Navigation Links
Overactive nerves in head and neck may account for 'ringing in the ears'

Do your ears ring after a loud concert" Nerves that sense touch in your face and neck may be behind the racket in your brain, University of Michigan researchers say.

Touch-sensing nerve cells step up their activity in the brain after hearing cells are damaged, a study by U-M Kresge Hearing Research Institute scientists shows. Hyperactivity of these touch-sensing neurons likely plays an important role in tinnitus, often called ringing in the ears. The study, now online in the European Journal of Neuroscience, will appear in the journals first January issue.

The research findings were made in animals, but they suggest that available treatments such as acupuncture, if used to target nerves in the head and neck, may provide relief for some people plagued by tinnitus, says Susan E. Shore, Ph.D., lead author of the study and research professor in the Department of Otolaryngology and the Kresge Hearing Research Institute at the U-M Medical School.

People with tinnitus sense ringing or other sounds in their ears or head when there is no outside source. Whether its mild and intermittent or chronic and severe, tinnitus affects about one in 10 people. An estimated 13 million people in Western Europe and the United States seek medical advice for it. It is a growing problem for war veterans. Since 2000, the number of veterans receiving service-connected disability for tinnitus has increased by at least 18 percent each year, according to the American Tinnitus Association.

Increasing numbers of baby boomers are also finding that when they cant hear as well as they used to, tinnitus seems to move in. The condition commonly occurs with hearing loss, but also after head or neck trauma such as whiplash or dental work.

Tinnitus varies in individuals from a faint, high-pitched tone to whooshing ocean waves to annoying cricket-like chirping or screeching brakes. For some, it is constant and debilitating.

Some people, oddly enough, find that if they clench the jaw or press on the face or neck, they can temporarily stop tinnitus, or in some cases bring it on. To understand tinnitus and its strange link to touch sensations, Shore and her research team have conducted a series of studies in guinea pigs, measuring nerve activity in a part of the brain called the dorsal cochlear nucleus that processes auditory and other signals.

In normal hearing, the dorsal cochlear nucleus is the first stop in the brain for sound signals arriving from the ear via the auditory nerve. Its also a hub where multitasking neurons process sensory signals from other parts of the brain.

In this study, we showed that when there is a hearing loss, other parts of the brain that normally convey signals to the cochlear nucleus have an enhanced effect, says Shore, who is also an associate professor in the Department of Molecular and Integrative Physiology at the U-M Medical School.

When you take one source of excitation away, another source comes in to make up for it. The somatosensory system is coming in, but may overcompensate and help cause tinnitis, she says.

The somatosensory system is a nerve network in the body that provides information to the brain about touch, vibration, skin temperature and pain. The part of the system that provides sensations from the face and head, called the trigeminal system, brings signals to the cochlear nucleus that help us hear and speak.

But when people experience hearing loss or some other event, such as having a cavity filled or a tooth implanted, these neurons from the face and head can respond like overly helpful relatives in a family crisis. The resulting neuron firings in the cochlear nucleus, like too many phone calls, create the din of tinnitus, a phantom sound produced in the brain.

In the study, Shore and the papers second author Seth Koehler, a U-M Ph.D. student in the U-M departments of Otolaryngology and Biomedical Engineering measured the patterns of activity of neurons in the brains of normal and deafened guinea pigs. They used a 16-electrode array to measure signals from the trigeminal nerve and multisensory neurons in the dorsal cochlear nucleus. When they compared results in the two groups, they found clear differences in trigeminal nerve activity.

The study shows that in deafened animals, the somatosensory response is much stronger than in animals with normal hearing, Shore says.

Shores research team knew from earlier research that some neurons in the cochlear nucleus become hyperactive after hearing damage, and this hyperactivity has been linked to tinnitus in animals.

This study shows that it is only those neurons that receive somatosensory input that become hyperactive, she says, which should make the search for treatments for tinnitus in some people more straightforward.

