# Interpeak intervals of cortical components (P1-N1-P2): a comparative study between typical individuals and those with tinnitus disorder

## TL;DR

The study found that people with tinnitus have longer neural response times in certain brainwave components compared to those without tinnitus.

## Contribution

This study introduces new evidence linking tinnitus to altered central auditory processing through LLAEP interpeak interval analysis.

## Key findings

- Individuals with tinnitus had significantly longer P1-P2 interpeak intervals in both ears.
- There was a trend toward significance in N1-P2 interpeak intervals in the right ear.
- These findings suggest central auditory processing dysfunction in tinnitus patients.

## Abstract

To compare neural response times among cortical components of the Long-Latency Auditory Evoked Potential (LLAEP) by measuring latency and interpeak intervals in individuals with and without tinnitus.

This was an analytical, cross-sectional, and quantitative study. A total of 28 participants were included, divided into two groups: the Control Group, comprising 12 individuals without tinnitus perception, and the Study Group, comprising 16 individuals diagnosed with tinnitus disorder. Assessments were conducted over two sessions. Initially, all participants underwent a semi-structured anamnesis, basic audiological evaluation, behavioral tests of central auditory processing, as well as neuropsychological and tinnitus assessments. On the second day, verbal LLAEP and neurodiagnostic ABR were performed. The responses were compared by analyzing the latency of P1, N1, and P2 potentials. A between-group comparison was conducted using an independent sample t-test.

A statistically significant difference was observed in the interpeak intervals of P1-P2 potentials, as well as a trend toward significance in N1-P2 interpeak intervals between groups in the right ear. Additionally, a significant difference was found in P1-P2 interpeak intervals between groups in the left ear.

Individuals with tinnitus disorder exhibited longer interpeak intervals, suggesting central auditory processing dysfunction and increased neural response within auditory processing pathways.

Comparar tempo de resposta neural entre os componentes corticais do Potencial Evocado Auditivo de Longa Latência, medindo a latência e interpicos em indivíduos com e sem zumbido.

Estudo de caráter analítico, transversal e quantitativo. Participaram do estudo 28 indivíduos, divididos em dois grupos: Grupo Controle, composto por 12 indivíduos sem percepção do zumbido e Grupo Estudo, composto por 16 participantes com transtorno do zumbido. As avaliações foram divididas em dois dias. Inicialmente todos os pacientes foram submetidos a anamnese semi-estruturada, avaliação audiológica básica, testes comportamentais do processamento auditivo central, avaliação neuropsicológica e do zumbido. No segundo dia, foram realizados o PEAC-verbal e o PEATE-neurodiagnóstico. Foram comparadas as respostas da avaliação por meio da latência dos potenciais P1, N1, P2. A análise de comparação entre os grupos foi realizada por meio do teste T para amostras independentes.

Evidenciou-se diferença estatisticamente significante dos valores de interpicos dos potenciais P1-P2 e tendências à significância entre N1-P2 entre os grupos na orelha direita e na comparação de interpicos dos potenciais P1-P2 entre grupos na orelha esquerda.

Indivíduos com transtorno do zumbido apresentaram interpicos maiores, o que sugere desorganização do funcionamento auditivo central e aumento de resposta entre as interconexões neurais no processamento acústico.