Haims: Cognitive decline can be associated with hearing loss | VailDaily.com

Haims: Cognitive decline can be associated with hearing loss

Scientific research is proving that there is a definitive correlation between hearing loss and the development of cognitive decline. Research studies from Johns-Hopkins University and the Centre for Healthy Brain Ageing in Sydney, Australia, are two of a number of high-profile studies that have confirmed the association.

In a recent study, Dr. Frank Lin, Ph.D, at Johns Hopkins found that people who have mild hearing loss are at twice the risk of dementia than people with no hearing loss. If this wasn’t concerning enough, the study also found that people with moderate hearing loss are three times more likely to be at risk, and people who have severe loss are five times more likely to develop dementia.

Hearing is a brain activity — if you don’t use it, you lose it. Sound is delivered to our brain via the auditory nerve in the form of electrical impulses. As the brain is deprived of sound activity, it makes accommodations to utilize other parts of the brain. Over time, the temporal lobe, the part of the brain responsible for hearing, can shrink from lack of use. Dr. Lin’s research confirms this, and he has stated, “Brain scans show us that hearing loss may contribute to a faster rate of atrophy in the brain.”

The Sydney Memory and Ageing Study conducted at CHeBA began in 2005 and has found that there are “significant associations” between self-reported hearing loss and cognition, as well as increased risk for mild cognitive impairment or dementia. While the findings from the study indicate that more research is needed, of the 1,037 adults aged 70-90 who were without dementia, the study found that after six years, participants who reported moderate-to-severe hearing loss were 1.5 times more likely to have mild cognitive impairment or dementia.

At the same time as researchers across the globe are learning more about the association of auditory loss and cognitive decline, they are also attempting to learn more about the link between brain atrophy and hearing loss — specifically the loss of gray matter. Researchers are using neuroimaging to learn more about this causality and the regions of the brain that are affected.

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Beyond the temporal lobe, researchers have found that the anterior cingulate and the prefrontal cortex also experience atrophy associated with hearing loss. The anterior cingulate is the part of the brain responsible for emotional and cognitive functions, and the prefrontal cortex is the part of the brain associated with planning complex cognitive behavior, personality expression and decision making.

The causation of multiple parts of the brain experiencing atrophy from auditory loss is not arbitrary. Study after study has provided conclusive evidence that hearing loss is not only associated with atrophy, but also a decline in cortical gray matter — both of which have effects on cognition.

While we cannot do anything about the effects aging has on our brain, we can be proactive in mitigating other influences that acerbate the further development of brain atrophy.

Hearing aids may help

Addressing hearing loss in its early development may help lower the chances of becoming afflicted with dementia. Professor Henry Brodaty, co-director of CHeBA, has stated that “Studies are now emerging that hearing aids may reduce this risk (dementia).” As well, a recent study published in National Center for Biotechnology Information substantiated that people with mild cognitive impairment that used hearing aids “were at significantly lower risk of developing all-cause dementia compared to those not using hearing aids.”

Read, listen to music, and keep the brain stimulated. Challenging your brain with mental exercise and auditory acuity is proving to activate processes that help maintain individual brain cells, stimulate communication among them, and promote a healthier brain.

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