Many people with temporomandibular joint syndrome (TMJ), a condition that causes frequent pain in the jaw, experience tinnitus. Shores research could lead to a better understanding of this link. In people with TMJ, the somatosensory system is disrupted and inflamed. Shore says that its possible that in this situation, as in hearing loss, somatosensory neurons stir excessive neuron activity in the cochlear nucleus.


Contact: Anne Rueter
University of Michigan Health System

Related medicine news :

1. Protein in human hair shows promise for regenerating nerves
2. WeissComm Partners Makes 10 New Hires as It Wins New Accounts and Grows Existing Business
3. World fertility experts to meet in Montreal - IVF and IVM patients to provide first-person accounts at 14th World Congress
4. Small Army Takes on Cure for Diabetes and New Approach to Ending World Poverty with Addition of Non-Profit Accounts
5. American Academy of Dermatology Association Commends President Bush for Signing Tanning Accountability and Notification (TAN) Act
6. Sutter Moves to Reduce Public Accountability, Slash Hospital Beds
7. BancTec Showcases Accounts Payable and Healthcare Solutions at The Association for Financial Professionals (AFP) Annual Conference
8. New Study Shows Lower Costs, Increased Consumer Engagement in Account-Based Health Plans
9. Big ticket: Youll spend more thinking about your bank account than about your wallet
10. Symmetry Medical Provides Update of Previously Disclosed Accounting Review at Sheffield, UK Operating Unit
11. Better detection accounts for increase in cases of thyroid cancer
Post Your Comments:
Related Image:
Overactive nerves in head and neck may account for 'ringing in the ears'
(Date:10/13/2017)... ... October 13, 2017 , ... Lori R. Somekh, founder of the Law ... organization of elder law and special needs planning attorneys. “Membership in ElderCounsel helps our ... a forum to network with elder law attorneys nationwide,” said Somekh. , ...
(Date:10/13/2017)... ... , ... Many families have long-term insurance that covers care for a family ... for care if the client has a cognitive impairment diagnosis. , “What this ... often waived, so the benefits from their insurance start immediately,” said Mechell Vieira, owner ...
(Date:10/13/2017)... ... October 13, 2017 , ... Ellevate Network, the leading network for ... for action towards gender equality at their inaugural Summit in New York City in ... reached a social audience of over 3 million. To watch the Mobilize Women video, ...
(Date:10/13/2017)... ... ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh, has released a ... books in the Holy Scriptures, Revelation. The Book of Revelation paints a picture of ... have tossed it off as mere rubbish, but Yisrayl Hawkins says that is because ...
(Date:10/13/2017)... Fairfax, VA (PRWEB) , ... October 13, 2017 ... ... provider of DevOps and Agile Software Development, has been awarded a contract by ... (EATS) Blanket Purchase Agreement (BPA) aims to accelerate the enterprise use of Agile ...
Breaking Medicine News(10 mins):
(Date:9/28/2017)... , Sept. 28, 2017 Hill-Rom Holdings, Inc. ... earnings conference call and webcast on Friday, November 3, ... (EDT) and ending at approximately 8:30 a.m. (CDT) / ... the company,s 2017 financial performance and guidance for 2018, ... initiatives to enhance operational performance, and long-range financial outlook ...
(Date:9/27/2017)...  Commended for their devotion to personalized service, SMP Pharmacy ... one in the South Florida Business Journal,s 50 Fastest-Growing Companies, ... list, the national specialty pharmacy has found its niche.  To ... soon be honored by SFBJ as the 2017 Power Leader ... to receive his award in October, Bardisa said of the ...
(Date:9/25/2017)... 25, 2017   Montrium , an industry ... today—from the IQPC Trial Master Files & Inspection ... that EastHORN Clinical Services has selected eTMF ... TMF management. EastHORN, a leading European contract research ... increase transparency to enable greater collaboration with sponsors, ...
Breaking Medicine Technology: