficient to delineate EVBCEOP as a new epileptic syndrome, as well as to predict a good outcome prospectively at the time of the first examination. SUBJECTS The subjects were 649 children with localization-related epilepsies (LREs) observed in our hospital for >4 years. METHODS We applied the International Classification of Epilepsies and Epileptic Syndromes to the 649 patients and identified patients who had EVBCEOP from among those with nonspecific idiopathic LRE. The inclusion criteria were to satisfy all five criteria and all but one criterion (i.e., either ictal vomiting or occipital EEG paroxysms). We were blind as to the outcomes and selected patients who satisfied the following three of the five criteria at the time of the first examination, (a) normal development before the onset, (b) epilepsy onset age between 2 and 8 years, and (c) occipital EEG foci. We attempted to determine whether the outcome can be predicted prospectively, and whether the presence or absence of ictal vomiting affects the prognosis. RESULTS We identified 19 patients who satisfied all five criteria, 22 who exhibited all but occipital EEG foci, and 21 who exhibited all but ictal vomiting. The incidence of status convulsivus was higher in those with ictal vomiting than in those without ictal vomiting (p < 0.05). Interictal EEG performed every 6 months showed shifting and multiplication of EEG foci in 42 and 52% of all subjects, respectively. We identified 57 patients, 42 (74%) of whom were in remission by age 12 years. The number of patients who experienced remission did not differ significantly between those with (76%, n = 25) and without (72%, n = 32) ictal vomiting (p > 0.05). CONCLUSIONS Nosologically, EVBCEOP appears to constitute the earliest form of idiopathic epileptic syndrome different from classic BCEOP. However, its clinical spectrum, ranging from the absence of ictal vomiting to a combination of extraoccipital and multifocal EEG foci, is broad, such that further prospective study is expected to reveal the exact prerequisite criteria for determining the border of this epileptic syndrome and for clarifying the clinical spectrum within this syndrome.
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Affiliation(s)
- H Oguni
- Department of Pediatrics, Tokyo Women's Medical College, Japan
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Abstract
OBJECTIVE To report clinical and EEG features in 5 adults with unusual, fast rhythmic discharges accompanying absence seizures. DESIGN AND METHODS The 5 patients presented with uncontrolled seizures. All had EEG-video monitoring with recorded seizures. Video seizures were reviewed and ictal as well as interictal epileptiform activity was analyzed. The patients were followed up after appropriate therapy for a minimum of 6 months. RESULTS There were 3 women and two men, with a mean age of 37 years (range: 23-59). Two patients had onset of absence seizures in childhood, one in adolescence and two after age 20. All patients also had generalized tonic-clonic seizures. Ictal EEG recordings showed generalized spike and wave (SW) discharges of variable dominant frequencies (2.5-6 Hz) and intermingled 10-15 Hz generalized rhythmic discharges which also occurred in isolation or as the dominant activity. Interictal recordings showed similar but shorter 2.5-6 Hz generalized SW discharges. The background activity was normal in 3 patients and mildly slow in two who had very frequent absence seizures during the recording period. Four patients became seizure free and one had 75% improvement on appropriate antiabsence therapy. CONCLUSIONS The fast 10-15 Hz rhythmic discharges that we report appear to occur mostly in adult patients with absence, as well as, generalized tonic-clonic seizures. They can occur in isolation or be embedded in more typical SW discharges accompanying typical absence seizures. Their presence does not imply a poor prognosis for seizure control.
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Affiliation(s)
- T Fakhoury
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
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Aguglia U, Gambardella A, Le Piane E, Messina D, Russo C, Oliveri RL, Zappia M, Quattrone A. Idiopathic generalized epilepsies with versive or circling seizures. Acta Neurol Scand 1999; 99:219-24. [PMID: 10225351 DOI: 10.1111/j.1600-0404.1999.tb07350.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To describe the electroclinical features of the idiopathic generalized epilepsies (IGEs) with versive or circling seizures. METHODS Sixteen patients with versive or circling seizures and interictal electroclinical features of IGE were studied. Patients with insufficient clinical or imaging data, with a follow-up period less than 1 year or with partial seizures in addition to the versive or circling ones were excluded from the study. All patients underwent full interictal clinical and neurophysiological studies. The EEG patterns of 13 versive or circling seizures from 4 patients were also analyzed. RESULTS A specific IGE syndrome was recognized in 9 out of the 16 patients (56%). More specific, 1 patient had childhood absence epilepsy (CAE), 4 had juvenile absence epilepsy (JAE), and 4 had juvenile myoclonic epilepsy (JME). No specific IGE syndrome was recognizable in the remaining 7 patients (44%). These 7 patients had a juvenile epileptic syndrome (mean age at onset of seizures was 15.7 years) characterized by versive or circling seizures followed or not by generalized tonic-clonic fits. Three main EEG patterns were identified during versive or circling seizures: 1) generalized spike-and-wave discharges at 3-4 cps; 2) generalized polyspike-and-wave discharges at 1 to 2.5 cps beginning with generalized fast activity at 12-14 cps, and 3) generalized spike-and-wave discharges at 3-4 cps intermingled with fast activity at 12-14 cps. Most patients had good response to treatment on a single drug regimen (mainly valproic acid). CONCLUSIONS Versive or circling seizures may occur in the context of an IGE. Although many individuals share the features of different IGE syndromes including CAE, JAE and JME, a consistent number of patients, who show circling or versive seizures solely, remain without a specific syndromic diagnosis. When occurring in the context of IGE, circling or versive seizures do not worsen the prognosis.
