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De Tiège X, Trotta N, Op de beeck M, Bourguignon M, Marty B, Wens V, Nonclercq A, Goldman S, Van Bogaert P. Neurophysiological activity underlying altered brain metabolism in epileptic encephalopathies with CSWS. Epilepsy Res 2013; 105:316-25. [DOI: 10.1016/j.eplepsyres.2013.02.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 01/03/2013] [Accepted: 02/27/2013] [Indexed: 11/28/2022]
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Matsumoto JY, Stead M, Kucewicz MT, Matsumoto AJ, Peters PA, Brinkmann BH, Danstrom JC, Goerss SJ, Marsh WR, Meyer FB, Worrell GA. Network oscillations modulate interictal epileptiform spike rate during human memory. ACTA ACUST UNITED AC 2013; 136:2444-56. [PMID: 23803305 DOI: 10.1093/brain/awt159] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Eleven patients being evaluated with intracranial electroencephalography for medically resistant temporal lobe epilepsy participated in a visual recognition memory task. Interictal epileptiform spikes were manually marked and their rate of occurrence compared between baseline and three 2 s periods spanning a 6 s viewing period. During successful, but not unsuccessful, encoding of the images there was a significant reduction in interictal epileptiform spike rate in the amygdala, hippocampus, and temporal cortex. During the earliest encoding period (0-2000 ms after image presentation) in these trials there was a widespread decrease in the power of theta, alpha and beta band local field potential oscillations that coincided with emergent focal gamma frequency activity. Interictal epileptiform spike rate correlated with spectral band power changes and broadband (4-150 Hz) desynchronization, which predicted significant reduction in interictal epileptiform spike rate. Spike-triggered averaging of the field potential power spectrum detected a burst of low frequency synchronization 200 ms before the interictal epileptiform spikes that arose during this period of encoding. We conclude that interictal epileptiform spikes are modulated by the patterns of network oscillatory activity that accompany human memory offering a new mechanistic insight into the interplay of cognitive processing, local field potential dynamics and interictal epileptiform spike generation.
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Affiliation(s)
- Joseph Y Matsumoto
- Mayo Systems Electrophysiology Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
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Abstract
Benign epilepsy with centrotemporal spikes, early-onset childhood occipital epilepsy (Panayiotopoulos syndrome [PS]) and late-onset childhood occipital epilepsy (Gastaut type [LOCE-G]) are the principal pediatric focal epilepsy syndromes. They share major common characteristics: the appearance and resolution of electroclinical features are age related, there is a strong genetic predisposition, the clinical course is often mild with infrequent and easy to control seizures, interictal epileptiform activity is disproportionately abundant when compared with the clinical correlate, and tends to potentiate and generalize during sleep. In this review, we outline the relevant pathophysiology underlying this electroclinical spectrum. Then, the initial description of individual syndromes is followed by a summary of overlapping features and intermediate presentations that question the boundaries between these entities and provide the basis for the concept of a childhood seizure susceptibility syndrome. Additionally, we outline the main features of the related epileptic encephalopathies. An outlook on potential future lines of research completes this review.
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Chavakula V, Sánchez Fernández I, Peters JM, Popli G, Bosl W, Rakhade S, Rotenberg A, Loddenkemper T. Automated quantification of spikes. Epilepsy Behav 2013; 26:143-52. [PMID: 23291250 DOI: 10.1016/j.yebeh.2012.11.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 11/16/2012] [Accepted: 11/23/2012] [Indexed: 11/18/2022]
Abstract
Methods for rapid and objective quantification of interictal spikes in raw, unprocessed electroencephalogram (EEG) samples are scarce. We evaluated the accuracy of a tailored automated spike quantification algorithm. The automated quantification was compared with the quantification by two board-certified clinical neurophysiologists (gold-standard) in five steps: 1) accuracy in a single EEG channel (5 EEG samples), 2) accuracy in multiple EEG channels and across different stages of the sleep-wake cycles (75 EEG samples), 3) capacity to detect lateralization of spikes (6 EEG samples), 4) accuracy after application of a machine-learning mechanism (11 EEG samples), and 5) accuracy during wakefulness only (8 EEG samples). Our method was accurate during all stages of the sleep-wake cycle and improved after the application of the machine-learning mechanism. Spikes were correctly lateralized in all cases. Our automated method was accurate in quantifying and detecting the lateralization of interictal spikes in raw unprocessed EEG samples.
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Fitzgerald Z, Thayer Z, Mohamed A, Miller LA. Examining factors related to accelerated long-term forgetting in epilepsy using ambulatory EEG monitoring. Epilepsia 2013; 54:819-27. [DOI: 10.1111/epi.12090] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Zoë Fitzgerald
- Department of Psychology; Macquarie University; Sydney; New South Wales; Australia
| | | | - Armin Mohamed
- Department of Neurosciences; Royal Prince Alfred Hospital; Sydney; New South Wales; Australia
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Cordelli DM, Garavelli L, Savasta S, Guerra A, Pellicciari A, Giordano L, Bonetti S, Cecconi I, Wischmeijer A, Seri M, Rosato S, Gelmini C, Della Giustina E, Ferrari AR, Zanotta N, Epifanio R, Grioni D, Malbora B, Mammi I, Mari F, Buoni S, Mostardini R, Grosso S, Pantaleoni C, Doz M, Poch-Olivé ML, Rivieri F, Sorge G, Simonte G, Licata F, Tarani L, Terazzi E, Mazzanti L, Cerruti Mainardi P, Boni A, Faravelli F, Grasso M, Bianchi P, Zollino M, Franzoni E. Epilepsy in Mowat-Wilson syndrome: delineation of the electroclinical phenotype. Am J Med Genet A 2013; 161A:273-84. [PMID: 23322667 DOI: 10.1002/ajmg.a.35717] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 09/20/2012] [Indexed: 12/26/2022]
Abstract
Mowat-Wilson syndrome (MWS) is a genetic disease caused by heterozygous mutations or deletions of the ZEB2 gene and is characterized by distinctive facial features, epilepsy, moderate to severe intellectual disability, corpus callosum abnormalities and other congenital malformations. Epilepsy is considered a main manifestation of the syndrome, with a prevalence of about 70-75%. In order to delineate the electroclinical phenotype of epilepsy in MWS, we investigated epilepsy onset and evolution, including seizure types, EEG features, and response to anti-epileptic therapies in 22 patients with genetically confirmed MWS. Onset of seizures occurred at a median age of 14.5 months (range: 1-108 months). The main seizure types were focal and atypical absence seizures. In all patients the first seizure was a focal seizure, often precipitated by fever. The semiology was variable, including hypomotor, versive, or focal clonic manifestations; frequency ranged from daily to sporadic. Focal seizures were more frequent during drowsiness and sleep. In 13 patients, atypical absence seizures appeared later in the course of the disease, usually after the age of 4 years. Epilepsy was usually quite difficult to treat: seizure freedom was achieved in nine out of the 20 treated patients. At epilepsy onset, the EEGs were normal or showed only mild slowing of background activity. During follow-up, irregular, diffuse frontally dominant and occasionally asymmetric spike and waves discharges were seen in most patients. Sleep markedly activated these abnormalities, resulting in continuous or near-to-continuous spike and wave activity during slow wave sleep. Slowing of background activity and poverty of physiological sleep features were seen in most patients. Our data suggest that a distinct electroclinical phenotype, characterized by focal and atypical absence seizures, often preceded by febrile seizures, and age-dependent EEG changes, can be recognized in most patients with MWS.
