Efeitos do potencial de ação neural sobre a percepção de fala em usuários de implante coclear

Abstract

El ectrically Evoked Compound Action Potential is a measure of synchronous cochlear nerve fibers activity elicited by electrical stimulation of the cochlear implant. The electrophysiological nerve responses may contribute to explain the variability in individual performance of cochlear implant recipients. Aim: To compare speech perception tests' performances of cochlear implant users according to the presence or absence of intraoperative neural telemetry responses. Material and Method: Prospective study design with 100 "Nucleus 24" cochlear implant users divided in two groups according to the presence or absence of intraoperative neural telemetry responses. Speech perception tests were performed after 6 months of continuous use of the device and compared among groups. Results: Intraoperative action potentials were observed in 72 % of individuals. Open-set sentence test results were better in implant users who had neural telemetry responses when compared to implant users in whom this potential was absent (averages 82.8 % versus 41 %, p = 0.005). There was a strong association between post meningitis-related deafness and absence of intraoperative potentials. Conclusion: The absence of intraoperative neural telemetry responses was associated with worse performances in speech perception tests and meningitis as etiology of deafness. On the other hand, the presence of these potentials suggests excellent prognosis.

Longitudinal Analysis of the Absence of Intraoperative Neural Response Telemetry in Children using Cochlear Implants

“…The values obtained for the threshold of neural responses per electrode (1,6,11,16, and 22) were initially analyzed in a descriptive manner. The Mann-Whitney test was used to establish the relationships between the absence of response and age and the absence of response and length of deprivation…”

“…This is likely because in the present study, only children were analyzed, and otosclerosis is known to be predominantly present in the adult population. Electrodes 1,6,11,16, and 22 were tested using the default settings in the Custom Sound (Cochlear) software, which is programmed to record the NRT responses from the bundle of electrodes allocated in the cochlea. The recorded responses therefore must have originated from every cochlear area to detect possible tonotopic interferences in the ECAP responses.…”

“…3 Guedes et al found that the absence of responses was correlated with limited prognosis. 11 The continued use of CIs has tended to result in the emergence of the action potential after some months of stimulation. Even longitudinal studies on neural responses, however, have failed to mention the possibility of the appearance of a response or the average time required for the onset of such a response.…”

Speech perception in adolescents with pre-lingual hearing impairment with cochlear implants

“…nonetheless, it is necessary to review our concepts of benefit and good results, thus restructuring the pre-implant evaluation which started to emphasize language assessment, social insertion and expectations concerning the cochlear implant, besides enjoying hearing with a hearing aid 5,6 . The few studies about the benefits brought about by the cochlear implant to teenage patients have varied results [7][8][9][10] .…”

Implante coclear: correlação da recuperação neural, privação auditiva e etiologia

“…Studies have shown variation in the threshold and growth curve of the wave amplitude of ECAPs (4-7) among individuals and etiologies (4,5,6,8,9,10,11,12). Further research is necessary to correlate the refractory properties of the auditory nerve to the etiology of hearing loss, duration of deafness and responses to auditory nerve stimulation through the use of personal sound amplification products (PSAPs) before cochlear implantation.…”