Resposta da hemodinâmica cerebral para estímulos auditivos e sua relação com desempenho auditivo e de linguagem em crianças usuárias de implante coclear

Abstract

Introduction: Functional Near-Infrared Spectroscopy (fNIRS) records cerebral hemodynamics to speech stimuli in Cochlear Implant (CI) users. The characterization of fNIRS and the establishment of its association with auditorylinguistic development can contribute to prognosis and monitoring in this population. Purposes: To define the fNIRS acquisition parameters in CI users, through a systematic review and characterize the cortical responses obtained by fNIRS, associating such responses with auditory and language performance in a child using a Hearing Aids (HA) and CI. Method: Two studies were carried out. Study 1 is a systematic review of fNIRS acquisition parameters in CI users (Prospero, number CRD42022358346). The search took place in the following databases: PubMed, EMBASE, LILACS, Web of Science, Science Direct, Scopus, PsycINFO, CENTRAL, IEEE Xplore and in gray literature: Google Scholar web search; Proquest (theses and dissertations), with the acronym PECOS. Studies with CI users in any age group, submitted to fNIRS with speech stimuli, were included. Study 2, approved by the Institutional Ethics Committee under opinion number 5,989,435, is a clinical case of a girl, with a chronological age of eight years and an auditory age of five years and two months, user of CI in the left ear and hearing aids in the right ear undergoing auditory rehabilitation for five years. Clinical protocols were applied to characterize auditory-linguistic performance and fNIRS (NIRXSport1) with speech stimuli /ba/ and /da/ was presented in a free field, with electronic devices turned on, in a habituation and dishabituation paradigm to identify auditory detection and discrimination. Eight emitters and eight detectors were used, positioned in the temporal lobe of both cerebral hemispheres, totaling 20 channels. Results: In study 1,671 articles were found in the database and 216 in the search for additional literature. After removing duplicates, analyzing titles and abstracts in phase 1 and the complete work in phase 2, 18 studies from the database and one from additional literature were included, totaling 19. Of these, 13 presented a low risk of bias. The selected studies showed uniformity in the following fNIRS acquisition parameters in CI users: wakefulness (awake); use of auditory stimulation of words and phrases presented in a free field; display of visual stimuli; recording of the temporal region bilaterally and three centimeters between the optodes. In study 2, the child showed auditory and language development within the developmental milestones and cortical responses to speech stimuli, with no significant difference between the cerebral hemispheres. Final considerations: Although some of the fNIRS acquisition parameters in CI users are common, there are still divergences in their acquisition in this population due to the variability of the objectives of each research. Given the feasibility of this tool for visualizing brain physiological responses to speech stimuli, as observed in both studies carried out, it is important that multicenter studies are carried out to strengthen the applicability of fNIRS in prognosis and monitoring in auditory rehabilitation.