Mismatch negativity in patients with (central) auditory processing disorders

Summary: 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. Keywords: hearing, auditory evoked potentials, hearing disorder