Cognitive Assessment in Elderly Cochlear Implant Recipients: Long-Term Analysis

Abstract

Objectives: To examine long-term speech and cognition outcomes in older adult cochlear implant (CI) recipients. First, by evaluating if CI performance was maintained over an extended follow-up period regardless of preoperative cognitive status. Secondly, by evaluating if there was a difference in the rate of cognitive decline between preoperative mild and normal cognition following CI over an extended period of time.

Study design and setting: Retrospective cohort study.

Methods: CI recipients ≥65 years of age implanted between 2009 and 2014 with 4+ years follow up. Pre- and postoperative audiometric and speech outcome assessments were collected. Cognitive status was measured using the mini mental status examination (MMSE) at numerous time points.

Results: Fifty-three patients met inclusion. Patients were divided into two groups based on preoperative MMSE with scores considered normal (28-30) and those with mildly impaired cognition (MIC, scores 25-27). Audiometric and speech performance improved significantly at one-year post implantation and this was maintained without significant change at 4+ years, regardless of cognitive status. Mixed modeling analysis controlling for age demonstrated no significant difference in the rate of cognitive decline at 4+ years post implantation between the normal cognition cohort (1.74; 95%CI 0.89-2.6) and MIC (2.9; 95%1.91-3.88).

Conclusion: Speech performance was significantly improved and sustained after CI in both normal cognition and MIC patients. The rate of cognitive decline in older adult CI patients appears to be similar regardless of preoperative cognitive status. Although results demonstrate rates of cognitive decline following CI did not differ between cognition groups over 4+ years, future studies will need to further investigate this over extended time periods with a more comprehensive cognitive testing battery.

Level of evidence: 4 Laryngoscope, 133:2379-2387, 2023.

Keywords: Cochlear implant; cognition; elderly; hearing loss; mini mental status examination.