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Affiliation(s)
- Duccio Maria Cordelli
- Child Neurology and Psychiatry Unit, S Orsola Malpighi Hospital, University of Bologna, Bologna, Italy.
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Sand T, Breivik N, Herigstad A. EEG-utredning ved AD/HD. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 2013; 133:312-6. [DOI: 10.4045/tidsskr.12.0224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Sánchez Fernández I, Loddenkemper T, Peters JM, Kothare SV. Electrical status epilepticus in sleep: clinical presentation and pathophysiology. Pediatr Neurol 2012; 47:390-410. [PMID: 23127259 DOI: 10.1016/j.pediatrneurol.2012.06.016] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 06/20/2012] [Indexed: 10/27/2022]
Abstract
Electrical status epilepticus in sleep involves an electroencephalographic pattern where interictal epileptiform activity is potentiated in the transition from wakefulness to sleep. Near-continuous spikes and waves that occupy a significant proportion of nonrapid eye movement sleep appear as a result of sleep-potentiated epileptiform activity. This electroencephalographic pattern appears in different electroclinical syndromes that present three common characteristics with different degrees of severity: seizures, sleep-potentiated epileptiform activity, and neuropsychologic regression. Continuous spikes and waves during sleep comprise the severest epileptic encephalopathy in the electroclinical spectrum. Landau-Kleffner syndrome presents with intermediate severity. Some "benign" pediatric focal epileptic syndromes represent the mildest end of this continuum. Based on published data, we provide a framework for clinical and electrical events. The underlying mechanisms leading to sleep potentiation of epileptiform activity in electrical status epilepticus in sleep are incompletely understood. A genetic basis or acquired early developmental insult may disrupt the normal maturation of neuronal networks. These factors may dynamically alter normal processes of brain development, leading to an age-related pattern of electroclinical expression of electrical status epilepticus in sleep.
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Affiliation(s)
- Iván Sánchez Fernández
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Abstract
There is a substantial body of evidence that spontaneous recurrent seizures occur in a subset of patients with Alzheimer disease (AD), especially the familial forms that have an early onset. In transgenic mice that simulate these genetic forms of AD, seizures or reduced seizure threshold have also been reported. Mechanisms underlying the seizures or reduced seizure threshold in these mice are not yet clear and are likely to be complex, because the synthesis of amyloid β (Aβ) involves many peptides and proteases that influence excitability. Based on transgenic mouse models of AD where Aβ and its precursor are elevated, it has been suggested that seizures are caused by the downregulation of the Nav1.1 sodium channel in a subset of GABAergic interneurons, leading to a reduction in GABAergic inhibition. Another mechanism of hyperexcitability appears to involve tau, because deletion of tau reduces seizures in some of the same transgenic mouse models of AD. Therefore, altered excitability may be as much a characteristic of AD as plaques and tangles-especially for the familial forms of AD.
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Neves RSDC, de Souza Silva Tudesco I, Jardim AP, Caboclo LOSF, Lancellotti C, Ferrari-Marinho T, Hamad AP, Marinho M, Centeno RS, Cavalheiro EA, Scorza CA, Yacubian EMT. Granule cell dispersion is associated with memory impairment in right mesial temporal lobe epilepsy. Seizure 2012; 21:685-90. [DOI: 10.1016/j.seizure.2012.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 07/13/2012] [Accepted: 07/14/2012] [Indexed: 11/16/2022] Open
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Jaseja H, Jaseja B, Badaya S, Tonpay P. Treatment of interictal epileptiform discharges (IEDs) in patients with cerebral palsy for an improved prognostic outcome and quality of life: emerging evidence. Epilepsy Behav 2012; 25:473. [PMID: 23092695 DOI: 10.1016/j.yebeh.2012.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 08/11/2012] [Indexed: 02/08/2023]
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Epileptic encephalopathies in adults and childhood. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:205131. [PMID: 23056934 PMCID: PMC3465907 DOI: 10.1155/2012/205131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 03/28/2012] [Accepted: 06/10/2012] [Indexed: 02/02/2023]
Abstract
Epileptic encephalopathies are motor-mental retardations or cognitive disorders secondary to epileptic seizures or epileptiform activities. Encephalopaties due to brain damage, medications, or systemic diseases are generally not in the scope of this definition, but they may rarely accompany the condition. Appropriate differential diagnosis of epileptic seizures as well as subclinical electroencephalographic discharges are crucial for management of seizures and epileptiform discharges and relative regression of cognitive deterioration in long-term followup. Proper antiepileptic drug, hormonal treatment, or i.v. immunoglobulin choice play major role in prognosis. In this paper, we evaluated the current treatment approaches by reviewing clinical electrophysiological characteristics of epileptic encephalopathies.
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Epileptic Encephalopathies with Status Epilepticus during Sleep: New Techniques for Understanding Pathophysiology and Therapeutic Options. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:642725. [PMID: 22934163 PMCID: PMC3420558 DOI: 10.1155/2012/642725] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 07/09/2012] [Accepted: 07/09/2012] [Indexed: 11/17/2022]
Abstract
Encephalopathy with status epilepticus during sleep (ESES) is an epileptic encephalopathy, as defined by the International League Against Epilepsy (ILAE) Task Force on Classification and Terminology, that is, a condition in which the epileptic processes themselves are believed to contribute to the disturbance in cerebral function. Clinical manifestations of ESES are heterogeneous: apart from different seizure types, they consist in combinations of cognitive, motor, and behavioural disturbances associated with a peculiar electroencephalographic pattern of paroxysmal activity significantly activated during slow sleep, which culminates in a picture of continuous spikes and waves during sleep (CSWS). The pathophysiological mechanisms underlying this condition are still incompletely understood. Establishing a clear-cut correlation between EEG abnormalities and clinical data, though interesting, is very complex. Computer-assisted EEG analyses especially if combined with functional magnetic resonance imaging (EEG-fMRI) and metabolic neuroimaging have recently emerged as useful approaches to better understand the pathophysiological processes underlying ESES. Treatment of ESES is not just limited to seizures control but it should be focused on controlling neuropsychological outcome through an improvement of the continuous epileptiform activity. General agreement on treatment guidelines is still lacking. Implementation of new techniques might allow a better understanding of the pathophysiology of ESES and could enhance therapeutics options.
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166
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Badawy RAB, Johnson KA, Cook MJ, Harvey AS. A mechanistic appraisal of cognitive dysfunction in epilepsy. Neurosci Biobehav Rev 2012; 36:1885-96. [PMID: 22617705 DOI: 10.1016/j.neubiorev.2012.05.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 03/24/2012] [Accepted: 05/13/2012] [Indexed: 12/14/2022]
Abstract
A strong relationship between the clinical characteristics of epilepsy and the nature of cognitive impairments associated with the condition has been found, but the nature of this relationship appears to be quite complex and not well understood. This review presents a summary of the research on the interaction between cognition and epilepsy, surveyed from a mechanistic perspective with the aim of clarifying factors that contribute to the co-existence of both disorders. The physiological basis underpinning cognitive processing is first reviewed. The physiology of epilepsy is reviewed, with emphasis placed on interictal discharges and seizures. The nature of the impact of epilepsy on cognition is described, with transient and prolonged effects distinguished. Finally, the complexity of the co-morbidity between cognitive dysfunction and epilepsy is discussed in relation to childhood and adult-onset epilepsy syndromes and severe epileptic encephalopathies. Structural and functional abnormalities exist in patients with epilepsy that may underpin both the cognitive dysfunction and epilepsy, highlighting the complexity of the association. Research, possibly of a longitudinal nature, is needed to elucidate this multifactorial relationship between cognitive dysfunction and epilepsy.
