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Samuel F Berkovic - One of the best experts on this subject based on the ideXlab platform.
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why do seizures in Generalized Epilepsy often occur in the morning
Neurology, 2009Co-Authors: Radwa A B Badawy, Richard A L Macdonell, Graeme D Jackson, Samuel F BerkovicAbstract:Objective: We used transcranial magnetic stimulation to investigate the effect of diurnal variability on cortical excitability in patients with Epilepsy. Methods: Thirty drug-naive patients with Epilepsy (20 idiopathic Generalized Epilepsy [IGE], including 10 juvenile myoclonic Epilepsy [JME], and 10 focal Epilepsy) and 10 control subjects without Epilepsy were studied both early in the morning and late in the afternoon. We measured the mean motor thresholds and constructed recovery curves at short (2–15 msec) and long (50–400 msec) interstimulus intervals. Results: An increase in cortical excitability indicated by decreased short and long intracortical inhibition was observed early in the morning compared to the afternoon in patients with JME. In other IGE syndromes, there was decreased long intracortical inhibition only. No effect was found in subjects with focal Epilepsy or controls without Epilepsy. Conclusion: Cortical excitability measured by transcranial magnetic stimulation increases early in the morning in patients with idiopathic Generalized Epilepsy, particularly in juvenile myoclonic Epilepsy, but not in subjects with focal Epilepsy or controls without Epilepsy. This may explain the increased seizure susceptibility in this cohort at this time of day.
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Generalized Epilepsy in hypothalamic hamartoma evolution and postoperative resolution
Neurology, 2003Co-Authors: Jeremy L Freeman, A S Harvey, Jeffrey V Rosenfeld, J A Wrennall, C A Bailey, Samuel F BerkovicAbstract:Objective: To better understand the epileptogenesis of symptomatic Generalized Epilepsy in patients with hypothalamic hamartoma and intractable Epilepsy, many of whom experience remission of Generalized seizures and slow spike-wave discharges following surgery. Methods: The authors documented the evolution of symptomatic Generalized Epilepsy in 12 of 20 children who underwent transcallosal microsurgical hypothalamic hamartoma resection. In seven patients they recorded intraoperative EEG from the hamartoma and simultaneously from the scalp and frontal cortex before, during, and after resection. Results: Gelastic seizures began on average at 6 months of age (range birth to 3 years); tonic seizures began at 6 years (range 2 months to 9 years). Normal EEG were reported in early childhood; thereafter, abnormalities were progressive. Interictal spike-wave was recorded intraoperatively over the scalp and cortex in six patients, but not from the hypothalamic hamartoma. Hamartoma resection had no immediate effect on cortical spike-wave, but waking spike-wave was absent in seven patients on subsequent postoperative EEG. Tonic seizures ceased in 11 of 12 patients, but 6 of these had postoperative Generalized seizures that resolved over 1 to 6 months. Conclusion: Gelastic seizures in hypothalamic hamartoma arise from the hamartoma itself; the interictal spike-wave does not. The evolution of EEG abnormalities, the development of Generalized seizures years after onset of gelastic seizures, and the postoperative running down of interictal spike-wave and Generalized seizures in these patients may reflect secondary epileptogenesis.
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Generalized Epilepsy with febrile seizures plus mutation of the sodium channel subunit scn1b
Neurology, 2002Co-Authors: Robyn H Wallace, Ingrid E Scheffer, Samuel F Berkovic, G Parasivam, Scott A Barnett, Geoffrey Wallace, G R Sutherland, J C MulleyAbstract:Generalized Epilepsy with febrile seizures plus (GEFS(+)) is an important childhood genetic Epilepsy syndrome with heterogeneous phenotypes, including febrile seizures (FS) and Generalized epilepsies of variable severity. Forty unrelated GEFS(+) and FS patients were screened for mutations in the sodium channel beta-subunits SCN1B and SCN2B, and the second GEFS(+) family with an SCN1B mutation is described here. The family had 19 affected individuals: 16 with typical GEFS(+) phenotypes and three with other Epilepsy phenotypes. Site-specific mutation within SCN1B remains a rare cause of GEFS(+), and the authors found no evidence to implicate SCN2B in this syndrome.
