Lateralidade da atividade do sistema olivococlear medial eferente: estudo preliminar

Efferent Auditory Pathways Inhibition in Turner syndrome

PURPOSE

The goal of this study is to investigate the efferent auditory pathways inhibition in Turner's syndrome and to relate it to the cytogenetic profile.

METHODS

This is a cross-sectional study with a comparison group. A sample with 94 participants divided into two groups: The study group was a sample of 40 patients diagnosed with Turner's syndrome (17.6 years of age). The control group was composed of 54 volunteers (18.9 years of age), female, without syndrome. The selected individuals were submitted to efferent auditory pathways inhibition research.

RESULTS

The mean of the inhibitory effect of the efferent auditory pathway in the study group in the right ear was 0.4 dB and in the comparison group it was 1.9 dB, however in the left ear the mean of the inhibitory effect of the efferent auditory pathway was 1.4 dB in the study group and 0.8 dB in the comparison group. The inhibitory effect of the efferent auditory pathway was present in 14 individuals with monosomy and in 15 with other cytogenetic alterations.

CONCLUSIONS

In the study group, the efferent auditory pathways inhibition value was significantly higher in the left ear and significantly lower than the control group in the right ear. There was no significant difference in efferent auditory pathways inhibition of right ear and left ear between the karyotype types.

Peri-intraventricular hemorrhage: Study of the inhibitory effect of auditory efferent pathway

Abstract: Purpose: to determine the functioning of the efferent auditory system in premature newborns with intraventricular hemorrhage. Method: the sample consisted of 44 newborns, divided into two groups. The study group was composed of 22 premature newborns with intraventricular hemorrhage/and the control group was composed of 22 newborns without intraventricular hemorrhage, matched to the study group for gestational age, correct gestational age and sex. The groups were submitted to the evaluation of the inhibitory effect of auditory efferent in otoacoustic emissions (equipment ILOv6-Otodynamics Ltda®) and auditory evoked potential with and without contralateral noise (equipment SmartEP-Intelligent Hearing Systems®). Results: newborns with intraventricular hemorrhage exhibited a higher occurrence of central hearing alteration as well as a lesser occurrence of the inhibitory effect of auditory efferent in otoacoustic emissions and auditory evoked potential compared to the newborns without this condition. An association was found between central hearing alteration and a lower occurrence of inhibitory effect. Agreement was found between the inhibitory effect test on otoacoustic emissions and latency of the auditory evoked potential. Conclusion: premature newborns with intraventricular hemorrhage have a greater occurrence of functional abnormality of the afferent auditory system, which can be effectively identified through an evaluation of the inhibitory effect of auditory efferent in otoacoustic emissions evoked by a transient stimulus and latency parameter in the brainstem auditory evoked potential.

Electroacoustic and electrophysiological auditory assessment in aphasic individuals

ABSTRACT Purpose: to verify the functioning of the outer hair cells and the medial efferent olivocochlear system, and the integrity of the auditory pathways in the brainstem up to the auditory cortex, in aphasic individuals. Methods: the sample comprised 20 individuals - 10 without aphasia and 10 with it, aged from 21 to 58 years. The procedures used were the research of the otoacoustic emissions by a transient stimulus with and without noise, and the cognitive potential (tone-burst and speech stimuli). The findings were analyzed based on descriptive statistics. Results: the suppression effect was more present in individuals without aphasia when compared with the aphasic ones. In the cognitive potential, the mean latency values of P3 was within normality standards, with a higher latency in the individuals presented with aphasia for the tone-burst stimulus in both ears. A statistically significant difference of the P3-N2 amplitude was observed for the tone-burst stimulus, comparing the ears in both groups, and for speech stimulus only to the left ear in both groups. Conclusions: aphasic individuals did not present significant differences regarding suppression of the otoacoustic emissions. As for the cognitive potential, the aphasic individuals presented higher latency values when compared to those with no aphasia.