RESUMO
Idiopathic or genetic generalized epilepsies (IGE) constitute an electroclinically well-defined group that accounts for almost one third of all people with epilepsy. They consist of four well-established syndromes and some other rarer phenotypes. The main four IGEs are juvenile myoclonic epilepsy, childhood absence epilepsy, juvenile absence epilepsy and IGE with generalized tonic-clonic seizures alone. There are three main seizure types in IGE, namely generalized tonic-clonic seizures, typical absences and myoclonic seizures, occurring either alone or in any combination. Diagnosing IGEs requires a multidimensional approach. The diagnostic process begins with a thorough medical history with a specific focus on seizure types, age at onset, timing and triggers. Comorbidities and family history should be questioned comprehensively. The EEG can provide valuable information for the diagnosis, including specific IGE syndromes, and therefore contribute to their optimal pharmacological treatment and management.
Assuntos
Eletroencefalografia , Epilepsia Tipo Ausência/diagnóstico , Epilepsia Generalizada/diagnóstico , Epilepsia Mioclônica Juvenil/diagnóstico , Guias de Prática Clínica como Assunto , Convulsões/diagnóstico , Criança , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/fisiopatologia , Epilepsia Generalizada/classificação , Epilepsia Generalizada/fisiopatologia , Humanos , Epilepsia Mioclônica Juvenil/classificação , Epilepsia Mioclônica Juvenil/fisiopatologia , Convulsões/classificação , Convulsões/fisiopatologia , SíndromeRESUMO
OBJECTIVE: The study provides updated information about the distribution of seizures, epilepsies, and etiologies of epilepsy in the general child population, and compares the old and new classification systems from the International League Against Epilepsy (ILAE). METHODS: The study platform was the Norwegian Mother and Child Cohort Study. Cases of epilepsy were identified through registry linkages and sequential parental questionnaires. Epilepsy diagnoses were validated using a standardized protocol, and seizures, epilepsies, and etiologies were classified according to the old (ILAE 1981/1989) and new (ILAE 2017) classifications. Information was collected through medical record reviews and/or parental telephone interviews. RESULTS: The study population included 112,744 children aged 3-13 years at the end of follow-up on December 31, 2012. Of these, there were 606 children with epilepsy (CWE). Distribution of seizure types varied by age of onset. Multiple seizure types were common with early onset. Focal epilepsies were the most common, occurring in 317 per 100,000 children in the study population and in 59% of CWE. Generalized epilepsies were found in 190 per 100,000 (35% of CWE). CWE with onset during the first 2 years of life had an even distribution of focal and generalized epilepsies, whereas focal epilepsies became dominant at later ages of onset. A definite cause of epilepsy had been demonstrated in 33% of CWE. The ILAE 1989 classification allowed for a broad syndrome category in 93% of CWE and a defined epileptic syndrome in 37%. With the ILAE 2017 classification, 41% of CWE had a defined epileptic syndrome and 63% had either a defined syndrome or structural-metabolic etiology. SIGNIFICANCE: The distribution of seizures and epilepsies is strongly dependent on age of onset. Despite diagnostic advances, the causes of epilepsy are still unknown in two-thirds of CWE. The ILAE 2017 classifications allow for a higher precision of diagnoses, but at the expense of leaving more epilepsies classifiable only at the mode of onset level.