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Generalized Epilepsy with febrile seizures plus: A common childhood‐onset genetic Epilepsy syndrome
Annals of Neurology, 2001Co-Authors: Rita Singh, Kathryn M. Crossland, Ingrid E Scheffer, Samuel F BerkovicAbstract:We examined the phenotypic variation and clinical genetics in nine families with Generalized Epilepsy with febrile seizures plus (GEFS+). This genetic Epilepsy syndrome with heterogeneous phenotypes was hitherto described in only one family. We obtained genealogical information on 799 individuals and conducted detailed evaluation of 272 individuals. Ninety-one individuals had a history of seizures and 63 had Epilepsy consistent with the GEFS+ syndrome. Epilepsy phenotypes were febrile seizures (FS) in 31, febrile seizures plus (FS+) in 15, FS+ with other seizure types (atonic, myoclonic, absence, or complex partial) in 8, and myoclonic–astatic Epilepsy in 9 individuals. Inheritance was autosomal dominant with approximately 60% penetrance. This study confirms and expands the spectrum of GEFS+ and provides new insights into the phenotypic relationships and genetics of FS and the Generalized epilepsies of childhood. Moreover, the ability to identify large families with this newly recognized common, childhood-onset, Generalized genetic Epilepsy syndrome suggests that it should be a prime target for attempts to identify genes relevant to FS and Generalized Epilepsy. Ann Neurol 1999;45:75–81
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A New Locus for Generalized Epilepsy with Febrile Seizures Plus Maps to Chromosome 2
American journal of human genetics, 2000Co-Authors: I. Lopes-cendes, Ingrid E Scheffer, Samuel F Berkovic, Marylène Rousseau, Eva Andermann, Guy A. RouleauAbstract:Generalized Epilepsy with febrile seizures plus (GEFS+) is a recently recognized but relatively common form of inherited childhood-onset Epilepsy with heterogeneous Epilepsy phenotypes. We genotyped 41 family members, including 21 affected individuals, to localize the gene causing Epilepsy in a large family segregating an autosomal dominant form of GEFS+. A genomewide search examining 197 markers identified linkage of GEFS+ to chromosome 2, on the basis of an initial positive LOD score for marker D2S294 (Z=4.4, recombination fraction [θ] = 0). A total of 24 markers were tested on chromosome 2q, to define the smallest candidate region for GEFS+. The highest two-point LOD score (Zmax=5.29; θ=0) was obtained with marker D2S324. Critical recombination events mapped the GEFS+ gene to a 29-cM region flanked by markers D2S156 and D2S311, with the idiopathic Generalized Epilepsy locus thereby assigned to chromosome 2q23-q31. The existence of the heterogeneous Epilepsy phenotypes in this kindred suggests that seizure predisposition determined by the GEFS+ gene on chromosome 2q could be modified by other genes and/or by environmental factors, to produce the different seizure types observed.
Wendyl Dsouza - One of the best experts on this subject based on the ideXlab platform.
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Generalized polyspike train an eeg biomarker of drug resistant idiopathic Generalized Epilepsy
Neurology, 2018Co-Authors: Udaya Seneviratne, Yanping Sun, Piero Perucca, Zhibin Chen, Meng Kee Tan, Terence J Obrien, Wendyl DsouzaAbstract:Objective To identify clinical and EEG biomarkers of drug resistance in adults with idiopathic Generalized Epilepsy. Methods We conducted a case-control study consisting of a discovery cohort and a replication cohort independently assessed at 2 different centers. In each center, patients with the idiopathic Generalized Epilepsy phenotype and Generalized spike-wave discharges on EEG were classified as drug-resistant or drug-responsive. EEG changes were classified into predefined patterns and compared between the 2 groups in the discovery cohort. Factors associated with drug resistance in multivariable analysis were tested in the replication cohort. Results The discovery cohort included 85 patients (29% drug-resistant and 71% drug-responsive). Their median age at assessment was 32 years and 50.6% were female. Multivariable analysis showed that higher number of seizure types ever experienced (3 vs 1: odds ratio [OR] = 31.1, 95% confidence interval [CI]: 4.5–214, p Conclusion Generalized polyspike train during sleep may be an EEG biomarker for drug resistance in adults with idiopathic Generalized Epilepsy.
