PP416 - Evidence of Neuroplasticity in Older Adults Induced by Hearing Aid Use Through Auditory Evoked Potentials: Systematic Review and Meta-Analysis

Abstract:
This systematic review and meta-analysis evaluated the impact of hearing aid use on long-latency auditory evoked potentials (LLAEPs) in older adults with sensorineural hearing loss. Nine studies were included, with evidence suggesting that prolonged use of hearing aids can induce neuroplastic changes in the Central Auditory Nervous System (CANS), particularly in the latency and amplitude of P1, N1, and P2 components. However, the results were heterogeneous and inconsistent, highlighting the need for further research with rigorous methodologies. These findings have implications for optimizing auditory rehabilitation protocols in aging populations.

Summary:
Rationale/Purpose
Neuroplasticity, the capacity of the brain to reorganize itself in response to sensory stimulation, is a critical aspect of auditory rehabilitation. In older adults with sensorineural hearing loss (SNHL), the deprivation of auditory input can lead to maladaptive cortical reorganization, negatively impacting speech perception and cognitive function. Hearing aids (HAs) reintroduce auditory stimuli, potentially restoring cortical function. This systematic review and meta-analysis aimed to synthesize evidence on the effects of HA use on long-latency auditory evoked potentials (LLAEPs) in older adults to determine the extent of neuroplastic changes and their implications for rehabilitation.

Design
A comprehensive literature search was conducted in PubMed, Scopus, Web of Science, and Cochrane Library, including studies evaluating the impact of HAs on LLAEPs in adults aged 50 and older with SNHL. The inclusion criteria comprised studies with pre- and post-HA adaptation measures of LLAEP components (P1, N1, and P2) and a comparison of outcomes. Risk of bias was assessed using ROBINS-I and RoB 2 tools, and data were synthesized using meta-analytic techniques where appropriate.

Results
Nine studies met the inclusion criteria, encompassing 207 participants. The results indicated that prolonged HA use (≥6 months) was associated with a decrease in N1 and P2 latencies and an increase in P2 amplitude, suggesting enhanced cortical processing. However, shorter adaptation periods (≤12 weeks) yielded inconsistent results, indicating that cortical reorganization may require extended periods of stimulation. Meta-analysis revealed significant heterogeneity (I² ≥ 60%), reflecting variability in study designs, HA fitting protocols, and participant characteristics.

Conclusions
This review provides evidence that HA use can induce beneficial neuroplastic changes in the CANS of older adults, although the effects are influenced by factors such as duration of use and degree of hearing loss. The variability in results underscores the need for standardized research protocols and longitudinal studies to establish the clinical utility of LLAEPs as biomarkers of HA adaptation. These findings can inform clinicians on optimizing HA fitting and follow-up protocols to support long-term auditory and cognitive health in aging populations.