WASHINGTON, D.C. - Researchers at Georgetown University Medical Center and the National Institutes of Health (NIH) have, for the first time, used a “bionic” ear to restore hearing in a patient with von Hippel-Lindau disease. They say this advance offers new hope for individuals with the rare disorder, which can produce both benign and malignant tumors in ears, as well as in the eyes, brain, and kidneys.
The advance was possible, researchers say, because their years of research into the disease showed that these tumors often do not affect the cochlear nerve necessary for receipt of sound in the brain. The device they used is known as a cochlear implant, which stimulates the cochlear nerve endings with electrical impulses. It is predominately used to treat the deaf.
“Based on our understanding of how these tumors affect the inner ear, we felt that a cochlear implant could work, and it did,” said the study’s lead author, H. Jeffrey Kim, M.D., an associate professor in the Department of Otolaryngology ? Head and Neck Surgery, and a part-time investigator at the NIH, where the surgery was performed. Two years after the surgery, the implant has significantly improved the quality of life of the patient, he said.
Based on this successful surgery, which was published as a case report online in May for the of the journal Otology & Neurology, patients with von Hippel-Lindau disease with significant bilateral hearing loss may be now be candidates for a cochlear implant, Kim said. The disease, caused by inheritance of a mutated tumor suppressor gene, occurs in 1 out of 36,000 live births, and about 10 percent of these patients develop tumors in their ears ? often in both. To date, the only effective option to help control these tumors is surgery, which is often successful when operated early, he said. Loss of hearing is sudden, and hearing aids don’t help if the hearing loss is too severe, Kim said.
These tumors occur in the endolymphatic sac, part of the inner ear labyrinth of fluid passages. They are benign, but are invasive, and can cause hemorrhages that lead to tinnitus, vertigo, and hearing loss. Kim and his colleagues have been following a population of patients with the disorder and are national leaders in characterizing the disorder’s effect on the ears. They have published a series of findings in such journals as the New England Journal of Medicine (NEJM).
Kim’s research also sheds light on other ear problems, including Meniere’s disease, a disorder of the inner ear that can affect hearing and balance due to inner fluid imbalance probably regulate by the same endolymphatic sacs. “This is a much more common condition, so we hope that what we learn from von Hippel-Lindau disease may help in the treatment of hearing problems that affect many of us,” he said.
Funding for the study came from the National Institute on Deafness and Other Communication Disorders and the National Institute of Neurological Diseases and Stroke.
About Georgetown University Medical Center
Georgetown University Medical Center is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through our partnership with MedStar Health). Our mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis -- or "care of the whole person." The Medical Center includes the School of Medicine and the School of Nursing and Health Studies, both nationally ranked, the world-renowned Lombardi Comprehensive Cancer Center and the Biomedical Graduate Research Organization (BGRO).