ABSTRACT
The kindling phenomenon is classically investigated in epileptology research. The present study aims to provide further information about hippocampal kindling through computational processing data. Adult Wistar rats were implanted with dorsal hippocampal and frontal neocortical electrodes to perform the experiment. The processing data was obtained using the Spike2 and Matlab softwares. An inverse relationship between the number of "wet dog shakes" and the Racine's motor stages development was found. Moreover it was observed a significant increase in the afterdischarge (AD) duration and its frequency content. The highest frequencies were, however, only reached at the beginning of behavioral seizures. During the primary AD, fast transients (ripples) were registered in both hippocampi superimposed to slower waves. This experiment highlights the usefulness of computational processing applied to animal models of temporal lobe epilepsy and supports a relevant role of the high frequency discharges in temporal epileptogenesis.
O fenômeno de kindling é classicamente utilizado no campo da epileptologia experimental. Este trabalho objetiva aprofundar a análise do modelo kindling hipocampal através de processamento computacional. Ratos wistar adultos receberam eletrodos hipocampais dorsais e neocorticais frontais para a realização do experimento. O processamento dos dados encontrados foi realizado pelos softwares Matlab e Spike2. Encontrou-se uma relação inversa entre wet dog shakes e o desenvolvimento dos estágios motores de Racine. A duração e o conteúdo de freqüência das pós-descargas hipocampais aumentaram durante o processo, sendo observadas descargas de alta freqüência (ripples) em ambos os hipocampos durante as pós-descargas primárias, superimpostas a ondas lentas. As mais altas freqüências, entretanto, foram apenas atingidas com o início das crises epilépticas. A utilização de sistemas computacionais para a confecção e análise do modelo de epilepsia temporal é ressaltada e reforça-se a relevância do papel das altas freqüências na epileptogênese temporal.
Subject(s)
Animals , Female , Male , Rats , Epilepsy, Temporal Lobe/physiopathology , Hippocampus/physiopathology , Kindling, Neurologic/physiology , Disease Models, Animal , Rats, Wistar , Signal Processing, Computer-AssistedABSTRACT
Introducción. Establecer las diferencias neurocognitivas entre las epilepsias pediátricas parciales del lóbulo frontal y del temporal. Métodos. En una investigación clínica de tipo transversal, descriptiva y prolectiva, se analizaron pacientes pediátricos con epilepsia parcial entre los 6 y 12 años de edad, de ambos sexos, en el Departamento de Neurología del Hospital Infantil de México Federico Gómez. Posterior a dividir a los pacientes en epilepsias parciales del lóbulo frontal y temporal, se aplicaron pruebas neurocognitivas, evaluación del cociente intelectual (CI), atención, memoria de trabajo, funciones ejecutivas y ejecución visuoespacial. Además, se evaluaron con resultados de electroencefalograma, neuroimagen y examen físico. Resultados. Se evaluaron 37 pacientes de ambos sexos (22 hombres, 15 mujeres) con epilepsia parcial del lóbulo frontal (17) y del lóbulo temporal (20). Las principales diferencias cognitivas entre estos dos tipos de epilepsia fueron: CI (promedio 82 en las epilepsias frontales y 97 en las epilepsias temporales) con mayor impacto en la memoria de trabajo y la ejecución vi-suoespacial en pequeños con epilepsia frontal. Los pacientes con epilepsia del lóbulo temporal presentaron mayores problemas en la atención de ejecución y de los test de memoria. Conclusiones. Los pacientes con epilepsia parcial del lóbulo frontal tienen mayor impacto sobre las habilidades neurocognitivas. Se considera muy importante esta evaluación con el fin de iniciar un soporte temprano con abordajes terapéuticos en este grupo de epilepsias, intentando revertir el impacto de crisis sobre las capacidades sociales y académicas.
Introduction. Objective: The purpose of this clinical trial was to differentiate the neurocognitive performance between frontal and temporal seizures in pediatric epilepsy. This is an important issue related to measure the impact of the different type of seizures in the neurodevelopment of children with epilepsy. Methods. We analyzed patients with partial epilepsy between 6 and 12 years old, both genders, in the Neurology Department of the Hospital Infantil de Mexico. After classifying frontal and temporal epilepsies, neurocognitive, IQ, attention, working memory, executive functions and visuospatial performance tests were applied. Likewise, EEG, neuroimaging, social evaluation and physical examination were performed. Results. Thirty-seven patients both genders (22 males; 15 females) with frontal partial seizures (17) and temporal partial seizures (20) were evaluated. The main neurocognitive differences between these 2 types of epilepsy were IQ (mean 82 in frontal epilepsy and 97 in temporal epilepsy) a higher impact on working memory and visuospatial performance was observed in infants with frontal epilepsy. The patients with temporal epilepsy had more problems in executing attention and long memory tests. Conclusion. Frontal partial seizures had more impact on the neurocognitive abilities than temporal partial seizures in the studied patients. This observation should be taken into account for the early treatment of children with epilepsy.
ABSTRACT
PURPOSE: To identify brain dominance for language functions with DLT and correlate these results with those obtained from fMRI in patients suffering from intractable temporal lobe epilepsy. METHOD: This study reports on 13 patients who underwent pre-surgical epileptic evaluation between April and October 2004 at the Epilepsy Surgery Program, Hospital Sao Lucas, PUCRS. In DLT, dominance was assessed through a consonant-vowel task, whereas in fMRI patients performed a verb generation task. RESULTS: Our results identified a correlation between the fMRI lateralization index and the DLT ear predominance index and reply difference index (r=0.6, p=0.02; Pearson Correlation Coefficient), showing positive correlation between results obtained from fMRI and DLT. CONCLUSION: DLT was found to significantly correlate with fMRI. These findings indicate that DLT (a non-invasive procedure) could be a useful tool to evaluate language brain dominance in pre-surgical epileptic patients as it is cheaper to perform than fMRI.
