Hearing loss and cognition in the Baltimore Longitudinal Study of Aging

Associations Between Measures of Auditory Function and Brief Assessments of Cognition

Purpose The two primary purposes of this report are (a) to compare the results of three brief cognitive screens in older adults and (b) to examine associations between performance on each of the screens and auditory function measured either concurrently or 9 years earlier. Method This was a prospective longitudinal study of 98 adults (66 women) with baseline ages ranging from 40 to 85 years. The mean interval between T1 baseline and T2 follow-up measurements was 8.8 years with a range from 7 to 11 years. Measures of hearing threshold, gap detection, and auditory temporal-order identification were completed at T1 and T2. The Mini-Mental State Examination was completed at T1 and T2, whereas the Montreal Cognitive Assessment (MoCA) and A Quick Test were completed at T2 only. Results Higher scores and pass rates were obtained for the Mini-Mental State Examination than for the MoCA or the A Quick Test. The measures were moderately correlated among themselves and with the Wechsler Adult Intelligence Scale-Third Edition. Significant associations emerged frequently between auditory and cognitive functions, most often for the auditory measure of temporal-order identification, including dichotic measures of this ability. Conclusions From this evaluation, the MoCA emerged as the preferred test for clinicians desiring a quick assessment of the cognitive function of their older patients. Auditory temporal-order identification is associated with cognitive function and explains about 10%-20% of the variation in cognitive function independent of age and hearing loss. Supplemental Material https://doi.org/10.23641/asha.12986021.

The Influence of Aging, Hearing, and Tinnitus on the Morphology of Cortical Gray Matter, Amygdala, and Hippocampus

Age related hearing loss (presbycusis) is a natural process represented by elevated auditory thresholds and decreased speech intelligibility, especially in noisy conditions. Tinnitus is a phantom sound that also potentially leads to cortical changes, with its highest occurrence coinciding with the clinical onset of presbycusis. The aim of our project was to identify age, hearing loss and tinnitus related structural changes, within the auditory system and associated structures. Groups of subjects with presbycusis and tinnitus (22 subjects), with only presbycusis (24 subjects), young tinnitus patients with normal hearing (10 subjects) and young controls (17 subjects), underwent an audiological examination to characterize hearing loss and tinnitus. In addition, MRI (3T MR system, analysis in Freesurfer software) scans were used to identify changes in the cortical and subcortical structures. The following areas of the brain were analyzed: Heschl gyrus (HG), planum temporale (PT), primary visual cortex (V1), gyrus parahippocampus (PH), anterior insula (Ins), amygdala (Amg), and hippocampus (HP). A statistical analysis was performed in R framework using linear mixed-effects models with explanatory variables: age, tinnitus, laterality and hearing. In all of the cortical structures, the gray matter thickness decreased significantly with aging without having an effect on laterality (differences between the left and right hemispheres). The decrease in the gray matter thickness was faster in the HG, PT and Ins in comparison with the PH and V1. Aging did not influence the surface of the cortical areas, however there were differences between the surface size of the reported regions in the left and right hemispheres. Hearing loss caused only a borderline decrease of the cortical surface in the HG. Tinnitus was accompanied by a borderline decrease of the Ins surface and led to an increase in the volume of Amy and HP. In summary, aging is accompanied by a decrease in the cortical gray matter thickness; hearing loss only has a limited effect on the structure of the investigated cortical areas and tinnitus causes structural changes which are predominantly within the limbic system and insula, with the structure of the auditory system only being minimally affected.

Hearing Loss

Hearing loss is highly prevalent and may significantly affect how we age. Although the population is aging, relatively few adults receive treatment for hearing loss. Internists are a critical partner to audiologists and otolaryngologists in caring for the adult population with hearing loss. This review provides a primer on diagnosing and managing hearing loss.

Hearing Loss in Alzheimer's Disease Is Associated with Altered Serum Lipidomic Biomarker Profiles

Recent data have found that aging-related hearing loss (ARHL) is associated with the development of Alzheimer’s Disease (AD). However, the nature of the relationship between these two disorders is not clear. There are multiple potential factors that link ARHL and AD, and previous investigators have speculated that shared metabolic dysregulation may underlie the propensity to develop both disorders. Here, we investigate the distribution of serum lipidomic biomarkers in AD subjects with or without hearing loss in a publicly available dataset. Serum levels of 349 known lipids from 16 lipid classes were measured in 185 AD patients. Using previously defined co-regulated sets of lipids, both age- and sex-adjusted, we found that lipid sets enriched in phosphatidylcholine and phosphatidylethanolamine showed a strong inverse association with hearing loss. Examination of biochemical classes confirmed these relationships and revealed that serum phosphatidylcholine levels were significantly lower in AD subjects with hearing loss. A similar relationship was not found in normal subjects. These data suggest that a synergistic relationship may exist between AD, hearing loss and metabolic biomarkers, such that in the context of a pathological state such as AD, alterations in serum metabolic profiles are associated with hearing loss. These data also point to a potential role for phosphatidylcholine, a molecule with antioxidant properties, in the underlying pathophysiology of ARHL in the context of AD, which has implications for our understanding and potential treatment of both disorders.

Effects of cochlear hair cell ablation on spatial learning/memory

Current clinical interest lies in the relationship between hearing loss and cognitive impairment. Previous work demonstrated that noise exposure, a common cause of sensorineural hearing loss (SNHL), leads to cognitive impairments in mice. However, in noise-induced models, it is difficult to distinguish the effects of noise trauma from subsequent SNHL on central processes. Here, we use cochlear hair cell ablation to isolate the effects of SNHL. Cochlear hair cells were conditionally and selectively ablated in mature, transgenic mice where the human diphtheria toxin (DT) receptor was expressed behind the hair-cell specific Pou4f3 promoter. Due to higher Pou4f3 expression in cochlear hair cells than vestibular hair cells, administration of a low dose of DT caused profound SNHL without vestibular dysfunction and had no effect on wild-type (WT) littermates. Spatial learning/memory was assayed using an automated radial 8-arm maze (RAM), where mice were trained to find food rewards over a 14-day period. The number of working memory errors (WME) and reference memory errors (RME) per training day were recorded. All animals were injected with DT during P30-60 and underwent the RAM assay during P90-120. SNHL animals committed more WME and RME than WT animals, demonstrating that isolated SNHL affected cognitive function. Duration of SNHL (60 versus 90 days post DT injection) had no effect on RAM performance. However, younger age of acquired SNHL (DT on P30 versus P60) was associated with fewer WME. This describes the previously undocumented effect of isolated SNHL on cognitive processes that do not directly rely on auditory sensory input.

Heightening our vigilance towards patient well-being

OBJECTIVE

Audiology patients frequently experience psychosocial difficulties created by their hearing loss or exacerbated by the loss. Clinicians are not always attuned to the unstated emotional undercurrents which may signal a need for further discussion or referral. This article aims to heighten audiologists' vigilance towards patient well-being.

DESIGN

A series of case vignettes with sample dialogue demonstrate the need for heightened clinical awareness of confounding consequences patients may grapple with and possible responses to these issues.

CONCLUSIONS

Beyond hearing loss, contributing detractors to patient well-being can be difficult to recognise for clinicians, and exploration and discussions may feel challenging to broach. A heightened vigilance within patient care calls upon audiologists to be alert for concerns or conditions beyond hearing loss that may be threatening our patients or further decreasing the quality of their lives and that of their families.

Embedding and Sustaining a Focus on Function in Specialty Research and Care

Function and the independent performance of daily activities are of critical importance to older adults. Although function was once a domain of interest primarily limited to geriatricians, transdisciplinary research has demonstrated its value across the spectrum of medical and surgical care. Nonetheless, integrating a functional perspective into medical and surgical therapeutics has yet to be implemented consistently into clinical practice. This article summarizes the presentations and discussions from a workshop, "Embedding/Sustaining a Focus on Function in Specialty Research and Care," held on January 31 to February 1, 2019. The third in a series supported by the National Institute on Aging and the John A. Hartford Foundation, the workshop aimed to identify scientific gaps and recommend research strategies to advance the implementation of function in care of older adults. Transdisciplinary leaders discussed implementation of mobility programs and functional assessments, including comprehensive geriatric assessment; integrating cognitive and sensory functional assessments; the role of culture, environment, and community in incorporating function into research; innovative methods to better identify functional limitations, techniques, and interventions to facilitate functional gains; and the role of the health system in fostering integration of function. Workshop participants emphasized the importance of aligning goals and assessments and adopting a team science approach that includes clinicians and frontline staff in the planning, development, testing, and implementation of tools and initiatives. This article summarizes those discussions.

