The effect of cochlear implant on auditory cortical plasticity in children with congenital deafness

 A cochlear implant (CI) is now the standard treatment option for management of children with profound hearing loss. Cortical auditory evoked potential (CAEP) is a non-invasive procedure that can be used to objectively assess the maturation of the auditory cortex in children. The objective of current study was to investigate the effect of CI on central auditory plasticity in children through a novel CAEPs recording. Subjects and

In this analytic cross-sectional study, 42 children with profound prelingual hearing loss (age range: 2-3 years) participated. The CAEP responses were recorded across "before implantation ", "4-month post-implantation", and "8-month post-implantation" time points via HearLab system. For all children, the latency and wave amplitude of P1 wave was determined in response to /m/, /g/ and /s/ speech stimuli.

The maen latency of P1 wave was significantly reduced for all speech stimuli after implantation compared to pre-CI time point (p <0.001). Similarly, the amplitude of P1 was significantly increased for after CI compared to pre-CI condition (p <0.001). Furthermore, the comparison of the latency and wave amplitude of the P1 in response to different speech stimuli demonstrated that the lowest latency and the largest amplitude was belong to /g/, and /m/ stimuli, respectively.

Our findings indicated that the latency and amplitude of CAEPs after implantation were reduced and increased, respectively. These results providing a document for increased neural activity (neuroplasticity) in auditory cortex region in children who underwent cochlear implantation at appropriate time.