Potencial evocado auditivo de longa latência-P300 em indivíduos normais: valor do registro simultâneo em Fz e Cz

Abstract

O P300 é um Potencial Evocado Auditivo denominado potencial endógeno por refletir o uso funcional que o indivíduo faz do estímulo auditivo, sendo altamente dependente das habilidades cognitivas, entre elas atenção e discriminação auditiva. É um procedimento de avaliação objetiva, mas que depende da experiência do avaliador em detectar os picos das ondas, sendo importante a utilização de métodos de registro que facilitem a análise da presença de resposta e a interpretação dos resultados. OBJETIVO: Analisar o Potencial Evocado Auditivo de Longa Latência-P300 obtido com a utilização de dois eletrodos ativos posicionados em Fz e Cz. MATERIAIS E MÉTODOS: Participaram deste estudo 33 indivíduos de ambos os gêneros com idade entre 7 e 34 anos, audição normal e sem fator de risco para problemas mentais. RESULTADOS: Os resultados demonstraram que não houve diferença estatisticamente significante para a latência de N2 e P3 e amplitude do P3 quando analisado o gênero e nem correlação com a idade dos indivíduos. Houve forte correlação destas medidas com o posicionamento dos eletrodos em Fz e Cz. CONCLUSÃO: O posicionamento dos eletrodos ativos em Fz e Cz pode ser considerado um recurso a mais para auxiliar na análise clínica do P300.

Potencial evocado auditivo de longa latência: diferenças na forma de contagem do estímulo raro

“…The same data were evident in the literature 24 on studies showing significant differences between genders in N1, P2 and N2 latencies, being the major latencies in males, treating healthy young adults in a normative study. Our study disagrees with the literature findings of a study 3 with normal subjects that take into account the simultaneous recording value in Fz and Cz, which found no statistically significant difference between genders for latency of N2 components.…”

“…A sequence of waves takes part of LLAEPs, they are: positive 1 (P1), negative 1 (N1), positive 2 (P2), negative 2 (N2) and positive 3 (P3) 2 . The potential (P1, N1, P2, N2) are considered to be exogenous to be influenced by the physical characteristics of the stimulus, such as intensity, duration and frequency 3 and the potential P3 is the delayed wave that appears after the P1-N1-P2-N2 complex with latency of approximately 300ms in individuals with normal integrity and functionality of cortical structures. This potential is considered endogenous; it depends on the individual attention span, different from the potential P1, N1, P2 and N2, which are exogenous and not dependent on the individual's attention to be elicited.…”

“…The cortical potentials suffer interference factors such as test parameters (intensity, type of stimulus, task type, interval between stimulus) and conditions of the individual (age, gender, cognitive skills, body temperature) 5 . Therefore, P3 is influenced mainly by events related to cognitive abilities, being used as an investigative tool of information processing -coding, selection, memory and decision-making 1,3 . So that P3 is generated, it is required to occur discrimination of a rare stimulus, among others frequent the same modality and different physical characteristics 6,7 .…”

Resolução temporal e potenciais corticais em diferentes níveis de proficiência da língua inglesa

“…Part of the positive and negative waves LLAEP, subdivided into potential exogenous or cortical evoked potentials (P1, P2, N1, N2), which are influenced by the physical characteristics of the stimulus, such as intensity, duration and frequency, and the endogenous or cognitive potential (P3), predominantly influenced by events related to cognitive skills 7 .…”

Audição e linguagem em crianças nascidas a termo e pré-termo

“…Currently, the Cortical Auditory Evoked Potential (CAEP) has been used to evaluate the onset of cortical processing, in other words, the detection at the level of the auditory cortex (3) . The positive wave 1 (P1), negative 1 (N1), positive 2 (P2) are part of CAEP, which are called exogenous components of the Long Latency Auditory Evoked Potential (LLAEP), as they are influenced by the physical characteristics of the stimulus, such as intensity, duration and frequency (4) and they do not depend on any response of the evaluated subject (3) . CAEP emerged as a procedure that is able to measure the degree of maturation of the central auditory pathways in an objective way by analyzing the changes concerning morphology and latency values of P1-P2-N1 components, over time (4,5) .…”