Exploring the genetic relationship between hearing impairment and Alzheimer's disease

INTRODUCTION

Hearing loss has been identified as the potentially largest modifiable risk factor for Alzheimer's disease (AD), estimated to account for a similar increase in AD risk as the apolipoprotein E (APOE) gene.

METHODS

We investigated the genetic relationship between hearing loss and AD, and sought evidence for a causal relationship.

RESULTS

We found a significant genetic overlap between hearing impairment and AD and a polygenic risk score for AD was able to significantly predict hearing loss in an independent cohort. Additionally, regions of the genome involved in inflammation were identified to be shared between hearing difficulty and AD. However, causality tests found no significant evidence of a causal relationship between these traits in either direction.

DISCUSSION

Overall, these results show that the relationship between hearing difficulty and AD may, in part, be due to shared genes and immune response pathways between the traits. However, currently available data do not support a causal relationship.

Impact of hearing loss and vestibular decline on cognition in Alzheimer's disease: a prospective longitudinal study protocol (Gehoor, Evenwicht en Cognitie, GECkO)

INTRODUCTION

Dementia is a prevalent disease affecting a growing number of the ageing population. Alzheimer's disease (AD) is the most common cause of dementia. Previous research investigated the link between hearing loss and cognition, and the effect of vestibular dysfunction on cognition. Hearing loss and, to a lesser extent, vestibular decline both result in a decreasing cognitive function. However, their interaction should not be underestimated. The aim of this study is to assess the effect of hearing loss, vestibular decline and their interaction on cognition in people suffering from mild cognitive impairment (MCI) and dementia due to AD (ADD).

METHODS AND ANALYSIS

We designed a prospective longitudinal study to assess the effect of hearing loss and vestibular decline on cognition. A total of 100 cognitively impaired elderly (between 55 and 84 years of age), consisting of 60 patients with MCI due to AD and 40 patients with ADD will be included. The control group will consist of individuals with preserved cognition group-matched based on age, hearing level and vestibular function. A comprehensive assessment is performed at baseline, 12-month and 24-month follow-ups. The primary outcome measure is the change in the Repeatable Battery for the Assessment of Neuropsychological Status adjusted for Hearing-impaired individuals total score, a cognitive test battery assessing different cognitive domains. Secondary outcome measures include additional neuropsychological assessments, cortical auditory-evoked potentials, and evaluation of general and disease-specific health-related quality of life. Variables include cognitive, audiological and vestibular evaluation. Variance analyses will assess the effect of hearing loss and vestibular decline on cognition. More precisely, the link between hearing loss and non-spatial cognitive functioning, the effect of vestibular decline on spatial cognition and the impact of both factors on the rate of conversion from MCI due to AD to ADD will be investigated.

ETHICS AND DISSEMINATION

The study protocol was approved by the ethical committee of the Antwerp University Hospital on 4 February 2019 with protocol number B300201938949. The findings will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04385225).

Blast-induced hearing loss suppresses hippocampal neurogenesis and disrupts long term spatial memory

Acoustic information transduced by cochlear hair cells is continuously relayed from the auditory pathway to other sensory, motor, emotional and cognitive centers in the central nervous system. Human epidemiological studies have suggested that hearing loss is a risk factor for dementia and cognitive decline, but the mechanisms contributing to these memory and cognitive impairments are poorly understood. To explore these issues in a controlled experimental setting, we exposed adult rats to a series of intense blast wave exposures that significantly reduced the neural output of the cochlea. Several weeks later, we used the Morris Water Maze test, a hippocampal-dependent memory task, to assess the ability of Blast Wave and Control rats to learn a spatial navigation task (memory acquisition) and to remember what they had learned (spatial memory retention) several weeks earlier. The elevated plus maze and open field arena were used to test for anxiety-like behaviors. Afterwards, hippocampal cell proliferation and neurogenesis were evaluated using bromodeoxyuridine (BrdU), doublecortin (DCX), and Neuronal Nuclei (NeuN) immunolabeling. The Blast Wave and Control rats learned the spatial navigation task equally well and showed no differences on tests of anxiety. However, the Blast Wave rats performed significantly worse on the spatial memory retention task, i.e., remembering where they had been two weeks earlier. Deficits on the spatial memory retention task were associated with significant decreases in hippocampal cell proliferation and neurogenesis. Our blast wave results are consistent with other experimental manipulations that link spatial memory retention deficits (long term memory) with decreased cell proliferation and neurogenesis in the hippocampus. These results add to the growing body of knowledge linking blast-induced cochlear hearing loss with the cognitive deficits often seen in combat personnel and provide mechanistic insights into these extra auditory disorders that could lead to therapeutic interventions.

Hearing loss and cognitive decline in the general population: a prospective cohort study

Background

Previous studies identifying hearing loss as a promising modifiable risk factor for cognitive decline mostly adjusted for baseline age solely. As such a faster cognitive decline at a higher age, which is expected considering the non-linear relationship between cognition and age, may have been overlooked. Therefore it remains uncertain whether effects of hearing loss on cognitive decline extend beyond age-related declines of cognitive function.

Methods

3,590 non-demented participants were eligible for analysis at baseline, and a maximum of 837 participants were eligible for the longitudinal analysis. Hearing loss was defined at baseline. Cognitive function was measured at baseline and at follow-up (4.4 years [SD: 0.2]). Multivariable linear regression analysis was used for the cross-sectional analysis. Linear mixed models were used to assess the longitudinal association between hearing loss and cognitive decline over time while adjusting for confounders and the interaction of age and follow-up time.

Results

Hearing loss was associated with lower cognitive function at baseline. Moreover, hearing loss was associated with accelerated cognitive decline over time on a memory test. After additionally adjusting for the interaction between age and follow-up time, we found that hearing loss did not accelerate cognitive decline anymore.

Conclusions

Hearing loss was associated with lower cognitive function at baseline and accelerated cognitive decline on a memory test. The association between hearing loss and accelerated cognitive decline was non-significant after additional adjustment for non-linear age effects. More evidence is needed to ensure the role of hearing loss as a modifiable risk factor for cognitive decline.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10208-8) contains supplementary material, which is available to authorized users.

New methodologies in ageing research

Ageing is arguably the most complex phenotype that occurs in humans. To understand and treat ageing as well as associated diseases, highly specialised technologies are emerging that reveal critical insight into the underlying mechanisms and provide new hope for previously untreated diseases. Herein, we describe the latest developments in cutting edge technologies applied across the field of ageing research. We cover emerging model organisms, high-throughput methodologies and machine-driven approaches. In all, this review will give you a glimpse of what will be pushing the field onwards and upwards.

Linking anatomical and physiological markers of auditory system degeneration with behavioral hearing assessments in a mouse (Mus musculus) model of age-related hearing loss

Age-related hearing loss is a very common sensory disability, affecting one in three older adults. Establishing a link between anatomical, physiological, and behavioral markers of presbycusis in a mouse model can improve the understanding of this disorder in humans. We measured age-related hearing loss for a variety of acoustic signals in quiet and noisy environments using an operant conditioning procedure and investigated the status of peripheral structures in CBA/CaJ mice. Mice showed the greatest degree of hearing loss in the last third of their lifespan, with higher thresholds in noisy than in quiet conditions. Changes in auditory brainstem response thresholds and waveform morphology preceded behavioral hearing loss onset. Loss of hair cells, auditory nerve fibers, and signs of stria vascularis degeneration were observed in old mice. The present work underscores the difficulty in ascribing the primary cause of age-related hearing loss to any particular type of cellular degeneration. Revealing these complex structure-function relationships is critical for establishing successful intervention strategies to restore hearing or prevent presbycusis.

Smell, an Underrated Early Biomarker for Brain Aging

Olfaction is in addition to touch the most ancient of our senses, developing already in the womb it decays progressively from 65 years of age with a more pronounced impairment associated with dementia. Despite its clinical relevance and testing accessibility, smell remains an overlooked biomarker, which is rarely used by neurologists in the early screening phase. In this perspective article, we outline the reasons underlying the lack of awareness for this sense. In an attempt to put olfaction forward as an early biomarker for pathological brain aging, we draw a comparison with vision and hearing, regarded as more relevant for general health. This perspective article wants to encourage further studies aimed at understanding the mechanisms responsible for the early smell dysfunction in individuals a decade or more before the onset of cognitive symptoms.