OBJETIVO: Identificar a dominância cerebral para funções de linguagem através do teste de escuta dicótica (TED) e correlacionar com os resultados de ressonância magnética funcional (RMf) em pacientes com epilepsia refratária de lobo temporal. MÉTODO: Foram estudados 13 pacientes com epilepsia refratária de lobo temporal, que realizaram avaliações pré-cirúrgicas no período de abril a outubro de 2004 no Programa de Cirurgia de Epilepsia do Hospital São Lucas da PUCRS. Realizada investigação da dominância hemisférica para linguagem através do TED Consoante-Vogal e da RMf pela geração de verbos. RESULTADOS: Verificou-se a existência de correlação entre os índices de lateralidade (RMf) e os índices de predomínio de orelha e de diferença de resposta (TED) (r=0,6, p=0,02). CONCLUSÃO: Existe correlação entre os resultados obtidos através da RMf (índice de lateralidade) e do TED (índice de predomínio de orelha e índice de diferença de resposta) em pacientes com epilepsia refratária de lobo temporal.
Subject(s)
Adolescent , Adult , Female , Humans , Male , Middle Aged , Epilepsy, Temporal Lobe/physiopathology , Functional Laterality/physiology , Language , Dichotic Listening Tests , Diffusion Magnetic Resonance ImagingABSTRACT
OBJETIVO: Identificar as regiões cerebrais responsáveis pelas funções de linguagem através de Ressonância Magnética funcional (RMf) em pacientes com epilepsia refratária de lobo temporal. METODOLOGIA: Foi realizada RMf utilizando-se o paradigma de geração de verbos. Os pacientes ouviam palavras concretas e eram orientados a pensar na sua finalidade, sem verbalizar (ex: faca-cortar). Utilizou-se o cálculo de índice de lateralidade (IL) e a verificação do grau de ativação das áreas classicamente envolvidas na linguagem. RESULTADOS E CONCLUSÕES: Constatou-se que 92,3 por cento dos pacientes investigados apresentaram linguagem em hemisfério esquerdo, e 7,7 por cento, linguagem mista. Observou-se que existe maior freqüência de pacientes com ativação nas regiões de Broca esquerda, Córtex Pré-motor esquerdo, área de Wernicke esquerda e Córtex Auditivo esquerdo.
PURPOSE: The purpose of this study was to identify the brain regions for language functions with the functional Magnetic Resonance Image (fMRI) in patients suffering from intractable temporal lobe epilepsy. METHODS: During fMRI, patients performed a verb-generation task. They heard concrete words through headphones and were asked to think of their utility (e.g. pencil - to write), without verbalizing or making any facial or tongue movements, keeping silent and with eyes shut. A laterality index (LI) was calculated and we verify the brain regions activities for language. RESULTS AND CONCLUSIONS: Our results identified that that 92.3 percent of the patients analyzed by fMRI presented left hemisphere language and 7.7 percent presented mixed language representation. It was observed more patients with activation in left Broca area, left pré-motor cortex, left Wernicke area and left hearing cortex.
Subject(s)
Humans , Magnetic Resonance Imaging , Dominance, Cerebral , Epilepsy, Temporal Lobe , Language , Drug Resistant EpilepsyABSTRACT
INTRODUÇÃO: Pacientes com epilepsia temporal e esclerose hipocampal unilateral tem, na sua grande maioria das vezes, as suas crises e as alterações eletroencefalográficas interictais originando-se do lado da lesão. Mesmo alguns pacientes nos quais os registros de escalpo mostram as crises originando-se da região temporal contralateral à atrofia do hipocampo, registros invasivos têm mostrado que a região de início das crises é, na realidade, ipsilateral à atrofia. No entanto isso talvez não seja verdadeiro para todos pacientes. OBJETIVO: Nesse artigo é relatado uma paciente com atrofia hipocampal unilateral, mas cujas crises, tanto no escalpo quando com registros subdurais, mostram vir da região temporal contralateral. RESULTADO: A paciente tem atrofia hipocampal à direita mas cujo EEG interictal mostrava predomínio de descargas à esquerda, bem como crises vindo daí. O registro com strips subdurais mostrou origem das crises à esquerda. CONCLUSÃO: Possivelmente alguns pacientes com epilepsia temporal têm as crises vindo do hipocampo menos atrófico.
INTRODUCTION: Most patients with temporal lobe epilepsy and hippocampal sclerosis have the seizures and the interictal electroencephalographic abnormalities coming from the side of atrophic hippocampus. Even some patients on whom the seizures seem to arise from the contralateral temporal lobe, invasive recordings have shown that the seizures actually come from that atrophic side. But this may not be always the case. OBJECTIVE: We report a patient with a unilateral hippocampal atrophy and the seizures, seen both on the scalp as well with subdural strips, come from the contralateral temporal lobe. A patient with right hippocampal atrophy had most of the interictal discharges coming from the left temporal lobe, as well her seizures. Invasive recordings with subdural strips also showed seizures arising from the left temporal lobe. CONCLUSION: There might be some patients with temporal lobe epilepsy whose seizures come from the less.