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Affiliation(s)
- Radwa A B Badawy
- Department of Clinical Neurosciences, St. Vincent's Hospital, Melbourne, Victoria, Australia; Department of Medicine, Melbourne, Victoria, Australia; Electrical and Electronic Engineering, Melbourne, Victoria, Australia. ,
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167
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Fernández IS, Peters JM, Hadjiloizou S, Prabhu SP, Zarowski M, Stannard KM, Takeoka M, Rotenberg A, Kothare SV, Loddenkemper T. Clinical staging and electroencephalographic evolution of continuous spikes and waves during sleep. Epilepsia 2012; 53:1185-95. [PMID: 22578248 DOI: 10.1111/j.1528-1167.2012.03507.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE Currently, in continuous spikes and waves during sleep (CSWS) there is a lack of systematic assessments of the clinically relevant stages and the evolution of the electroencephalographic features. The aim of this study is to describe the evolution over time of clinical and electroencephalographic features in CSWS. METHODS We enrolled patients from our video-electroencephalography (EEG) monitoring unit with CSWS and with overnight EEG studies with at least one overnight assessment per year over a minimum period of 3 years. We studied clinical presentation and electroencephalographic features. We calculated the (1) spike-wave percentage (SWP) as the percentage of 1-s bins containing at least one spike-wave complex and (2) spike frequency (SF) as the number of spikes per 100 s. KEY FINDINGS Nine children (six boys) met the inclusion criteria during a 15-year period. Seven (78%) had an abnormal development prior to the epilepsy onset, and in two (22%) seizures were the only presenting symptom. Median age at epilepsy onset was 2 years (range 2 days to 4 years), at neuropsychological regression 5.1 years (4-7.7 years), and at seizure freedom 8.6 years (6.5-11.4 years). Median duration and range of clinically relevant stages were as follows: dormant stage (birth-epilepsy onset median 2 years, range 2 days-4 years), prodromal stage (epilepsy onset-neuropsychological regression 3.9 years, range 0.9-7.7 years), acute stage (neuropsychological regression-seizure freedom 2.9 years, range 2.1-6.6 years), and residual stage (after seizure freedom). Seven patients (78%) had a structural lesion on neuroimaging. At last follow-up (median 11.4 years, range 7.2-20.3 years), eight patients (89%) were receiving antiepileptic treatment, and all patients had residual neurocognitive deficits. During the acute stage, SWP was <85% in 13 (42%) of 31 assessments, and after seizure freedom, 3 of 5 patients (60%) had SWP >85%. Evolution of electroencephalographic patterns included increasing-decreasing, continuously elevated, and fluctuating patterns (33.3% each). There was good correlation between SWP and SF (Spearman correlation-coefficient = 0.942; p < 0.0001). SF, which can exceed 100%, reflected changes in electroencephalography pattern in more detail than SWP, which cannot exceed 100% and therefore has a ceiling effect. SIGNIFICANCE Our series systematically studied the age of occurrence of the significant clinical events. These may assist in defining clinical stages, which can provide a useful framework for future clinical trials in patients with CSWS. The severity of the epileptiform discharges on EEG did not always correlate with seizure frequency and severity; epileptiform discharges could be prominent after seizure freedom and fluctuated along the course of the disease. The values of SWP and SF correlated well, but SWP based on 1-s bins has the potential disadvantage of a ceiling effect.
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Affiliation(s)
- Iván Sánchez Fernández
- Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts 02115, USA
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168
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Larsson PG, Bakke KA, Bjørnæs H, Heminghyt E, Rytter E, Brager-Larsen L, Eriksson AS. The effect of levetiracetam on focal nocturnal epileptiform activity during sleep--a placebo-controlled double-blind cross-over study. Epilepsy Behav 2012; 24:44-8. [PMID: 22494796 DOI: 10.1016/j.yebeh.2012.02.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 01/28/2012] [Accepted: 02/27/2012] [Indexed: 10/28/2022]
Abstract
Electric Status Epilepticus during Sleep (ESES) occurs in children with and without epilepsy. It may be related to disturbances as autism spectrum disorder, attention-deficit hyperactivity disorder and acquired aphasia (Landau-Kleffner syndrome). Antiepileptic drug (AED) treatment has been reported in small studies without placebo control. This study was designed to assess AED effect in a placebo-controlled double-blind cross-over study. Levetiracetam (LEV) was chosen based on clinical evidence. Eighteen patients fulfilled the inclusion criteria. The mean spike index at baseline was 56, falling to a mean of 37 at the end of the LEV treatment period. Assessed with a 2-way ANOVA, there is a significant treatment effect (p<0.0002). To the best of our knowledge, this is the first placebo-controlled double-blind cross-over study for any AED in patients with ESES. The effect of LEV is comparable with its effect in treatment of epileptic seizures.
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169
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Sánchez Fernández I, Hadjiloizou S, Eksioglu Y, Peters JM, Takeoka M, Tas E, Abdelmoumen I, Rotenberg A, Kothare SV, Riviello JJ, Loddenkemper T. Short-term response of sleep-potentiated spiking to high-dose diazepam in electric status epilepticus during sleep. Pediatr Neurol 2012; 46:312-8. [PMID: 22520353 DOI: 10.1016/j.pediatrneurol.2012.02.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 02/14/2012] [Indexed: 11/29/2022]
Abstract
We describe the short-term effects of high-dose oral diazepam on sleep-potentiated epileptiform activity in patients with electric status epilepticus during sleep. We enrolled patients treated with high-dose oral bedtime diazepam from 2001-2009. We defined spike percentage as the percentage of 1-second bins containing at least one spike, and calculated it during three randomly selected 5-minute samples of wakefulness throughout the day and during the first 5 minutes of every hour of non-rapid eye movement sleep at night. In this study, patients were considered to demonstrate sleep-potentiated epileptiform activity when their spike percentage during sleep was increased by ≥50% compared with wakefulness. Twenty-nine children (18 boys) were included (median age, 7.4 years). Twenty-four hours after receiving high-dose diazepam, epileptiform activity was significantly reduced (76.7% at baseline vs 40.8% 24 hours after high-dose diazepam; Wilcoxon signed ranks test, Z = -4.287, P < 0.0001). Seven patients (24.1%) manifested mild, reversible side effects during the first 48 hours after diazepam administration. High-dose oral diazepam effectively and safely reduced epileptiform activity in patients with electric status epilepticus during sleep.
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Affiliation(s)
- Iván Sánchez Fernández
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts 02115, USA
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Pereira AM, Bruni O, Ferri R, Nunes ML. Sleep instability and cognitive status in drug-resistant epilepsies. Sleep Med 2012; 13:536-41. [DOI: 10.1016/j.sleep.2011.12.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 11/27/2011] [Accepted: 12/10/2011] [Indexed: 11/24/2022]
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Yang T, Luo C, Li Q, Guo Z, Liu L, Gong Q, Yao D, Zhou D. Altered resting-state connectivity during interictal generalized spike-wave discharges in drug-naïve childhood absence epilepsy. Hum Brain Mapp 2012; 34:1761-7. [PMID: 22431250 DOI: 10.1002/hbm.22025] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 11/17/2011] [Accepted: 11/29/2011] [Indexed: 02/05/2023] Open
Abstract
PURPOSE To investigate the intrinsic brain connections at the time of interictal generalized spike-wave discharges (GSWDs) to understand their mechanism of effect on brain function in untreated childhood absence epilepsy (CAE). METHODS The EEG-functional MRI (fMRI) was used to measure the resting state functional connectivity during interictal GSWDs in drug-naïve CAE, and three different brain networks-the default mode network (DMN), cognitive control network (CCN), and affective network (AN)-were investigated. RESULTS Cross-correlation functional connectivity analysis with priori seed revealed decreased functional connectivity within each of these three networks in the CAE patients during interictal GSWDS. It included precuneus-dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontal cortex (DMPFC), and inferior parietal lobule in the DMN; DLPFC-inferior frontal junction (IFJ), and pre-supplementary motor area (pre-SMA) subregions connectivity disruption in CCN; ACC-ventrolateral prefrontal cortex (VLPFC) and DMPFC in AN; There were also some regions, primarily the parahippcampus, paracentral in AN, and the left frontal mid orb in the CCN, which showed increased connectivity. CONCLUSIONS The current findings demonstrate significant alterations of resting-state networks in drug naïve CAE subjects during interictal GSWDs and interictal GSWDs can cause dysfunction in specific networks important for psychosocial function. Impairment of these networks may cause deficits both during and between seizures. Our study may contribute to the understanding of neuro-pathophysiological mechanism of psychosocial function impairments in patients with CAE.
