Cochlear Implantation Is Associated with Reduced Incidence of Dementia in Severe Hearing Loss

Abstract

Objectives: Hearing loss is recognized as a potentially modifiable risk factor for dementia in midlife. This study aimed to investigate the association between rehabilitation methods and dementia risk in patients with severe to profound hearing loss. Design: Using the nationwide population data from South Korea, individuals with severe to profound hearing loss were identified. Individuals aged 40 to 79 were then divided into 3 groups according to the type of auditory rehabilitation they received in the period between 2005 and 2010, namely cochlear implant (CI), hearing aid (HA), or no rehabilitation (NR). No hearing loss (NHL) group (with normal hearing) consisted of individuals without hearing loss. Dementia incidence was followed up to 2022. Results: The study involved 649 individuals in the CI group, 35,076 in the HA, 16,494 in the NR, and 1,280,788 in the NHL group. The groups that received auditory rehabilitation (HA and CI groups) had a significantly reduced risk of dementia compared with the NR group, with the CI group showing the most pronounced reduction. The CI group demonstrated a lower risk of dementia than the HA group and had a similar dementia risk to the NHL group. Conclusions: In individuals with severe to profound hearing loss, rates of dementia were lower in CI users than in HA users. Moreover, the risk of dementia in those undergoing CI surgery is comparable to that of individuals with normal hearing.