Age-related hearing loss and provider-patient communication across primary and secondary care settings: a cross-sectional study

BACKGROUND

The prevalence of age-related hearing loss (ARHL) increases with age. Older adults are amongst the most dependent users of healthcare and most vulnerable to medical error. This study examined health professionals' strategies, as well as level of formal training completed, for communication with older adults with ARHL, and their views on the contribution of ARHL to suboptimal quality of patient care.

METHODS

A 17-item questionnaire was distributed to a sample of Irish primary care physicians, as well as hospital-based clinicians providing inpatient palliative care and geriatric services.

RESULTS

A total of 172 primary care physicians and 100 secondary care providers completed the questionnaire. A total of 154 (90%) primary and 97 (97%) secondary care providers agreed that ARHL had a negative impact on quality of care. Across both settings, 10% of respondents reported that communication issues contributed to multiple medication error events each year. Although only 3.5% of secondary care providers and 13% of primary care physicians attended formal training on communication with hearing-impaired patients, 66.5% of respondents were confident in their capacity to communicate with these patients. Primary care physicians reported that they either never used assistive hearing technology (44%) or were unfamiliar with this technology (49%).

CONCLUSIONS

Primary and secondary care health providers reported that ARHL reduces patient care quality and may initiate errors leading to patient harm. Formal training addressing the communication needs of ARHL patients appears to be underdeveloped, and there is a limited familiarity with assistive hearing technology. This is both an error in health professional training and healthcare services.

Changes in the Auditory Association Cortex in Dementing Illnesses

OBJECTIVE

To evaluate the relationship between degree of cognitive impairment and gray-matter density changes in the auditory cortex.

STUDY DESIGN

Retrospective case-control.

PATIENTS

Six hundred sixty-three patients of a tertiary referral center cognitive disorders clinic.

INTERVENTION

Magnetic resonance imaging.

MAIN OUTCOME MEASURES

Ratios of gray matter density of the primary auditory cortex (A1) to whole brain and auditory association cortex (AAC) to whole brain in patients with Alzheimer's disease (AD) compared with mild cognitive impairment (MCI) and patients with a mini-mental state exam (MMSE) scores ≤25 versus >25.

RESULTS

After multivariate analysis, a statistically significant difference between AAC to brain ratios for patients with a MMSE ≤25 (n = 325) compared with >25 (n = 269) was found, with values -0.03 (95% CI -0.04 to -0.02, p < 0.0001) on the left and -0.04 (95% CI -0.06 to -0.03, p < 0.0001) on the right. The adjusted average difference of left and right AAC to brain ratios between AD patients (n = 218) compared with MCI patients (n = 121) was also statistically significant, at -0.03 (95% CI -0.05 to -0.01, p = 0.004) and -0.05 (95% CI -0.07 to -0.03, p < 0.0001), respectively. There was no statistically significant difference in the left or right A1 to brain ratios between the MMSE groups or between the AD and MCI groups.

CONCLUSIONS

The AAC for patients with MMSE ≤25 and for those with AD shows decreased gray matter density when compared with patients with better cognitive function. No difference was detected in A1, raising the possibility that patients may have intact neural hearing, but impaired ability to interpret sounds.

Does hearing loss lead to dementia? A review of the literature

Recent studies have revealed a correlation between aging-related hearing loss and the likelihood of developing Alzheimer Disease. However, it is not yet known if the correlation simply reflects the fact that these two disorders share common risk factors or whether there is a causal link between them. The answer to this question carries therapeutic implications. Unfortunately, it is not possible to study the question of causality between aging-related hearing loss and dementia in human subjects. Here, we evaluate the research surrounding induced-hearing loss in animal models on non-auditory cognition to help infer if there is any causal evidence linking hearing loss and a more general dementia. We find ample evidence that induction of hearing loss in animals produces cognitive decline, particularly hippocampal dysfunction. The data suggest that noise-exposure produces a toxic milieu in the hippocampus consisting of a spike in glucocorticoid levels, elevations of mediators of oxidative stress and excitotoxicity, which as a consequence induce cessation of neurogenesis, synaptic loss and tau hyperphosphorylation. These data suggest that hearing loss can lead to pathological hallmarks similar to those seen in Alzheimer's Disease and other dementias. However, the rodent data do not establish that hearing loss on its own can induce a progressive degenerative dementing illness. Therefore, we conclude that an additional "hit", such as aging, APOE genotype, microvascular disease or others, may be necessary to trigger an ongoing degenerative process such as Alzheimer Disease.

Are auditory processing and cognitive performance assessments overlapping or distinct? Parsing the auditory behaviour of older adults

OBJECTIVE

Auditory processing predicts cognitive decline, including dementia, in older adults. Auditory processing involves the understanding, interpretation, and communication of auditory information. Cognition is linked to auditory processing; however, it is disputed whether auditory processing is a separate construct distinct from cognition. The purpose of this study was to determine if auditory processing is distinct from cognition in older adults.

DESIGN

Participants completed 14 cognitive and auditory processing assessments. Assessments were subjected to exploratory factor analysis with principal components extraction and varimax rotation with Kaiser normalisation. Study sample: 213 community-dwelling older adults (M = 71.39 years, 57% female, 93% Caucasian, M = 16 years education) with and without mild cognitive impairment (MCI) participated.

RESULTS

Four factors were identified, explaining 66.3% of the total variance: (1) executive functions, visual processing speed, and dichotic auditory processing, (2) auditory processing of degraded speech, (3) memory, and (4) auditory temporal processing of nonspeech.

CONCLUSIONS

Two domains of auditory processing (processing degraded speech and temporal processing) account for unique variance to which cognitive measures are not sensitive, while measures of auditory dichotic processing appear to be tapping similar abilities as measures of cognition. Older adults who perform poorly on dichotic measures should be screened for cognitive impairment.

Tinnitus and risk of Alzheimer's and Parkinson's disease: a retrospective nationwide population-based cohort study

Tinnitus has been implied as a “soft” sign of neurodegenerative disease, which is characterized by progressive loss of neuronal function, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). This study aimed to determine whether the risk of developing AD/PD increases after having tinnitus. We conducted a retrospective matched cohort study with 12,657 tinnitus patients and 25,314 controls from the National Health Insurance Research Database (NHIRD) in Taiwan with almost 10 years follow-up. Tinnitus-related risk on developing AD/PD followingly was determined by the Cox regression to identify potential confounding factors. Through the 10-year follow-up period, 398 individuals with tinnitus (3.1%) and 501 control individuals (2.0%) developed AD (P < 0.001), and 211 tinnitus patients (1.7%) and 249 control patients (1.0%) developed PD (P < 0.001). Compared with controls, patients with tinnitus were 1.54 times more likely to develop AD (95% confidence interval (CI) 1.34–1.78, P < 0.001) and 1.56 times more likely to develop PD (95% CI 1.29–1.89, P < 0.001), after adjusting confounding factors. Our results indicate an association between tinnitus and higher risk of developing AD and PD. Additional physical comorbidities may also increase the risk of developing AD and PD.

Cognitive Screening of Adults With Postlingual Hearing Loss: A Systematic Review

Objective

To systematically review the evidence for the use of cognitive screening tools for adults with postlingual hearing loss.

Data Sources

PubMed, Embase, Scopus, PsycINFO (EBSCO), CINAHL (EBSCO), and CENTRAL (Cochrane Library) electronic databases were searched from inception until October 4, 2018.

Review Methods

Articles were reviewed for inclusion by 2 independent reviewers. The references of included articles were hand-searched for additional relevant articles. Data were extracted by 2 independent extractors.

Results

Of 2092 articles imported from the search, 81 were included for the review. Nearly a third (31%, n = 25) included patients with profound hearing loss. In total, 23 unique tools were used for 105 unique applications. The Mini Mental Status Exam (MMSE) was the most commonly used (54%, n = 55), followed by the Montreal Cognitive Assessment (MoCA) (19%, n = 10). Nearly half of the tools were used to define patient inclusion or exclusion in a study (48%, n = 50), followed by examination of a change after an intervention (26%, n = 27). Two articles attempted to study the validity of the MMSE and MoCA for screening patients with mild to moderate hearing loss and found mixed effects of the auditory components. There were no validation studies identified from the search.