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Affiliation(s)
- Tianhua Yang
- Department of Neurology, West China Hospital, Si Chuan University, Cheng du, Sichuan, People's Republic of China
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172
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Bender AC, Morse RP, Scott RC, Holmes GL, Lenck-Santini PP. SCN1A mutations in Dravet syndrome: impact of interneuron dysfunction on neural networks and cognitive outcome. Epilepsy Behav 2012; 23:177-86. [PMID: 22341965 PMCID: PMC3307886 DOI: 10.1016/j.yebeh.2011.11.022] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 11/26/2011] [Accepted: 11/27/2011] [Indexed: 12/22/2022]
Abstract
Dravet syndrome (DS) is a childhood disorder associated with loss-of-function mutations in SCN1A and is characterized by frequent seizures and severe cognitive impairment. Animal studies have revealed new insights into the mechanisms by which mutations in this gene, encoding the type I voltage-gated sodium channel (Na(v)1.1), may lead to seizure activity and cognitive dysfunction. In this review, we further consider the function of fast-spiking GABAergic neurons, one cell type particularly affected by these mutations, in the context of the temporal coordination of neural activity subserving cognitive functions. We hypothesize that disruptions in GABAergic firing may directly contribute to the poor cognitive outcomes in children with DS, and discuss the therapeutic implications of this possibility.
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Affiliation(s)
- Alex C Bender
- Department of Neurology, Neuroscience Center at Dartmouth, Dartmouth Medical School, Hanover, NH 03756, USA.
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Bruni O, Novelli L, Mallucci A, Corte MD, Romeo A, Ferri R. Benign Rolandic and Occipital Epilepsies of Childhood. Sleep Med Clin 2012. [DOI: 10.1016/j.jsmc.2011.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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175
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Wisniewski I, Wendling AS, Manning L, Steinhoff BJ. Visuo-spatial memory tests in right temporal lobe epilepsy foci: clinical validity. Epilepsy Behav 2012; 23:254-60. [PMID: 22341968 DOI: 10.1016/j.yebeh.2011.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 11/09/2011] [Accepted: 12/13/2011] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To examine the appropriateness of visual memory tests as an identification method for right mesial temporal lobe dysfunctions in an epilepsy patient group and to study the relationship and possible overlap with non-memory cognitive domains and demographic variables. METHODS Eighty preoperative candidates with mesial temporal lobe epilepsy (TLE) were examined using the "Corsi Block-Tapping Test", "Diagnosticum für Cerebralschädigung" (DCS), the path subtest of the "Verbaler und Visueller Merkfähigkeitstest" (VVM), and the Rey-Osterrieth Complex Figure Test (ROCF). Factorial analyses were performed on raw scores to determine the effect of epilepsy-related variables, interictal epileptiform discharges (IEDs) and presence of cortical dysgenesis, on visual and verbal memory parameters. Sensitivity, specificity and Receiver Operating Characteristic (ROC) curves were calculated based on normative data. Furthermore, Spearman correlations between memory and non-memory cognitive tasks were performed. RESULTS The scores for test sensitivity and specificity and the ROC curves illustrate the tests' poor capacity to lateralize the functional deficit zone even when epilepsy-related factors, such as cortical dysgenesis or presence of contralateral IEDs were controlled. Significant correlations were found between the visual memory measures and nonverbal reasoning, processing speed, attentional flexibility, and visual planning. CONCLUSION These neuropsychological tests are not sensitive enough to lateralize the epileptogenic focus in temporal lobe epilepsy patients since in addition to learning and consolidation processes, they measure additional cognitive domains. These results have implications for clinical neuropsychologists, in terms of test choice and the interpretation in the context of presurgical diagnostics.
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176
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Zhu PJ, Huang W, Kalikulov D, Yoo JW, Placzek AN, Stoica L, Zhou H, Bell JC, Friedlander MJ, Krnjević K, Noebels JL, Costa-Mattioli M. Suppression of PKR promotes network excitability and enhanced cognition by interferon-γ-mediated disinhibition. Cell 2012; 147:1384-96. [PMID: 22153080 DOI: 10.1016/j.cell.2011.11.029] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 09/06/2011] [Accepted: 11/02/2011] [Indexed: 01/20/2023]
Abstract
The double-stranded RNA-activated protein kinase (PKR) was originally identified as a sensor of virus infection, but its function in the brain remains unknown. Here, we report that the lack of PKR enhances learning and memory in several behavioral tasks while increasing network excitability. In addition, loss of PKR increases the late phase of long-lasting synaptic potentiation (L-LTP) in hippocampal slices. These effects are caused by an interferon-γ (IFN-γ)-mediated selective reduction in GABAergic synaptic action. Together, our results reveal that PKR finely tunes the network activity that must be maintained while storing a given episode during learning. Because PKR activity is altered in several neurological disorders, this kinase presents a promising new target for the treatment of cognitive dysfunction. As a first step in this direction, we show that a selective PKR inhibitor replicates the Pkr(-/-) phenotype in WT mice, enhancing long-term memory storage and L-LTP.
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Affiliation(s)
- Ping Jun Zhu
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
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177
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Parisi P, Verrotti A, Paolino MC, Castaldo R, Ianniello F, Ferretti A, Chiarelli F, Villa MP. "Electro-clinical syndromes" with onset in paediatric age: the highlights of the clinical-EEG, genetic and therapeutic advances. Ital J Pediatr 2011; 37:58. [PMID: 22182677 PMCID: PMC3267655 DOI: 10.1186/1824-7288-37-58] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 12/19/2011] [Indexed: 12/13/2022] Open
Abstract
The genetic causes underlying epilepsy remain largely unknown, and the impact of available genetic data on the nosology of epilepsy is still limited. Thus, at present, classification of epileptic disorders should be mainly based on electroclinical features. Electro-clinical syndrome is a term used to identify a group of clinical entities showing a cluster of electro-clinical characteristics, with signs and symptoms that together define a distinctive, recognizable, clinical disorder. These often become the focus of treatment trials as well as of genetic, neuropsychological, and neuroimaging investigations. They are distinctive disorders identifiable on the basis of a typical age onset, specific EEG characteristics, seizure types, and often other features which, when taken together, permit a specific diagnosis which, in turn, often has implications for treatment, management, and prognosis. Each electro-clinical syndrome can be classified according to age at onset, cognitive and developmental antecedents and consequences, motor and sensory examinations, EEG features, provoking or triggering factors, and patterns of seizure occurrence with respect to sleep. Therefore, according to the age at onset, here we review the more frequently observed paediatric electro-clinical syndrome from their clinical-EEG, genetic and therapeutic point of views.
