Relationship Between Untreated Hearing Loss and Dementia

Studies at John Hopkins University have linked untreated hearing loss to decreases in cognitive functioning. They have reported, “For individuals older than 60 years, more than one-third of the risk of dementia was associated with hearing loss.” More recently, researchers at both John Hopkins and the National Institute on Aging have reported: the brain atrophy that normally occurs with age appears to be fast-tracked in older adults with hearing loss.

Dr. Shawn Key, Au.D., with Better Hearing and Balance Connection, stated, “Hearing loss means a loss of cellular function in the inner ear, leading to less stimulation of the auditory nerve. With a decrease of neural stimulation over time, the nerve bers become weaker and neural atrophy may occur.”

Frank Lin, M.D., an otologist with John Hopkins, and his colleagues reviewed the magnetic resonance imaging (MRI) studies over the course of 10 years for patients with normal hearing and patients with hearing loss. They found that “participants whose hearing was impacted at the start of the study had accelerated rates of brain atrophy compared to those with normal hearing.”

Research studies have also suggested that persons with untreated hearing loss are likely to become frustrated and socially isolated, and this isolation has been linked to depression. With less social stimulation, there is less activation of the parts of the brain that process speech and language.

In fact, Lin’s research found signi cant atrophy in the superior, middle and inferior temporal gyri – brain structures responsible for processing sound and speech. However, the auditory cortex does not only process sound and language. For example, the middle and inferior temporal gyri also plays a role in memory and sensory integration, and have been shown to be involved in the early stages of mild cognitive impairment and Alzheimer’s disease.

Untreated hearing loss can lead to social withdraw an isolation. Researchers at the University of Colorado at Denver have also directly linked social withdraw/ isolation to dementia/Alzheimer’s disease. Dr. Key also stated, “Obviously, the sooner we can amplify to correct a hearing loss, the less likely neural atrophy will occur and the greater success at maintaining neural integrity of the auditory nerves and auditory cortex.” But, Dr. Key went on to state that if the hearing aids are not worn consistently (as many waking hours per day as possible), atrophy is still likely. He encourages those with hearing loss to utilize hearing aids in order to improve understanding, avoid social isolation, and improve quality of life.

Dr. Gretchen Magee, Au.D. (owner) and Dr. Shawn Key, Au.D. are audiologists with Better Hearing and Balance Connection, located at 407 Town Center East in Bella Vista and at 906 NW 8th Street in Bentonville. Call 479-657-6464 to schedule a free hearing screening and hearing aid consultation today!

Dr. Lin stated, “If hearing loss is potentially contributing to these differences we’re seeing on MRI, you want to treat it before these brain structural changes take place.”