How Does Cochlear Implantation Lead to Improvements on a Cognitive Screening Measure?

Purpose Cognitive screening tools to identify patients at risk for cognitive deficits are frequently used by clinicians who work with aging populations in hearing health care. Although some studies show improvements in performance on cognitive screening exams when hearing loss intervention is provided in the form of a hearing aid or cochlear implant (CI), it is worth examining whether these improvements are attributable to increased auditory access to test items. This study aimed to examine whether performance and pass rate on a cognitive screening measure, the Montréal Cognitive Assessment (MoCA), improve as a result of CI, whether improved performance on auditory-based test items drives changes in MoCA performance, and whether postoperative MoCA performance relates to post-CI speech perception ability. Method Data were collected in adult CI candidates pre-implantation and 6 months postimplantation to examine the effect of intervention on MoCA performance. Participants were 77 CI users between the ages of 55 and 85 years. Participants completed the MoCA, administered audiovisually, and speech perception testing with monosyllabic (CNC) words at both intervals. Results Compared to 31 participants pre-operatively, 45 participants passed the MoCA postoperatively, which was a significant difference in pass rate. An improvement in MoCA scores could be attributed primarily to improvement in the "Delayed Recall" test domain, which was auditory based. Post-CI MoCA performance was related to post-CI CNC speech perception performance. Conclusions Improved performance and pass rates were demonstrated on the traditional MoCA test of cognitive screening from before to 6 months after CI. Improvements could primarily be attributed to better performance on a delayed recall task dependent on auditory access, and post-CI MoCA scores were related to post-CI speech perception abilities. Further studies are needed to investigate the application of cognitive screening tools in patients receiving hearing loss interventions, and these interventions' impact on patients' real-world functioning.