How can near infrared spectroscopy be informative about the brain activation of children using a hearing implant? Preliminary case-control findings

ABSTRACT The auditory rehabilitation mechanism with cochlear implants can activate specific cortical regions of the brain similar to those of hearing people. Near-infrared spectroscopy (fNIRS) is a neuroimaging tool that makes it possible to evaluate the cortical development of implanted children. Objective: To investigate the molecular imaging response, reflected by difference in cortical oxygenation, in a deaf child with a cochlear implant compared to hearing children, observe and report auditory performance verifying correspondence with fNIRS findings. Methods: Comparative case study using the fNIRS technique to evaluate the child's cortical activation on the day of device activation with three hearing children of the same hearing age. The recorded data was processed with Brainstorm software and statistical analysis was performed with the Power F test in relation to the baseline and the Permutation test for comparison. Longitudinal analysis of the implanted child's audiological data was carried out, as well as auditory perception and language questionnaires. Results: No statistical differences were found between cortical activation of the implanted child and hearing children of the same hearing age. An improvement in the child's auditory perception and language performance can be observed after using the implant. Conclusion: The evolution of auditory responses was observed, showing cortical maturation after activation of the cochlear implant seen in the molecular image, concomitantly with the use of hearing aids and speech therapy. It was observed that fNIRS is a neuroimaging technique capable of recording cortical changes in children with and without implants, being a promising tool.