Right now we are actively recruiting volunteers with hearing loss to participate in an outpatient research study to understand the genes that cause non-syndromic autosomal dominant hearing loss (DFNA).
Specially Timed Signals Reduce Tinnitus Symptoms
In a double-blind clinical trial with 21 subjects, University of Michigan Medical School professor Susan Shore, Ph.D. (1987 and 1992–95 ERG) and team showed an experimental device could help people with tinnitus (hearing ringing or buzzing in the absence of an external sound source). Fusiform cells, the main neurons in the brainstem’s dorsal cochlear nucleus region, help the brain focus on where sounds are coming from, and help tune out sensations that result from the movement of our own head and neck (known as somatosensory inputs). The team’s previous work in animals showed that loud noise can trigger a change in the nerve cells’ activity—altering its timing so that the cells fire off synchronized signals spontaneously instead of waiting for an actual sound from the environment.
This phantom signal is transmitted into other centers where perception occurs. To stop the signal, the device uses “bimodal auditory-somatosensory stimulation,” which plays a sound into the ears, alternating it with precisely timed, mild electrical pulses delivered to the cheek or neck. Both are aimed at pushing the damaged nerve cells back to typical activity. In the trial, whose results were published in Science Translational Medicine on September 2018, participants using a sham treatment experienced no effect, but those who used the device daily for four weeks reported a decrease in tinnitus and an improved quality of life. —University of Michigan
Stenting to Relieve One Specific Cause of Pulsatile Tinnitus
By Jayne Wallace for the Weill Cornell Medicine Brain and Spine Center
The Centers for Disease Control and Prevention estimates that 15 percent of the U.S. population, or 48 million people, have some type of tinnitus, hearing a ringing or buzzing in the absence of an external sound source.
Pulsatile tinnitus, in contrast, usually has a sound source. In these cases, affecting fewer than 10 percent of tinnitus patients, sounds are caused by turbulence in the blood flow around the ear. And among these cases, intracranial hypertension comprises about 8 percent of cases. This is when narrowing in one of the large veins in the brain causes a disturbance in the blood flow, leading to the pulsatile tinnitus.
Dural arteriovenous fistula, MRA showed only subtle alterations as a result of atypical flows in the right transverse sinus (arrow). Photo courtesy of Deutsches Ärzteblatt International.
“Traditionally there has been no good treatment for many of these patients who are told to learn to live with it,” says Athos Patsalides, M.D., an interventional neuroradiologist at New York City’s Weill Cornell Medicine Brain and Spine Center, where he also serves as an associate professor of radiology in neurological surgery.
Till now, available treatments—medication or more complicated surgery—were either ineffective or produced side effects and other problems just as bad or worse. “That’s why we started the clinical trials for venous sinus stenting, a minimally invasive procedure that is very effective in alleviating the narrowing in the vein,” says Patsalides, who pioneered the use of VSS to treat patients with idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri because the symptoms tend to mirror those of a brain tumor.
“Many IIH patients suffer from vision loss, headaches, and pulsatile tinnitus, and I saw a pattern with patients experiencing resolution of the pulsatile tinnitus immediately after VSS,” Patsalides says.
This led to the possibility of using VSS for selected patients with pulsatile tinnitus. After the Food and Drug Administration approved the clinical trial, it began in May 2016 and has an estimated completion date of January 2021.
“In the stenting procedure, with the patient under general anesthesia, we insert a tiny, soft catheter into a vein located in the upper part of the leg and thread it up to the affected vein in the brain,” Patsalides says.
A self-expanding stent is deployed into the narrowed segment of the vein, relieving the stenosis, restoring normal blood flow, and reducing or eliminating the pulsatile tinnitus. “Happily, the patient is typically discharged from the hospital within 24 to 48 hours,” he says.
To learn more, see weillcornellbrainandspine.org. Hearing Health Foundation notes that the trial is ongoing, and that the procedure is potentially able to address only one specific cause of pulsatile tinnitus and should not be taken as a solution for other forms of tinnitus, which often has no known cause.
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