Assuntos
Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/etiologia , Internacionalidade , Vigilância da População , Convulsões/classificação , Convulsões/etiologia , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Epilepsia Tipo Ausência/diagnóstico , Feminino , Seguimentos , Humanos , Masculino , Noruega/epidemiologia , Vigilância da População/métodos , Convulsões/diagnóstico , SíndromeAssuntos
Epilepsia Tipo Ausência/fisiopatologia , Estado Epiléptico/fisiopatologia , Adolescente , Idade de Início , Anticonvulsivantes/uso terapêutico , Eletroencefalografia , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/tratamento farmacológico , Humanos , Levetiracetam , Masculino , Pessoa de Meia-Idade , Piracetam/análogos & derivados , Piracetam/uso terapêutico , Estado Epiléptico/classificação , Estado Epiléptico/tratamento farmacológico , Ácido Valproico/uso terapêuticoAssuntos
Epilepsia Tipo Ausência/diagnóstico , Epilepsia Tipo Ausência/enfermagem , Epilepsia/diagnóstico , Epilepsia/enfermagem , Narcolepsia/diagnóstico , Narcolepsia/enfermagem , Adulto , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/uso terapêutico , Criança , Pré-Escolar , Epilepsia/classificação , Epilepsia Tipo Ausência/classificação , Feminino , Humanos , Lactente , Masculino , Narcolepsia/classificação , Diagnóstico de EnfermagemRESUMO
Absence seizures are idiopathic epilepsies characterized by impairment of consciousness and generalized 2.5-4 Hz spike and slow wave discharges. This prospective study was performed to classify and define properties of subgroups of absence epilepsies. We included 31 patients, of whom seven were in the differential diagnosis group. On admission, absence epilepsy provisional diagnosis was considered in 16 patients clinically and in the other 15 patients based on routine EEG findings. Ictal EEGs were recorded by video-EEG monitoring in 23 of the patients (totally 202 ictal recordings). Patients were diagnosed as childhood absence epilepsy (n=8), juvenile absence epilepsy (n=10), juvenile myoclonic epilepsy (n=3), eyelid myoclonia with absences (n=2), and perioral myoclonia with absences (n=1). Neuroimaging, video-EEG monitoring and especially ictal recordings are important for classification of epilepsies in addition to history, physical examination and routine EEG findings. Video-EEG monitoring is required to classify, to make differential diagnosis and to determine the treatment plan and prognosis.
Assuntos
Eletroencefalografia , Epilepsia Tipo Ausência/diagnóstico , Idade de Início , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Diagnóstico Diferencial , Epilepsias Mioclônicas/classificação , Epilepsias Mioclônicas/diagnóstico , Epilepsias Mioclônicas/fisiopatologia , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/fisiopatologia , Feminino , Humanos , Masculino , Neuroimagem , Prognóstico , Estudos Prospectivos , Estatísticas não Paramétricas , Turquia , Gravação em VídeoRESUMO
UNLABELLED: Early-onset pure absence epilepsy has not yet considered in the International League Against Epilepsy classification, but several reports have supported its existence as a distinct epileptic syndrome primarily manifesting with typical absences in early childhood. This review summarizes the current understanding on this epilepsy. CONCLUSIONS: Early-onset pure absence epilepsy is a distinct epilepsy characterized by absences starting from a few months to 4 years of age, normal early psychomotor development, good antiepileptic drug seizure control and normal intellectual outcome.
Assuntos
Epilepsia Tipo Ausência/epidemiologia , Idade de Início , Pré-Escolar , Epilepsia/classificação , Epilepsia Tipo Ausência/classificação , Humanos , Lactente , SíndromeRESUMO
Absence seizures with bilateral spike-wave (SW) complexes at 3Hz are divided into the childhood form, with onset at around 6 years of age, and the juvenile form, with onset usually at 12 years of age. These seizures typically last 9-12s and, at times, are activated by hyperventilation and occasionally by photic stimulation. Generalized tonic-clonic (GTC) seizures may also occur, especially in the juvenile form. There may be cognitive changes, in addition to linguistic and behavioral problems. Possible mechanisms for epileptogenesis may involve GABAergic systems, but especially T-calcium channels. The thalamus, especially the reticular nucleus, plays a major role, as does the frontal cortex, mainly the dorsolateral and orbital frontal areas, to the extent that some investigators have concluded that absence seizures are not truly generalized, but rather have selective cortical networks, mainly ventromesial frontal areas and the somatosensory cortex. The latter network is a departure from the more popular concept of a generalized epilepsy. Between the "centrencephalic" and "corticoreticular" theories, a "unified" theory is presented. Proposed genes include T-calcium channel gene CACNA1H, likely a susceptible gene in the Chinese Han population and a contributory gene in Caucasians. Electroencephalography has revealed an interictal increase in prefrontal activity, essential for the buildup of the ictal SW complexes maximal in that region. Infraslow activity can also be seen during ictal SW complexes. For treatment, counter to common belief, ethosuximide may not increase GTC seizures, as it reduces low-threshold T-calcium currents in thalamic neurons. Valproic acid and lamotrigine are also first-line medications. In addition, zonisamide and levetiracetam can be very helpful in absence epilepsy.
