PORTLAND, Ore. - In the largest U.S. clinical trial of its kind funded by the Veterans Affairs (VA) Rehabilitation Research and Development Service, researchers at the VA Portland Medical Center and Oregon Health & Science University found that transcranial magnetic stimulation significantly improved tinnitus symptoms for more than half of study participants. Their findings were published today in the journal JAMA Otolaryngology - Head & Neck Surgery.
"For some study participants, this was the first time in years that they experienced any relief in symptoms. These promising results bring us closer to developing a long-sought treatment for this condition that affects an enormous number of Americans, including many men and women who have served in our armed forces," said Robert L. Folmer, Ph.D., research investigator with the National Center for Rehabilitative Auditory Research at the VA Portland Health Care System and associate professor of Otolarynology/Head and Neck Surgery in the OHSU School of Medicine.
One of the most common health conditions in the country, tinnitus affects nearly 45 million Americans. People with this audiological and neurological condition hear a persistent sound - that can range from ringing or buzzing to a hissing or white noise hum - when there is no external sound source. The distraction can impair people's ability to sleep or concentrate and is sometimes disabling.
According to the Centers for Disease Control and Prevention, nearly 15 percent of Americans experience some degree of tinnitus. Currently, there are no proven treatments available. So, patients with the condition often develop coping strategies to manage their reaction to tinnitus.
Military veterans are at greater risk of developing the condition. Tinnitus is the most prevalent service connected disability in the VA health system. Study participants were a mix of veterans and non-veterans.
"We applaud the work of Dr. Folmer and his colleagues. The results of the joint National Center for Rehabilitative Auditory Research/OHSU study are promising for tinnitus patients everywhere," said Melanie West, Chair of the American Tinnitus Association's Board of Directors, the premier member-based tinnitus organization. "We are committed to finding solutions for tinnitus and excited to see the progression of TMS clinical trials producing positive results for some patients."
To conduct this research, Folmer and colleagues, including Sarah Theodoroff, Ph.D., used a TMS system that generates a cone-shaped magnetic field that penetrates the scalp and skull to interact with brain tissue. The higher the stimulation intensity, the deeper the magnetic field can penetrate and affect neural activity. Currently, the Food and Drug Administration has approved transcranial magnetic stimulation only for treatment of depression.
All 64 participants enrolled in the study received one pulse of TMS per second to their skull just above the ear to target the auditory cortex in the brain. Participants underwent TMS sessions on 10 consecutive workdays, receiving 2,000 pulses of TMS per session. Of the 32 participants who received the "active" TMS treatment, 18 people found their symptoms were alleviated for at least six months. To participate in the study, patients were required to have had tinnitus for at least a year or more.
A significant number of participants who had tinnitus for more than 20 years were pleased to receive some relief from TMS treatment. In light of these encouraging results, Dr. Folmer hopes to conduct a larger clinical trial to refine protocols for the eventual clinical use of TMS for tinnitus.
The study, "Repetitive Transcranial Magnetic Stimulation Treatment for Chronic Tinnitus: Results of a Randomized, Placebo-Controlled Clinical Trial," was authored by Folmer, Theodoroff, Linda Casiana, M.S., Yongbing Shi, M.D., Ph.D., Susan Griest, M.P.H., and Jay Vachhani, Au.D.
The study was funded by the VA Rehabilitation Research and Development Service.
The VA National Center for Rehabilitative Auditory Research (NCRAR) located at Portland VA Medical Center is one of the Centers of Excellence funded by the VA Rehabilitation Research and Development (RR&D) Service. NCRAR investigators and staff members facilitate its mission to improve the quality of life of Veterans and others with hearing and balance problems through clinical research, technology development, and education that leads to better patient care. NCRAR's research focuses on the diagnosis, prevention and rehabilitation of auditory system disorders. NCRAR contributes to the VA's mission to recruit, mentor and train the next generation of clinicians and clinical researchers. NCRAR also provides information to Veterans and the public about hearing conservation, how to prevent further hearing loss and how to manage tinnitus. Profiles of NCRAR investigators and descriptions of projects can be found at http://www.ncrar.research.va.gov.
Oregon Health & Science University is a nationally prominent research university and Oregon's only public academic health center. It serves patients throughout the region with a Level 1 trauma center and nationally recognized Doernbecher Children's Hospital. OHSU operates dental, medical, nursing and pharmacy schools that rank high both in research funding and in meeting the university's social mission. OHSU's Knight Cancer Institute helped pioneer personalized medicine through a discovery that identified how to shut down cells that enable cancer to grow without harming healthy ones. OHSU Brain Institute scientists are nationally recognized for discoveries that have led to a better understanding of Alzheimer's disease and new treatments for Parkinson's disease, multiple sclerosis and stroke. OHSU's Casey Eye Institute is a global leader in ophthalmic imaging, and in clinical trials related to eye disease.