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CC BY-NC-ND 4.0 · Arq Neuropsiquiatr 2016; 74(07): 536-543
DOI: 10.1590/0004-282X20160082
ARTICLES

Clinical electroencephalogram (EEG) evaluation is improved by the amplitude asymmetry index

Avaliação da assimetria de amplitudes amplia o uso clínico do eletroencefalograma (EEG)
Francisco José Carchedi Luccas
1   Hospital São Luiz, Neurofisiologia Clínica, Neurofisiologia Clínica, São Paulo SP, Brasil;
,
Thalita Bártolo
2   Hospital São Luiz, Neurofisiologia Clínica, Biomedicina, São Paulo SP, Brasil.
,
Nayara Lucio da Silva
2   Hospital São Luiz, Neurofisiologia Clínica, Biomedicina, São Paulo SP, Brasil.
,
Barbara Cavenaghi
2   Hospital São Luiz, Neurofisiologia Clínica, Biomedicina, São Paulo SP, Brasil.
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ABSTRACT

Cerebral hemispheres, although similar, are neither completely symmetrical in structure nor equivalent in function. EEG asymmetry studies have been directed more to frequency than to amplitude analysis.

Objective Better definition of normal amplitude asymmetry values on the classical EEG frequency bands.

Results EEG amplitude asymmetry index (AAI) is physiologically low in normal adults, differences usually lesser than 7%.

Conclusion Persistent or intermittent amplitude asymmetry regional differences higher than 7% may be suggestive of pathology after adequate correlation with clinical data and EEG classical visual analysis.

RESUMO

Os hemisférios cerebrais não são simétricos em morfologia ou funções. Tradicionalmente, os estudos de assimetria do EEG focaram mais na análise de frequências do que na de amplitudes.

Objetivo Contribuir para melhor definição dos valores normais de assimetria de amplitudes nas faixas de frequência clássicas do EEG.

Resultados O índice de assimetria de amplitudes é fisiologicamente baixo em adultos, usualmente menor do que 7%.

Conclusão Se adequadamente correlacionadas aos dados clínicos e à análise visual do EEG, assimetrias persistentes ou intermitentes de amplitude acima de 7% podem ser sugestivas de patologia.

Electroencephalography - amplitude - asymmetry
Eletroencfalografia - amplitude - assimetria


Publication History

Received: 26 April 2015

Accepted: 18 May 2016

Article published online:
06 September 2023

© 2023. Academia Brasileira de Neurologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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