In a randomized clinical trial involving 99 participants with somatic tinnitus, statistically significant reductions in tinnitus loudness level were observed after bi-sensory treatment (combined sound and somatosensory) but not after sound-only treatment.
“Tinnitus, the perception of sound in the absence of external stimuli, occurs in approximately 15% of the U.S. adult population, with 10% of these individuals reporting it as debilitating,” said senior author Professor Susan Shore, a researcher at the University of Michigan, and colleagues.
“Characteristic of most individuals with tinnitus, up to 80% can manipulate the volume, pitch, or tonal quality of their tinnitus by performing head or neck movements, termed somatic tinnitus.”
“This group of individuals was chosen for our new study as somatic tinnitus involves the somatosensory system, which has been shown to play an important role in the development of tinnitus.”
“While there have been substantial advances in the understanding of neural mechanisms underlying tinnitus, the development of treatments has proven challenging, and there are currently no FDA-approved treatments.”
For the study, the authors recruited 99 individuals (mean age 47 years; 59 males) with somatic tinnitus.
Candidates with bothersome, somatic tinnitus, as well as normal-to-moderate hearing loss, were eligible to participate.
“After enrollment, participants received a portable device developed and manufactured by in2being, LLC, for in-home use,” Professor Shore said.
“The devices were programmed to present each participant’s personal tinnitus spectrum, which was combined with electrical stimulation to form a bi-sensory stimulus, while maintaining participant and study team blinding.”
The participants were randomly assigned to one of two groups. The first group received bi-sensory, or active, treatment first, while the second received sound-alone, or control, treatment.
For the first six weeks, participants were instructed to use their devices for 30 minutes each day.
The next six weeks gave participants a break from daily use, followed by six more weeks of the treatment not received in the beginning of the study.
Every week, participants completed the Tinnitus Functional Index and Tinnitus Handicap Inventory, which are questionnaires that measure the impact tinnitus has on individuals’ lives. They also had their tinnitus loudness assessed during this time.
The researchers found that when participants received the bi-sensory treatment, they consistently reported improved quality of life, lower handicap scores and significant reductions in tinnitus loudness.
However, these effects were not seen when receiving sound-only stimulation.
Further, more than 60% of participants reported significantly reduced tinnitus symptoms after the six weeks of active treatment, but not control treatment.
This is consistent with an earlier study by the team, which showed that the longer participants received active treatment, the greater the reduction in their tinnitus symptoms.
“This study paves the way for the use of personalized, bi-sensory stimulation as an effective treatment for tinnitus, providing hope for millions of tinnitus sufferers,” Professor Shore said.
The findings were published in the journal JAMA Network Open.
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Gerilyn R. Jones et al. 2023. Reversing Synchronized Brain Circuits Using Targeted Auditory-Somatosensory Stimulation to Treat Phantom PerceptsA Randomized Clinical Trial. JAMA Netw Open 6 (6): e2315914; doi: 10.1001/jamanetworkopen.2023.15914