Conclusion

Many different cognitive screening tools have been used to study patients with postlingual hearing loss. The effects of the auditory components of these tools may be deleterious but ultimately remain unclear from the available evidence. To date, there has been no validation of any cognitive screening tool to be used for adults with postlingual hearing loss.

Association of Hearing Loss With Psychological Distress and Utilization of Mental Health Services Among Adults in the United States

IMPORTANCE

Psychological distress affects health and health care utilization. Hearing loss (HL) is highly prevalent and undertreated, and it may be a potentially modifiable risk factor for psychological distress.

OBJECTIVE

To investigate the association between HL, psychological distress, and mental health care utilization among adults in the United States.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included 25 665 individuals aged 18 years and older who participated in the 2017 National Health Interview Survey, a home-based nationally representative cross-sectional survey of noninstitutionalized US adults conducted by trained interviewers.

EXPOSURES

Self-reported hearing and hearing aid use.

MAIN OUTCOMES AND MEASURES

Kessler psychological distress scale (scores ≥5 indicating moderate distress), self-reported use of medication to treat depression or anxiety symptoms, and use of mental health services in the past year.

RESULTS

A total of 25 665 adults (mean [SD] age 47.0 [18.1] years, 51.7% [95% CI, 51.0%-52.5%] women, weighted to be representative of the US adult population) were included in the analysis. Compared with 11 558 participants (49.3%; 95% CI, 48.2%-50.5%) with no HL, the 9390 (35.3%; 95% CI, 34.4%-36.2%) with mild HL and 4717 (15.4%; 95% CI, 14.8%-16.0%) with moderate or worse HL had increased odds of moderate psychological distress (mild HL: odds ratio [OR], 1.49; 95% CI, 1.35-1.62; moderate HL: OR, 2.12; 95% CI, 1.87-2.41) and were more likely to report antidepressant medication use (mild HL: OR, 1.39; 95% CI, 1.17-1.67; moderate HL: OR, 2.07; 95% CI, 1.70-2.57), and antianxiety medication use (mild HL: OR, 1.39; 95% CI, 1.16-1.67; moderate HL: OR, 1.94; 95% CI, 1.57-2.39). Moderate HL was associated with increased odds of use of mental health services (moderate HL: OR, 1.53; 95% CI, 1.30-1.79). Among individuals with moderate HL, those with hearing aids (1066 [22.6%]) were less likely to experience psychological distress than those without hearing aids (3651 [77.4%]; OR, 0.66; 95% CI, 0.53-0.83).

CONCLUSIONS AND RELEVANCE

In a large nationally representative sample of US adults, self-reported HL was associated with both greater psychological distress and increased rates of antidepressant and antianxiety medication use and utilization of mental health services. Further research is needed to investigate whether HL may be a modifiable risk factor for these outcomes.

Does Hearing Loss in the Elderly Individuals Conform to Impairment of Specific Cognitive Domains?

BACKGROUND

It is well known that age-related hearing loss (ARHL) is strongly associated with dementia. Different hypotheses have been considered to explain this link, including sensorial deprivation, the reduction in cognitive reserve, and the presence of shared pathological pathways (microvascular damage of the brain).

AIMS

We carried out a study of the audiological and neuropsychological characteristics of a sample of hearing impaired but cognitively healthy individuals (HIH). The aim of our study was to carefully outline the neuropsychological profile of the patients in order to verify whether hearing loss correlated with deficits in specific cognitive domains.

RESULTS

Episodic memory is affected by the presence of hearing loss, while semantic competences, syntactic, and grammar skills seem not to be affected. Furthermore, some audiological features linked to the intelligibility of spoken words can predict the presence of executive dysfunction; the same does not apply to memory impairment.

CONCLUSION

In HIH, executive functions are widely employed in maintaining an acceptable level of comprehension of spoken language; consequently, other cognitive domains and instrumental abilities in HIH are not properly supported. Thus, it is arguable that programs of hearing rehabilitation for HIH could restore the allocation of attentional resources to the functioning of other cognitive domains.

Age-related Hearing Loss Is Strongly Associated With Cognitive Decline Regardless of the APOE4 Polymorphism

OBJECTIVE

To examine the association between hearing impairment and cognitive decline and to identify possible risk factors for presbycusis.

STUDY DESIGN

Cross-sectional survey in prospective cohort study.

SETTING

University hospital.

PATIENTS

A total of 322 participants aged >60 years, for whom all the below data were available, were enrolled in the study. There were 168 females and 154 males with a median age of 71 years (range: 60-89 yrs).

INTERVENTIONS

PROST (Project in Sado for Total Health), a medical database in Sado island Japan, was analyzed.

MAIN OUTCOME MEASURES

Data on pure-tone audiometry, mini-mental state examination (MMSE), polymorphism of apolipoprotein E4 (ApoE4), diabetes mellitus, hypertension, smoking, and alcohol consumption were extracted. Hearing impairment was defined as an average frequency between 0.25 and 8 kHz that exceeded 30 dB. Multivariate analysis was used to identify which of the above factors could predict the hearing impairment. Hearing threshold of each Hz was compared between the ApoE4 (+/+), (+/-), and (-/-) groups.

RESULTS

Among various factors, only low MMSE scores (<24) showed significant association with hearing impairment. There were no differences in the hearing threshold of all frequencies between ApoE status groups.

CONCLUSIONS

Hearing impairment was associated with low MMSE sores, regardless of the ApoE4 status. If ApoE4 status would be a common upstream predictor for both the hearing and cognitive impairment, hearing threshold would be related to ApoE4 status. However, these results may suggest that hearing impairment may be causally related to the cognitive dysfunction, perhaps via the cognitive load mechanisms.

Hearing loss and cognitive function among Chinese older adults: the role of participation in leisure activities

BACKGROUND

Hearing loss, a highly prevalent sensory impairment affecting older adults, is a risk factor for cognition decline. However, there were very limited studies on this association in low-resource countries. This study aimed to assess the association between self-reported hearing loss and cognitive decline, and whether engagement in leisure activities moderated this association among older adults in China.

METHODS

Data were obtained from two waves of the nationally representative survey of China Longitudinal Healthy Longevity Survey (CLHLS) between 2011/12-2014. Eight thousand eight hundred forty-four individuals aged 65 years old or above with a dichotomized measure of self-reported hearing status were included. Modified Mini-Mental Examination (MMSE) was used to measure global cognition. Fixed-effects models were used to estimate whether leisure activity engagement moderated the association of self-perceived hearing loss with global cognitive change in the overall sample and sex subsamples.

RESULTS

Self-reported hearing loss was associated with cognitive impairment, with an odds ratio of 2.48 [1.22, 5.06]. Sex difference in the association of hearing loss and cognitive impairment was not found. Self-reported hearing loss was associated with cognitive decline, with 8% increase in risk compared with those with normal hearing. Frequent engagement in leisure activities moderated the association between hearing loss and cognitive decline for the whole and male samples.

CONCLUSION

Hearing loss was associated with cognitive decline, and leisure activities engagement moderated the association among males rather than females.

Clinical Performance Evaluation of a Personal Sound Amplification Product vs a Basic Hearing Aid and a Premium Hearing Aid

Importance

Hearing loss is a highly prevalent condition with multiple negative associated outcomes, yet few persons with hearing loss have hearing aids (HAs). Personal sound amplification products (PSAPs) could be an alternative low-cost solution to HAs, but data are lacking on the performance of PSAPs.

Objective

To evaluate the clinical efficacy of a PSAP by comparing its performance with that of a basic HA and a premium HA in participants with mild, moderate, and moderately severe hearing impairment.

Design, Setting, and Participants

A prospective, single-institution cohort study was performed with a total of 56 participants, including 19 with mild hearing loss, 20 with moderate hearing loss, and 17 with moderately severe hearing loss. All participants underwent 4 clinical hearing tests with each of the PSAP, basic HA, and premium HA, and all completed an evaluative questionnaire.

Interventions

All hearing devices (PSAP, basic HA, and premium HA) were applied by a clinician to prevent bias and order effects; participants were blinded to the device in use, and sequence of devices was randomized.

Main Outcomes and Measures

The study used the Korean version of the hearing in noise test, the speech intelligibility in noise test, listening effort measurement using a dual-task paradigm, pupillometry, and a self-rating questionnaire regarding sound quality and preference. These tests were administered under the following 4 hearing conditions: unaided hearing, use of PSAP, use of basic HA, and use of premium HA.

