Evaluating the Impact of Cochlear Implantation on Cognitive Outcomes in Older Adults: A 5-Year Follow-Up

Objective: To assess the long-term impact of cochlear implantation (CI) on cognitive outcomes in older adults 5 years post-implantation. Study design: Prospective, interventional study. Setting: Tertiary care center. Patients: Cochlear implant recipients aged 65 or older. Interventions: Subjects underwent preoperative cognitive testing with a novel battery of validated neuropsychological tests including those assessing global cognition (Mini-Mental Status Exam), verbally based cognition (Digit span, Stroop, Hopkins Verbal Learning Test-Revised, Hayling Sentence Completion) and comparable visually-based cognition [Spatial span, d2 Test of Attention, Brief Visuospatial Memory Test-Revised (BVMT-R), Trail Making Test Part B]. Testing was repeated 5 years postoperatively. Main outcome measures: Cognitive outcomes assessed with cognitive testing battery. Results: After 5.71±1.14 years after CI, 16 subjects (mean age 83±7.22 y, 93.75% male, 87.5% with normal preoperative cognitive status) repeated the cognitive battery. In comparison to preoperative testing, subjects showed stable performance on 4 of 11 cognitive test scores, including those assessing global cognition, auditory attention, verbal learning and memory, and auditory-based executive functioning. Conversely, there was a significant decrease on a verbal test of executive functioning (Stroop Color-Word: Z=-2.557, P =0.011) and all visually based tests of attention (d2 total correct scores Z=-2.667, P =0.008; spatial span total score: Z=-2.388, P =0.017, BVMT-R: total raw score Z=-2.615, P =0.009, BVMT-R delayed raw score Z=-2.829, P =0.005; trails B seconds: Z=-2.158, P =0.031). Conclusions: In a 5-year follow-up of CI, participants demonstrated stability on a global scale in addition to 3 other verbally based cognitive measures. When contrasted with declines on all visually based analog cognitive tests, these preliminary findings in a small and select sample, suggest a beneficial role of CI in enhancing cognition in older recipients. Professional practice gap and educational need: The long-term effect of CI on cognitive status of older adults who are at risk of dementia associated with hearing loss. Learning objective: Learners will better understand the long-term impact of CI on cognition in older adults. Desired result: To demonstrate that CI in older adults can improve cognition in certain domains, whereas other domains are unaffected or continue to decline with age. Level of evidence: Level III. Indicate irb or iacuc: IRB 00083983, The University of Utah.