Assuntos
Epilepsia Tipo Ausência/fisiopatologia , Epilepsia Tipo Ausência/terapia , Adulto , Anticonvulsivantes/uso terapêutico , Encéfalo/fisiopatologia , Eletroencefalografia , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/epidemiologia , Epilepsia Tipo Ausência/genética , Epilepsia Tipo Ausência/psicologia , Epilepsia Generalizada/fisiopatologia , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Estado Epiléptico/fisiopatologia , Estimulação Magnética TranscranianaRESUMO
According to the international classification of epileptic seizures (1981) generalized seizures present ictal signs indicating seizure onset in both hemispheres whereas focal seizures present ictal signs pointing to one hemisphere at seizure onset. Recent neurophysiological studies using MEG, EEG, and fMRI suggest that in case of idiopathic generalized absence epilepsies, activity predominates in specific networks, which include frontoparietal cortical as well as subcortical areas of both hemispheres. In these network regions, epileptic activity can occur circumscribed and focal as spike or spike-wave activity but also widely distributed, bilateral, and homologous. As a consequence to the classification of "generalized" epileptic seizures and syndromes, it might be possible to distinguish a subgroup: regional bilateral homologous epilepsies. These must be distinguished from a pure culture of focal frontal lobe epilepsies, which can also be accompanied by the lead symptom of absences.
Assuntos
Mapeamento Encefálico/métodos , Encéfalo/fisiopatologia , Epilepsia Tipo Ausência/diagnóstico , Epilepsia Tipo Ausência/fisiopatologia , Modelos Neurológicos , Rede Nervosa/fisiopatologia , Epilepsia Tipo Ausência/classificação , HumanosRESUMO
PURPOSE: To investigate the focal interictal EEG abnormalities in adult patients with absence seizures (ASs) and to identify their clinical, EEG and semiological correlates. METHODS: Fifty patients older than 18 years, diagnosed as having IGE with AS documented with ictal recordings. Interictal focal sharp or spike-waves and strictly focal paroxysmal slow activity were considered as focal EEG features. The patients having focal EEG features were classified as "Group I", whereas the remaining of them was classified as "Group II". RESULTS: We observed focal findings in 34% of the patients, mainly in frontotemporal (41%), and frontal (29%) regions. There were no significant differences with respect to the clinical parameters such as sex, epilepsy duration, positive family history and the age of the onset between the groups. Psychiatric co-morbidities were significantly higher in Group I when compared to Group II (P=0.00). Accompanying automatisms were higher in Group I, whereas eye deviation during absences was higher in Group II. In Group I, the asymmetry of the ictal discharges was more frequently observed. Focal EEG features were more frequently seen in juvenile absence epilepsy syndrome, without reaching a significance level. CONCLUSION: The focal findings in adult absence epilepsy patients could have some unknown etio-pathogenetic and prognostic implications. We emphasize the cautious interpretation of isolated interictal focal EEG abnormalities to prevent a wrong diagnosis of focal epilepsy in patients who may indeed suffer from generalized epilepsy.
Assuntos
Córtex Cerebral/fisiopatologia , Eletroencefalografia , Epilepsia Tipo Ausência/patologia , Adulto , Idoso , Anticonvulsivantes/uso terapêutico , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/tratamento farmacológico , Epilepsia Tipo Ausência/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
We studied the clinical and electroencephalographic features in 30 children who were diagnosed with childhood absence epilepsy. According to their EEG pattern we divided the 30 children into two groups: group A: 11 children with classical absences whose ictal EEG showed primary generalized spikes and waves and group B: 19 children with frontal onset of the EEG epileptic abnormalities ('frontal group'). In the frontal group, more frequently complex absences were seen. Although the majority of children responded very well to valproate monotherapy, ethosuximide has to be added in 3 children of the frontal group to achieve seizure freedom. In the frontal group, also more learning and behavioural problems were encountered. This study largely confirms a previous study of Lagae et al. [Lagae L, Pauwels J, Monte B, Verhelle J, Vervisch J. Frontal absences in children. Eur J Pediatr Neurol 2001;5:243-251]. It seems that frontal onset absences constitute a specific subtype within the childhood absence epilepsies.
