August 13, 2021
3 minutes to read
Biography / Disclosures
Davis holds a doctorate in audiology and a bachelor’s degree in communication sciences and disorders from the University of Cincinnati. She owns Victory Hearing & Balance in Austin, Texas, where she specializes in hearing loss, hearing processing disorders, hearing protection, hearing training, cochlear implants, and advanced digital hearing aids. She is passionate about improving communication for her patients.
Disclosures: Davis reports that she is a paid consultant for Cognivue.
There is a strong link between sensory input and cognition. In fact, according to Livingston and colleagues, hearing loss is the primary modifiable risk factor for dementia.
The prevalence of hearing loss doubles with every decade of life, affecting about two-thirds of people over the age of 70, and yet it is vastly under-corrected, with less than 25% of those affected using hearing aids (Lin et al.)
Functional MRI studies have shown that with even mild hearing loss, the brain begins to compensate for the loss of sensory input. The visual system helps fill in the blanks via lip reading and other visual cues.
While this can be useful at the time, it shifts the responsibility for hearing from the temporal lobes to the frontal lobe of the brain, increasing the cognitive load on the frontal lobe and reducing its cognitive reserves. Essentially, the brain sacrifices executive function and memory tasks that are supposed to be handled by this part of the brain in an attempt to regain the necessary sensory stimulation.
Now imagine the impact on cognition if the person also has vision problems in addition to hearing loss. We call this ‘double sensory loss’ and it’s usually associated with severe communication difficulties, a higher risk of falls, greater social isolation and depression (which also contribute to dementia) and more. generally having difficulty with activities of daily living.
The good news is that vision and hearing loss can in many cases be corrected. There is some evidence that we can begin to reverse neuronal reorganization of the brain in as little as 6 months with properly fitted hearing aids (Glick et al.), Although it is not yet known whether the cognitive changes associated with the loss long-term sensory can really be reversed.
Due to the strong connection between hearing loss and cognition, I began to assess cognitive performance in my practice using a 5 minute self-administered computerized screening tool called Cognivue Thrive. This validated and objective test assesses memory, executive function, visuospatial abilities, reaction time and processing speed.
When I find that cognitive performance is below expectations, I first deal with the patient’s hearing loss. I find that around 77% will perform better on cognitive tests 60 days after being fitted with hearing aids. Since patients can have multiple risk factors for dementia, I also ask them about their vision and other potentially untreated conditions, such as diabetes, hypertension, and sleep disturbances. If their cognitive performance does not improve, a full workup by their primary care physician or neurologist may be needed.
There are great opportunities for audiologists and optometrists to work together to change the risk of dementia and falls for our patients. Here are 5 things you can do this year:
- Encourage everyone over 40 to have a hearing test;
- Ask your patients if they have difficulty hearing in situations where there is background noise. If so (or if they have difficulty hearing a speaker wearing a mask), they probably need a hearing test;
- Establish referral relationships with audiologists in your community;
- Consider hosting a Hearing Loss Awareness Month. Each January is Vision Loss Awareness Month in my practice, when I try to pay close attention to visual needs and make even more eye care referrals than usual; and
- If you don’t do cognitive tests in your office, consider referring someone who does.
I find that when patients understand the connection between cognition and their senses, they are more motivated to treat hearing or visual loss. The potential to protect their brains helps overcome barriers of cost, technological change, and social stigma.
Cahn-Hidalgo D, et al. World J Psychiatr. 2020; doi: 10.5498 / wjp.v10.i1.1.
Glick H, Sharma A. The Brain on Hearing Aids: Can Hearing Aid Treatment Improve Neurocognitive Function in Age-Related Hearing Loss? Hearing of the Rev. 2021. https://www.hearingreview.com/hearing-products/hearing-aids/neurocognitive-function.
Lin FR, et al. Aging Mental health. 2014; doi: 10.1080 / 13607863.2014.915924.
Livingston G, et al. Lancet. 2020; doi.org/10.1016/S0140-6736 (20) 30367-6.
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Jill Davis, AuD, holds a doctorate in audiology and a bachelor’s degree in communication sciences and disorders from the University of Cincinnati. She owns Victory Hearing & Balance in Austin, Texas, where she specializes in hearing loss, hearing processing disorders, hearing protection, hearing training, cochlear implants, and advanced digital hearing aids. She is passionate about improving communication for her patients.
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