Researchers at Johns Hopkins Medicine are developing an implant to improve quality of life in those with bilateral vestibular hypofunction (BVH).
BVH — the loss of the inner ears’ sense of balance — has symptoms that can hinder walking, cause dizziness and decrease quality of life, but the researchers believe their implant can facilitate walking, relieve dizziness and improve quality of life, according to a news release.
The surgically implanted stimulator electrically bypasses malfunctioning areas of the inner ear to partially restore the sensation of balance. Results from a study of eight patients using the device were published in the New England Journal of Medicine.
Vestibular rehabilitation exercises are currently the standard therapy for BVH, while doctors advise patients with BVH to avoid medications that damage the inner ear (such as ototoxic drugs) or suppress brain function (sedatives), the researchers say.
Dr. Charley Della Santina, professor of otolaryngology-head and neck surgery & biomedical engineering at Johns Hopkins University School of Medicine & director of the Johns Hopkins Vestibular NeuroEngineering Laboratory, worked with his colleagues to modify a cochlear implant designed to improve hearing loss.
The cochlear implant, which electrically stimulates the inner ear’s cochlear nerve, was modified to activate the nearby vestibular nerve in response to signals from a motion sensor on the patient’s head, helping to drive head and eye reflexes that maintain clearer vision during head movement and reduce the need to exert conscious effort to avoid falls.
“Although about 20 individuals had been implanted elsewhere with devices used to stimulate the vestibular nerve in a laboratory setting, participants in this trial are true pioneers — the first to use a vestibular implant as a long-term, 24-hour-per-day sensory restoration treatment,” Della Santina, a senior study author, said in the release.
Researchers observed eight BVH patients with the vestibular implant, assessing them before implantation, then at six months and one year after. All eight patients experienced some hearing loss in the implanted ear, while five maintained hearing in the implanted ear was sufficient to use a telephone without a hearing aid. Three experienced greater hearing loss.
They observed an overall improvement in the quality of life and relief from the struggles caused by BVH.
“Improvement in performance on standardized clinical tests of balance and walking has been remarkable,” study lead author and Johns Hopkins biomedical engineering doctoral candidate Margaret Chow said. “Even more gratifying is that our patients have been able to return to activities that enrich their daily lives, such as exercising, riding a bike, gardening or dancing at a daughter’s wedding.”