Results

The study included 56 participants with a mean age of 56 years (interquartile range, 48-59 years); 29 (52%) were women. In the mild and moderate hearing loss groups, there was no meaningful difference between PSAP, basic HA, and premium HA for speech perception (Cohen d = 0.06-1.05), sound quality (Cohen d = 0.06-0.71), listening effort (Cohen d = 0.10-0.92), and user preference (PSAP, 41%; basic HA, 28%; premium HA, 31%). However, for the patients with moderately severe hearing loss, the premium HA had better performance across most tests (Cohen d = 0.60-1.59), and 70% of participants preferred to use the premium HA.

Conclusions and Relevance

The results indicate that basic and premium HAs were not superior to the PSAP in patients with mild to moderate hearing impairment, which suggests that PSAPs might be used as an alternative to HAs in these patient populations. However, if hearing loss is more severe, then HAs, especially premium HAs, should be considered as an option to manage hearing loss.

Hearing Aid Prevalence and Factors Related to Use Among Older Adults From the Hispanic Community Health Study/Study of Latinos

Importance

Hearing loss is highly prevalent in the rapidly growing and aging Hispanic/Latino population in the United States. However, little is known or understood about hearing aid use among US adults from Hispanic/Latino backgrounds.

Objective

To describe hearing aid prevalence and factors associated with hearing aid use among US adults of Hispanic/Latino backgrounds.

Design, Setting, and Participants

Cross-sectional data were collected between 2008 and 2011 from 4 field centers (Bronx, New York; Chicago, Illinois; Miami, Florida; and San Diego, California) as part of the multisite Hispanic Community Health Study/Study of Latinos. Included individuals were adults aged 45 to 76 years with hearing loss (pure-tone average ≥25 dB HL) from randomly selected households in the 4 field centers and were from self-reported Hispanic/Latino backgrounds, including Central American, Cuban, Dominican, Mexican, Puerto Rican, South American, and mixed or other backgrounds. Analysis, including age- and background-weighted prevalence estimates and multivariate logistic regression using survey methodology, was conducted from 2017 to 2018.

Main Outcomes and Measures

The primary outcome of interest was self-reported hearing aid use. The a priori hypothesis was that hearing aid prevalence estimates among included Hispanic/Latino adults would be less than recently published estimates of the general US population, and that poorer hearing, higher perceived need, older age, and higher acculturation would be associated with hearing aid use.

Results

Of 1898 individuals with hearing loss, 1064 (56.1%) were men, and the mean (SE) age was 60.3 (0.3) years. A total of 87 (4.6%) included individuals reported hearing aid use. Increased odds of self-reported use was associated with poorer measured hearing (odds ratio [OR], 1.06; 95% CI, 1.03-1.09), higher Hearing Handicap Inventory-Screening scores (OR, 1.06; 95% CI, 1.03-1.08), access to health insurance coverage (OR, 2.30; 95% CI, 1.20-4.37), and place of residence (OR, 2.42; 95% CI, 1.17-5.02) in an adjusted logistic regression model.

Conclusions and Relevance

Findings revealed underuse of hearing aids among adults from Hispanic/Latino backgrounds. A primary factor related to use was lack of health insurance, which suggests that access influenced hearing aid use. Changes to policy and clinical service provision are needed to increase hearing aid use among aging Hispanic/Latino adults in the United States.

Hearing Impairment in Old Age

BACKGROUND

Hearing impairment associated with old age (presbycusis) is becoming more common because the population is aging.

METHODS

This review is based on publications retrieved by a selective search in Medline and Google Scholar, including individual studies, meta-analyses, guidelines, Cochrane reviews, and other reviews.

RESULTS

The cardinal symptom of presbycusis is impaired communication due to bilateral hearing impairment. Patients may be unaware of the problem for a long time because of its insidious progression. Evidence suggests that untreated hearing impair- ment in old age can have extensive adverse effects on the patient's mental, physical, and social well-being. Early detection is possible with the aid of simple diagnostic tests or suitable questionnaires. In most cases, bilateral hearing aids are an effective treatment. Surgery is rarely indicated. For patients with uni- or bilateral deafness, a cochlear implant is the treatment of choice. These treatments can improve many patients' quality of life.

CONCLUSION

The small amount of evidence that is currently available suggests that presbycusis is underdiagnosed and under- treated in Germany. Early detection by physicians of all specialties, followed in each case by a specialized differential diagnostic evaluation, is a desirable goal.

Reduced suprathreshold auditory nerve responses are associated with slower processing speed and thinner temporal and parietal cortex in presbycusis

Epidemiological evidence shows an association between hearing loss and dementia in elderly people. However, the mechanisms that connect hearing impairments and cognitive decline are still unknown. Here we propose that a suprathreshold auditory-nerve impairment is associated with cognitive decline and brain atrophy. Methods: audiological, neuropsychological, and brain structural 3-Tesla MRI data were obtained from elders with different levels of hearing loss recruited in the ANDES cohort. The amplitude of waves I (auditory nerve) and V (midbrain) from auditory brainstem responses were measured at 80 dB nHL. We also calculated the ratio between wave V and I as a proxy of suprathreshold brainstem function. Results: we included a total of 101 subjects (age: 73.5 ± 5.2 years (mean ± SD), mean education: 9.5 ± 4.2 years, and mean audiogram thresholds (0.5–4 kHz): 25.5 ± 12.0 dB HL). We obtained reliable suprathreshold waves V in all subjects (n = 101), while replicable waves I were obtained in 92 subjects (91.1%). Partial Spearman correlations (corrected by age, gender, education and hearing thresholds) showed that reduced suprathreshold wave I responses were associated with thinner temporal and parietal cortices, and with slower processing speed as evidenced by the Trail-Making Test-A and digit symbol performance. Non-significant correlations were obtained between wave I amplitudes and other cognitive domains. Conclusions: These results evidence that reduced suprathreshold auditory nerve responses in presbycusis are associated with slower processing speed and brain structural changes in temporal and parietal regions.

Age-related hearing loss influences functional connectivity of auditory cortex for the McGurk illusion

Age-related hearing loss affects hearing at high frequencies and is associated with difficulties in understanding speech. Increased audio-visual integration has recently been found in age-related hearing impairment, the brain mechanisms that contribute to this effect are however unclear. We used functional magnetic resonance imaging in elderly subjects with normal hearing and mild to moderate uncompensated hearing loss. Audio-visual integration was studied using the McGurk task. In this task, an illusionary fused percept can occur if incongruent auditory and visual syllables are presented. The paradigm included unisensory stimuli (auditory only, visual only), congruent audio-visual and incongruent (McGurk) audio-visual stimuli. An illusionary precept was reported in over 60% of incongruent trials. These McGurk illusion rates were equal in both groups of elderly subjects and correlated positively with speech-in-noise perception and daily listening effort. Normal-hearing participants showed an increased neural response in left pre- and postcentral gyri and right middle frontal gyrus for incongruent stimuli (McGurk) compared to congruent audio-visual stimuli. Activation patterns were however not different between groups. Task-modulated functional connectivity differed between groups showing increased connectivity from auditory cortex to visual, parietal and frontal areas in hard of hearing participants as compared to normal-hearing participants when comparing incongruent stimuli (McGurk) with congruent audio-visual stimuli. These results suggest that changes in functional connectivity of auditory cortex rather than activation strength during processing of audio-visual McGurk stimuli accompany age-related hearing loss.

Hearing impairment is associated with enhanced neural tracking of the speech envelope

Elevated hearing thresholds in hearing impaired adults are usually compensated by providing amplification through a hearing aid. In spite of restoring hearing sensitivity, difficulties with understanding speech in noisy environments often remain. One main reason is that sensorineural hearing loss not only causes loss of audibility but also other deficits, including peripheral distortion but also central temporal processing deficits. To investigate the neural consequences of hearing impairment in the brain underlying speech-in-noise difficulties, we compared EEG responses to natural speech of 14 hearing impaired adults with those of 14 age-matched normal-hearing adults. We measured neural envelope tracking to sentences and a story masked by different levels of a stationary noise or competing talker. Despite their sensorineural hearing loss, hearing impaired adults showed higher neural envelope tracking of the target than the competing talker, similar to their normal-hearing peers. Furthermore, hearing impairment was related to an additional increase in neural envelope tracking of the target talker, suggesting that hearing impaired adults may have an enhanced sensitivity to envelope modulations or require a larger differential neural tracking of target versus competing talker to segregate speech from noise. Lastly, both normal-hearing and hearing impaired participants showed an increase in neural envelope tracking with increasing speech understanding. Hence, our results open avenues towards new clinical applications, such as neuro-steered prostheses as well as objective and automatic measurements of speech understanding performance.

