Another pathway to explain this association, he said, is the possibility that hearing loss causes problems in communication, which cause social isolation, which then causes dementia. “The link between social isolation and dementia is established, but noone knows the pathophysiology behind it yet,” he said. A third pathway may be the possibility of a common pathology underlying hearing loss and dementia.
Explore This IssueJanuary 2011
“The key thing is that none of these three pathways are mutually exclusive and it would be difficult to prove that one is completely wrong and one completely right,” Dr. Lin said. “I think there will always be a combination of the three depending on who you are and what caused your hearing loss.”
For Dr. Ferrucci, finding an association between hearing loss and dementia is not without consequences. “If a connection with dementia is linked to lack of communication and neuroplasticity, then correcting the hearing loss will improve the chance of not developing dementia or cognitive decline,” he said.
Dr. Lin also sees the implications of this research as having a dramatic impact on the “horrible disease process” of dementia. “The prevalence of dementia doubles every 20 years, so that by 2050 about one in 45 Americans will have dementia,” he said, emphasizing that even delaying the onset of dementia by one year will drop the prevalence by 10 to 15 percent 40 years from now.
“If hearing loss is associated with dementia, then the natural corollary is that if you intervene with a hearing aid or cochlear implant, then perhaps you could delay the onset of dementia,” he said.
—Bill Dickinson, AuD
A Relatively Easy Fix
The benefits of hearing aids for people suffering from hearing loss are well established and are sufficient for most people with hearing loss, except for those with severe or profound hearing loss, who may benefit more from cochlear implants.
According to M. Jennifer Derebery, MD, associate at the House Ear Clinic, Inc. and clinical professor of otolaryngology at the University of Southern California School of Medicine in Los Angeles, surveys show that over 8 percent of hearing aid wearers are quite satisfied with their hearing aids. Only a small percentage of people who actually need hearing aids use them, however.