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Affiliation(s)
- U Aguglia
- Institute of Neurology, School of Medicine, University of Catanzaro, Italy
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47
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Agathonikou A, Panayiotopoulos CP, Giannakodimos S, Koutroumanidis M. Typical absence status in adults: diagnostic and syndromic considerations. Epilepsia 1998; 39:1265-76. [PMID: 9860061 DOI: 10.1111/j.1528-1157.1998.tb01324.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To study the electroclinical features of typical absence status (TAS) in adults with syndromes of idiopathic generalized epilepsies (IGEs). METHODS Twenty-one patients with one or more spells of TAS were identified among 136 consecutive adult patients with IGEs. All patients with TAS had comprehensive electroclinical investigations and EEG or video-EEG recorded absences. RESULTS TAS occurred in 24.4% of 86 patients who had IGEs with typical absences alone or in combination with other seizures presisting in adult life. The prevalence of TAS appeared to be syndrome related, ranging from as high as 57.1% in perioral myoclonia with absences and 46.2% in "phantom" absences with GTCS to as low as 6.7% in juvenile myoclonic epilepsy. A varying degree of impairment of cognition was the cardinal clinical symptom shared in all TAS, but corresponding syndromes of IGE were often betrayed by other symptoms such as eyelid or perioral myoclonia. In phantom absences with GTCS, TAS was more numerous (p < or = 0.05) and more frequently the first overt seizure type (p = 0.006) than in any other IGE. Only in the syndrome of eyelid myoclonia with absences, TAS was always situation related, mainly as a result of antiepileptic drug discontinuation. CONCLUSIONS The clinical EEG semiology and prevalence of TAS appear to be syndrome related with the highest prevalence in the syndromes of perioral myoclonia with absences and phantom absences with GTCS (p = 0.0024).
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MESH Headings
- Adult
- Age Factors
- Anticonvulsants/therapeutic use
- Cognition Disorders/diagnosis
- Cognition Disorders/epidemiology
- Comorbidity
- Electroencephalography/statistics & numerical data
- Epilepsies, Myoclonic/classification
- Epilepsies, Myoclonic/diagnosis
- Epilepsies, Myoclonic/epidemiology
- Epilepsy, Absence/classification
- Epilepsy, Absence/diagnosis
- Epilepsy, Absence/epidemiology
- Epilepsy, Generalized/classification
- Epilepsy, Generalized/diagnosis
- Epilepsy, Generalized/epidemiology
- Humans
- London/epidemiology
- Monitoring, Physiologic
- Prevalence
- Syndrome
- Treatment Outcome
- Videotape Recording
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Affiliation(s)
- A Agathonikou
- Department of Clinical Neurophysiology and Epilepsies, St. Thomas' Hospital, London, England
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48
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Ferrie CD, Agathonikou A, Panayiotopoulos CP. Electroencephalography and video-electroencephalography in the classification of childhood epilepsy syndromes. J R Soc Med 1998; 91:251-9. [PMID: 9764078 PMCID: PMC1296700 DOI: 10.1177/014107689809100504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- C D Ferrie
- Department of Paediatric Neurology, Leeds General Infirmary, UK
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49
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Abstract
Rotatory seizures have been reported in association with focal intracranial lesions. This type of seizure was also described in patients with primary generalized epilepsies. To our knowledge, there is only one previous publication denoted an association between juvenile myoclonic epilepsy (JME) and rotatory seizures. We present two female patients with JME and rotatory seizures together. The onset of myoclonic jerks and generalized tonic clonic (GTC) seizures was in their midteens. Their interictal EEGs showed bilateral symmetric spike and polyspike wave discharges. The rotatory seizures of the patients started at age of 26 and 33 years, respectively. In one of the patients, turning to the left was followed by three or four complete turns, after then, she had GTC seizures. The other patient has turned to the right with only one or two turns and sometimes continued with GTC seizures. Neuroradiologic investigations including brain CT, MRI, and SPECT were performed. Response to valproate therapy of rotatory seizures was good. We believe that rotatory seizures are rarely seen in JME patients, and this causes false diagnosis which lead unsuitable drug choice.
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Affiliation(s)
- M A Topçuoğlu
- Department of Neurology, Hacettepe University Hospitals, Ankara, Turkey
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Panayiotopoulos CP, Koutroumanidis M, Giannakodimos S, Agathonikou A. Idiopathic generalised epilepsy in adults manifested by phantom absences, generalised tonic-clonic seizures, and frequent absence status. J Neurol Neurosurg Psychiatry 1997; 63:622-7. [PMID: 9408104 PMCID: PMC2169820 DOI: 10.1136/jnnp.63.5.622] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVES To describe the clinical and EEG features of adult patients with very mild absences, late onset generalised tonic clonic seizures, and frequent absence status. METHODS Patients were referrals to a clinic for epilepsies. They all had clinical assessment and EEG, video EEG, or both for documentation of absences. RESULTS Of 86 adults with idiopathic generalised epilepsies and EEG/video-EEG documented absences, 13 patients showed similar clinico-EEG features with: (a) "phantom absences" consisting of mild ictal impairment of cognition associated with brief (3-4 s), generalised 3-4 Hz spike/multiple spike and slow wave discharges; (b) infrequent, mainly late onset, generalised tonic clonic seizures, and (c), absence status which occurred in six of them either in isolation or terminating with generalised tonic clonic seizures. None of the patients had myoclonic jerks or photosensitivity. Two patients were father and daughter and another patient had a family history of infrequent generalised tonic clonic seizures. CONCLUSION It seems that this is an idiopathic generalised epilepsy syndrome in adults which has not been previously recognised.
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Affiliation(s)
- C P Panayiotopoulos
- Department of Clinical Neurophysiology and Epilepsies, St Thomas' Hospital, London, UK
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