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electroencephalography in the diagnosis of genetic Generalized Epilepsy syndromes
Frontiers in Neurology, 2017Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Genetic Generalized Epilepsy (GGE) consists of several syndromes diagnosed and classified on the basis of clinical and electroencephalographic (EEG) features. The EEG signature of GGE is bisynchronous, symmetric and Generalized spike-wave complex. Other typical EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, eye-closure sensitivity, fixation-off sensitivity and photoparoxysmal response. However, admixed with typical changes, atypical epileptiform discharges are also commonly seen in GGE. There are circadian variations of Generalized epileptiform discharges. Activation procedures such as sleep, sleep deprivation, hyperventilation, intermittent photic stimulation, eye closure and fixation-off are useful techniques to increase the yield of EEG abnormalities. Specific triggers such as pattern stimulation and cognitive tasks are useful in eliciting reflex seizure-related EEG abnormalities in selected patients. Distinct electrographic abnormalities to help classification can be identified among different electroclinical syndromes.
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the prognosis of idiopathic Generalized Epilepsy
Epilepsia, 2012Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Summary Prognosis describes the trajectory and long-term outcome of a condition. Most studies indicate a better prognosis in idiopathic Generalized Epilepsy (IGE) in comparison with other Epilepsy syndromes. Studies looking at the long-term outcome of different IGE syndromes are relatively scant. Childhood absence Epilepsy appears to have a higher rate of remission compared to juvenile absence Epilepsy. In absence epilepsies, development of myoclonus and Generalized tonic–clonic seizures predicts lower likelihood of remission. Although most patients with juvenile myoclonic Epilepsy (JME) achieve remission on antiepileptic drug therapy, <20% appear to remain in remission without treatment. Data on the prognosis of other IGE syndromes are scarce. There are contradictory findings reported on the value of electroencephalography as a predictor of prognosis. Comparisons are made difficult by study heterogeneity, particularly in methodology and diagnostic criteria.
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the electroencephalogram of idiopathic Generalized Epilepsy
Epilepsia, 2012Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Idiopathic Generalized Epilepsy (IGE) is classified into several subsyndromes based on clinical and electroencephalography (EEG) features. The EEG signature of IGE is bisynchronous, symmetric, and Generalized spike-wave complex; although focal, irregular, and so called "fragments" of discharges are not uncommon. Other characteristic EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, and photoparoxysmal response. Both human and animal data suggest involvement of the thalamus and the cortex in the generation of spike-wave discharges in IGE. Circadian variations of Generalized epileptiform discharges are well described, and these can be useful in diagnostic confirmation. Those discharges tend to occur more often after awakening and during cyclic alternating pattern phase-A of non-rapid eye movement sleep. Activation procedures such as hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are useful techniques to increase the yield of both interictal and ictal EEG abnormalities. Although not in routine use, specific triggers such as pattern stimulation and cognitive tasks may also be of value in eliciting rare reflex seizure-related EEG abnormalities. Variations of EEG abnormalities are evident between different electroclinical syndromes. EEG is also affected by certain external as well as internal factors, which should be borne in mind when interpreting EEG studies in IGE.
Ingrid E Scheffer - One of the best experts on this subject based on the ideXlab platform.
