Electroencephalography abnormalities in generalized epilepsy and their predictors: A multicenter experience

Background: In spite of the overwhelming significance of knowledge of basic elements of electroencephalography (EEG) in its application to the diagnostic workup and the management of patients with suspected or already established generalized epilepsy (GE), there is a dearth of data on the pattern and utility of clinical variables that can independently determine EEG abnormalities in GE. Objective: The study was designed to evaluate the frequency and pattern of EEG abnormality as well as assess the utility of clinical variables in predicting the likelihood of an abnormal EEG in GE. Methods: It was a cross-sectional study involving the analysis of EEGs of consecutive patients with clinical diagnosis of idiopathic GE from three centers over a 7-year period. Information on sociodemographic and seizure variables was obtained. The International Federation of Societies for Electroencephalography and Clinical Neurophysiology definition of interictal epileptiform discharges (interictal epileptiform activity [IEA]) was adopted in the study. Results: A total of 403 patients comprising 242 (60%) males and 161 (40%) females with clinical diagnosis of GE had EEG. Their age ranged between 2 weeks and 70 years, with a median age of 21 years and an interquartile age of 26 years. Two hundred and thirty-seven (58.8%) and 213 (52.9%) patients had abnormal EEG and IEA, respectively. Before adjustment for confounders, female gender (P = 0.0001), pediatric age group (P = 0.0388), duration of epilepsy of 1­4 years (P = 0.01387), uncontrolled seizure (P = 0.0060), and seizure frequency (P = 0.0001) were significantly associated with the presence of abnormal EEG. However, age, female gender, poor seizure control, and seizure frequencies were the independent predictors of EEG abnormality. Conclusion: The study showed that about 58% of patients with GE patients had abnormal EEG. Age, poor seizure control, and high frequency of seizure were independent predictors of the presence of EEG abnormality

Crisis febriles simples y complejas, epilepsia generalizada con crisis febriles plus, FIRES y nuevos síndromes / [Simple febrile seizure, complex seizure, generalized epilepsy with febrile seizure plus, FIRES and new syndromes].

Febrile seizures are the most common seizures in childhood. They have been observed in 2-5

of children before the age of 5, but in some populations this figure may increase to 15

. It is a common cause of pediatric hospital admissions and cause of anxiety for parents. Febrile seizures could be the first manifestation of epilepsy. About 13

of epileptic patients have a history of febrile seizure, and 30

have had recurrent febrile seizures. Their phenotypic characteristics allow, in the majority of cases, a classification of the seizure, an elaboration of a prognosis and to assume a specific therapeutic attitude. It is possible to describe a spectrum according to their severity, from the benign simple seizure to the more complex, febrile seizure plus, Dravet’syndrome, and FIRES. During the past decade, molecular genetic studies have contributed to the identification of genetic factors involved in febrile seizure and related disorders, making the necessity of a careful follow up of these patients in order to detect risk factors earlier. We have reviewed the medical literature to update current knowledge of febrile seizures, their prognosis and their relation to new epileptic syndromes.

The clinical spectrum of malformations of cortical development

BACKGROUND: Malformations of cortical development (MCD) usually manifest in childhood with epilepsy, developmental delay and focal neurological abnormalities. OBJECTIVE: To evaluate the presentation and severity of epilepsy in the different types of MCD. METHOD: We evaluated the first 100 consecutive patients with a neuroimaging diagnosis of MCD. They were identified among all the high resolution magnetic resonance imaging exams performed at our service between 1997 and 2001. The causes of referral were diverse, according to the routine of the neurology outpatient clinic. After magnetic resonance imaging diagnosis of the subtype of MCD a detailed clinical assessment was performed. RESULTS: There were 55 females and 45 males, with ages ranging from five months to 71 years old (mean=15.2 years). Seventy-seven patients presented with epilepsy. Sixty-one had partial epileptic syndromes, 13 secondary generalized syndromes, and in three, the type of epileptic syndrome could not be established. Epilepsy was less frequent in patients with the MCD subtypes of polymicrogyria and schizencephaly (p<0.001). Patients with schizencephaly and polymicrogyria had their seizures more easily controlled by antiepileptic drugs (p<0.001). CONCLUSION: That the frequency of epilepsy is lower and seizures are more easily controlled in the setting of polymicrogyria and schizencephaly. Patients with MCD frequently present with secondary generalized epilepsy early in childhood.

