Hearing loss may be an early sign of dementia

Gradual hearing loss is a common symptom of aging, but in some people it may also be an early sign of Alzheimer's disease.

Gradual hearing loss is a common symptom of aging, but in some people it may also be an early sign of Alzheimer’s disease or other types of dementia, a new study suggests.

The risk of dementia appears to rise as hearing declines. Older people with mild hearing impairment — those who have difficulty following a conversation in a crowded restaurant, say — were nearly twice as likely as those with normal hearing to develop dementia, the study found. Severe hearing loss nearly quintupled the risk of dementia.

Health.com: 25 signs and symptoms of Alzheimer’s Disease

It’s unclear why the loss of hearing and mental function might go hand in hand. Brain abnormalities may contribute independently to both conditions, but it’s also possible that hearing problems can help bring on dementia, the researchers say. Hearing loss may lead to social isolation (which itself has been linked to dementia), for instance, or it may interfere with the brain’s division of labor.

Q&A: Alzheimer’s trial disconnect

While preclinical studies identify ways to prevent Alzheimer’s disease in animals, human trials test these same therapies in symptomatic patients — long after they are most likely to be effective

Alzheimer’s disease (AD) is a growing threat that currently afflicts some 35 million people worldwide. Without the advent of preventive therapies, the neurodegenerative disease will strike as many as 100 million people by 2050. And while laboratory studies in animal models of AD continue to uncover promising avenues for disease prevention, clinical trials in humans target patients who are already showing signs of neural degeneration.

Image: Wikimedia commons, Alzheimer Forschung Initiative e.V.

Disease biologist Todd Golde of University of Florida College of Medicine talked to The Scientist about this disconnect, its consequences, and possible solutions to the problem — the topic of an opinion piece he co-authored, published online today (January 26) in Neuron.

Test for early Alzheimer’s ‘seems possible’

Cognitive skills decline with dementia

UK experts say they may have found a way to check for Alzheimer’s years before symptoms appear.

A lumbar puncture test combined with a brain scan can identify patients with early tell-tale signs of dementia, they believe.

Ultimately, doctors could use this to select patients to try out drugs that may slow or halt the disease.

Currently there is no single test or cure for dementia, a condition that affects over 800,000 people in the UK.