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Childhood-onset Generalized Epilepsy in Bainbridge-Ropers syndrome
Epilepsy research, 2018Co-Authors: Kenneth A. Myers, Susan M. White, Shehla Mohammed, Kay Metcalfe, Andrew E. Fry, Elisabeth Wraige, Pradeep C. Vasudevan, Meena Balasubramanian, Ingrid E SchefferAbstract:Bainbridge-Ropers syndrome is a genetic syndrome caused by heterozygous loss-of-function pathogenic variants in ASXL3, which encodes a protein involved in transcriptional regulation. Affected individuals have multiple abnormalities including developmental impairment, hypotonia and characteristic facial features. Seizures are reported in approximately a third of cases; however, the epileptology has not been thoroughly studied. We identified three patients with pathogenic ASXL3 variants and seizures at Austin Health and in the DECIPHER database. These three patients had novel de novo ASXL3 pathogenic variants, two with truncation variants and one with a splice site variant. All three had childhood-onset Generalized Epilepsy with Generalized tonic-clonic seizures, with one also having atypical absence seizures. We also reviewed available clinical data on five published patients with Bainbridge-Ropers syndrome and seizures. Of the five previously published patients, three also had Generalized tonic-clonic seizures, one of whom also had possible absence seizures; a fourth patient had absence seizures and possible focal seizures. EEG typically showed features consistent with Generalized Epilepsy including Generalized spike-wave, photoparoxysmal response, and occipital intermittent rhythmic epileptiform activity. Bainbridge-Ropers syndrome is associated with childhood-onset Generalized Epilepsy with Generalized tonic-clonic seizures and/or atypical absence seizures.
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Generalized Epilepsy with febrile seizures plus and classical idiopathic Generalized Epilepsy
2010Co-Authors: Yuehua Zhang, Ingrid E SchefferAbstract:The idiopathic Generalized epilepsies (IGE) comprise two major groups: the classical IGE and Generalized Epilepsy with febrile seizures plus (GEFS+). The classical IGE syndromes include childhood absence Epilepsy; juvenile absence Epilepsy; juvenile myoclonic Epilepsy; and Epilepsy with Generalized tonic-clonic seizures alone. GEFS+ is a familial Epilepsy syndrome, characterized by a spectrum of phenotypes. The phenotypes of GEFS+ include febrile seizures (FS), febrile seizures plus (FS+), FS/ FS+ and absences, myoclonic, atonic or partial seizures, myoclonic-astatic Epilepsy and severe myoclonic Epilepsy of infancy. Our study of 121 individuals in 20 families, where 84 had previously recognized GEFS+ phenotypes, expands the phenotypic spectrum of GEFS+ syndrome to include afebrile Generalized tonic-clonic seizures with Generalized spike wave or normal EEG in the absence of FS. To date, there are three ion channel genes (SCN1A, SCN1B and GABRG2) confi rmed as having a role in GEFS+, but none has been implicated in the majority of patients with GEFS+ phenotypes, such as those found in small families. Indeed it is likely that in most families, GEFS+ is a polygenic disorder resulting from the cumulative effect of a number of genes of lesser effect rather than the genes so far characterized in the few large families ascertained. Small GEFS+ families and bilineal inheritance in some add support for complex inheritance in a signifi cant proportion of families. The phenotypes of classical IGE occur in some GEFS+ families. The percentage of classical IGE phenotypes is 9% (11/121) of affected individuals in our study. This suggests that classical IGE phenotypes and GEFS+ phenotypes overlap in some GEFS+ families. Our study provides new insights into the inter-relationship of GEFS+ and classical IGE, where shared genetic determinants probably account for the overlap of these syndromes in some families.