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Affiliation(s)
- Pasquale Parisi
- NESMOS Department, Chair of Pediatrics, Child Neurology, Faculty of Medicine and Psychology, Sapienza University, Via di Grottarossa, 1035-1039, Rome,00189, Italy.
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178
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Feldwisch-Drentrup H, Ihle M, Quyen MLV, Teixeira C, Dourado A, Timmer J, Sales F, Navarro V, Schulze-Bonhage A, Schelter B. Anticipating the unobserved: prediction of subclinical seizures. Epilepsy Behav 2011; 22 Suppl 1:S119-26. [PMID: 22078512 DOI: 10.1016/j.yebeh.2011.08.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 08/23/2011] [Indexed: 11/26/2022]
Abstract
Subclinical seizures (SCS) have rarely been considered in the diagnosis and therapy of epilepsy and have not been systematically analyzed in studies on seizure prediction. Here, we investigate whether predictions of subclinical seizures are feasible and how their occurrence may affect the performance of prediction algorithms. Using the European database of long-term recordings of surface and invasive electroencephalography data, we analyzed the data from 21 patients with SCS, including in total 413 clinically manifest seizures (CS) and 3341 SCS. Based on the mean phase coherence we investigated the predictive performance of CS and SCS. The two types of seizures had similar prediction sensitivities. Significant performance was found considerably more often for SCS than for CS, especially for patients with invasive recordings. When analyzing false alarms triggered by predicting CS, a significant number of these false predictions were followed by SCS for 9 of 21 patients. Although currently observed prediction performance may not be deemed sufficient for clinical applications for the majority of the patients, it can be concluded that the prediction of SCS is feasible on a similar level as for CS and allows a prediction of more of the seizures impairing patients, possibly also reducing the number of false alarms that were in fact correct predictions of CS. This article is part of a Supplemental Special Issue entitled The Future of Automated Seizure Detection and Prediction.
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179
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Atkins M, Nikanorova M. A prospective study of levetiracetam efficacy in epileptic syndromes with continuous spikes-waves during slow sleep. Seizure 2011; 20:635-9. [DOI: 10.1016/j.seizure.2011.06.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 05/19/2011] [Accepted: 06/15/2011] [Indexed: 11/17/2022] Open
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Sarco DP, Boyer K, Lundy-Krigbaum SM, Takeoka M, Jensen F, Gregas M, Waber DP. Benign rolandic epileptiform discharges are associated with mood and behavior problems. Epilepsy Behav 2011; 22:298-303. [PMID: 21862414 PMCID: PMC5030107 DOI: 10.1016/j.yebeh.2011.06.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 06/14/2011] [Accepted: 06/16/2011] [Indexed: 11/23/2022]
Abstract
Children with benign rolandic epilepsy (BRE) experience elevated rates of cognitive, behavioral, and affective problems. Frequent epileptiform spike discharges may impair behavioral functioning. To elucidate this relationship, we evaluated associations between the EEG spike frequency index (SI) and parental ratings of psychosocial adjustment and executive functioning in school-aged children with EEGs typical of BRE. Twenty-one children (6-12 years) participated. Parents completed validated questionnaires at a median of 5 months (range: 1-8) after a routine outpatient EEG. The EEG SI was calculated for wakefulness and sleep. The strength of association between the SI and behavioral variables was evaluated by simple and multivariate correlation. Higher awake and sleep SIs were associated with more symptoms of depression (P<0.001), aggression and conduct problems (P<0.01). Higher sleep SI was associated with executive dysfunction and anxiety (P<0.05). Symptoms of hyperactivity and inattention had no correlation. Increased epileptiform activity in children with BRE may predict higher rates of mood and behavioral problems.
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Affiliation(s)
- Dean P. Sarco
- Department of Neurology, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA, USA
- Department of Neurology, Children’s Hospital Boston, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Katrina Boyer
- Department of Neurology, Children’s Hospital Boston, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Children’s Hospital Boston, Boston, MA, USA
| | - Shannon M. Lundy-Krigbaum
- Department of Neurology, Children’s Hospital Boston, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Children’s Hospital Boston, Boston, MA, USA
| | - Masanori Takeoka
- Department of Neurology, Children’s Hospital Boston, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Frances Jensen
- Department of Neurology, Children’s Hospital Boston, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Matt Gregas
- Department of Neurology, Children’s Hospital Boston, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Deborah P. Waber
- Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Children’s Hospital Boston, Boston, MA, USA
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181
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Impaired slow wave sleep downscaling in encephalopathy with status epilepticus during sleep (ESES). Clin Neurophysiol 2011; 122:1779-87. [DOI: 10.1016/j.clinph.2011.01.053] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 12/08/2010] [Accepted: 01/11/2011] [Indexed: 11/22/2022]
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182
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Pediatric epileptology. Epilepsy Behav 2011; 22:32-7. [PMID: 21530413 DOI: 10.1016/j.yebeh.2011.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 02/10/2011] [Indexed: 11/22/2022]
Abstract
Challenges facing children with epilepsy are understanding the neurobiology of pharmacoresistance of epileptic encephalopathies and the development of effective surgical treatment options for those with "non-lesional" epilepsy. Although, understanding the genetics of childhood epilepsy has advanced, an effective treatment intervention has not occurred. Recently, understanding the neurobiology of hamartin and tuberin in the development of epilepsy and cognitive impairment associated with tuberous sclerosis complex allowed the development of sirolimus and everolimus to be used in human clinical trials. In spite of these breakthroughs a large number of children are likely to be outside the scope of interventional therapies. For such patients the burden of seizures is onerous and psycho-social consequences debilitating. Surgical resective options are often limited by the lack of a well defined epileptic lesion. Co-registered synthesis of advanced functional, structural and electrographic seizure onset allows identification of a focus in patients thought to have "non-lesional" epilepsy. Developments of a Pipeline for prospective data sharing are likely to increase understanding and validation of the epileptogenic zone and offer the hope of seizure freedom. Two outstanding young investigators provide a review of their exciting research and its implications in pediatric epilepsy.
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183
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Hippocampal-dependent spatial memory in the water maze is preserved in an experimental model of temporal lobe epilepsy in rats. PLoS One 2011; 6:e22372. [PMID: 21829459 PMCID: PMC3144225 DOI: 10.1371/journal.pone.0022372] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 06/27/2011] [Indexed: 02/06/2023] Open
Abstract
Cognitive impairment is a major concern in temporal lobe epilepsy (TLE). While different experimental models have been used to characterize TLE-related cognitive deficits, little is known on whether a particular deficit is more associated with the underlying brain injuries than with the epileptic condition per se. Here, we look at the relationship between the pattern of brain damage and spatial memory deficits in two chronic models of TLE (lithium-pilocarpine, LIP and kainic acid, KA) from two different rat strains (Wistar and Sprague-Dawley) using the Morris water maze and the elevated plus maze in combination with MRI imaging and post-morten neuronal immunostaining. We found fundamental differences between LIP- and KA-treated epileptic rats regarding spatial memory deficits and anxiety. LIP-treated animals from both strains showed significant impairment in the acquisition and retention of spatial memory, and were unable to learn a cued version of the task. In contrast, KA-treated rats were differently affected. Sprague-Dawley KA-treated rats learned less efficiently than Wistar KA-treated animals, which performed similar to control rats in the acquisition and in a probe trial testing for spatial memory. Different anxiety levels and the extension of brain lesions affecting the hippocampus and the amydgala concur with spatial memory deficits observed in epileptic rats. Hence, our results suggest that hippocampal-dependent spatial memory is not necessarily affected in TLE and that comorbidity between spatial deficits and anxiety is more related with the underlying brain lesions than with the epileptic condition per se.
