Idiopathic generalised epilepsy in adults manifested by phantom absences, generalised tonic-clonic seizures, and frequent absence status

Panayiotopoulos, C. P.; Koutroumanidis, M; Giannakodimos, S.; Agathonikou, A.

doi:10.1136/jnnp.63.5.622

Cited by 87 publications

(100 citation statements)

References 12 publications

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“…Although VPA also blocks Na' channels and enhances the effects of GABA on postsynaptic GABAa receptors ( S S ) , its antiabsence effect may be attributed to decreases in GABA release caused by the negative feedback via GABAa autoreceptors and reductions in GABAergic transmission at postsynaptic GABAb receptors (56). Vigabatrin, a GABA transaminase inhibitor that increases GABA concentrations at the synaptic cleft, worsens typical AS in humans when added to PHT (57) or CBZ (58). This paradoxical effect of vigabatrin may be attributed to enhancement of GABAergic systems (52)(53)(54) in the context of iatrogenically induced paradoxical responses by PHT or CBZ.…”

Section: Discussionmentioning

confidence: 99%

Refractory Idiopathic Absence Status Epilepticus: A Probable Paradoxical Effect of Phenytoin and Carbamazepine

2000

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Summary: Purpose:To compare the frequency of seizures and status epilepticus and their response to first-line drugs in patients with idiopathic generalized epilepsies receiving carbamazepine or phenytoin to those receiving other drugs or no treatment.Methods: We performed a retrospective chart review of all cases of idiopathic generalized epilepsies treated by the authors between 1985 and 1994. We compared seizure frequency and mean intravenous benzodiazepine dose required to control absence status epilepticus, intraindividually in subjects on carbamazepine or phenytoin before and after discontinuation of these compounds, and interindividually to subjects without treatment or receiving other drugs.Results: Bouts of absence or tonic-clonic status epilepticus and seizures in subjects treated with phenytoin or carbamazepine at therapeutic concentrations were considerably more frequent and proved intractable to treatment with valproic acid or benzodiazepines, compared with a cohort of subjects also with idiopathic generalized epilepsies, but naive to, or receiving subtherapeutic or therapeutic doses of other agents.Conclusions: Our observations strongly suggest that therapeutic concentrations of phenytoin and carbamazepine exacerbate idiopathic generalized epilepsies. Subjects in whom absence is one of the seizure types seem at a particularly high risk for responding paradoxically. These findings underscore the value of accurate classification of seizures and particularly the syndromic approach to diagnosis and point to the potential for iatrogenic complications with indiscriminate use of antiseizure drugs. Key Words: Idiopathic generalized epilepsiesAbsence status epilepticus-Refractoriness-Paradoxical effects-Phenytoin-Carbamazepine.Convulsive status epilepticus refractory to appropriate treatment is well recognized and comprises a sizable percentage of all cases of status (1,2). In contrast, idiopathic generalized absence status epilepticus (IGASE), refractory to appropriate drugs, is rate (3-6). A survey of the literature revealed that complete control was attained in 93% of cases from 10 different studies (7).Paradoxical increases in seizure frequency is a recognized, but difficult-to-document, adverse effect of antiepileptic agents (8-10). The main limitation evident in the existing body of literature is a lack of systematic observations over reasonably long periods of time to minimize the confounding effect of the inherently high variability in seizure frequency, a phenomenon known as "regression of seizure frequency to the median" (9, I 1 ).In addition, the majority of reported cases have been patients with symptomatic epilepsy. We report eight carefully studied cases (Group 1) with idiopathic generalized epilepsy (ICE) on phenytoin (PHT) and carbamazepine (CBZ) with very frequent, seemingly intractable absence (AS) and tonic-clonic seizures who presented in absence status epilepticus (ASE) that proved refractory to intravenous high-dose benzodiazepines (BZDs). The lack of response in these cases was in star...

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Section: Discussionmentioning

confidence: 99%

Refractory Idiopathic Absence Status Epilepticus: A Probable Paradoxical Effect of Phenytoin and Carbamazepine

2000

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“…The etiologic factors and relations between each syndrome are not clearly understood. Some authors postulate that IGE syndrome in adults is a new syndrome (11,12), whereas the concept of a continuum among IGE subjects is debated (13,14). In this study, we looked for etiologically related syndromic differences between the classic group of IGE and the adultonset group of IGE.…”

Section: Discussionmentioning

confidence: 99%

EEG in Adult‐onset Idiopathic Generalized Epilepsy

Yenjun

Harvey²,

Marini

et al. 2003

Epilepsia

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Summary:Purpose: It remains controversial whether adultonset idiopathic generalized epilepsy (IGE) is a distinct syndrome or a continuum among IGE syndromes. EEG is the only known biologic marker of IGE and helps differentiate many of its classic subsyndromes. In this study, we looked for the differences in the EEG findings of IGE of classic adolescent onset versus adult onset that may suggest syndromic heterogeneity.Methods: Seventy-six patients (47 adolescent-onset IGE, 29 adult-onset IGE) with a clinical and EEG diagnosis of IGE were included. We defined IGE with age at onset of 11-20 years as adolescent-onset IGE and age at onset of 20 years or after as adult-onset IGE. Patients with first-decade onset of seizures, delayed EEGs, and no EEG available for review were excluded. The first EEG was performed within 24 h of the seizure, and if negative, a sleep-deprived EEG was done. All EEGs were reviewed in detail with respect to the background activity and the generalized spike-wave (GSW) characteristic.Results: EEGs (87; 56 adolescent-onset IGE, 31 adult-onset IGE) were systematically reviewed. Background was normal in all patients. The morphology, amplitude, duration, frequency, occurrence, or activation of the GSW pattern did not differ between these two groups.Conclusions: No differences of EEG features were found between the classic adolescent-onset and the adult-onset IGE. This supports the hypothesis that they share common biologic determinants and exist along a life-long age spectrum of classic IGE.

