audiology

Hearing Loss—Linked to Dementia

Epidemiological studies have uncovered a link between dementia and hearing loss. In fact, these studies show that hearing loss may be responsible for 1/10th of the 47 million cases worldwide. Published in the journal Neuron, a team at Newcastle University has put forth a new theory to explain how a disorder of the ear can lead to Alzheimer’s disease—a concept never looked at before. This new understanding may be a significant step towards advancing research into Alzheimer’s disease, preventing the illness for future generations.

Newcastle experts considered three key aspects:

  • A common underlying cause for hearing loss and dementia
  • Lack of sound-related input leading to brain shrinking
  • Cognitive impairment resulting in people having to engage more brain resources to compensate for hearing loss, which made that part of the brain unavailable for other tasks

Findings:

The Newcastle team proposed a new angle, focusing on the memory centers deep in the brain. “Mechanisms for difficult listening” is a central theme for the research group. Their work indicates that this part of the brain, typically associated with long-term memory for places and events, is also involved in short-term storage and manipulation of auditory information. Dr. Will Sedley, from Newcastle University’s Faculty of Medical Sciences, said: “The memory system engaged in difficult listening is the most common site for the onset of Alzheimer’s disease.” Professor Tim Griffiths, from Newcastle University’s Faculty of Medical Sciences, said: “The challenge has been to explain how a disorder of the ear can lead to a degenerative problem in the brain. We suggest a new theory based on how we use the area of the brain generally considered to be the memory center when we have difficulty listening in real-world environments.” This is a huge step in Alzheimer’s research, opening the door to new treatment possibilities (once more information has been uncovered.) For now, the researchers “propose that altered activity in the memory system caused by hearing loss and the Alzheimer’s disease process trigger each other. Researchers now need to examine this mechanism in models of the pathological process to test if this new theory is right.”

Why it matters:

Preventing hearing loss is already crucial for keeping members of the community engaged, and not feeling isolated. If this new theory proves to be true, then caring for hearing loss is more vital than we ever thought. That’s why it’s important to pay attention to your body and what it’s telling you. If you’re experiencing trouble hearing, then act! Give us a call and set up and in-person or TeleHealth appointment. Let us diagnose and treat whatever we find. Together, we can ensure you’re at tip-top hearing health shape for years to come!

Advances in Audiology Research

The ability to completely restore hearing is still beyond the range of current technology. The good news is, research is ongoing, bringing solutions closer and closer every year. Recent discoveries provide new understandings about how we hear, which may lead to new treatments. The fact of the matter is, the auditory system is a very complex sensory organ. In fact, both doctors and scientists are still discovering how the ear and the brain function together to hear. We DO know that fine, microscopic hair cells within the cochlea are responsible for translating noises into sounds that the brain can understand. When these hair cells die or are destroyed—from age, loud noise, or chemicals—hearing loss occurs.

Many scientists have been able to regrow sensory hair cells in a lab, but in order for those to function properly to restore hearing, they must connect with nearby nerve cells. This is complicated because a number of pathways are needed for this to occur; and the exact process is still a mystery. The exciting news is that recent studies have revealed several methods to activate the signal pathway, which could lead the way to restoring hearing—but there’s still a lot to be learned.

Scientists know when sound waves enter the ear, inner ear hair cells in the cochlea bend. This bending opens a pore on the hair cell allowing chemicals to enter the auditory nerve. This transfer is critical in converting sound to an electrical signal the brain can interpret. However, the key to opening that pore still remains unknown. Recently, there was a protein identified as the mechanical gate keeper of the pore, which is a big clue, but it still remains a bit of a mystery. Certainly, we need to keep our ears to the ground.

Cochlear implants are used by people with profound hearing loss. They are surgically implanted and bypass the inner ear to send sounds directly to the brain. Due to the difficulty in placing the implant into specific nerve cells, patients may experience distortion in their hearing, which means there’s room for improvement. As research continues, a variety of ways of looking into and repairing hearing loss are being developed. Optogenetics—the use of light-sensitive proteins to control living cells—is one of them, and it may solve the implantation problem presented by cochlear implants. For now, optogenetics is still in its experimental stage—but it’s yet another innovation to keep listening for.

Researchers are developing new for drugs to treat damaged nerves and cells deep inside the ear. The beauty of this treatment procedure lies in its use of the natural function of the ears. Fluid inside the cochlea moves constantly, which means drugs placed in the fluid dissolve quickly or get swept into their target areas, making them effective. In fact, scientists have developed a protein that sticks to the cells and stimulates neurons to grow and start working. This is all good news! As we work together to treat hearing loss, it’s important to keep up with the latest scientific discoveries. Who knows what the next decade will bring?

As always, getting treatment when you need it is crucial for any condition. If you or someone close to you is suffering from hearing loss, don’t ignore it! Schedule a time to see us and let us help—your hearing health is our priority. Whether you want an in-person appointment, or a TeleHealth visit, we’ve got you covered!