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Updated: Aug 9, 2025
Author Spotlight: Advancements in Impedance Monitoring for Cochlear Implant Surgery
Published on: August 4, 2023
Longitudinal Changes in BDNF and MMP-9 Protein Plasma Levels in Children after Cochlear Implantation
Monika Matusiak1,2, Dominika Oziębło2,3, Monika Ołdak2,3
1Oto-Rhino-Laryngosurgery Clinic, Institute of Physiology and Pathology of Hearing, M Mochnackiego 10, 02-042 Warsaw, Poland.
Insights
Early cochlear implantation in congenitally deaf children enhances auditory skill development. Younger children implanted before age 1 showed faster auditory progress and distinct neurotrophic factor (BDNF) level changes compared to older counterparts.
Area of Science:
- Neuroscience
- Audiology
- Developmental Pediatrics
Background:
- Congenital deafness impacts auditory development.
- Early intervention, such as cochlear implantation, is crucial.
- Age at implantation may influence outcomes and underlying biological mechanisms.
Purpose of the Study:
- To investigate the impact of age at cochlear implantation on auditory development.
- To analyze plasma levels of matrix metalloproteinase-9 (MMP-9) and brain-derived neurotrophic factor (BDNF) in relation to implantation timing.
- To compare outcomes between early (<1 year) and later (≥1 year) implanted children and a healthy control group.
Main Methods:
- Longitudinal study of 59 children undergoing cochlear implantation, divided into two age subgroups (early vs. later implantation).
- Measurement of plasma MMP-9, BDNF, and pro-BDNF levels at 0, 8, and 18 months post-implantation.
- Auditory development assessment using the LittlEARs Questionnaire (LEAQ); comparison with 49 age-matched healthy controls.
Main Results:
- The younger subgroup (implanted <1 year) exhibited higher BDNF levels at 0 and 18 months and lower initial LEAQ scores.
- Significant differences were observed in BDNF level changes (0-8 months) and LEAQ score changes (0-18 months) between subgroups.
- MMP-9 levels decreased over time in both subgroups; significant differences in protein levels were noted between the older subgroup and controls.
Conclusions:
- Early cochlear implantation (<1 year) is associated with faster auditory skill development and distinct neurotrophic factor profiles.
- Age at implantation significantly impacts neurobiological markers and auditory progress.
- Findings highlight the critical window for cochlear implantation in optimizing auditory outcomes.
Abstract:
Congenitally deaf children who undergo cochlear implantation before 1 year of age develop their auditory skills faster than children who are implanted later. In this longitudinal study, a cohort of 59 implanted children were divided into two subgroups according to their ages at implantation-below or above 1 year old-and the plasma levels of matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), and pro-BDNF were measured at 0, 8, and 18 months after cochlear implant activation, while auditory development was simultaneously evaluated using the LittlEARs Questionnaire (LEAQ). A control group consisted of 49 age-matched healthy children. We identified statistically higher BDNF levels at 0 months and at the 18-month follow-ups in the younger subgroup compared to the older one and lower LEAQ scores at 0 months in the younger subgroup. Between the subgroups, there were significant differences in the changes in BDNF levels from 0 to 8 months and in LEAQ scores from 0 to 18 months. The MMP-9 levels significantly decreased from 0 to 18 months and from 0 to 8 months in both subgroups and from 8 to 18 months only in the older one. For all measured protein concentrations, significant differences were identified between the older study subgroup and the age-matched control group.
