Since 2013, there has been much attention in the media regarding a possible relationship between hearing loss and cognitive function in the aging population. Dr. Frank Lin from John Hopkins University School of Medicine studied older adults with hearing loss, finding that they had a 24% higher risk of cognitive impairment compared with normal-hearing individuals, accompanied by a sooner decline. The evaluation measured executive function: the skills necessary to pay attention, focus, plan and organize, remember information, problem solve and adapt one’s behavior. Participants were followed for 6 years. Results indicated that on average, people with hearing loss showed a significant cognitive decline after 7.7 years. Normal hearing individuals showed a similar decline after 10.9 years. A follow-up study by Dr. Lin found that hearing loss was independently associated with new cases of dementia.
There are many ideas about the relationship between hearing loss, poorer cognitive function, and dementia. Sensory disorders, such as hearing loss, may cause cognitive changes. Alternatively, other factors, such as inflammation, vascular damage, or specific protein accumulation may contribute to both sensory system damage and cognitive dysfunction.
In recent research, Newcastle University experts considered three key aspects; a common underlying cause for hearing loss and dementia; a lack of sound-related input leading to brain shrinking; and cognitive impairment resulting in people having to engage more brain resources to compensate for hearing loss, which then becomes unavailable for other tasks.
The team proposed a new angle that focuses on the memory centers deep in the temporal lobe. Their recent work indicates that this part of the brain, typically associated with long-term memory for places and events, is also involved in short-term storage and manipulation of auditory information.
They consider explanations for how changes in brain activity due to hearing loss might directly promote the presence of abnormal proteins that cause Alzheimer’s disease, therefore triggering the disease.
The experts developed the theory of this important link with hearing loss by bringing together findings from a variety of human studies and animal models. Future work will continue to look at this area.
There have been numerous articles about the relationship between hearing aid use and cognitive decline in newspapers, periodicals, and newsletters available to the public. Future studies and research will clarify this relationship. Loneliness and social isolation are related to Dementia. Hearing aid use will help to maintain communication and social interaction, maintaining an individual’s well-being.
References:
Pallarito, Karen, “Evidence for Connection Between Cognitive Decline and Hearing Loss Continues to Mount”, The Hearing Journal, March 2013, Volume 66, Number 3, p. 39-42 and
Newcastle University. “Understanding the link between hearing loss and dementia.” ScienceDaily, 1 September 2020.
