Hearing Loss Linked to DementiaSunday, August 30th, 2015, 8:49 pm
A Cautionary Tale
Mounting evidence has established a strong link between untreated hearing loss and diminished cognitive function, including dementia. Studies also link untreated hearing loss to other medical and emotional problems, including depression.
The following studies show a strong link between hearing loss and dementia, reinforced by related statistical and brain scan studies, and backed by compelling theories for how hearing loss causes dementia.
A 2011 study by Johns Hopkins and the National Institute on Aging found that older adults with hearing loss were significantly more likely to develop dementia than the elderly adults with normal hearing, even after accounting for other conditions such as hypertension, which are known to cause dementia.
A 2013 Johns Hopkins study showed that seniors with hearing loss were more likely to develop problems thinking and remembering than seniors with normal hearing, and the rate of cognitive decline was 30-40% faster for the seniors with initial hearing loss, than for those who retained normal hearing into their senior years.
A 2014 study by Johns Hopkins found strong evidence that hearing loss is linked to accelerated brain tissue loss in elderly adults. In particular, study participants with impaired hearing at the onset of the study lost more than an additional cubic centimeter of brain tissue each year compared with those with normal hearing, and a significant fraction of the lost brain tissue occurred in areas of the brain responsible for sound and speech processing.
A 2015 study by the University of Colorado’s Department of Speech Language and Hearing Science, found that the brain responds to hearing loss by reorganizing it’s neuronal priorities to compensate for the brain shrinkage associated with the hearing loss. In this manner, the brain area devoted to hearing (left, below) can be reassigned to other brain functions, like processing visual patterns (right)…even with mild age-related hearing loss. As a result, areas of the brain previously responsible for higher-level decision-making are reassigned to hearing and sound processing. Unfortunately, this also serves to decrease the resources available for maintaining thinking and memory, thus increasing the overall load on the brains of aging adults. Investigators believe these compensatory adaptations may explain why hearing loss is linked to dementia, as reported in the these and other studies.
The findings from these and other studies add to a growing list of health consequences associated with hearing loss, including a higher risk of dementia, falls, hospitalizations, and generally diminished physical and mental health.
The Bottom Line? The evidence serves as a cautionary tale: hearing loss can end badly!
See our Brochure on Hearing Loss and Dementia, here