February 6, 2017

Hearing and Brain Health

Have you ever noticed how many people wear glasses? I have friends that will rotate between various frames and contact lenses depending on their mood or outfit of the day. Thick black frames to look studious, a fun color frame for a more whimsical look and contact lenses for date nights. According to the Vision Council of America, approximately 75% of adults use some sort of vision correction, and 64% of them wear eyeglasses.  I find it interesting that so many people with less than perfect vision are ready to put on bold eyeglasses but those with hearing loss severe enough to affect their daily conversations refuse to wear discreet hearing instruments.   There are many reasons people give for not wanting to wear hearing instruments, which I will not go into now, but there is one very good reason as to why you SHOULD wear hearing instruments…for your BRAIN HEALTH.

Currently the World Health Organization estimates there are about 35 million people living with dementia. That number is expected to triple by 2050. So why am I, an Audiologist, blogging about dementia? For two reasons. First there have been several studies published that show a link between untreated hearing loss and dementia. These studies also have found that early hearing instrument use can lower or at least prolong the onset of dementia. Second, I have firsthand knowledge of the dreadful effects of dementia so if I can help even one person or family by sharing this information it is worth the effort.

My mom was diagnosed with a rare form of dementia known as visual agnosia in 2003. At the time, she was only 58 years YOUNG and just beginning to enjoy life as an empty-nester! My family and I had never heard of visual agnosia and did not completely understand what lay ahead for us. Prior to her diagnosis, my mom would constantly be washing her eye glasses and we would tease her about her inability to see through the tiniest speck of dust.  She scheduled multiple appointments with her eye doctor claiming her vision had changed and was repeatedly told that her prescription was the same. Finally, after numerous appointments her eye doctor suggested she see a specialist at the Mayo Clinic. It was there that they confirmed her eye doctor’s suspicion of visual agnosia. Visual agnosia is a form of dementia where the brain is unable to make sense of, or recognize what it sees. We watched my mom struggle as she slowly lost the ability to recognize objects, friends and family. The disease continued to progress until she was unable to form a sentence, walk, or feed herself. This story is hard for me to share as it is so personal but I share it for the purpose of helping others.

Even though nothing could be done to slow the progression of this disease for my mom, there is a way to slow it down for those with hearing loss. Studies completed by Frank R. Lin, M.D., Ph.D. and colleagues at Johns Hopkins Medical Institution, found that older adults with hearing loss are more likely to develop dementia. They further found that as the severity of the hearing loss increased so did their risk of dementia.   The study included 639 individuals age 36-90 without dementia. Participants initially underwent cognitive and hearing testing between 1990 and 1994. They were then followed for the development of dementia and Alzheimer’s disease through May 31, 2008. Through repeated testing the study found participants with a hearing loss were at an increased risk of developing dementia. The study concluded the link between hearing loss and dementia was related to the hearing loss causing exhaustion of cognitive reserve during conversations. This leads to an aversion of social situations causing social isolation, resulting in the elimination of sensory nerve fibers in the brain.

On a more positive note a study by Jamie Desjardins, Ph.D., an assistant professor in the speech-language pathology program at the University of Texas at El Paso found that hearing aids improve brain function in people with hearing loss. Desjardins studied a group of individuals between the ages of 50 and 60 with bilateral sensorineural hearing loss who had never worn hearing aids. The participants were given cognitive tests to measure working memory, selective attention and processing speed abilities. These participants were then fit with hearing aids and after two weeks of hearing aid use the test revealed an increase in scores for recalling words in working memory and selective attention test. They also found the processing speed at which participants selected the correct response was faster. Participants had exhibited significant improvement in their cognitive function due to hearing aid use. Desjardins summed it up well in her study when she said “Think about somebody who is still working and they’re not wearing hearing aids and they are spending so much of their brainpower just trying to focus on listening. They may not be able to perform their job as well. Or if they can, they’re exhausted because they are working so much harder. They are more tired at the end of the day and it’s a lot more taxing. It affects their quality of life.”

If you suspect you have a hearing loss, take the first step and schedule an appointment for a hearing test. If you believe your spouse, family member, or friend has a hearing loss take the time to talk to them and share your concern. Many times, the person with hearing loss is the last to know they have it. Your action for yourself or others can improve brain function as much as overcome hearing loss.

1. F. R. Lin, E. J. Metter, R. J. O’Brien, S. M. Resnick, A. B. Zonderman, L. Ferrucci. Hearing Loss and Incident Dementia. Archives of Neurology, 2011; 68 (2): 214 DOI: 10.1001/archneurol.2010.362
2. University of Texas at El Paso. “Hearing aids improve memory, speech.” ScienceDaily. ScienceDaily, 28 January 2016.