Central and peripheral auditory changes and cognitive decline in ageing

Hearing loss (HL) is a common disorder of the elderly, and is associated with communication difficulties and social isolation. Most recently, HL has been inconsistently linked to cognitive decline and it has been postulated that HL may be an independent risk factor for dementia. The aim of this thesis is to determine whether HL is associated with cognitive decline during normal and/or pathological ageing by specifically investigating contributions from peripheral HL, central auditory processing and the psychosocial pathway. Results show that central auditory processing was linked with cognition during normal and pathological ageing, but there was no independent association with peripheral hearing levels or psychosocial factors. The prevalence of HL was not significantly higher in the patient sample compared with matched controls, nor did HL influence the cognitive profiles in normal ageing or neurodegeneration. There was, however, a statistically significant interaction between HL and decline in executive function only in participants with HL who were high performers at baseline, thereby suggesting that peripheral HL is not an independent risk factor for cognitive decline. Higher scores on central auditory processing were associated with better performance on a test of visual long term memory, after controlling for the effects of peripheral HL, and could predict decline in cognitive performance over time on the Short Cognitive Evaluation battery. In keeping with this, the severity of pathological cognitive impairment was closely related to central auditory processing performance, and patients with mild cognitive impairment recruited the right hemisphere for linguistic processing, which was corroborated with findings of increased grey matter in the right auditory association areas. In summary, it was concluded that the inconsistent findings in the literature may be due to differing influence of HL on normal and pathological cognitive ageing. Peripheral and central hearing changes may be a marker of impending neuronal decline or vulnerability to dementia in people with pathological cognitive impairment, but during healthy ageing, HL does not influence cognitive performance or increase the risk of developing dementia

Testing central auditory processing abilities in older adults with and without dementia using the consonant-vowel dichotic listening task

Background: Hearing loss and dementia are linked, although the roles of peripheral and central auditory dysfunction are not well defined. Many behavioral measures of hearing are confounded by the overlapping cognitive functions required to perform the tests. Objective: To collect pilot data to identify how central auditory function, measured using a dichotic listening test that indexes both auditory and cognitive components under different attentional conditions, differs among people with mild cognitive impairment (MCI), dementia and controls, and how performance relates to neuropsychological results. Method: Fifty-eight participants (17 MCI, 11 dementia and 30 controls) undertook hearing screening, the Bergen consonant-vowel dichotic listening paradigm, and a short battery of neuropsychological tests chosen to index attention and executive control. Dichotic listening was assessed under three attentional conditions (non-forced, forced right ear and forced left) amongst older adults with normal cognitive function, MCI and dementia. Results: We report two main findings: (a) The expected right ear advantage under non-forced conditions, was seen in controls and patients with dementia but not in people with MCI, who showed equal numbers of correct responses from both ears (i.e., a lack of asymmetry); (b) Performance under forced attentional conditions was significantly associated with disease progression (i.e., control > MCI > dementia) and performance on the cognitive tasks. Conclusion: The reduction in asymmetry on dichotic listening tasks may be a marker of MCI and reflect underlying compensatory mechanisms. Use of this test could aid stratification of patients with memory disorders. Whether abnormalities could predict dementia onset needs longitudinal investigation in a larger sample

Self-reported hearing difficulties are associated with loneliness, depression and cognitive dysfunction during the COVID-19 pandemic

Objective To investigate whether hearing difficulties exacerbate the damaging effects of enforced social distancing due to the COVID-19 pandemic on isolation and loneliness, and lead to accelerated mental health issues and cognitive dysfunction. Design Rapid online survey. Participants completed a series of online questionnaires regarding hearing ability, socialisation (pre- and during-pandemic), loneliness, anxiety, depression and cognitive function. Study sample A total of 80 participants over the age of 70 with access to the internet. Results There was a significant reduction in socialisation levels from pre-pandemic in this population. Hearing difficulties were significantly associated with greater levels of loneliness, depression and self-perceived cognitive dysfunction after controlling for age, gender, and level of education. Additionally, compared to pre-pandemic, people with hearing difficulties had increased odds of reporting worsened anxiety, depression, and memory during the COVID-19 pandemic, although only the effect of hearing difficulties on the change in memory reached statistical significance after controlling for age, gender, and level of education. Conclusions The worse the self-reported hearing abilities are, the greater the negative impact of enforced social distancing on depression, loneliness and cognitive function

Hearing Assessment and Rehabilitation for People Living With Dementia

Hearing impairment commonly co-occurs with dementia. Audiologists, therefore, need to be prepared to address the specific needs of people living with dementia (PwD). PwD have needs in terms of dementia-friendly clinical settings, assessments, and rehabilitation strategies tailored to support individual requirements that depend on social context, personality, background, and health-related factors, as well as audiometric HL and experience with hearing assistance. Audiologists typically receive limited specialist training in assisting PwD and professional guidance for audiologists is scarce. The aim of this review was to outline best practice recommendations for the assessment and rehabilitation of hearing impairment for PwD with reference to the current evidence base. These recommendations, written by audiology, psychology, speech-language, and dementia nursing professionals, also highlight areas of research need. The review is aimed at hearing care professionals and includes practical recommendations for adapting audiological procedures and processes for the needs of PwD

International Practice Recommendations for the Recognition and Management of Hearing and Vision Impairment in People with Dementia

Hearing, vision, and cognitive impairment commonly co-occur in older people. However, the rate of recognition and appropriate management of combined hearing and vision impairment in people with dementia impairment is low. The aim of this work was to codevelop internationally relevant, multidisciplinary practice recommendations for professionals involved in the diagnosis, care, and management of older people with these concurrent conditions