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“…Estas manifestações estão associadas a complexos espícula-onda lenta generalizados no eletroencefalograma (EEG) 3,4 . Em alguns pacientes, o diagnóstico diferencial entre crises parciais complexas e crises de ausências pode ser difícil, levando a um diagnóstico inadequado da síndrome epiléptica 3,[5][6][7] . O objetivo deste estudo foi avaliar os fatores mais frequentemente associados a dificuldades no diagnóstico diferencial entre crises tipo ausências e mioclonias e crises parciais e assim tentar indicar elementos diagnósticos na rotina que possam ser úteis para o neurologista geral e epileptologista em fase de treinamento.…”

Section: Dr Fernando Cendes -Departamento De Neurologia Faculdade Dunclassified

Epilepsias generalizadas idiopáticas diagnosticadas incorretamente como epilepsias parciais

Mory

Guerreiro

et al. 2002

Arq. Neuro-Psiquiatr.

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RESUMO -A epilepsia generalizada idiopática (EGI) frequentemente não é diagnosticada corretamente em adultos, com sérias consequências para os pacientes. O objetivo deste estudo foi avaliar os fatores mais frequentemente associados a dificuldades no diagnóstico diferencial entre epilepsias parciais e generalizadas em adultos. Avaliamos 41 pacientes com diagnostico de crises parciais complexas com elementos de anamnese e EEG indicando um possível diagnóstico diferencial. Foi possível a mudança do diagnóstico de epilepsia parcial para EGI em 25 pacientes: 22 (88%) com EMJ; um com ausência juvenil, um com síndrome de ausências com mioclonias periorais e um com ausência com mioclonias palpebrais. Mioclonias, uma das características da EMJ e outras formas de EGI, geralmente não eram espontaneamente relatadas pelos pacientes. Abalos mioclônicos unilaterais eram confundidos com crises parciais motoras. Ausências breves e pouco frequentes e anormalidades focais no EEG contribuíram para o não reconhecimento de EGI. Todos os 25 pacientes apresentavam crises sem controle adequado antes da revisão diagnóstica. Após o diagnóstico correto e mudança para monoterapia com acido valpróico ou valproato de sódio, 19 (76%) ficaram livre de crises e seis (24%) dos 25 pacientes apresentaram melhora significativa. A associação de lamotrigina em três destes pacientes propiciou redução significativa da frequência de crises. Em conclusão, anamnese detalhada e questionamento direcionado para determinar a presença de mioclonias e crises tipo ausência e a sua interpretação no contexto clínico são fundamentais para o diagnóstico correto das EGI em adultos. PALAVRAS-CHAVE: epilepsia, diagnostico, tratamento, EEG. Idiopathic generalized epilepsies misdiagnosed as partial epilepsiesABSTRACT -Idiopathic generalized epilepsy (IGE) is often not recognized with serious consequences on the sufferers. We examined factors contributing to the missed diagnosis of IGE in 41 adults attending our epilepsy clinic with diagnosis of partial epilepsy who had semiology or EEG findings suggesting a possible differential diagnosis. After careful re-evaluation, the diagnosis of IGE was established in 25 patients: 22 (88%) with JME, one with juvenile absence, one with perioral myoclonia with absences, one with eyelid myoclonia with typical absences. Myoclonic jerks, the hallmark of the JME and other IGE, were not usually reported by patients or misdiagnosed as focal motor seizures. Brief and infrequent absence seizures and focal EEG abnormalities were other factors contributing to not recognizing JME. All 25 patients did not achieve seizure control before re-evaluation of diagnosis. After appropriate diagnosis of IGE and change of AED to valproate or valproic acid, 19 (76%) became seizure free and six (24%) had a significant improvement on seizure control. Association with lamotrigine provided further improvement in three of these patients. An appropriate questioning to identify myoclonic and absence seizures and a proper interpretation in the context of whole clini...

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Idiopathic generalised epilepsy in adults manifested by phantom absences, generalised tonic-clonic seizures, and frequent absence status

Cited by 87 publications

References 12 publications

Refractory Idiopathic Absence Status Epilepticus: A Probable Paradoxical Effect of Phenytoin and Carbamazepine

Refractory Idiopathic Absence Status Epilepticus: A Probable Paradoxical Effect of Phenytoin and Carbamazepine

EEG in Adult‐onset Idiopathic Generalized Epilepsy

Epilepsias generalizadas idiopáticas diagnosticadas incorretamente como epilepsias parciais

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