Evaluation of Cognitive Functioning Before and After Cochlear Implantation in Adults Aged 55 Years and Older at Risk for Mild Cognitive Impairment

Importance: Given the rapidly rising dementia incidence, management of modifiable risk factors, such as hearing loss, is vital. Multiple studies have demonstrated an improvement of cognitive functioning in older adults with severe hearing loss after cochlear implantation; however, few of these studies, to the authors' knowledge, specifically analyzed participants achieving poor cognitive results preoperatively. Objective: To evaluate the cognitive functioning of older adults with severe hearing loss at risk for mild cognitive impairment (MCI) before and after cochlear implantation. Design, Setting, and Participants: This prospective, longitudinal cohort study performed at a single center reports data obtained over a 6-year period (April 2015 to September 2021) of an ongoing prospective, longitudinal cohort study on cochlear implant outcomes in older adults. A consecutive sample of older adults with severe hearing loss eligible for cochlear implantation was included. All participants obtained a Repeatable Battery for the Assessment of Neuropsychological Status for hearing-impaired patients (RBANS-H) total score indicative of MCI preoperatively. Participants were assessed before cochlear implant activation and 12 months after cochlear implant activation. Intervention: The intervention consisted of cochlear implantation. Main Outcome and Measure: The primary outcome measure was cognition, measured by the RBANS-H. Results: A total of 21 older adult cochlear implant candidates were included in the analysis (mean [SD] age, 72 [9] years; 13 [62%] men). Cochlear implantation was associated with an improvement of overall cognitive functioning 12 months after activation (median [IQR] percentile, 5 [2-8] vs 12 [7-19]; difference, 7 [95% CI, 2-12]). Eight participants (38%) surpassed the MCI cutoff (16th percentile) postoperatively, while the overall median cognitive score remained under this cutoff. In addition, participants' speech recognition in noise improved, with a lower score indicating improvement (mean [SD] score, +17.16 [5.45] vs +5.67 [6.3]; difference, -11.49 [95% CI, -14.26 to -8.72]), after cochlear implant activation. Improvement of speech recognition in noise was positively associated with improvement in cognitive functioning (rs, -0.48 [95% CI, -0.69 to -0.19]). Years of education, sex, RBANS-H version, and symptoms of depression and anxiety were not related to the evolution in RBANS-H scores. Conclusions and Relevance: In this prospective, longitudinal cohort study, cognitive functioning and speech perception in noise showed a clinically meaningful improvement 12 months after cochlear implant activation in older adults with severe hearing loss at risk for MCI, suggesting that cochlear implantation is not contraindicated in cochlear implant candidates with cognitive decline and should be considered after multidisciplinary evaluation.