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Generalized Epilepsy with febrile seizures plus mutation of the sodium channel subunit scn1b
Neurology, 2002Co-Authors: Robyn H Wallace, Ingrid E Scheffer, Samuel F Berkovic, G Parasivam, Scott A Barnett, Geoffrey Wallace, G R Sutherland, J C MulleyAbstract:Generalized Epilepsy with febrile seizures plus (GEFS(+)) is an important childhood genetic Epilepsy syndrome with heterogeneous phenotypes, including febrile seizures (FS) and Generalized epilepsies of variable severity. Forty unrelated GEFS(+) and FS patients were screened for mutations in the sodium channel beta-subunits SCN1B and SCN2B, and the second GEFS(+) family with an SCN1B mutation is described here. The family had 19 affected individuals: 16 with typical GEFS(+) phenotypes and three with other Epilepsy phenotypes. Site-specific mutation within SCN1B remains a rare cause of GEFS(+), and the authors found no evidence to implicate SCN2B in this syndrome.
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Generalized Epilepsy with febrile seizures plus: A common childhood‐onset genetic Epilepsy syndrome
Annals of Neurology, 2001Co-Authors: Rita Singh, Kathryn M. Crossland, Ingrid E Scheffer, Samuel F BerkovicAbstract:We examined the phenotypic variation and clinical genetics in nine families with Generalized Epilepsy with febrile seizures plus (GEFS+). This genetic Epilepsy syndrome with heterogeneous phenotypes was hitherto described in only one family. We obtained genealogical information on 799 individuals and conducted detailed evaluation of 272 individuals. Ninety-one individuals had a history of seizures and 63 had Epilepsy consistent with the GEFS+ syndrome. Epilepsy phenotypes were febrile seizures (FS) in 31, febrile seizures plus (FS+) in 15, FS+ with other seizure types (atonic, myoclonic, absence, or complex partial) in 8, and myoclonic–astatic Epilepsy in 9 individuals. Inheritance was autosomal dominant with approximately 60% penetrance. This study confirms and expands the spectrum of GEFS+ and provides new insights into the phenotypic relationships and genetics of FS and the Generalized epilepsies of childhood. Moreover, the ability to identify large families with this newly recognized common, childhood-onset, Generalized genetic Epilepsy syndrome suggests that it should be a prime target for attempts to identify genes relevant to FS and Generalized Epilepsy. Ann Neurol 1999;45:75–81
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A New Locus for Generalized Epilepsy with Febrile Seizures Plus Maps to Chromosome 2
American journal of human genetics, 2000Co-Authors: I. Lopes-cendes, Ingrid E Scheffer, Samuel F Berkovic, Marylène Rousseau, Eva Andermann, Guy A. RouleauAbstract:Generalized Epilepsy with febrile seizures plus (GEFS+) is a recently recognized but relatively common form of inherited childhood-onset Epilepsy with heterogeneous Epilepsy phenotypes. We genotyped 41 family members, including 21 affected individuals, to localize the gene causing Epilepsy in a large family segregating an autosomal dominant form of GEFS+. A genomewide search examining 197 markers identified linkage of GEFS+ to chromosome 2, on the basis of an initial positive LOD score for marker D2S294 (Z=4.4, recombination fraction [θ] = 0). A total of 24 markers were tested on chromosome 2q, to define the smallest candidate region for GEFS+. The highest two-point LOD score (Zmax=5.29; θ=0) was obtained with marker D2S324. Critical recombination events mapped the GEFS+ gene to a 29-cM region flanked by markers D2S156 and D2S311, with the idiopathic Generalized Epilepsy locus thereby assigned to chromosome 2q23-q31. The existence of the heterogeneous Epilepsy phenotypes in this kindred suggests that seizure predisposition determined by the GEFS+ gene on chromosome 2q could be modified by other genes and/or by environmental factors, to produce the different seizure types observed.
Christopher Skidmore - One of the best experts on this subject based on the ideXlab platform.
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Lacosamide use in refractory idiopathic primary Generalized Epilepsy.
Epilepsy & behavior : E&B, 2011Co-Authors: Andro Zangaladze, Christopher SkidmoreAbstract:Treatment of refractory idiopathic primary Generalized Epilepsy can be very challenging, with limited drug options, especially in young women of childbearing age. Here we describe the cases of two young women with refractory idiopathic primary Generalized Epilepsy refractory to multiple antiepileptic drugs in monotherapy or combination before achieving a long-term remission with adjunctive lacosamide (LCS) treatment. Larger, randomized prospective studies are necessary to establish the effectiveness of lacosamide in these patients.