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184
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Continuous spike and waves during sleep and electrical status epilepticus in sleep. J Clin Neurophysiol 2011; 28:154-64. [PMID: 21399511 DOI: 10.1097/wnp.0b013e31821213eb] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Continuous spike and waves during sleep is an age-related epileptic encephalopathy that presents with neurocognitive regression, seizures, and an EEG pattern of electrical status epilepticus during sleep. Patients usually present around 5 years of age with infrequent nocturnal unilateral motor seizures that progress within 1 to 2 years to a severe epileptic encephalopathy with frequent seizures of different types, marked neurocognitive regression, and an almost continuous spike-wave EEG pattern during slow-wave sleep. The pathophysiology of continuous spike and waves during sleep is not completely understood, but the corticothalamic neuronal network involved in physiologic oscillating patterns of sleep is thought to be switched into a pathologic discharging mode. Early developmental injury and/or genetic predisposition may play a role in the potentiation of age-related hyperexcitability in the immature brain. A better understanding of the mechanisms leading to electrical status epilepticus during sleep may provide additional therapeutic targets that can improve the outcome of seizures, EEG pattern, and cognitive development in patients with continuous spike and waves during sleep.
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185
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Millichap JG, Millichap JJ, Stack CV. Utility of the electroencephalogram in attention deficit hyperactivity disorder. Clin EEG Neurosci 2011; 42:180-4. [PMID: 21870470 DOI: 10.1177/155005941104200307] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An electroencephalogram (EEG) has not been routinely utilized in the evaluation of children with attention deficit hyperactivity disorder (ADHD). The utility of the EEG in ADHD is unclear. A recent study in our laboratory using sleep and sleep deprivation routinely found one in four non-epileptic children evaluated for attention deficit disorder has epileptiform discharges in the EEG, more than half focal. The majority of abnormalities (97.5%) occur in sleep and sleep-deprived records compared to 7% in prior wake only records. A review of eight publications showed that laboratories using awake only as routine EEG recordings report a relatively low prevalence of epileptiform discharges, whereas the higher prevalence of epileptiform discharges is seen in those with more prolonged sleep recordings. We have determined that sleep deprivation and sleep are essential to rule out an abnormal EEG in attention deficit disorder. In patients with attention deficit disorder complicated by epilepsy, stimulant therapy is generally safe, provided seizures are controlled by antiepileptic medication. Patients with epilepsy or subclinical electrographic abnormalities not treated with anticonvulsants are at increased risk of seizures when stimulant therapy is introduced, especially extended-release methylphenidate. Apart from an increase in risk of seizures and need for caution in use of stimulants, studies show that epileptiform discharges in the electroencephalogram are linked to a better response of attention deficit to methylphenidate and a higher cognitive performance. Transient cognitive impairment related to subclinical electrographic abnormalities responds to antiepileptic medication. An EEG is important in selected cases of attention deficit disorder and is useful in choice of medication, especially in children with lack of awareness and transient cognitive impairment.
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Affiliation(s)
- J Gordon Millichap
- Division of Neurology, Epilepsy Center, Children's Memorial Hospital, Northwestern University Medical School, Chicago, IL 60614, USA.
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186
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Numis AL, Major P, Montenegro MA, Muzykewicz DA, Pulsifer MB, Thiele EA. Identification of risk factors for autism spectrum disorders in tuberous sclerosis complex. Neurology 2011; 76:981-7. [PMID: 21403110 DOI: 10.1212/wnl.0b013e3182104347] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE The purpose of this study was to assess the prevalence of and to identify epidemiologic, genetic, electrophysiologic, and neuroanatomic risk factors for autism spectrum disorders (ASD) in a cohort of patients with tuberous sclerosis complex (TSC). METHODS A total of 103 patients with TSC were evaluated for ASD. A retrospective review of patients' records was performed, including mutational analysis. EEG reports were analyzed for the presence of ictal and interictal epileptiform features. Brain MRI scans were evaluated for TSC neuropathology, including tuber burden. RESULTS Of the 103 patients with TSC, 40%were diagnosed with an ASD. On univariate analysis, patients with ASD were less likely to have mutations in the TSC1 gene. Patients with ASD also had an earlier age at seizure onset and more frequent seizures. On EEG, those with ASD had a significantly greater amount of interictal epileptiform features in the left temporal lobe only. On MRI, there were no differences in the regional distribution of tuber burden, although those with TSC2 and ASD had a higher prevalence of cyst-like tubers. CONCLUSIONS The development of ASD in TSC is not well understood. Given our findings, ASD may be associated with persistent seizure activity early in development in particular brain regions, such as those responsible for social perception and communication in the left temporal lobe. The presence of cyst-like tubers on MRI could provide a structural basis or marker for ASD pathology in TSC, although studies assessing their effect on cortical function are needed.
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Affiliation(s)
- A L Numis
- Department of Neurology, Massachusetts General Hospital, Boston, USA
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187
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Kulandaivel K, Holmes GL. Power spectral analysis in infants with seizures: relationship to development. Epilepsy Behav 2011; 20:700-5. [PMID: 21439912 DOI: 10.1016/j.yebeh.2011.02.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 02/12/2011] [Accepted: 02/15/2011] [Indexed: 11/26/2022]
Abstract
There is increasing evidence that there is a strong relationship between brain oscillations and neurocognitive function. We used EEG power spectral analysis to determine if frequency and power provide an independent measure of developmental impairment in infants. We examined the spectral power of EEGs in 200 infants between 6 and 24 months of age who were evaluated for seizures. Infants were stratified into three age groups 6-12, 12-18, and 18-24 months, and development assessments were coded as normal, moderately delayed, and severely delayed. Compared with the normal infants, children with developmental delay had lower mean frequencies and greater delta and less theta and alpha power. Delta/theta and theta/alpha ratios were highly significant indicators of developmental status. This study demonstrates that frequency and power of brain oscillations during wakefulness is a strong predictor of development in infants. The findings support the concept that normal oscillatory activity is critical for normal cognitive function during development.
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Affiliation(s)
- Kandan Kulandaivel
- Department of Neurology, Neuroscience Center at Dartmouth, Dartmouth Medical School, Hanover, NH 03756, USA
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188
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Abstract
Eclampsia is defined in the obstetrical literature as the occurrence of unexplained seizure during pregnancy in a woman with preeclampsia. In the Western world, the incidence of eclampsia is ~1 per 2000 to 1 per 3000 pregnancies, but the incidence is 10-fold higher in tertiary referral centers and undeveloped countries where there is poor prenatal care, and in multi-fetal gestations. Nearly 1 in 50 women with eclampsia die as do 1 in 14 of their offspring, and mortality rates are considerably higher in undeveloped countries. Eclampsia is also associated with significant life-threatening complications, including neurological events. Seizure acutely can cause stroke, haemorrhage, oedema and brain herniation and thus lead to epilepsy and cognitive impairment later in life.