INTRODUÇÃO: As malformações do desenvolvimento cortical (MDC) geralmente se manifestam na infância, na forma de crises epilépticas, retardo do desenvolvimento neuropsicomotor ou anormalidades focais. OBJETIVO: Avaliar a apresentação clínica e a gravidade da epilepsia nos diferentes tipos de MDC. MÉTODO: Cem pacientes com diagnóstico de MDC estabelecido por neuroimagem foram avaliados. Os pacientes foram identificados através de exames de ressonância magnética de alta resolução realizados entre 1997 e 2001. As causas para investigação por imagem foram diversas, conforme as indicações de rotina dos ambulatórios de neurologia. Após a determinação do subtipo de MDC, uma avaliação clínica detalhada foi realizada. RESULTADOS: Entre os 100 pacientes, 55 eram do sexo feminino e 45 do masculino, com idade variando entre 5 meses e 71 anos (média=15,2 anos). Setenta e sete pacientes apresentaram epilepsia. Sessenta e um tinham síndrome epiléptica parcial, 13 síndrome epiléptica secundariamente generalizada e em três, o tipo de crise não pode ser definido. Epilepsia foi menos freqüente em pacientes com polimicrogiria e esquizencefalia (p<0.001). As crises epilépticas foram controladas mais facilmente por drogas antiepilépticas em pacientes com polimicrogiria e esquizencefalia (p<0.001). CONCLUSÃO: A freqüência de epilepsia é menor e as crises são mais facilmente controladas em pacientes com polimicrogiria e esquizencefalia. Pacientes com MDC freqüentemente apresentam síndrome epiléptica secundariamente generalizada.

Event related evoked potential responses in epileptic patients.

The effect of epilepsy on cognitive functions has been investigated in this study. The P300 auditory event related potentials (AERP), Wechsler Adult Performance Intelligence Scale (WAPIS--Indian Adaptation) & Digit Span Test (DST) have been used to assess the cognitive status. Twenty primary generalised epilepsy patients and 20 normal controls were subjected to WAPIS & DST testing and their AERP recorded. On comparative statistical analysis, epileptic subjects were found to have significantly higher N2 & P300 latencies and lower P300 amplitude, WAPIS-IQ scores & DST scores. These findings suggest that there is a general decline of cognitive functions in epileptics especially the memory, attention, concentration and speed of mental processing and as also corroborated by P300 and that P300 can be used as an additional sensitive parameter to assess the cognitive status.

Polygraphic characterization of the sleep-epilepsy patterns in a hydranencephalic child with severe generalized seizures of the lennox-gastaut syndrome

This is the report of a hydranenecephalic child with severe generalized seizures of the Lennox-Gastaut Syndrome (LGS) who lacked the development of the entire cerebral hemispheres and had preserved the brain stem, cerebellum, hypothalamus and a portion of the thalamus as evidenced by radiological and/or physiological studies. Conventional polygraphic sleep studies in these patients showed presence of scalp EEG and other peripheral, somatic and vegetative signs characterizing the wakefulness, quiet sleep and active sleep stages. Absence of the vertex waves and disrupted sleep spindles were the major qualitative EEG abnormalities. In contrast, quantitative abnormalities in duration, latency and number of sleep cycles found in this patient were similar to those found in other children with Idiopathic Lennox-Gastaut Syndrome (ILGS). A substantial reduction in the number of interictal EEG spikes and a shortening of the ictal clonic EEG activities without concomitant EMG jerks were the most distinct epileptiform abnormalities in this child. In contrast, his basic polygraphic patterns of the tonic and apneic seizures were similar to those found in other children with ILGS. Data obtained from this child suggest that both the sleep stages and the generalized seizures of the ILGS basically depend more on the integrity of the brain stem than on the telecephalic structures

Epilepsia fotosensible: aspectos clínicos y electroencefalográficos / Photosensitive epilepsy: clinics and electroencephalografic aspect

El objetivo de este estudio es la evaluación clínica y electroencefalográfica de las epilepsias fotosensibles. Se analizaron 14 pacientes (p) con epilepsia fotosensible EF, 9 de ellos con EF pura y 5 p con crisis autoinducidas. 10 fueron varones y 4 mujeres. Edad media de comienzo de las crisis autoinducidas 5 ñ 2 años (2-8) y de la epilepsia fotosensible pura, 9 ñ 3 años (4-13). El tiempo de seguimiento fué de 11 ñ 10 años (1-30). A todos se les realizó un electroencefalograma (EEG) con estimulación luminosa intermitente (ELI) en 1994. Las crisis fueron inducidas por el sol en 3 p, televisión (TV) en 4 p, sol y TV en 4 p, y video-juegos en 3 pacientes; 12 epilepsias fueron idiopáticas y 2 sintomáticas. Antecedentes familiares de epilepsia se determinaron en un 43 por ciento. Luego del tratamiento, 5 p normalizaron su EEG (35,71 por ciento) pero 9 p (64,29 por ciento) conservan la respuesta anormal a la ELI y de éstos últimos 7 continúan con crisis. Todos los p con crisis por video-juegos una vez comenzado el tratamiento normalizaron el EEG y no presentaron más crisis. Conclusión: Entre las epilepsias fotosensibles puras aquellas inducidas por video-juegos parecen ser las más benignas. La persistencia del EEG con respuesta fotoconvulsiva predice el pobre control de las crisis fotosensibles