Hearing Loss and Dementia: Where to From Here?

Victorian era psychologists were the first to comment on associations between sensory and cognitive function. More recently, hearing loss has been shown as a marker of risk for dementia. However, it is not known whether this association represents a causal impact of hearing loss, nor whether treating hearing loss may help prevent dementia. Most studies on relationships between hearing loss and cognitive outcomes are observational, are at risk of confounding, and cannot reach conclusions about causation. A recent high quality randomized controlled trial, relatively uncommon in audiology, reported no impact of a comprehensive hearing intervention in mitigating cognitive decline in older adults. Although secondary analysis revealed potential benefits in a sub-sample of adults, this finding may be spurious. Encouraging policymakers, patients, and other health care practitioners to address hearing loss in terms of dementia prevention may be inappropriate on the grounds of both relevance at individual level and lack of clear evidence of benefit. In addition, advocating need to address hearing loss in terms of mitigating dementia risk may reduce the importance of addressing hearing loss in its own right. Linking hearing loss to dementia risk may also exacerbate the stigma of hearing loss, inadvertently discouraging people from seeking help for hearing. We suggest that treating hearing loss may have important benefits in preventing or delaying diagnosis of dementia via improving orientation and functioning in daily life, without changing the underlying pathology. Rather than linking hearing loss to dementia risk, we suggest a positive message focusing on the known benefits of addressing hearing loss in terms of improved communication, quality of life, and healthy aging.

Do people with cognitive impairment benefit from cochlear implants? A scoping review.

PURPOSE: To identify and evaluate the evidence for the benefits of cochlear implants for people with cognitive impairment or dementia in terms of speech recognition, quality of life, behavioural and psychological symptoms of dementia, cognition, function in daily life, mental well-being, and caregiver burden. METHODS: Ten electronic databases were searched systematically from inception to December 2023 for studies reporting on outcomes for cochlear implants that included adults identified with cognitive impairment, mild cognitive impairment, or dementia. RESULTS: Thirteen studies were included in this review with a combined total of 222 cochlear implant patients with cognitive impairment, mild cognitive impairment. Two studies were non-randomised controlled design, the remainder were single group studies, case series or single case studies. Evidence suggested that people with cognitive impairment benefit in terms of improved speech recognition from cochlear implants, although they may benefit less than those with healthy cognition and the degree of benefit depends on the level of cognitive impairment. There was no evidence for increased adverse events among those with cognitive impairment. There was limited or no evidence for any other outcome. CONCLUSION: People with cognitive impairment or dementia do benefit from cochlear implants. To inform policy and clinical practice, further data are needed about the broader benefits of cochlear implants for people with cognitive impairment or dementia, and referral, eligibility, and cochlear implant support needs for people with cognitive impairment and their caregivers.

What are the Correlates of Hearing Aid Use for People Living With Dementia?

OBJECTIVES: To identify correlates of hearing aid use in people with dementia and age-related hearing loss. METHODS: Bivariate and multivariate logistic regression analyses of predictor variables from 239 participants with dementia and hearing loss in the European SENSE-Cog Randomized Controlled Trial (Cyprus, England, France, Greece, and Ireland). RESULTS: In multivariate analysis, four variables were significantly associated with hearing aid use: greater self-perceived hearing difficulties (OR 2.61 [CI 1.04-6.55]), lower hearing acuity (OR .39 [CI .2-.56]), higher cognitive ability (OR 1.19 [CI 1.08-1.31]), and country of residence. Participants in England had significantly increased odds of use compared to Cyprus (OR .36 [CI .14-.96]), France (OR .12 [CI .04-.34]) or Ireland (OR .05 [CI .01-.56]) but not Greece (OR 1.13 [CI .42-3.00]). CONCLUSIONS: Adapting interventions to account for cognitive ability, country of residence, self-perceived hearing difficulties, and hearing acuity may support hearing aid use in people with dementia.

Enablers and Barriers to Hearing aid Use in People Living With Dementia.

Hearing loss is highly prevalent in dementia; however, people with dementia are less likely to use hearing aids consistently than people with intact cognition are. This qualitative study is the first of its kind to explore factors that influence hearing aid use from the perspective of community-living people with mild to moderate dementia and their care partners. Eleven UK-based dyads from the European SENSE-Cog Randomized Controlled Trial of a sensory intervention for people with dementia completed semi-structured interviews based on the Theoretical Domains Framework (TDF). Our findings suggest that the TDF domains environmental context and resources, behavioral regulation, reinforcement, and social influences are of greatest relevance to hearing aid use in dementia. Within these domains, we identified a range of factors that may influence the target behavior of hearing aid use. The findings suggest that adoption of multifaceted, flexible intervention approaches may support hearing aid use in dementia.

"I don't really know how to help her." Family caregivers' capabilities, opportunities and motivations to provide hearing support to long-term care home residents with dementia.