Udaya Seneviratne - One of the best experts on this subject based on the ideXlab platform.
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Generalized polyspike train an eeg biomarker of drug resistant idiopathic Generalized Epilepsy
Neurology, 2018Co-Authors: Udaya Seneviratne, Yanping Sun, Piero Perucca, Zhibin Chen, Meng Kee Tan, Terence J Obrien, Wendyl DsouzaAbstract:Objective To identify clinical and EEG biomarkers of drug resistance in adults with idiopathic Generalized Epilepsy. Methods We conducted a case-control study consisting of a discovery cohort and a replication cohort independently assessed at 2 different centers. In each center, patients with the idiopathic Generalized Epilepsy phenotype and Generalized spike-wave discharges on EEG were classified as drug-resistant or drug-responsive. EEG changes were classified into predefined patterns and compared between the 2 groups in the discovery cohort. Factors associated with drug resistance in multivariable analysis were tested in the replication cohort. Results The discovery cohort included 85 patients (29% drug-resistant and 71% drug-responsive). Their median age at assessment was 32 years and 50.6% were female. Multivariable analysis showed that higher number of seizure types ever experienced (3 vs 1: odds ratio [OR] = 31.1, 95% confidence interval [CI]: 4.5–214, p Conclusion Generalized polyspike train during sleep may be an EEG biomarker for drug resistance in adults with idiopathic Generalized Epilepsy.
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electroencephalography in the diagnosis of genetic Generalized Epilepsy syndromes
Frontiers in Neurology, 2017Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DsouzaAbstract:Genetic Generalized Epilepsy (GGE) consists of several syndromes diagnosed and classified on the basis of clinical and electroencephalographic (EEG) features. The EEG signature of GGE is bisynchronous, symmetric and Generalized spike-wave complex. Other typical EEG features include polyspikes, polyspike-wave discharges, occipital intermittent rhythmic delta activity, eye-closure sensitivity, fixation-off sensitivity and photoparoxysmal response. However, admixed with typical changes, atypical epileptiform discharges are also commonly seen in GGE. There are circadian variations of Generalized epileptiform discharges. Activation procedures such as sleep, sleep deprivation, hyperventilation, intermittent photic stimulation, eye closure and fixation-off are useful techniques to increase the yield of EEG abnormalities. Specific triggers such as pattern stimulation and cognitive tasks are useful in eliciting reflex seizure-related EEG abnormalities in selected patients. Distinct electrographic abnormalities to help classification can be identified among different electroclinical syndromes.
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Can EEG Differentiate Among Syndromes in Genetic Generalized Epilepsy
Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society, 2017Co-Authors: Udaya Seneviratne, Graham Hepworth, Mark J. Cook, Wendyl D'souzaAbstract:PURPOSE To evaluate EEG differences among syndromes in genetic Generalized Epilepsy based on quantified data. METHODS Twenty-four-hour ambulatory EEGs were recorded in consecutive patients diagnosed with genetic Generalized Epilepsy. All epileptiform EEG abnormalities were quantified into density scores (total duration of epileptiform discharges per hour). One-way analysis of variance was conducted to find out differences in EEG density scores among the syndromes. Generalized linear mixed models were also fitted to explore the association between the proportion of "pure" Generalized spike-wave paroxysms and fragments (without intervening polyspikes/polyspike-waves) and the syndromes. RESULTS In total, 6,923 epileptiform discharges were analyzed from 105 abnormal EEGs. In the analysis of variance, six EEG variables were significantly different among syndromes: total spike density (P = 0.001), total polyspike and polyspike-wave density (P = 0.049), Generalized spike-wave-only density (P < 0.001), Generalized paroxysm density (P < 0.001), Generalized paroxysm duration mean (P = 0.018), and Generalized paroxysm duration maximum (P = 0.009). The density of epileptiform discharges and the paroxysm durations were the highest in juvenile absence Epilepsy followed by juvenile myoclonic Epilepsy, childhood absence Epilepsy, and Generalized Epilepsy with tonic-clonic seizures only. Generalized linear mixed models revealed that "pure" Generalized spike-wave discharges (without intervening polyspikes/polyspike waves) tended to be more frequent in absence epilepsies, although the difference was not statistically significant (P = 0.21). CONCLUSIONS The findings of this study suggest that the density and duration of epileptiform discharges can help differentiate among genetic Generalized Epilepsy syndromes.
