A potentially important link between Alzheimer's and hearing loss is indicated in results from a row of studies going back almost a decade spent studying correlations between Alzheimer's disease and co-existing conditions. New research conducted at the University of Wisconsin-Madison showed that left untreated, mild to moderate hearing loss contributes to cognitive decline and may be an early indicator for Alzheimer's disease. The study's researchers presented their findings at the 2017 Alzheimer's Association International Conference in London.
Researchers at Johns Hopkins looked at how hearing loss could be influencing cognitive decline, and in each study, patients with hearing loss had higher rates of dementia. In one group, subjects with hearing loss were 24 percent more likely to have Alzheimer's. In another group, the worse a subject's hearing loss was, the more likely they were to develop dementia.
While the results were corollary, not casual, researchers believe that changes in the part of the brain in charge of hearing and processing auditory information could be related to the effects of Alzheimer's, since more processing power has to be siphoned off to feed the listening and comprehension process. The increased cognitive load required by lessened hearing leaves less ability to maintain solid memory retention or manage cognitive functions.
While hearing loss doesn't automatically mean cognitive loss will follow, the evidence suggests that lessening the effects of hearing loss could slow or halt cognitive decline. When researchers at a hospital in Paris provided cochlear implant to patients with deafness in at least one ear, and tracked cognitive performance before and after, 80 percent showed cognitive improvement within a year - nearly double the efficacy of FDA-approved drugs for treating dementia.
A 2016 study in El Paso, TX, showed that wearing hearing aids could help halt and even reverse cognitive decline, something that brings hope to many with relatives who are starting to show signs of declining mental acuity. A goal for many hearing health professionals is now to find ways to increase hearing aid use, as currently only around 20 percent of those with the most hearing loss (aged 70 and up) use hearing aids regularly.
Left untreated, mild to moderate hearing loss contributes to cognitive decline and may be an early indicator for Alzheimer’s disease – but treating hearing loss can reverse cognitive decline.