People with tinnitus - a ringing or other "phantom" sounds in their ears - may benefit from a treatment that sends electromagnetic pulses into the brain, suggests a new study.
Transcranial magnetic simulation (TMS) is not currently available for the average person with tinnitus, but the study's lead author hopes it will someday be used along with existing therapies like hearing aids and symptom management strategies.
"I don't see TMS replacing all that, but I see it as another option for helping some patients," said Robert Folmer of Portland Veterans Affairs Medical Center and Oregon Health and Science University.
"Tinnitus is more likely to occur in people with hearing loss or people who had a lot of noise exposure," he said. "So it's usually associated with damage to the auditory system."
For the treatment, electric current running through a coil placed on the scalp generates a magnetic field that affects nearby brain cells.
Read: Managing tinnitus using mindfulness
"It's the magnetic field that penetrates the scalp and skull and interacts with brain tissue," Folmer told Reuters Health. The therapy is already approved in the U.S. for treatment of depression, he added.
Past studies have found that people with tinnitus have increased neural activity in regions of the brain associated with hearing even when there is no sound, Folmer said.
"When we deliver one pulse per second of TMS, that low rate of TMS stimulation can suppress neural activity in that region," he said.
How the new study was done
For the new study of 64 people with significant ringing in their ears, the researchers randomly assigned half the participants to receive 2,000 TMS pulses during sessions over 10 consecutive business days. The other half of the participants received sham TMS. The sessions lasted approximately 35 minutes each.
The participants then periodically filled out questionnaires about the severity of their tinnitus over the next six months.
Overall, 56 percent of participants receiving TMS improved by the end of the 10 sessions, compared to 22 percent of the participants who received sham TMS.
"Some people responded quite well," Folmer said. "We were surprised they maintained their improvement throughout the six months of follow-up. I thought if people showed an improvement it would be short-lived."
By the end of the six months, 66 percent of the TMS group had improved, compared to 38 percent of the sham group.
None of the participants dropped out of the trial because of side effects, but Folmer said sometimes TMS can cause jaw movement or eye twitching. In those cases, he said the intensity of the pulses is turned down.
While people who responded to the treatment typically sustained their improvements over the six months, larger studies are needed before TMS is offered to people with tinnitus, the researchers write in JAMA Otolaryngology-Head and Neck Surgery.
In a previous study, Dr. Jay Piccirillo from the Washington University School of Medicine in St. Louis found that TMS did not help tinnitus, but he told Reuters Health that the difference in results between the two studies may be due to differences in the groups studied.
For example, the participants in his study were younger, had more severe tinnitus and had very low depression scores (see Reuters Health).
"There is probably some effect," said Piccirillo, who wasn't involved in the new study. "We just don't know in whom and what place to stimulate and how much."
Folmer said it's difficult to say how much a TMS session for tinnitus would cost, because it's not approved to treat that condition.
"For people with tinnitus, they should try the management strategies that are available now," he advised.
Source JAMA Otolaryngology-Head and Neck Surgery.