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189
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Isaev D, Zhao Q, Kleen JK, Lenck-Santini PP, Adstamongkonkul D, Isaeva E, Holmes GL. Neuroaminidase reduces interictal spikes in a rat temporal lobe epilepsy model. Epilepsia 2011; 52:e12-5. [PMID: 21366554 DOI: 10.1111/j.1528-1167.2011.02988.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Interictal spikes have been implicated in epileptogenesis and cognitive dysfunction in epilepsy. Unfortunately, antiepileptic drugs have shown poor efficacy in suppressing interictal discharges; novel therapies are needed. Surface charge on neuronal membranes provides a novel target for abolishing interictal spikes. This property can be modulated through the use of neuraminidase, an enzyme that decreases the amount of negatively charged sialic acid. In the present report we determined whether applying neuraminidase to brains of rats with a history of status epilepticus would reduce number of interictal discharges. Following pilocarpine-induced status epilepticus, rats received intrahippocampal injections of neuraminidase, which significantly decreased the number of interictal spikes recorded in the CA1 region. This study provides evidence that sialic acid degradation can reduce the number of interictal spikes. Furthermore, the results suggest that modifying surface charge created by negatively charged sialic acid may provide new opportunities for reducing aberrant epileptiform events in epilepsy.
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Affiliation(s)
- Dmytro Isaev
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev, Ukraine
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190
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Abstract
INTRODUCTION Learning Disorders (LD) are defined as disorders that interfere with academic performance or with daily activities that require reading, writing or mathematical skills in subjects with a normal intelligence quotient (IQ). The prevalence of LD in the general population has been found to be 2-10%, and reading disorders are the most frequent subtype. Epilepsy is one of the most common serious neurological disorders in childhood. LD are more common in children with epilepsy than in the general population. As a consequence, the risk of cognitive impairment in children with epilepsy is high, and a review of the literature needs to be fully presented. METHODS Narrative review including articles regarding LD in children with various epileptic syndromes published in the international medical literature. RESULTS LD are more frequent among children with epilepsy. The etiology is multifactorial, being affected by the type of epileptic syndrome, the age of onset and the antiepileptic treatment being selected. LD can be either permanent or state-dependent. Each category has different treatment protocols and prognosis. CONCLUSIONS Despite the fact that the findings of the studies discussed in our article support the evidence that epilepsy in childhood impairs the cognitive function, we should not underestimate the role of demographic and psychosocial factors on academic performance of children with epilepsy. Despite the high prevalence of LD, a healthy family and school environment can help reduce its impact on the patient's quality of life.
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191
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Chan S, Baldeweg T, Cross JH. A role for sleep disruption in cognitive impairment in children with epilepsy. Epilepsy Behav 2011; 20:435-40. [PMID: 21310668 DOI: 10.1016/j.yebeh.2010.12.047] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 12/27/2010] [Accepted: 12/28/2010] [Indexed: 12/01/2022]
Abstract
Early-onset epilepsy is associated with a poor cognitive outcome, with the cumulative burden of both ictal and interictal epileptiform discharges likely to contribute significantly. Memory consolidation has been shown to occur during sleep in healthy children, with an associated electroencephalographic signature. This may be disrupted in children with epilepsy, who exhibit a high incidence of sleep disorders, whether directly related to their seizures or as a comorbidity. Conversely, seizure semiology may be influenced by sleep. In this review we present clinical and experimental evidence that suggests that the disruption of sleep architecture by epileptiform discharges may be an important factor contributing to cognitive impairment in children with epilepsy.
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Affiliation(s)
- S Chan
- Neurosciences Unit, UCL Institute of Child Health, London, UK
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192
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Tramoni E, Felician O, Barbeau EJ, Guedj E, Guye M, Bartolomei F, Ceccaldi M. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy. Brain 2011; 134:816-31. [DOI: 10.1093/brain/awr002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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193
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Hughes JR. A review of the relationships between Landau-Kleffner syndrome, electrical status epilepticus during sleep, and continuous spike-waves during sleep. Epilepsy Behav 2011; 20:247-53. [PMID: 21242107 DOI: 10.1016/j.yebeh.2010.10.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 10/14/2010] [Accepted: 10/14/2010] [Indexed: 11/16/2022]
Abstract
The goal of this report is to review the relationships between Landau-Kleffner syndrome (LKS), electrical status epilepticus during sleep (ESES), and continuous spike-waves during sleep (CSWS). LKS is a clinical syndrome involving mainly acquired aphasia and sometimes seizures. Other clinical findings include cognitive impairments and global regression of behavior. The EEG may evolve from more benign conditions into ESES (or CSWS), seen in 50% of patients with LKS, or may also show focal findings. Seizures include atypical absence, generalized tonic-clonic, atonic, and partial motor attacks. Effective medications are discussed. The EEG patterns CSWS and ESES are likely equivalent terms. CSWS is used by some authors, and ESES by others. Patients with these patterns usually show mental retardation, seizures, and global regression. More benign EEG patterns, like focal discharges, may develop into these more severe generalized patterns, which are associated with atypical absences, negative myoclonus, and cognitive disturbances. Memory disorders are common, because the nearly continuous generalized discharges in sleep do not allow for the memory consolidation that also occurs during sleep. Medications and possible etiologies are discussed.
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Affiliation(s)
- John R Hughes
- Department of Neurology, University of Illinois Medical Center at Chicago, Chicago, IL 60612, USA.
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194
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McAuley JW, Elliott JO, Patankar S, Hart S, Long L, Moore JL, Shneker BF. Comparing patients' and practitioners' views on epilepsy concerns: a call to address memory concerns. Epilepsy Behav 2010; 19:580-3. [PMID: 20889386 DOI: 10.1016/j.yebeh.2010.09.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 08/30/2010] [Accepted: 09/03/2010] [Indexed: 10/19/2022]
Abstract
The objective was to compare practitioners' impressions of patients' concerns with those expressed by the patients themselves. Prior to clinical interaction, adult patients with epilepsy and their established practitioners were asked to choose their top five concerns via a modified version of the Epilepsy Foundation Concerns Index. Patients with epilepsy (n=257) with varying degrees of seizure control from the outpatient clinic practices of five prescribing practitioners completed the modified concerns index. The three most frequent concerns reported by patients were having a seizure unexpectedly, issues related to driving, and memory problems. These were similar to those reported by the practitioners, though memory was much less of a concern expressed by the practitioner. For the paired data, the concern with the largest gap from the patients' perspective was "your memory." Though there was an overlap, patients were concerned more about life issues and practitioners were concerned about clinical issues. This should serve as a major "wakeup call" to address memory problems in patients with epilepsy, regardless of seizure control.
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Affiliation(s)
- James W McAuley
- College of Pharmacy, Ohio State University, Columbus, OH 43210, USA.
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195
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Parisi P, Spalice A, Nicita F, Papetti L, Ursitti F, Verrotti A, Iannetti P, Villa MP. "Epileptic encephalopathy" of infancy and childhood: electro-clinical pictures and recent understandings. Curr Neuropharmacol 2010; 8:409-21. [PMID: 21629447 PMCID: PMC3080596 DOI: 10.2174/157015910793358196] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 03/31/2010] [Accepted: 04/08/2010] [Indexed: 12/04/2022] Open
Abstract
There is growing interest in the diagnosis of cognitive impairment among children with epilepsy. It is well known that status of seizures control has to be carefully investigated because it can be sufficient "per se" to cause progressive mental deterioration conditions. Subclinical electroencephalographic discharges may have subtle effects on cognition, learning and sleep patterns, even in the absence of clinical or sub-clinical seizures. In this respect, electroencephalographic monitoring (long-term and nocturnal recording) and in particular an all night video-polysomnography (V-NPSG) record can be crucial to detect the presence of unrecognized seizures and/or an inter-ictal nocturnal EEG discharge increasing. Epileptic encephalopathies (EE) are a group of conditions in which the higher cognitive functions are deteriorate as a consequence of epileptic activity, which, in fact, consists of frequent seizures and/or florid and prolonged interictal paroxysmal discharges, focal or generalized. AEDs represent the first line in opposing the burden of both, the poor seizures control and the poor interictal discharges control, in the cognitive deterioration of EE affected children. Thus, to improve the long-term cognitive/behavioural prognosis in these refractory epileptic children, it should be taken into account both a good seizures control and a strict sleep control, choosing carefully antiepileptic drugs which are able to control not only seizures clinically recognizable but even the EEG discharges onset and its increasing and spreading during sleep. Here, we review the efficacy and safety of the newer AEDs that, to date, are used in the treatment of EE in infancy and childhood.