PURPOSE: Hearing loss is highly prevalent in long-term care home (LTCH) residents with dementia ("residents") and exacerbates confusion and communication difficulties. Residents rely on caregivers, including family, for hearing-related care. This study aims to understand the drivers of family caregivers' provision of hearing support to LTCH residents using the Behaviour Change Wheel. MATERIALS AND METHODS: This exploratory two-stage study was guided by the Capability, Opportunity, Motivation-Behaviour (COM-B) model and the Theoretical Domains Framework (TDF). A self-report survey (N = 87) and interviews (N = 6) explored drivers behind the provision of hearing support. Quantitative data were analysed using descriptive statistics and a within-participants ANOVA. Deductive coding of TDF domains alongside thematic analysis was used for qualitative data. RESULTS: Provision of hearing support was variable. Gaps in family caregivers' psychological capability, reflective motivation and physical opportunity were identified. Barriers included lacking knowledge, unclear caregiver responsibilities, deprioritising hearing support, COVID-19 restrictions and fragmented collaborations with audiology services. CONCLUSIONS: Future behaviour-change interventions to facilitate family caregivers' provision of hearing support to LTCH residents should include: Improving knowledge of how to provide effective hearing support, establishing caregiver responsibilities and increasing the resources for hearing support within LTCHs.

Interventions to aid family caregivers in providing hearing support for their relative with dementia should be designed to address gaps in capabilities, opportunities and motivations, as barriers are present in all three constructs.Audiologists should signpost family caregivers to educational resources about traditional hearing aids and assistive listening devices to be used within the long-term care homes (LTCH) and understand the benefits of domiciliary audiology appointments for LTCH residents.Care staff and family to discuss roles and responsibilities for hearing support and document these in care plans when the resident first moves to the LTCH e.g., accompanying resident to external audiology appointments.

A longitudinal study investigating the effects of noise exposure on behavioural, electrophysiological and self-report measures of hearing in musicians with normal audiometric thresholds.

Musicians are at risk of hearing loss and tinnitus due to regular exposure to high levels of noise. This level of risk may have been underestimated previously since damage to the auditory system, such as cochlear synaptopathy, may not be easily detectable using standard clinical measures. Most previous research investigating hearing loss in musicians has involved cross-sectional study designs that may capture only a snapshot of hearing health in relation to noise exposure. The aim of this study was to investigate the effects of cumulative noise exposure on behavioural, electrophysiological, and self-report indices of hearing damage in early-career musicians and non-musicians with normal hearing over a 2-year period. Participants completed an annual test battery consisting of pure tone audiometry, extended high-frequency hearing thresholds, distortion product otoacoustic emissions (DPOAEs), speech perception in noise, auditory brainstem responses, and self-report measures of tinnitus, hyperacusis, and hearing in background noise. Participants also completed the Noise Exposure Structured Interview to estimate cumulative noise exposure across the study period. Linear mixed models assessed changes over time. The longitudinal analysis comprised 64 early-career musicians (female n = 34; age range at T0 = 18-26 years) and 30 non-musicians (female n = 20; age range at T0 = 18-27 years). There were few longitudinal changes as a result of musicianship. Small improvements over time in some measures may be attributable to a practice/test-retest effect. Some measures (e.g., DPOAE indices of outer hair cell function) were associated with noise exposure at each time point, but did not show a significant change over time. A small proportion of participants reported a worsening of their tinnitus symptoms, which participants attributed to noise exposure, or not using hearing protection. Future longitudinal studies should attempt to capture the effects of noise exposure over a longer period, taken at several time points, for a precise measure of how hearing changes over time. Hearing conservation programmes for "at risk" individuals should closely monitor DPOAEs to detect early signs of noise-induced hearing loss when audiometric thresholds are clinically normal.

A cross-cultural study of the Montreal Cognitive Assessment for people with hearing impairment.

BACKGROUND: Cognitive screening tools enable the detection of cognitive impairment, facilitate timely intervention, inform clinical care, and allow long-term planning. The Montreal Cognitive Assessment for people with hearing impairment (MoCA-H) was developed as a reliable cognitive screening tool for people with hearing loss. Using the same methodology across four languages, this study examined whether cultural or linguistic factors affect the performance of the MoCA-H. METHODS: The current study investigated the performance of the MoCA-H across English, German, French, and Greek language groups (n = 385) controlling for demographic factors known to affect the performance of the MoCA-H. RESULTS: In a multiple regression model accounting for age, sex, and education, cultural-linguistic group accounted for 6.89% of variance in the total MoCA-H score. Differences between languages in mean score of up to 2.6 points were observed. CONCLUSIONS: Cultural or linguistic factors have a clinically significant impact on the performance of the MoCA-H such that optimal performance cut points for identification of cognitive impairment derived in English-speaking populations are likely inappropriate for use in non-English speaking populations. To ensure reliable identification of cognitive impairment, it is essential that locally appropriate performance cut points are established for each translation of the MoCA-H.