Millions of Americans hear ringing in their ears — a condition called tinnitus — but a new study shows an experimental device could help quiet the phantom sounds by targeting unruly nerve activity in the brain.
In a new paper in Science Translational Medicine, a team from the University of Michigan reports the results of the first animal tests and clinical trial of the approach, including data from 20 human tinnitus patients.
Based on years of scientific research into the root causes of the condition, the device uses precisely timed sounds and weak electrical pulses that activate touch-sensitive nerves, both aimed at steering damaged nerve cells back to normal activity.
Human participants reported that after four weeks of daily use of the device, the loudness of phantom sounds decreased and their tinnitus-related quality of life improved. A sham “treatment” using just sounds did not produce such effects.
Results from tests in guinea pigs and the double-blind human study funded by the Coulter Foundation validate years of preclinical research funded by the National Institutes of Health, including previous tests in guinea pigs.
The U-M team has new NIH funding for an additional clinical trial to further refine the approach. U-M holds a patent on the concept behind the device and is developing it for potential commercialization.
“The brain, and specifically the region of the brainstem called the dorsal cochlear nucleus, is the root of tinnitus,” says Susan Shore, Ph.D., the U-M Medical School professor who leads the research team. “When the main neurons in this region, called fusiform cells, become hyperactive and synchronize with one another, the phantom signal is transmitted into other centers where perception occurs.
“If we can stop these signals, we can stop tinnitus,” she continues. “That is what our approach attempts to do, and we’re encouraged by these initial parallel results in animals and humans.”