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Electroencephalography in the Diagnosis of Genetic Generalized Epilepsy Syndromes
Frontiers Media S.A., 2017Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl Jude D’souzaAbstract:Genetic Generalized Epilepsy (GGE) consists of several syndromes diagnosed and classified on the basis of clinical features and electroencephalographic (EEG) abnormalities. The main EEG feature of GGE is bilateral, synchronous, symmetric, and Generalized spike-wave complex. Other classic EEG abnormalities are polyspikes, epileptiform K-complexes and sleep spindles, polyspike-wave discharges, occipital intermittent rhythmic delta activity, eye-closure sensitivity, fixation-off sensitivity, and photoparoxysmal response. However, admixed with typical changes, atypical epileptiform discharges are also commonly seen in GGE. There are circadian variations of Generalized epileptiform discharges. Sleep, sleep deprivation, hyperventilation, intermittent photic stimulation, eye closure, and fixation-off are often used as activation techniques to increase the diagnostic yield of EEG recordings. Reflex seizure-related EEG abnormalities can be elicited by the use of triggers such as cognitive tasks and pattern stimulation during the EEG recording in selected patients. Distinct electrographic abnormalities to help classification can be identified among different electroclinical syndromes
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epileptiform k complexes and sleep spindles an underreported phenomenon in genetic Generalized Epilepsy
Journal of Clinical Neurophysiology, 2016Co-Authors: Udaya Seneviratne, Mark J. Cook, Wendyl DʼsouzaAbstract:Purpose: To study the frequency of epileptiform K-complexes and sleep spindles as well as clinical variables influencing those abnormalities. Methods: We prospectively performed 24-hour ambulatory EEGs in a cohort of patients with genetic Generalized Epilepsy diagnosed and classified according to the International League against Epilepsy criteria. Overlapping of epileptiform discharges with K-complexes and sleep spindles was defined as epileptiform K-complexes and epileptiform sleep spindles. The presence of epileptiform K-complexes and sleep spindles was tabulated for each patient, and frequencies were calculated. We performed multiple regression analysis to study the influence of clinical predictors on the occurrence of epileptiform K-complexes and sleep spindles. The predictor variables tested in the model were seizure-free duration, Epilepsy duration, genetic Generalized Epilepsy syndrome, number of antiepileptic drugs, use of sodium valproate, and use of lamotrigine. Results: A total of 107 patients (37 males and 70 females) were studied. The mean age was 28.5 ± 10.7 years (range, 13-58). Juvenile absence Epilepsy was the most common Epilepsy syndrome in the cohort (31.8%), followed by Generalized Epilepsy with tonic-clonic seizures only (26.2%), juvenile myoclonic Epilepsy (26.2%), and childhood absence Epilepsy (14%). Epileptiform K-complexes and sleep spindles were seen in 65.4% and 10.3% of patients, respectively. None of the clinical variables had any significant impact on the occurrence of epileptiform K-complexes and sleep spindles in our multivariable analysis. Conclusions: Epileptiform K-complexes are common in the sleep EEGs of patients diagnosed with genetic Generalized Epilepsy. This underreported phenomenon highlights the important association of arousals and epileptiform discharges in genetic Generalized Epilepsy.