STUDIES ON COGNITIVE DECLINE AND DEMENTIA

A number of studies in the last few years have been conducted to evaluate cognitive decline in older adults with hearing loss. The results demonstrate that hearing loss is independently associated with accelerated cognitive decline and cognitive impairment in older adults. The magnitude of these associations is clinically significant. Individuals with hearing loss had a 30–40% accelerated rate of cognitive decline. It was noted in the study, that even a mild hearing loss equated to a 7-year cognitive decline1. Other studies have confirmed these findings 2

STUDIES ON BRAIN LOSS

126 participants from the Baltimore Longitudinal Study on Aging underwent yearly magnetic resonance imaging (MRI) to track brain changes for up to 10 years. Participants whose hearing was already impaired at the start of the study had accelerated rates of brain tissue loss compared to those with normal hearing.3 Additionally, those with impaired hearing lost more than an additional cubic centimeter of brain tissue each year (that’s the size of a sugar cube every year!!) compared with those with normal hearing. Those with impaired hearing also had significantly more shrinkage in particular regions, including the superior, middle and inferior temporal gyri. These are brain structures responsible for processing sound and speech. Shrinkage in those areas might simply be a consequence of an “impoverished” auditory cortex, which could shrink from lack of stimulation. These structures don’t work in isolation, and their responsibilities don’t end at sorting out sounds and language. The middle and inferior temporal gyri play roles in memory and sensory integration and have been shown to be involved in the early stages of mild cognitive impairment and Alzheimer’s disease. If you are showing signs of memory loss, slower thought processing and difficulty understanding speech then please have your hearing checked by Hearing Professionals.

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1 Hearing Loss and Cognitive Decline Among Older Adults Frank R. Lin, M.D Ph.D.,1,2 Kristine Yaffe, M.D.,3,4 Jin Xia, M.S.,2 Qian-Li Xue, Ph.D.,2 Tamara B. Harris, M.D. M.S.,5 Elizabeth Purchase-Helzner, Ph.D.,6 Suzanne Satterfield, M.D. Dr.P.H.,7 Hilsa N. Ayonayon, Ph.D.,4 Luigi Ferrucci, M.D. Ph.D.,8 Eleanor M. Simonsick, Ph.D.,8 and for the Health ABC Study JAMA Intern Med. Feb 25, 2013; 173(4): 10.1001/jamainternmed.2013.1868. doi: 10.1001/jamainternmed.2013.1868

2 Relationship of Hearing Loss and Dementia: A Prospective, Population-Based Study *Richard Klaus Gurgel, *Preston Daniel Ward, †Sarah Schwartz, †‡§Maria C. Norton, kNorman L. Foster, and †§JoAnn T. Tschanz Otology & Neurotology 35:775Y781 Ó 2014, Otology & Neurotology, Inc.

3Association of hearing impairment with brain volume changes in older adults. Lin FR1, Ferrucci L2, An Y3, Goh JO4, Doshi J5, Metter EJ2, Davatzikos C5, Kraut MA6, Resnick SM3. Neuroimage. 2014 Apr 15;90:84-92. doi: 10.1016/j.neuroimage.2013.12.059. Epub 2014 Jan 9.