Hearing loss and cognitive decline among older adults with atrial fibrillation: the SAGE-AF study

Objective

To examine the association between hearing loss and cognitive function cross-sectionally and prospectively among older adults with atrial fibrillation (AF).

Methods

Patients with AF ≥ 65-year-old (n = 1244) in the SAGE (Systematic Assessment of Geriatric Elements)-AF study were recruited from five internal medicine or cardiology clinics in Massachusetts and Georgia. Hearing was assessed by a structured questionnaire at baseline. Cognitive function was assessed by Montreal Cognitive Assessment (MoCA) at baseline and one year. Cognitive impairment was defined as score ≤ 23 on the MoCA. The associations between hearing loss and cognitive function were examined by multivariable adjusted logistic regression.

Results

Participants with hearing loss (n = 451, 36%) were older, more likely to be male, and have depressive symptoms than patients without hearing loss. At baseline, 528 (42%) participants were cognitively impaired. Individuals with hearing loss were significantly more likely to have cognitive impairment at baseline [adjusted odds ratio (OR) = 1.37, 95% confidence interval (CI): 1.05–1.81]. Among the 662 participants who did not have cognitive impairment at baseline and attended the one-year follow-up visit, 106 (16%) developed incident cognitive impairment. Individuals with, versus those without, hearing loss were significantly more likely to develop incident cognitive impairment at one year (adjusted OR = 1.68, 95% CI: 1.07–2.64).

Conclusions

Hearing loss is a prevalent but under-recognized factor associated with cognitive impairment in patients with AF. Assessment for hearing loss may be indicated among these patients to identify individuals at high-risk for adverse outcomes.

Insula and Amygdala Atrophy Are Associated With Functional Impairment in Subjects With Presbycusis

Hearing loss is an important risk factor for dementia. However, the mechanisms that relate these disorders are still unknown. As a proxy of this relationship, we studied the structural brain changes associated with functional impairment in activities of daily living in subjects with age related hearing loss, or presbycusis. One hundred eleven independent, non-demented subjects older than 65 years recruited in the ANDES cohort were evaluated using a combined approach including (i) audiological tests: hearing thresholds and cochlear function measured by pure tone averages and the distortion product otoacoustic emissions respectively; (ii) behavioral variables: cognitive, neuropsychiatric, and functional impairment in activities of daily living measured by validated questionnaires; and (iii) structural brain imaging—assessed by magnetic resonance imaging at 3 Tesla. The mean age of the recruited subjects (69 females) was 73.95 ± 5.47 years (mean ± SD) with an average educational level of 9.44 ± 4.2 years of schooling. According to the audiometric hearing thresholds and presence of otoacoustic emissions, we studied three groups: controls with normal hearing (n = 36), presbycusis with preserved cochlear function (n = 33), and presbycusis with cochlear dysfunction (n = 38). We found a significant association (R²_D = 0.17) between the number of detected otoacoustic emissions and apathy symptoms. The presbycusis with cochlear dysfunction group had worse performance than controls in global cognition, language and executive functions, and severe apathy symptoms than the other groups. The neuropsychiatric symptoms and language deficits were the main determinants of functional impairment in both groups of subjects with presbycusis. Atrophy of insula, amygdala, and other temporal areas were related with functional impairment, apathy, and language deficits in the presbycusis with cochlear dysfunction group. We conclude that (i) the neuropsychiatric symptoms had a major effect on functional loss in subjects with presbycusis, (ii) cochlear dysfunction is relevant for the association between hearing loss and behavioral impairment, and (iii) atrophy of the insula and amygdala among other temporal areas are related with hearing loss and behavioral impairment.

The Relationship between Self-Rated Economic Status and Falls among the Elderly in Shandong Province, China

(1) Background: Older people are more vulnerable and likely to have falls and the consequences of these falls place a heavy burden on individuals, families and society. Many factors directly or indirectly affect the prevalence of falls. The aims of this study were to understand the prevalence and risk factors of falls among the elderly in Shandong, China; the relationship between economic level and falls was also preliminary explored. (2) Methods: Using a multi-stage stratified sampling method, 7070 elderly people aged 60 and over were selected in Shandong Province, China. General characteristics and a self-rated economic status were collected through face to face interviews. Chi-square tests, rank sum tests and two logistic regression models were performed as the main statistical methods. (3) Results: 8.59% of participants reported that they had experienced at least one fall in the past half year. There was a significant difference in experienced falls regarding gender, residence, marital status, educational level, smoking, drinking, hypertension, diabetes, coronary disease, and self-reported hearing. The worse the self-rated economic status, the higher the risk of falling, (poor and worried about livelihood, OR = 3.60, 95%; CI = 1.76–7.35). (4) Conclusions: Women, hypertension, diabetes and self-reported hearing loss were identified as the risk factors of falls in the elderly. The difference of economic level affects the falls of the elderly in rural and urban areas. More fall prevention measures should be provided for the elderly in poverty.

Patient Uptake, Experience, and Satisfaction Using Web-Based and Face-to-Face Hearing Health Services: Process Evaluation Study

BACKGROUND

Globally, access to hearing health care is a growing concern with 900 million people estimated to suffer from disabling hearing loss by 2050. Hearing loss is one of the most common chronic health conditions, yet access to hearing health care is limited. Incorporating Web-based (voice calling, messaging, or emailing) service delivery into current treatment pathways could improve access and allow for better scalability of services. Current electronic health studies in audiology have focused on technical feasibility, sensitivity, and specificity of diagnostic hearing testing and not on patient satisfaction, experiences, and sustainable models along the entire patient journey.

OBJECTIVE

This study aimed to investigate a hybrid (Web-based and face-to-face) hearing health service in terms of uptake, experience, and satisfaction in adult patients with hearing loss.

METHODS

A nonprofit hearing research clinic using online and face-to-face services was implemented in Durban, South Africa, using online recruitment from the clinic's Facebook page and Google AdWords, which directed persons to an online Web-based hearing screening test. Web-based and face-to-face care pathways included assessment, treatment, and rehabilitation. To evaluate the service, an online survey comprising (1) a validated satisfaction measurement tool (Short Assessment of Patient Satisfaction), (2) a process evaluation of all the 5 steps completed, and (3) personal preferences of communication methods used vs methods preferred was conducted, which was sent to 46 patients who used clinic services.

RESULTS

Of the patients invited, 67% (31/46) completed the survey with mean age 66 years, (SD 16). Almost all patients, 92% (30/31) reported that the online screening test assisted them in seeking hearing health care. Approximately 60% (18/31) of the patients accessed the online hearing screening test from an Android device. Patients stayed in contact with the audiologist mostly through WhatsApp instant messaging (27/31, 87%), and most patients (25/31, 81%) preferred to use this method of communication. The patients continuing with hearing health care were significantly older and had significantly poorer speech recognition abilities compared with the patients who discontinued seeking hearing health care. A statistically significant positive result (P=.007) was found between age and the number of appointments per patient. Around 61% (19/31) of patients previously completed diagnostic testing at other practices, with 95% (18/19) rating the services at the hybrid clinic as better. The net promoter score was 87, indicating that patients were highly likely to recommend the hybrid clinic to friends and family.

CONCLUSIONS

This study applied Web-based and face-to-face components into a hybrid clinic and measured an overall positive experience with high patient satisfaction through a process evaluation. The findings support the potential of a hybrid clinic with synchronous and asynchronous modes of communication to be a scalable hearing health care model, addressing the needs of adults with hearing loss globally.

Does Treating Hearing Loss in Older Adults Improve Cognitive Outcomes? A Review

Hearing loss is the third most prevalent health condition in older age. In recent years, research has consistently reported an association between hearing loss and mental health outcomes, including poorer cognitive performances. Whether treating hearing loss in elders improves cognition has been directly or indirectly addressed by several studies. This review aims at providing a synthesis of those results. Regarding the literature on hearing aids’ use and cognition, although the lack of interventional studies has to be underlined, observational data suggest that hearing aids positively impact long-term cognition, even though more research is necessary to ascertain this statement and provide information on the length or frequency of use required in order to observe benefits. Regarding cochlear implants in elders experiencing more severe auditory deprivation, the literature is scarcer. The available studies have many limitations and do not allow the drawing of clear conclusions. Taken together, the results are encouraging. Nevertheless, because hearing loss is suspected to account for 9% of dementia cases, and also because hearing loss is one of the few potentially modifiable factors from a dementia prevention perspective, the need to stimulate research to have clearer knowledge of the benefits of treating hearing loss on cognitive outcomes is urgent.

