ABSTRACT
UNLABELLED: Mismatch Negativity (MMN) is a long-latency auditory evoked potential that provides an objective index of discrimination skills and auditory sensorial memory. It may, therefore, be used as an electrophysiological evaluation of central auditory processing. AIM: To study MMN in patients with Central Auditory Processing Disorder - CAPD. STUDY METHOD: A prospective clinical study. MATERIAL AND METHOD: Eight individuals with CAPD, aged between nine and 14 years, were evaluated; there was also a control group. MMN was elicited for tone stimuli (tone bursts), differing in terms of frequency (MMNf - standard stimulus: 750 Hz and deviant stimulus: 1,000 Hz ), as well as duration (MMNd - standard stimulus: 100 ms and deviant stimulus: 50 ms; at 1,000 Hz). RESULTS: The presence of MMNf and of MMNd was statistically demonstrated in both groups. No significant statistical differences, however, were observed between MMNf and MMNd latencies and amplitude values in the two groups. Also, no significant statistical differences were observed between the MMNf and the MMNd among the groups. CONCLUSION: The CAPD individuals that were evaluated showed no changes in MMNf or MMNd.
Subject(s)
Auditory Perceptual Disorders/physiopathology , Evoked Potentials, Auditory/physiology , Hearing/physiology , Acoustic Stimulation/methods , Adolescent , Auditory Perception/physiology , Case-Control Studies , Child , Female , Humans , Male , Prospective Studies , Reaction TimeABSTRACT
O Mismatch Negativity (MMN) é um potencial evocado auditivo de longa latência que fornece uma medida objetiva das habilidades de discriminação e memória sensorial auditiva. Assim, pode ser utilizado como uma avaliação eletrofisiológica do processamento auditivo (central). OBJETIVO: Estudar o MMN em pacientes com Distúrbios do Processamento Auditivo (Central) - DPA(C). FORMA DO ESTUDO: Clínico prospectivo. MATERIAL E MÉTODO: Foram avaliados oito sujeitos com DPA(C), na faixa etária de nove a 14 anos, bem como um grupo controle. O MMN foi eliciado para estímulos tonais (tone bursts) diferindo quanto à freqüência (MMNf - estímulo padrão: 750Hz e estímulo diferente: 1000Hz ), bem como quanto à duração (MMNd - estímulo padrão: 100 ms e estímulo diferente: 50 ms; na freqüência de 1000Hz). RESULTADOS: A presença do MMNf e do MMNd foi comprovada estatisticamente em ambos os grupos estudados. Não foram constatadas diferenças significantes estatisticamente entre os valores de latência e de amplitude do MMNf e do MMNd obtidos nos dois grupos. Também não foram verificadas diferenças significantes estatisticamente entre o MMNf e o MMNd em nenhum dos grupos estudados. CONCLUSÃO: Os sujeitos com DPA(C) avaliados não apresentaram alterações no MMNf, nem no MMNd.
Mismatch Negativity (MMN) is a long-latency auditory evoked potential that provides an objective index of discrimination skills and auditory sensorial memory. It may, therefore, be used as an electrophysiological evaluation of central auditory processing. AIM: To study MMN in patients with Central Auditory Processing Disorder - CAPD. STUDY METHOD: A prospective clinical study. MATERIAL AND METHOD: Eight individuals with CAPD, aged between nine and 14 years, were evaluated; there was also a control group. MMN was elicited for tone stimuli (tone bursts), differing in terms of frequency (MMNf - standard stimulus: 750 Hz and deviant stimulus: 1,000 Hz ), as well as duration (MMNd - standard stimulus: 100 ms and deviant stimulus: 50 ms; at 1,000 Hz). RESULTS: The presence of MMNf and of MMNd was statistically demonstrated in both groups. No significant statistical differences, however, were observed between MMNf and MMNd latencies and amplitude values in the two groups. Also, no significant statistical differences were observed between the MMNf and the MMNd among the groups. CONCLUSION: The CAPD individuals that were evaluated showed no changes in MMNf or MMNd.
