ABSTRACT
ABSTRACT The use of methods to evaluate cortical activity in neonates has great importance in modern medicine, as it allows the observation and evaluation of several clinical aspects, which guarantees that the health team has knowledge about possible intervention measures that may be necessary in the treatment of newborns. Objective: This systematic review aimed to compare the main technologies available for the evaluation of brain functions in neonates, among them: the conventional electroencephalogram (EEG), the amplitude-integrated electroencephalogram (aEEG) and the geodesic sensor net EEG. Methods: A search was conducted forarticles from national and international periodicals included in the Web of Science, LILACS, SciELO and Medline electronic databases. Results: The search found 39 among 155 articles of interest and the analyses indicated that, in the clinical environment, the use of both conventional EEG and aEEG is highly recommended, as the combination of their functions allows, for example, a greater number of subclinical seizures to be detected. Conversely, the use of a geodesic sensor net EEG could be of great value, as it allows a large amount of data to be analyzed. Conclusion: This analysis may be useful in studies and research related to diseases and symptoms, such as seizures, a current challenge for neonatal neuromonitoring, as well as aspects of neurological development and functional studies. However, despite many advances in technology, electroencephalography in preterm neonates remains a challenge worldwide and still requires more robust research and efforts towards the best clinical assistance in this extremely early stage of life.
RESUMO Métodos para avaliar a atividade cortical em neonatos têm grande importância na Medicina moderna, pois permitem a observação e avaliação de diversos aspectos clínicos, garantindo que a equipe de saúde tenha conhecimento sobre possíveis medidas de intervenção que possam ser necessárias no tratamento de recém-nascidos. Objetivo: Esta revisão sistemática tem como objetivo comparar as principais tecnologias disponíveis para a avaliação das funções cerebrais em neonatos: eletroencefalograma convencional (EEG), eletroencefalograma de amplitude integrada (aEEG) e eletroencefalograma da rede do sensor geodésico. Métodos: Os artigos foram selecionados em periódicos nacionais e internacionais, incluídos nas bases de dados eletrônicas Web of Science, LILACS, SciELO e Medline. Resultados: Foram encontrados 39 artigos de interesse entre 155 artigos. As análises indicaram que, em relação ao ambiente clínico, o uso associativo de EEG convencional e aEEG é altamente recomendado, pois permite a combinação de funções, facilitando, por exemplo, que um maior número de convulsões sub-clínicas seja detectado. Por outro lado, o uso do eletroencefalograma da rede do sensor geodésico seria de grande valor, uma vez que permite que uma grande quantidade de dados seja analisada. Conclusão: Essa análise pode ser útil em estudos e pesquisas relacionados a doenças e sintomas, como convulsões, um desafio atual para a neuromonitorização neonatal, bem como aspectos de desenvolvimento neurológico e estudos funcionais. No entanto, apesar de muitos avanços tecnológicos, a eletroencefalografia em recém-nascidos prematuros ainda é um desafio em todo o mundo e requer pesquisas e esforços mais robustos para a melhor assistência clínica neste estágio extremamente precoce da vida.
Subject(s)
Humans , Infant, Newborn , Infant, Premature , Cerebral Cortex/diagnostic imaging , Electroencephalography/methods , Seizures/diagnostic imaging , Intensive Care Units, NeonatalABSTRACT
BACKGROUND: Although olfactory stimulation has been known to produce effects on human mood and cognition, the specific EEG patterns of activity was reported diversely. The purpose of this study was to investigate EEG changes by odorant using low resolution electromagnetic tomography (LORETA) in young healthy subjects. METHODS: The EEG's of nineteen (10 males, 9 females) non-smoking right-handed college students were recorded after odorant stimulation. A nineteen-channel EEG was recorded referenced to linked ears before and during olfactory stimulation. Olfactory stimulation was presented with lavender essential oil by blotter method. The LORETA power was computed from ten 2-s epochs, separately for the different EEG frequencies. The power values were logarithmically transformed and paired sample t-tests were done for each voxel and frequency band (1.5-30 Hz). Statistical results were displayed 3-dimensionally on the standard brain template. RESULTS: All subjects experienced positive feelings (relaxed and pleasant) by olfactory stimulation with lavender oil (p<0.01). The LORETA power of theta and alpha band was increased in the dorsolateral and medial frontal areas, predominantly in the posterior cingulate gyri. The alpha LORETA power was also increased in bilateral orbitofrontal regions and the left perisylvian region including the insular cortex. Beta power was increased in the posterior cingulated gyri and mesial temporal region, predominantly on the left side. CONCLUSIONS: These results suggest that olfaction associated with emotional feeling might induce brain electrical power changes not only in the limbic system but also in the neocortex with lateralization to the dominant hemisphere.