Researchers have found that hearing loss in older adults is associated with brain changes in areas related to sound processing and executive functions, which increase the risk of dementia. To reduce this risk, protective measures such as hearing aids and avoiding loud noises are recommended.
The increased risk of dementia associated with hearing loss may result from compensatory brain changes.
Hearing loss affects more than 60 percent of adults 70 and older in the United States and is associated with an increased risk of dementia. The reason for this association is not fully understood.
Research on hearing impairment and brain changes
To better understand the connection, researchers from the University of California San Diego and the Kaiser Permanente Washington Institute for Health Research used hearing tests and magnetic resonance imaging (MRI) to determine whether hearing loss is linked to differences in specific brain regions.
Research findings
Issued on November 21, 2023 Journal of Alzheimer’s DiseaseIn this observational study, researchers reported that individuals with hearing loss showed subtle structural differences in the auditory part of the temporal lobe and the areas of the frontal cortex involved in speech and language processing.
“These results suggest that hearing loss causes changes in brain areas involved in processing sounds as well as in brain areas involved in attention. The extra effort involved in trying to understand sounds may lead to significant changes in the brain’s susceptibility to dementia,” said principal investigator Linda K., professor emeritus and Senior Investigator at Kaiser Permanente Washington Health Research Institute.
Preventive measures and research method
“If so, interventions to reduce the cognitive effort required to understand speech—such as using subtitles on television and movies, live captions or speech-to-text applications, hearing aids, and timed visits with people in quiet, non-noise environments—may protect the brain and reduce the risk of forgetfulness. It may be necessary to reduce.”
While at UC San Diego, McEvoy led the study in collaboration with Reiss and UC San Diego School of Medicine investigators who collected data from the Rancho Bernardo Study of Healthy Aging, a longitudinal cohort study of residents of the Rancho Bernardo suburb of San Diego. In the year Started in 1972. For this analysis, 130 study participants underwent a hearing test at research clinic visits between 2003 and 2005 and then underwent an MRI scan between 2014 and 2016.
Conclusion and recommendations
The results of the study show that hearing impairment is associated with regionally specific brain changes that can be caused by sensory stimuli and the high effort required to understand auditory stimuli.
“The findings highlight the importance of protecting hearing by avoiding long-term exposure to loud noises, wearing hearing protectors and wearing noise protectors, and reducing the use of ototoxic medications,” said Associate Professor Emily T. Race, Ph.D. at the UC San Diego School of Medicine.
Reference: “Elevated Pure Tone Thresholds Are Associated with Altered Microstructure in Cortical Areas Involved in Auditory Processing and Attention Allocation” by Linda K. McEvoy, Jacqueline Bergstrom, Donald J. Hagler Jr., David Wing, and Emily T. Race, 21 November 2023; Journal of Alzheimer’s Disease.
DOI: 10.3233/JAD-230767
Co-authors include: Jaclyn Bergstrom, Donald J. Hagler Jr, David Wing and Emilie T. Reas, all of UC San Diego.
This research was funded in part by the National Institute on Aging (R00AG057797, R01AG077202, R01AA021187) and the American Federation for Aging Research/McKnight Foundation (311122-00001). Data collection for the Rancho Bernardo Healthy Aging Study was primarily provided by National Institutes of Health (HV012160, AA021187, AG028507, AG007181, DK31801, HL034591, HS06726, HL089622). Archiving and sharing of Rancho Bernardo study data was supported by the National Institute on Aging (AG054067).
Disclosures: Donald J. Hager Jr. is listed as an inventor on US Patent 9,568,580, 2017 “Identification of White Matter Fiber Tracts Using Magnetic Resonance Imaging (MRI)”. Other authors reported no conflict of interest.