Hearing thresholds and cognitive flexibility in young healthy individuals with normal hearing

Objective: Pure tone audiometry may seem to be a relatively easy task for the participant but it may involve cognitive as well as sensory abilities. The aim of this study is to examine the relationship between hearing thresholds in the frequency range 0.125-8 kHz and the core executive function cognitive flexibility in healthy individuals with normal hearing.Design: Experimental study measuring correlations between different pure-tone hearing threshold measures and cognitive flexibility. Pure tone air conduction audiometry (frequencies 0.125-8.0 kHz) and two tests of cognitive flexibility (information updating and shifting ability) were conducted.Study sample: Seventy-two subjects (aged between 21 and 36) with normal hearing (<20 dB HL) for the tested frequencies.Results: Four measures of average pure tone hearing thresholds were negatively correlated with cognitive flexibility.Conclusions: Pure-tone air conduction hearing thresholds seem to be related to cognitive flexibility in healthy individuals with normal hearing.

Auditory Evoked Responses in Older Adults With Normal Hearing, Untreated, and Treated Age-Related Hearing Loss

OBJECTIVES

The goal of this study was to identify the effects of auditory deprivation (age-related hearing loss) and auditory stimulation (history of hearing aid use) on the neural registration of sound across two stimulus presentation conditions: (1) equal sound pressure level and (2) equal sensation level.

DESIGN

We used a between-groups design, involving three groups of 14 older adults (n = 42; 62 to 84 years): (1) clinically defined normal hearing (≤25 dB from 250 to 8000 Hz, bilaterally), (2) bilateral mild-moderate/moderately severe sensorineural hearing loss who have never used hearing aids, and (3) bilateral mild-moderate/moderately severe sensorineural hearing loss who have worn bilateral hearing aids for at least the past 2 years.

RESULTS

There were significant delays in the auditory P1-N1-P2 complex in older adults with hearing loss compared with their normal hearing peers when using equal sound pressure levels for all participants. However, when the degree and configuration of hearing loss were accounted for through the presentation of equal sensation level stimuli, no latency delays were observed. These results suggest that stimulus audibility modulates P1-N1-P2 morphology and should be controlled for when defining deprivation and stimulus-related neuroplasticity in people with hearing loss. Moreover, a history of auditory stimulation, in the form of hearing aid use, does not appreciably alter the neural registration of unaided auditory evoked brain activity when quantified by the P1-N1-P2.

CONCLUSIONS

When comparing auditory cortical responses in older adults with and without hearing loss, stimulus audibility, and not hearing loss-related neurophysiological changes, results in delayed response latency for those with age-related hearing loss. Future studies should carefully consider stimulus presentation levels when drawing conclusions about deprivation- and stimulation-related neuroplasticity. Additionally, auditory stimulation, in the form of a history of hearing aid use, does not significantly affect the neural registration of sound when quantified using the P1-N1-P2-evoked response.

Experiences of hearing aid use among patients with mild cognitive impairment and Alzheimer's disease dementia: A qualitative study

Objectives:

Hearing aid usage supports communication and independence; however, many do not use their hearing aids. This study explored the experiences of hearing aid use in adults with mild cognitive impairment or Alzheimer’s disease.

Methods:

Participants completed semi-structured interviews which were analysed using thematic analysis. Ten people (six males, age range 75–86 years old) with mild cognitive impairment or Alzheimer’s disease who had been fitted with hearing aids were recruited to the study.

Results:

We identified four major themes: (1) memory and other cognitive barriers to using hearing aids, (2) practical aspects of hearing aids, (3) benefits of hearing aids, and (4) ambivalence towards hearing aids.

Conclusions:

Participants perceived a significant impact of cognitive impairment on the experience of using hearing aids. This population may benefit from targeted strategies to support use of hearing aids. The findings from this study can inform future research to optimise use of hearing aids in this population.

Cortical Neuroplasticity and Cognitive Function in Early-Stage, Mild-Moderate Hearing Loss: Evidence of Neurocognitive Benefit From Hearing Aid Use

Age-related hearing loss (ARHL) is associated with cognitive decline as well as structural and functional brain changes. However, the mechanisms underlying neurocognitive deficits in ARHL are poorly understood and it is unclear whether clinical treatment with hearing aids may modify neurocognitive outcomes. To address these topics, cortical visual evoked potentials (CVEPs), cognitive function, and speech perception abilities were measured in 28 adults with untreated, mild-moderate ARHL and 13 age-matched normal hearing (NH) controls. The group of adults with ARHL were then fit with bilateral hearing aids and re-evaluated after 6 months of amplification use. At baseline, the ARHL group exhibited more extensive recruitment of auditory, frontal, and pre-frontal cortices during a visual motion processing task, providing evidence of cross-modal re-organization and compensatory cortical neuroplasticity. Further, more extensive cross-modal recruitment of the right auditory cortex was associated with greater degree of hearing loss, poorer speech perception in noise, and worse cognitive function. Following clinical treatment with hearing aids, a reversal in cross-modal re-organization of auditory cortex by vision was observed in the ARHL group, coinciding with gains in speech perception and cognitive performance. Thus, beyond the known benefits of hearing aid use on communication, outcomes from this study provide evidence that clinical intervention with well-fit amplification may promote more typical cortical organization and functioning and provide cognitive benefit.

Findings of Impaired Hearing in Patients With Nonfluent/Agrammatic Variant Primary Progressive Aphasia

Question

What is the status of peripheral hearing in patients with nonfluent/agrammatic variant primary progressive aphasia (nfvPPA)?

Findings

Patients with nfvPPA performed worse on pure-tone audiometry than healthy older individuals or patients with Alzheimer disease, after controlling for age and general disease factors. In addition, these patients showed increased functional interaural audiometric asymmetry.

Meaning

Auditory system involvement in patients with nfvPPA is more substantial than previously recognized.

Importance

Despite being characterized as a disorder of language production, nonfluent/agrammatic variant primary progressive aphasia (nfvPPA) is frequently associated with auditory symptoms. However, to our knowledge, peripheral auditory function has not been defined in this condition.

Objective

To assess peripheral hearing function in individuals with nfvPPA compared with healthy older individuals and patients with Alzheimer disease (AD).

Design, Setting, and Participants

This cross-sectional single-center study was conducted at the Dementia Research Centre of University College London between August 2015 and July 2018. A consecutive cohort of patients with nfvPPA and patients with AD were compared with healthy control participants. No participant had substantial otological or cerebrovascular disease; all eligible patients fulfilling diagnostic criteria and able to comply with audiometry were included.

Main Outcomes and Measures

We measured mean threshold sound levels required to detect pure tones at frequencies of 500, 1000, 2000, 4000, and 6000 Hz in the left and right ears separately; these were used to generate better-ear mean and worse-ear mean composite hearing threshold scores and interaural difference scores for each participant. All analyses were adjusted for participant age.

Results

We studied 19 patients with nfvPPA (9 female; mean [SD] age, 70.3 [9.0] years), 20 patients with AD (9 female; mean [SD] age, 69.4 [8.1] years) and 34 control participants (15 female; mean [SD] age, 66.7 [6.3] years). The patients with nfvPPA had significantly higher scores than control participants on better-ear mean scores (patients with nfvPPA: mean [SD], 36.3 [9.4] decibels [dB]; control participants: 28.9 [7.3] dB; age-adjusted difference, 5.7 [95% CI, 1.4-10.0] dB; P = .01) and worse-ear mean scores (patients with nfvPPA: 42.2 [11.5] dB; control participants: 31.7 [8.1] dB; age-adjusted difference, 8.5 [95% CI, 3.6-13.4] dB; P = .001). The patients with nfvPPA also had significantly higher better-ear mean scores than patients with AD (patients with AD: mean [SD] 31.1 [7.5] dB; age-adjusted difference, 4.8 [95% CI, 0.0-9.6] dB; P = .048) and worse-ear mean scores (patients with AD: mean [SD], 33.8 [8.2] dB; age-adjusted difference, 7.8 [95% CI, 2.4-13.2] dB; P = .005). The difference scores (worse-ear mean minus better-ear mean) were significantly higher in the patients with nfvPPA (mean [SD], 5.9 [5.2] dB) than control participants (mean [SD], 2.8 [2.2] dB; age-adjusted difference, 2.8 [95% CI, 0.9-4.7] dB; P = .004) and patients with AD (mean [SD], 2.8 [2.1] dB; age-adjusted difference, 3.0 [95% CI, 0.9-5.1] dB; P = .005).

