Auditory middle latency evoked responses: a standardizing study

Abstract

The presence of auditory middle latency evoked responses allows us to make an evaluation of the peripheral and central auditory system integrity , as well as the nucleus and auditory ways existing until the level of the thalamus-cortical region and primary auditory cortex.

Aim: Our objective is to evaluate the presence or not of this numerous peaks, as well as, their latencies and intervals and extend to make a standardizing study. WAY OF STUDY: Contemporary study of Coorte with transversal cut and the outline was quantitative, descriptive e non experimental.

Material and method: Studying several peaks, positives and negatives, caused by the middle latency auditory potentials, in a population of young adults individuals, ranging from 18 to 30 years old, from both genders, with normal hearing. It was used a monoauricular resonant stimulation and a capitation, separately, in both cerebral hemispheres, with surface electrodes.

Results: In this research was verified that the analyzed crossings did not present statistically significant results and it was stipulated a pattern from the obtained results. Based on the non-statistical difference found we can affirm that to the Po waves was obtained respectively an average and standard deviation of 12,09 and 1,84; for Na 17,91 and 2,60; for Pa 29,41 and 5,66; for Nb 41,43 and 8,89; to for 51,44 ms e 12,63 and finally to the interval Na-Pa 11,52 and 4,99.

Conclusion: 1- The presence of the defluxions Po, Na, and Pa was verified in all the registers, whereas the defluxions Nb and Pb were absent in only 06 registers. 2- By having these registers, we evaluated that the inveiglement of these defluxions can be used as a reliable method to detect the average latency of the auditory potentials, by electrical generated activities, possibly in sites located in the thalamus-cortical area, evoked by sonorous stimulation. From that point, we establish a pattern of responses for young ones with normal hearing, helping us with future studies in patients with alterations in the hearing system.

Graph 1

Analysis of the registries obtained for each wave (Po, Na, Pa, Nb and Pb) and the Na-Pa interval, with standard deviation values, in the various criteria of stimulation and capture, related to the individuals participating in this study.