Assuntos
Epilepsia Tipo Ausência/diagnóstico , Lobo Frontal/fisiopatologia , Idade de Início , Criança , Pré-Escolar , Eletroencefalografia/métodos , Epilepsia Tipo Ausência/classificação , Feminino , Seguimentos , Humanos , MasculinoRESUMO
In a cohort of 275 Caucasians with a broad IGE phenotype, patients with absences were classified. Criteria of the 1989 Commission on Classification of the International League Against Epilepsy for Childhood Absence Epilepsy (CAE 1989 criteria) were compared with the stricter criteria of the ILAE Task Force for Classification and Terminology (CAE 2005 criteria). Among the 129 patients with absences without significant myoclonus, 50 had juvenile absence epilepsy 44 had CAE according to the CAE 1989 criteria and only 30 had CAE according to the CAE 2005 criteria. We found a significantly better outcome in patients considered as CAE by the CAE 2005 criteria, compared with those excluded. Strict criteria for classification of absence syndromes leave many patients unclassified. However, diagnostic criteria used to classify CAE patients have prognostic significance. We propose that patients are classified as having benign CAE or as having CAE with the adverse prognostic factors indicated.
Assuntos
Epilepsia Tipo Ausência/diagnóstico , Epilepsia Generalizada/diagnóstico , Estudos de Coortes , Comorbidade , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/epidemiologia , Epilepsia Generalizada/classificação , Epilepsia Generalizada/epidemiologia , Humanos , Imunoglobulina E/genética , Fenótipo , Prognóstico , Síndrome , Terminologia como Assunto , População Branca/genéticaRESUMO
Absence epilepsy is a form of generalized epilepsy commonly seen in children. The clinician is often presented with a patient whose electroencephalogram does not fit the typical absence pattern. The purpose of this study is to more closely examine both typical and atypical absence variants and their outcome. A retrospective chart review was performed on children diagnosed with absence epilepsy over the past 5 years at the University of Alberta. A total of 119 patients were reviewed. Patients were classified with typical or atypical absence seizures following International League Against Epilepsy criteria and electroencephalography (EEG) characteristics. Clinical seizure characteristics, magnetic resonance imaging (MRI), initial response to treatment, and outcome were examined. Seizure characteristics were similar in both the typical and atypical absence groups. Aura, complex automatisms, changes in tone, and incontinence were seen in both groups, although status epilepticus was found only in the atypical group. Associated comorbid conditions such as attention-deficit hyperactivity disorder (ADHD), learning disorders, and enuresis were found equally in both groups. Developmental delay was found more often in the atypical group. Of the typical group, 83% responded to an initial antiepileptic drug (either valproic acid or ethosuximide), whereas only 51% of the atypical group came under control. Remission at 2 years however, was similar between groups, with 76% of the typical group and 71% of the atypical group completely seizure free. Absence seizures in childhood, both typical and atypical, share similar clinical and electroencephalographic features and appear to be part of a continuum. Associated comorbid features such as ADHD, learning disorders, and developmental delay are also seen in both groups. The outcome for both types is excellent, although the atypical variants may be initially more difficult to control.
Assuntos
Anticonvulsivantes/uso terapêutico , Eletroencefalografia , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/diagnóstico , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Criança , Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/diagnóstico , Epilepsia Tipo Ausência/complicações , Epilepsia Tipo Ausência/terapia , Humanos , Deficiências da Aprendizagem/complicações , Deficiências da Aprendizagem/diagnóstico , Espectroscopia de Ressonância Magnética , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Resultado do TratamentoRESUMO
PURPOSE: Typical absence seizures differ from atypical absence seizures in terms of semiology, EEG morphology, network circuitry, and cognitive outcome, yet have the same pharmacological profile. We have compared typical to atypical absence seizures, in terms of the recruitment of different brain areas. Our initial question was whether brain areas that do not display apparent paroxysmal discharges during typical absence seizures, are affected during the ictal event in terms of synchronized activity, by other, distant areas where seizure activity is evident. Because the spike-and-wave paroxysms in atypical absence seizures invade limbic areas, we then asked whether an alteration in inhibitory processes in hippocampi may be related to the spread seizure activity beyond thalamocortical networks, in atypical seizures. METHODS: We used two models of absence seizures in rats: one of typical and the other of atypical absence seizures. We estimated phase synchronization, and evaluated inhibitory transmission using a paired-pulse paradigm. RESULTS: In typical absence seizures, we observed an increase in synchronization between hippocampal recordings when spike-and-wave discharges occurred in the cortex and thalamus. This indicates that seizure activity in the thalamocortical circuitry enhances the propensity of limbic areas to synchronize, but is not sufficient to drive hippocampal circuitry into a full paroxysmal discharge. Lower paired-pulse depression was then found in hippocampus of rats that displayed atypical absence seizures. CONCLUSIONS: These observations suggest that circuitries in brain areas that do not display apparent seizure activity become synchronized as seizures occur within thalamocortical circuitry, and that a weakened hippocampal inhibition may predispose to develop synchronization into full paroxysms during atypical absence seizures.
