Hearing Loss and Cognitive Decline in Older Adults

 

 Do you really think your incompetent doctor in everything stroke related will know and prevent this for you?

With your risk of dementia post stroke your doctor and hospital (If competent) need to create this protocol and have dementia prevention protocols on hand. 

1. A documented 33% dementia chance post-stroke from an Australian study?   May 2012.

2. Then this study came out and seems to have a range from 17-66%. December 2013.`    

3. A 20% chance in this research.   July 2013.

4. Dementia Risk Doubled in Patients Following Stroke September 2018  

Do you prefer your doctor and hospital incompetence NOT KNOWING? OR NOT DOING?

Hearing Loss and Cognitive Decline in Older Adults

Hearing loss affects an estimated 13% of adults in the United States, with prevalence roughly doubling to 27% among those aged 65 years and older.1 Among adults aged 71 and older, approximately 65% experience hearing impairment.2

Hearing loss is associated not only with social isolation, depression, and anxiety, but an accumulating body of research links hearing loss to cognitive decline and dementia.3,4 Early intervention, including the use of hearing aids, may modify this risk, underscoring the importance of timely identification and management.

Evidence Linking Hearing Impairment to Cognitive Decline

“Currently, there are numerous studies that show an association between untreated hearing loss and cognitive decline,” said Catherine Palmer, PhD, Director of Audiology, Chair, Department of Communication Sciences and Disorders, University of Pittsburgh.

In a 2023 meta-analysis, researchers observed an association between untreated hearing loss and performance on cognitive assessments such as the Mini-Mental State Examination and the Montreal Cognitive Assessment.4

International studies corroborate these findings. Research in Poland, Brazil, Canada, Japan, and France has reported links between hearing loss and cognitive decline or dementia.5-9 For example, a Polish cohort study found that mild cognitive impairment (MCI) was present in nearly 50% of participants with hearing loss compared to 26% of participants without hearing loss, with hearing loss increasing the odds of MCI by 34% (OR, 1.34; CI, 0.93-1.93).5

Further, a 2024 meta-analysis, which combined data from 50 studies encompassing more than 1.5 million participants, concluded that adult-onset hearing loss increases the risk for cognitive decline, dementia, MCI, and Alzheimer disease. The analysis further revealed a 16% increase in dementia risk for each 10-decibel worsening of hearing.10

 

We would do well to remind patients that all of these abilities go way beyond the ear: We hear with our brains.

Pathophysiological Mechanisms

Although mechanisms linking hearing loss and cognitive decline are still being investigated, several hypotheses have been proposed. “One theory is that hearing loss causes decreased stimulation of cognitive processing,” explained Seiji Shibata, MD, PhD, Otolaryngologist and Assistant Professor, Keck Medicine, University of Southern California. “In addition, there are a number of human and animal studies that have shown that there are structural changes in the auditory cortex associated with hearing loss.”

Kasia M Bieszczad, PhD, Associate Professor, Rutgers University, explained the hypothesis that “difficulty listening bears a burden on the brain that leads to brain dysfunction over time—this is the ‘cognitive load’ hypothesis.” There could also be an “indirect causation if hearing loss and difficulty listening lead to social isolation, and the social retraction over time—sometimes decades of isolation—leads to unhealthy brain function.”

The “common cause” hypothesis suggests that shared neurodegenerative processes may underlie both hearing loss and dementia. Dr Bieszczad explained, “I describe this as the auditory system being a ‘canary in the coal mine’ of cognitive decline.”

Clinical Screening and Assessment

Given the high prevalence of hearing loss and its associated comorbidities, the “recommendation is to get an annual hearing test by an audiologist or certified clinician for earlier detection,” Dr Shibata said. “I would also recommend getting a hearing test if a patient has been diagnosed with dementia.”

The American Academy of Otolaryngology-Head and Neck Surgery Clinical Practice Guideline for Age-Related Hearing Loss recommends screening for individuals aged 50 years and older.11 “Ideally, individuals would be screened at this time and receive a full hearing evaluation if they fail the screening,” Dr Palmer said. She emphasized that a “focus on hearing screening becoming ubiquitous in primary care and geriatric settings would support timely access to hearing care.”

