A comparison between averaged spikes and individual visually-analyzed spikes in rolandic epileptiform discharges

A comparison between averaged spikes and individual visually-analyzed spikes in rolandic epileptiform discharges

Alternative title Comparação por análise visual entre as espículas promediadas e as espículas individuais nas descargas epileptiformes rolândicas
Author Braga, Nadia I.o. Autor UNIFESP Google Scholar
Manzano, Gilberto Mastrocola Autor UNIFESP Google Scholar
Nóbrega, João Antonio Maciel Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract PURPOSE:This study compared some morphological features of individual rolandic epileptiform discharges, used to obtain an averaged estimate, with those of the resulting estimate. METHOD: Twenty-four averaged discharges from EEGs of 24 children showing rolandic spikes were compared with 480 individual discharges used in the averaging. The analysis was based on the occurrence of tangential dipole and double spike patterns. RESULTS: In 15 averaged discharges the tangential dipole pattern was found. Individual spikes used in the averaging process displayed the same pattern in 35-100% of them; in the remaining 9 averaged discharges, up to 20% of the individual spikes showed the same pattern, although this was not found in the averaged waveforms. Double spike pattern was found in 11 of the averaged waveforms and was recognized in 50-100% of its individual discharges, whereas up to 45% of individual spikes showed this pattern without expression in the averaged waveform. CONCLUSION: When visually analyzing an EEG with rolandic spikes, caution should be exercised in characterizing these patterns, since a few discharges showing them may not be expressed in the averaged waveform and the clinical correlations proposed for these patterns may not apply.

OBJETIVO: Comparar as características morfológicas das descargas epileptiformes rolândicas individuais usadas para se obter uma descarga promediada com a resultante promediada. MÉTODO: Vinte e quatro descargas promediadas dos EEG de 24 crianças com descargas epileptiformes rolândicas foram comparadas com as 480 descargas individuais utilizadas na promediação. A análise foi baseada na ocorrência de dipolo tangencial e dupla espícula. RESULTADOS: Em 15 descargas promediadas o dipolo tangencial estava presente. As espículas individuais usadas na promediação mostraram o mesmo padrão em 35-100% das descargas. Nas 9 descargas promediadas restantes, até 20% das descargas individuais apresentavam o padrão, embora este não estivesse presente na resultante promediada. O padrão dupla espícula foi encontrado em 11 descargas promediadas, tendo sido reconhecido em 50-100% das descargas individuais, enquanto até 45% das espículas individuais mostraram este padrão sem que este estivesse presente na resultante promediada. CONCLUSÃO: Quando se procede à analise visual de um EEG com descargas epileptiformes rolândicas é necessário cuidado na caracterização desses padrões, pois algumas descargas podem apresentá-los sem manter a sua expressão na resultante promediada e as correlações clínicas referentes a esse padrões podem não se aplicar.
Keywords EEG
rolandic epilepsy
tangential dipole
double spike
EEG epilepsia rolândica
dipolo tangencial
espícula dupla
Language English
Date 2002-09-01
Published in Arquivos de Neuro-Psiquiatria. Academia Brasileira de Neurologia - ABNEURO, v. 60, n. 3B, p. 699-701, 2002.
ISSN 0004-282X (Sherpa/Romeo)
Publisher Academia Brasileira de Neurologia - ABNEURO
Extent 699-701
Origin http://dx.doi.org/10.1590/S0004-282X2002000500002
Access rights Open access Open Access
Type Article
SciELO ID S0004-282X2002000500002 (statistics in SciELO)
URI http://repositorio.unifesp.br/handle/11600/1511

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