Tinnitus Research.

For the first time, scientists have located an area in the brain involved in the production of tinnitus. Tinnitus is a ringing, roaring, buzzing, or clicking sound that occurs inside the head. These findings are in a new study by Alan H. Lockwood, M.D., of the State University of New York in Buffalo and his colleagues, in the January 22, 1998, issue of Neurology.

Using positron-emission tomography (PET), Dr. Lockwood's group was able to map brain regions of individuals who had tinnitus in only one ear. These individuals also had the ability to change the loudness of their tinnitus by performing special movements of their face and mouth. Cerebral blood flow, an indication of increased brain activity, was measured while these individuals were at rest, and performed the movements that affected their tinnitus, and while listening to loud beeps or pure tones that were presented using ear phones. The PET scan detected changes in the auditory cortex, that part of the brain that processes sounds, on the side of the brain opposite the tinnitus. In contrast, the auditory cortex on both sides of the brain reacted to pure tones presented to one ear at a time. Since external tones presented to one ear affect both sides of the brain, the fact that the internal tones of tinnitus affect only one side of brain indicate that tinnitus may be initiated by brain activity rather than by the ear.

"This work represents a breakthrough and moves us a step closer to understanding the phenomenon of tinnitus. We feel certain that this study will lead to further research that will ultimately translate into treatment options for the millions of people who suffer with this difficult condition," said James F. Battey, M.D., Ph.D., Director, National Institute on Deafness and Other Communication Disorders (NIDCD), which funded the study.

The authors suggest that this study may improve knowledge of how tinnitus occurs and may lead to finding treatments. "Without objective information on how and where the condition originates, developing effective treatments has been difficult. We have taken a critical step down the road toward a cure for this disabling condition," said Lockwood. Ultimately, this study opens the door to further research such as the development of drugs to change the brain activity in the involved areas. Dr. Lockwood's colleagues are R.J. Salvi, Ph.D., M.L. Coad, B.A., M.L. Towsley, M.A., D.S. Wack, M.A., and B.W. Murphy, M.S., from the VA Western New York Health Care System and State University of New York, both in Buffalo.

Tinnitus is a symptom that accompanies many kinds of hearing loss. The phenomenon of tinnitus presents so many issues to address because there are many different experiences of tinnitus with many different causes. The mechanisms that produce tinnitus are not fully known and are associated with nearly all diseases and disorders of the ear that cause hearing loss. Controlling these mechanisms, therefore, may alleviate the tinnitus. As it is a symptom, tinnitus is difficult for the scientists to address. The NIDCD is supporting several biomedical research projects that cover a variety of aspects of the condition which will provide necessary data: developing a comprehensive database and an understanding of the phenomenon of tinnitus that accompanies sensorineural hearing loss; tinnitus and masking devices; the role of calcium imbalance in inducing cochlear tinnitus; and otoacoustic emissions and cochlear function. The NIDCD is also supporting several non-invasive imaging studies that will hopefully differentiate the various kinds of tinnitus.

As the nation's focal point for research in human communication, the NIDCD conducts and supports biomedical and behavioral research and research training on normal mechanisms as well as diseases and disorders of hearing, balance, smell, taste, voice, speech and language that affect 46 million Americans. The NIDCD is one of the institutes of the National Institutes of Health, the Nation's lead agency for biomedical and behavioral health research. More information on NIDCD research, programs, and activities can be found on the NIDCD web site at www.nih.gov/nidcd/.

Additional Information Resources:

NIDCD Information Clearinghouse
Address: 1 Communication Avenue
Bethesda, MD 20892-3456
Voice: 1-800-241-1044
TTY: 1-800-241-1055
E-mail: [e-mail]

American Tinnitus Association (ATA)
Address: P.O. Box 5
Portland, OR 97207
Voice: [phone]
8:30 a.m. - 5 p.m., Pacific time
Toll Free: [phone]
FAX: [phone]
Internet: http://www.teleport.com/~ata

American Academy of Otolaryngology-Head
and Neck Surgery (AAO-HNS)
Address: One Prince Street
Alexandria, VA 22314
Voice: [phone]
TTY: [phone]
FAX: [phone]
E-mail: [e-mail]
Internet: http://www.entnet.org

Self Help for Hard of Hearing People, Inc.
(SHHH)
Address: 7910 Woodmont Avenue
Suite 1200
Bethesda, MD 20814
Voice: [phone]
TTY: [phone]
FAX: [phone]
Internet: http:/www.shhh.org/

American Academy of Audiology (AAA)
Address: 8201 Greensboro Drive
Suite 300
McLean, VA 22102
Voice/TTY: [phone]
8 a.m. -5 p.m., eastern time
Toll Free: (800) AAA-2336
Internet: http://www.audiology.org

American Speech-Language-Hearing
Association (ASHA)
Address: 10801 Rockville Pike
Rockville, MD 20852
Voice/TTY: [phone]
Toll Free: [phone]
8:30 a.m. - 5 p.m., eastern time
FAX: [phone]
Internet: http://www.asha.org/

February 1998