Conclusions and Relevance

In this study, patients with nfvPPA performed worse on pure-tone audiometry than healthy older individuals or patients with AD, and the difference was not attributable to age or general disease factors. Cases of nfvPPA were additionally associated with increased functional interaural audiometric asymmetry. These findings suggest conjoint peripheral afferent and more central regulatory auditory dysfunction in individuals with nfvPPA.

Audiometric Age-Related Hearing Loss and Cognition in the Hispanic Community Health Study

BACKGROUND

Age-related hearing loss (HL), a common and treatable condition, has been associated with other age-related conditions. Late life cognitive impairment is a major public health concern that is rarely treatable. Studies examining the relationship between HL and cognition have been limited by non-Hispanic cohorts, small samples, or limited confounding control. We overcome these limitations in a large Hispanic cohort.

METHODS

This was a multisite cross-sectional study of 5,277 subjects at least 50 years old (Hispanic Community Health Study, HCHS). The main exposure was audiometric HL. The main outcome measure was neurocognitive performance ascertained by the Digit Symbol Substitution Test (DSST), Word Frequency Test, Spanish-English Verbal Learning Test (SEVLT), and Six-Item Screener.

RESULTS

The mean age was 58.4 years (SD = 6.2). A 20-dB (equivalent to a one-category worsening) increase in HL was associated with a -1.53 (95% CI, -2.11, -0.94) raw score point difference in the DSST, adjusting for demographics, hearing aid use, and cardiovascular disease. Similarly, a 20-dB increase in HL was associated with a -0.86 (-1.23, -0.49) point difference on the Word Frequency Test, -0.76 (-1.04, -0.47) on the SEVLT 3 trials, -0.45 (-0.60, -0.29) on the SELVT recall, and -0.07 (-0.12, -0.02) on the Six-Item Screener.

CONCLUSIONS

In the largest study of formal, audiometric HL and cognition to date, HL was independently associated with worse performance in a range of neurocognitive measures. Because HL is common and potentially treatable, it should be investigated as a modifiable risk factor for neurocognitive decline and dementia.

Temporal Sequence of Hearing Impairment and Cognition in the Baltimore Longitudinal Study of Aging

BACKGROUND

Hearing impairment (HI) could be a risk factor for cognitive decline, but cognition could plausibly also affect psychoacoustic assessment of hearing with audiometry. We examined the temporal sequence of hearing and cognitive function among nondemented, community-dwelling older adults.

METHODS

Hearing and cognition were assessed between 2012 and 2015 and 2 years thereafter in 313 nondemented participants aged ≥60 years in the Baltimore Longitudinal Study of Aging. Poorer hearing was defined by pure-tone average of 0.5-4 kHz tones in the better-hearing ear. Cognitive measures with either visual or auditory inputs were Trail-making Test Part B; Digit Symbol Substitution Test; California Verbal Learning Test immediate recall, short delay, and long delay; Digit Span Forward/Backward; Benton Visual Retention Test; and Mini-Mental State Examination. We used linear regression models for cross-sectional associations at each timepoint and autoregressive, cross-lagged models to evaluate whether baseline hearing impairment (Time 1) predicted cognitive performance 2 years after baseline (Time 2) and vice versa.

RESULTS

Cross-sectionally, there were no associations between poorer hearing and cognitive performance. Longitudinally, poorer hearing was associated with declines in California Verbal Learning Test immediate (β = -0.073, SE = 0.032, p = .024), short-delayed (β = -0.134, SE = 0.043, p = .002), long-delayed (β = -0.080, SE = 0.032, p = .012) recall, and Digit Span Forward (β = -0.074, SE = 0.029, p = .011).) from Time 1 to Time 2. Cognitive performance at Time 1 did not predict change in hearing status at Time 2.

CONCLUSIONS

Audiometric hearing impairment predicted short-term cognitive declines in both California Verbal Learning Test and auditory stimuli for attention.

Exploring prior diseases associated with incident late-onset Alzheimer's disease dementia

Studies have identified prior conditions associated with late-onset Alzheimer's disease dementia (LOAD), but all prior diseases have rarely been screened simultaneously in the literature. Our objective in the present study was to identify prior conditions associated with LOAD and construct pathways for them. We conducted a population-based matched case-control study based on data collected in the National Health Insurance Research database of Taiwan and the Catastrophic Illness Certificate database for the years 1997-2013. Prior diseases definitions were based on the first three digits of the codes listed in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Inclusion criteria required that each ICD-code existed for at least 1 year and incurred at least 2 outpatient visits or inpatient diagnosis. The case group comprised 4,600 patients newly diagnosed with LOAD in 2007-2013. The LOAD patients were matched by sex and age to obtain 4,600 controls. Using stepwise multivariate logistic regression analysis, diseases were screened for 1, 2 …, 9 years prior to the first diagnosis of LOAD. Path analysis was used to construct pathways between prior diseases and LOAD. Our results revealed that the following conditions were positively associated with the incidence of LOAD: anxiety (ICD-code 300), functional digestive disorder (ICD code 564), psychopathology-specific symptoms (ICD-code 307), disorders of the vestibular system (ICD-code 386), concussion (ICD-code 850), disorders of the urethra and urinary tract (ICD-code 599), disorders of refraction and accommodation (ICD-code 367), and hearing loss (ICD-code 389). A number of the prior diseases have previously been described in the literature in a manner identical to that in the present study. Our study supports the assertion that mental, hearing, vestibular system, and functional digestive disorders may play an important role in the pathogenesis of LOAD.

The Effect of Hearing Aid Use on Cognition in Older Adults: Can We Delay Decline or Even Improve Cognitive Function?

Hearing loss is a modifiable risk factor for dementia in older adults. Whether hearing aid use can delay the onset of cognitive decline is unknown. Participants in this study (aged 62–82 years) were assessed before and 18 months after hearing aid fitting on hearing, cognitive function, speech perception, quality of life, physical activity, loneliness, isolation, mood, and medical health. At baseline, multiple linear regression showed hearing loss and age predicted significantly poorer executive function performance, while tertiary education predicted significantly higher executive function and visual learning performance. At 18 months after hearing aid fitting, speech perception in quiet, self-reported listening disability and quality of life had significantly improved. Group mean scores across the cognitive test battery showed no significant decline, and executive function significantly improved. Reliable Change Index scores also showed either clinically significant improvement or stability in executive function for 97.3% of participants, and for females for working memory, visual attention and visual learning. Relative stability and clinically and statistically significant improvement in cognition were seen in this participant group after 18 months of hearing aid use, suggesting that treatment of hearing loss with hearing aids may delay cognitive decline. Given the small sample size, further follow up is required.

Neural Signatures of Working Memory in Age-related Hearing Loss

Age-related hearing loss affects the ability to hear high frequencies and therefore leads to difficulties in understanding speech, particularly under adverse listening conditions. This decrease in hearing can be partly compensated by the recruitment of executive functions, such as working memory. The compensatory effort may, however, lead to a decrease in available neural resources compromising cognitive abilities. We here aim to investigate whether mild to moderate hearing loss impacts prefrontal functions and related executive processes and whether these are related to speech-in-noise perception abilities. Nineteen hard of hearing and nineteen age-matched normal-hearing participants performed a working memory task to drive prefrontal activity, which was gauged with functional magnetic resonance imaging. In addition, speech-in-noise understanding, cognitive flexibility and inhibition control were assessed. Our results showed no differences in frontoparietal activation patterns and working memory performance between normal-hearing and hard of hearing participants. The behavioral assessment of further executive functions, however, provided evidence of lower cognitive flexibility in hard of hearing participants. Cognitive flexibility and hearing abilities further predicted speech-in-noise perception. We conclude that neural and behavioral signatures of working memory are intact in mild to moderate hearing loss. Moreover, cognitive flexibility seems to be closely related to hearing impairment and speech-in-noise perception and should, therefore, be investigated in future studies assessing age-related hearing loss and its implications on prefrontal functions.