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Affiliation(s)
- Pasquale Parisi
- Child Neurology, Headache Paediatric Center, Paediatric Sleep Centre, II Faculty of Medicine, “Sapienza University” c/o Sant’Andrea Hospital, Rome, Italy
| | - Alberto Spalice
- Child Neurology, Paediatric Department, I Faculty of Medicine, “Sapienza University” c/o Policlinico Umberto I, Rome, Italy
| | - Francesco Nicita
- Child Neurology, Paediatric Department, I Faculty of Medicine, “Sapienza University” c/o Policlinico Umberto I, Rome, Italy
| | - Laura Papetti
- Child Neurology, Paediatric Department, I Faculty of Medicine, “Sapienza University” c/o Policlinico Umberto I, Rome, Italy
| | - Fabiana Ursitti
- Child Neurology, Paediatric Department, I Faculty of Medicine, “Sapienza University” c/o Policlinico Umberto I, Rome, Italy
| | - Alberto Verrotti
- Child Neurology, Pediatric Department, University of Chieti, Italy
| | - Paola Iannetti
- Child Neurology, Paediatric Department, I Faculty of Medicine, “Sapienza University” c/o Policlinico Umberto I, Rome, Italy
| | - Maria Pia Villa
- Child Neurology, Headache Paediatric Center, Paediatric Sleep Centre, II Faculty of Medicine, “Sapienza University” c/o Sant’Andrea Hospital, Rome, Italy
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196
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Interictal epileptiform discharges in persons without a history of seizures: what do they mean? J Clin Neurophysiol 2010; 27:229-38. [PMID: 20634716 DOI: 10.1097/wnp.0b013e3181ea42a4] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Interictal epileptiform discharge (IED) is rarely observed in healthy volunteers without a history of seizures, but higher rates of occurrence are reported in children than in adults. Higher rates are also observed among neurologic inpatients and outpatients without a seizure history, but the risk of subsequent unprovoked seizures or epilepsy is low in healthy volunteers and patients. An exception is the patients with autism spectrum disorders, attention deficit/hyperactivity disorder, or cerebral palsy, who are predisposed to epilepsy development. However, it is currently unclear whether epilepsy risk is higher for patients with incidentally detected IED than for the patients without IED. Hospitalized patients with IED but no prior seizures often have underlying acute or progressive brain disorders. Although they have increased risk of acute seizures, the risk for subsequent unprovoked seizures or epilepsy is unknown and requires assessment on an individual basis. For patients who have psychogenic spells but no seizure history, the rate of IED detection is low, similar to that of healthy volunteers. The association between IED and transitory cognitive impairment has not been established in nonepileptic persons. Evidence thus far does not suggest that routine EEG screening of pilot candidates reduces risk of flight-related accidents.
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197
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Arc regulates spine morphology and maintains network stability in vivo. Proc Natl Acad Sci U S A 2010; 107:18173-8. [PMID: 20921410 DOI: 10.1073/pnas.1006546107] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Long-term memory relies on modulation of synaptic connections in response to experience. This plasticity involves trafficking of AMPA receptors (AMPAR) and alteration of spine morphology. Arc, a gene induced by synaptic activity, mediates the endocytosis of AMPA receptors and is required for both long-term and homeostatic plasticity. We found that Arc increases spine density and regulates spine morphology by increasing the proportion of thin spines. Furthermore, Arc specifically reduces surface GluR1 internalization at thin spines, and Arc mutants that fail to facilitate AMPAR endocytosis do not increase the proportion of thin spines, suggesting that Arc-mediated AMPAR endocytosis facilitates alterations in spine morphology. Thus, by linking spine morphology with AMPAR endocytosis, Arc balances synaptic downscaling with increased structural plasticity. Supporting this, loss of Arc in vivo leads to a significant decrease in the proportion of thin spines and an epileptic-like network hyperexcitability.
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198
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Fisher RS, Engel JJ. Definition of the postictal state: when does it start and end? Epilepsy Behav 2010; 19:100-4. [PMID: 20692877 DOI: 10.1016/j.yebeh.2010.06.038] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 06/17/2010] [Indexed: 11/19/2022]
Abstract
The postictal state is the abnormal condition occurring between the end of an epileptic seizure and return to baseline condition. Applying this definition operationally can be difficult, especially for complex partial seizures, where cognitive and sensorimotor impairments merge imperceptibly into the postictal state. Many patients are unaware of even having had a seizure. Electroencephalography sometimes helps to distinguish ictal from postictal periods, but may demonstrate focal slowing both during and after a seizure. Epileptiform electroencephalographic changes do not always correspond precisely to behavioral changes, especially with scalp recordings. The postictal state ends at the interictal state, but this too can be ambiguous. Interictal spikes and spike-waves can be associated with cognitive and behavioral impairments, suggesting that they may represent fragments of ictal episodes. Except where boundaries are clear, it is better to describe a sequence of behaviors and electroencephalographic changes, without labeling arbitrary stages as being ictal or postictal.
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Affiliation(s)
- Robert S Fisher
- Department of Neurology and Neurological Science, Stanford University School of Medicine, Stanford, CA 94305-5235, USA.
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199
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Khan OI, Zhao Q, Miller F, Holmes GL. Interictal spikes in developing rats cause long-standing cognitive deficits. Neurobiol Dis 2010; 39:362-71. [PMID: 20452427 PMCID: PMC2910186 DOI: 10.1016/j.nbd.2010.05.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2010] [Revised: 04/04/2010] [Accepted: 05/01/2010] [Indexed: 10/19/2022] Open
Abstract
Frequent interictal spikes are a common finding in the electroencephalograms of children with epileptic encephalopathies. While it is well recognized that interictal spikes are a biological marker of seizures and can lead to transitory cognitive impairment, whether interictal spikes can result in long-standing adverse effects on learning and memory in children is not known. Here we investigated the consequences of interictal spikes in rat pups without seizures on long-term learning and memory. Rat pups were given a low dose of flurothyl for 4h for 10 days during continuous electroencephalographic monitoring. Rats developed interictal spikes without seizures while age-matched controls under similar testing conditions had few interictal spikes. When rats were tested as adults, there was impairment in reference memory in the probe test of the Morris water maze, reference memory impairment in the four-trial radial-arm water maze and impaired long-term potentiation. Early-life interictal spikes resulted in impaired new cell formation and decreased cell counts in the hippocampus but did not cause an increase in apoptosis. This study, for the first time demonstrates that interictal spikes in rat pups without seizures can result in long-standing spatial cognitive impairment. Our findings suggest that suppressing IIS may be as important as treating seizures during brain development.
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Affiliation(s)
- Omar I Khan
- Department of Neurology, Neuroscience Center at Dartmouth, Dartmouth Medical School, Hanover, New Hampshire 03756, USA
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200
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Siniatchkin M, Groening K, Moehring J, Moeller F, Boor R, Brodbeck V, Michel CM, Rodionov R, Lemieux L, Stephani U. Neuronal networks in children with continuous spikes and waves during slow sleep. Brain 2010; 133:2798-813. [DOI: 10.1093/brain/awq183] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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