Cognitive Performance, Sociodemographic Factors, Pure-Tone Audiometry, and their Association with Speech Discrimination: A Prospective Population-Based Study of 1,061 Older Adults.

OBJECTIVE: Hearing loss is increasingly recognized as a chronic disease state with important health sequelae. Although considered a central component of routine audiometric testing, the degree to which various patient factors influence speech discrimination is poorly characterized to date. The primary objective of the current work was to describe associations of cognitive performance, sociodemographic factors, and pure-tone audiometry with speech discrimination in older adults. STUDY DESIGN: Prospective study. SETTING: Olmsted County, Minnesota. PATIENTS: There were 1,061 study participants 50 years or older at enrollment in the population-based Mayo Clinic Study of Aging between November 2004 and December 2019 who underwent formal audiometric and cognitive testing included in the current investigation. MAIN OUTCOME MEASURES: The primary outcome measure was word recognition scores (WRSs; measured as <100% vs 100% as well as continuous), with pure-tone averages (PTAs; 0.5, 1, 2, and 3 kHz), age, sex, years of education, state area deprivation index (ADI) quintiles, and global cognition z scores as explanatory features. RESULTS: The mean (SD) age among the 1,061 participants was 76 (9) years with 528 (50%) males. Participant age [OR (95% CI) for a 10-year increase of 1.8 (1.4-2.3), p < 0.001], male sex [OR = 2.6 (1.9-3.7), p < 0.001], and PTA [OR for a 10-dB hearing loss increase of 2.4 (2.1-2.8), p < 0.001] were all significantly associated with <100% WRSs, with the greatest explanatory ability attributable to the PTA. Years of education ( p = 0.9), state ADI quintile ( p = 0.6), and global cognitive performance ( p = 0.2) were not associated with WRS. The multivariable model demonstrated strong predictive ability for less than perfect WRSs, with a c index of 0.854. Similar results were seen for WRSs analyzed as continuous, with the multivariable model resulting in an R2 value of 0.433. CONCLUSIONS: Although PTA exhibited the greatest influence on speech discrimination, advancing age and male sex both independently increased the likelihood of having worse speech discrimination among older adults, even after accounting for years of education, neighborhood-level socioeconomic disadvantage, and cognitive function. These findings help identify patient factors that can be instrumental when designing screening programs for adult-onset hearing loss.

Association between hearing loss and development of dementia using formal behavioural audiometric testing within the Mayo Clinic Study of Aging (MCSA): a prospective population-based study.

BACKGROUND: Hearing loss has been identified as a potential major modifiable risk factor for developing dementia. This study examined associations between formal behavioural pure-tone and speech audiometry assessed by an audiologist with development of dementia in the Mayo Clinic Study of Aging (MCSA). METHODS: The MCSA is a prospective population-based study examining the incidence, prevalence, and risk factors of mild cognitive impairment and dementia in Olmsted County, Minnesota, USA. Participants undergo clinical examinations with neuropsychological testing at enrolment and every 15 months. Participants were 50 years or older at enrolment between Nov 29, 2004, and Dec 23, 2019, who underwent formal behavioural audiometric evaluation by an audiologist due to concerns about hearing loss or as a part of annual comprehensive health assessments. Associations of pure-tone average (PTA) and word recognition scores (WRS) with the development of dementia were evaluated using Cox proportional hazards regression with age as the timescale, and associations with changes in cognitive testing scores over time were evaluated using linear mixed-effects models. FINDINGS: Among 1200 eligible participants, the mean age at enrolment was 79 years (SD 9), 593 (49%) were men, and 207 developed dementia during a mean of 7·0 years (SD 3·7) of follow-up. After adjusting for sex, years of education, smoking status, diabetes, hypertension, apolipoprotein E ε4 carriership, and hearing rehabilitation (defined as hearing aid or cochlear implant use), neither PTA (hazard ratio [HR] per 10-decibels hearing level increase of 0·99 (95% CI 0·89-1·12; p=0·91) nor WRS (HR per 10% decrease of 0·98, 95% CI 0·89-1 ·07; p=0·65) was significantly associated with the development of dementia. However, both PTA and WRS were significantly associated with poorer performance in cognitive testing over time: participants with a PTA higher than 25 decibels hearing level or a WRS lower than 100% had significantly worse declines in cognitive testing scores. Informant-based hearing difficulties assessed by the participant's study partner were significantly associated with the development of dementia (HR 1·95, 95% CI 1·45-2·62; p<0·0001). INTERPRETATION: In this prospective population-based study, subjective informant-based hearing difficulties were associated with development of dementia, whereas objective measures on formal behavioural audiometry were predictive of poorer performance on cognitive testing over time but not the development of dementia. Other factors related to central processing might potentiate the effects of peripheral hearing loss detected on behavioural audiometric testing. FUNDING: National Institute of Health, the Alexander Family Alzheimer's Disease Research Professorship of the Mayo Clinic, the GHR Foundation, the Mayo Foundation for Medical Education and Research, the Liston Award, the Schuler Foundation, the Rochester Epidemiology Project medical records linkage system, and the National Institute on Aging.

Cochlear Implants and Magnetic Resonance Imaging: Experience With Over 100 Studies Performed With Magnets in Place.

OBJECTIVE: To evaluate adverse events and feasibility of performing 1.5-T MRI in patients with cochlear implants (CI) and auditory brainstem implants (ABI). SETTING: Single tertiary academic referral center. PATIENTS: CI and ABI recipients undergoing 1.5-T MRI without internal magnet removal. INTERVENTION(S): MRI after tight headwrap application. MAIN OUTCOME MEASURES: Adverse events, patient tolerance. RESULTS: A total of 131 MR studies in 79 patients were performed, with a total of 157 study ears. Sixty-one patients (77%) had unilateral devices. Four patients (5%) underwent MRI with ABI magnets in place. Sixteen patients (20%) had MRI-compatible devices that did not require a head wrap. There were no instances of device stimulation, device malfunction, or excessive heating of the receiver-stimulator package. Magnet tilt requiring manual repositioning occurred during seven studies (4.5%) and magnet displacement requiring operative intervention occurred during seven studies (4.5%). Significant pain where imaging had to be discontinued occurred during three episodes (2%). No adverse events were noted among patients who underwent MRI with an MRI-compatible magnet. CONCLUSIONS: MRI with CI or ABI magnets in place is associated with a low prevalence of adverse events when performed in a controlled setting. Many partial magnet displacements can be corrected with firm manual pressure. Devices with magnets that align with the field within their housing were not associated with any adverse events and do not require immobilization of the magnet during the scan. These may be valuable in patients with known or anticipated need for MRI.