Dr Bieszczad compared hearing screening to vision checks, saying, “Most people will understand what ’20/20′ means for vision, and they know their number. We might do well to promote knowing your ‘hearing number,’ and there is a great initiative on this point.”

For patients undergoing cognitive testing, Dr Palmer recommended ensuring a prior hearing assessment. “If the person has hearing loss, clinicians should, at a minimum, use an amplifier during cognitive screening or testing to account for any issues with audibility, given that most cognitive tests are delivered orally.” She continued, “Without amplification, the hearing loss may directly impact the test results, not because of cognition, but because the message wasn’t received clearly.”

Hearing Interventions and Cognitive Outcomes

“Several observational studies have reported some protection against cognitive losses in older adults who use well-fit hearing aids,” Dr Palmer said. In one meta-analysis, hearing aid use was associated with a 19% decrease in the long-term risk for cognitive decline.4

Additionally, a cross-sectional, prospective cohort study conducted in Japan found a significant negative correlation between hearing threshold and cognitive function among patients older than 55 years with hearing loss and no history of hearing aid use. In contrast, no such correlation was observed in those with hearing loss who had been using hearing aids for more than 3 years. The authors concluded that the average pure-tone audiometry hearing threshold of 38.75 dB or greater of hearing loss “may be a risk factor for cognitive decline among hearing aid non-users who are in midlife and beyond,” and that “long-term use of hearing aids may potentially reduce this risk.”7

However, in the multicenter ACHIEVE randomized controlled trial (Clinicaltrial.gov Identifier: NCT03243422) of 977 older adults, hearing aids did not reduce the progression of cognitive decline over a 3-year period.12 “But there is hope, because a subset of people that were already at higher risk for cognitive decline due to other factors, such as cardiovascular risk, did show a 48% reduction in the rate of cognitive decline if they wore hearing aids,” compared with participants in the control group, Dr Bieszczad said. “So all in all, wearing hearing aids may have an overall positive effect on hearing and brain health, but there is more to the story than hearing aids and auditory care.”12

Clinical Recommendations and Best Practices

To address hearing loss and potential cognitive risks, Dr Palmer emphasized that the “best approach is to provide well-fit hearing aids to individuals with hearing loss.”

“It is best to start using hearing aids prior to significant cognitive decline so the use is automatic and not something the individual is trying to learn when short-term memory might be impacted,” she advised. “Earlier intervention is best not only for the help it will provide but also to support long-term use.”

The US Food and Drug Administration’s 2022 approval of over-the-counter hearing aids has increased accessibility and affordability.13 However, Dr Shibata added,”In the event of moderate to severe sensorineural hearing loss, a cochlear implant has been shown to be effective towards improving cognitive function.”14

Dr Bieszczad suggested that clinicians promote the idea to patients that wearing hearing aids may help their cognitive brain health. “Some may find it a more compelling argument, and motivation, to wear hearing aids to possibly avoid dementia, rather than to ‘simply’ correct their hearing,” she explained.

Research Directions and Implications for Clinical Practice

Among the ongoing questions regarding this topic, Dr Shibata pointed to the need for further research to determine the exact mechanisms by which hearing loss may lead to dementia. “This kind of research will inform the development of new biomarkers and better neuroimaging for earlier detection and prevention.”

Dr Palmer cited the need for more research on the impact of improving hearing on the onset and progression of cognitive decline, though she emphasized the importance of not “overstating the relationship between hearing loss and cognitive decline given the current data.”15 She noted that statements from some professional groups have discussed “population-level risk, which is often misinterpreted as individual-level risk, making the risk appear larger than it may actually be.” 

Considering the possibility of an indirect “common cause” in hearing impairment and cognitive decline, researchers may “gain valuable insight into what process might be using the auditory system and then invent new therapies that can be tested in the auditory system and then applied to the whole brain to ultimately slow or stop the course of general cognitive decline,” Dr Bieszczad explained. “We might also find clever ways to use the auditory brain system to uncover very early life biomarkers that could identify people at risk decades before the onset of dementia,” allowing for earlier intervention.

She concluded, “Our most sophisticated abilities as humans have so much to do with how we hear and listen in the world. We use language, sing, play music, dance, and socialize, and these are all highly sophisticated cognitive functions rooted in sound, hearing, and listening… We would do well to remind patients that all of these abilities go way beyond the ear: We hear with our brains.”