Assuntos
Potenciais de Ação/fisiologia , Córtex Cerebral/fisiopatologia , Epilepsia Tipo Ausência/fisiopatologia , Recrutamento Neurofisiológico/fisiologia , Transmissão Sináptica/fisiologia , 4-Butirolactona/farmacologia , Animais , Córtex Cerebral/efeitos dos fármacos , Depressão Alastrante da Atividade Elétrica Cortical/fisiologia , Sincronização Cortical/estatística & dados numéricos , Modelos Animais de Doenças , Eletrodos Implantados , Eletroencefalografia/estatística & dados numéricos , Epilepsia Tipo Ausência/induzido quimicamente , Epilepsia Tipo Ausência/classificação , Hipocampo/efeitos dos fármacos , Hipocampo/fisiopatologia , Modelos Neurológicos , Inibição Neural/fisiologia , Vias Neurais/fisiopatologia , Ratos , Ratos Long-Evans , Tálamo/fisiopatologia , Dicloridrato de trans-1,4-Bis(2-clorobenzaminometil)ciclo-hexano/farmacologiaRESUMO
The prevalence of idiopathic generalized epilepsies (IGEs) has been assessed as being 15-20% of all epilepsies. The seizure types in IGEs are typical absences, myoclonic jerks, and generalized tonic-clonic seizures (TCS), alone or in varying combinations and with variable severity. The seizures tend to be more frequent on awakening and with sleep deprivation. This group of clinical conditions includes among others, age-related epilepsy syndromes of adolescence such as juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and IGE with generalized TCS or epilepsy with grand mal on awakening (EGMA). The classification of IGEs follows two schools of thought; one maintains that IGEs are a group of different and separate syndromes while the other suggests that IGEs are one biological continuum. Patients with IGEs may have mild impairment of cognitive functions, especially verbal memory and other frontal lobe functions, despite a normal IQ, and some seem to have characteristic personality traits, although further studies are needed to support this theory. They appear to lack a degree of self-control, to neglect their physical needs, and are poorly compliant with therapy. Some patients become obstinate and are impressionable. The cognitive and behavioral aspects of these patients suggest an involvement of frontal lobes.
Assuntos
Transtornos Cognitivos/diagnóstico , Epilepsia Generalizada/diagnóstico , Transtornos Mentais/diagnóstico , Adolescente , Fatores Etários , Epilepsia Tipo Ausência/classificação , Epilepsia Tipo Ausência/diagnóstico , Epilepsia Generalizada/classificação , Epilepsia Generalizada/fisiopatologia , Epilepsia Tônico-Clônica/classificação , Epilepsia Tônico-Clônica/diagnóstico , Lobo Frontal/fisiopatologia , Humanos , Transtornos Mentais/classificação , Epilepsia Mioclônica Juvenil/classificação , Epilepsia Mioclônica Juvenil/diagnóstico , Testes Neuropsicológicos , SíndromeRESUMO
In both the current (1981) ILAE Classification of Epileptic Seizures and the recently Proposed Diagnostic Scheme for People with Epilepsy and Epileptic Seizures, typical absence seizures are defined as generalized seizures, implying widespread subcortical and cortical neuronal involvement from onset with impairment of consciousness as the clinical hallmark. Clinical observations from three patients and clinical and experimental data from the literature suggest, however, that: (1) consciousness is retained in many typical absences; (2) the true hallmark of these seizures is arrest of motor initiation due to disturbance of pre-motor area frontal-lobe function; (3) typical absences and partial seizures from these areas may show similar clinical and EEG features and involve the same neuronal circuits. The neuronal system primarily involved in these seizures consists of a relatively limited cortico-thalamo-cortical circuit, including the reticular thalamic nucleus, the thalamocortical relay and the predominantly anterior and mesial frontal cerebral cortex, with the cortex probably acting as the primary driving site. Typical absences thus should not be classified or defined as generalized seizures, particularly since neuropathological and imaging studies increasingly argue for localized structural abnormalities, even in idiopathic or primary generalized epilepsy. These observations further highlight the intrinsic weaknesses of the current classification system for seizures and support further adaptations of the diagnostic system currently under development.