April 2020 WPLG Local10
A multidisciplinary team of otolaryngology and neurosurgery specialists at the UHealth, the University of Miami Health System has introduced an auditory brainstem implant (ABI) program -- one of just a handful in the U.S. -- that uses signals to bring back sound for people without auditory nerve function. The skull base surgery team performed UHealth’s first implant surgery in March 2019 on Hildeana Bodden, a woman in her 60s whose NF2 was causing her hearing to decline.
The team’s bilingual ABI audiologists, Dr. Sandra Velandia and Dr. Diane Martinez, were able to communicate with Hildeana in Spanish, her native language, at her activation. They obtained hearing responses on a majority of the device’s 21 contact electrodes. “She did remarkably well at the initial stimulation,” says Dr. Fred F. Telischi, chairman of UHealth’s Department of Otolaryngology.
An ABI works via electrodes surgically implanted on the brainstem. Patients wear an external processor that picks up sounds with a microphone, converts those sounds to electrical signals, and sends the signals to the electrodes on the brainstem. The patient can then perceive those signals as sound and pitch. During the surgery, state-of-the-art care and monitoring are crucial -- hitting the wrong area of the brainstem could trigger dizziness, facial or vocal cord paralysis or even vital sign changes. The ABI program’s multidisciplinary component is key to its success. “When we consider auditory implants, while the process begins with the surgeon, the best outcomes rely on the collaborative interactions among audiologists, electrophysiologists, psychologists, and family support,” says UHealth otolaryngologist Dr. Christine Dinh.
ABIs are approved by the Food and Drug Administration for people with neurofibromatosis type 2 (NF2), a condition that affects about one in 25,000 people. With NF2, tumours or their treatments damage the auditory nerve and cause profound hearing loss. Most people with NF2 generally are not candidates for cochlear implants, which require a working auditory nerve.
With a robust cochlear implant program in place since 1990, as well as one of the most experienced multispecialty skull base surgery programs, the team’s expertise in implanting and programming electronic hearing devices put them in a strong position to launch the ABI program.
Because of their more central location in the central nervous system’s auditory path, ABIs can’t generate the same high level (and sometimes even near normal) speech recognition seen with cochlear implants. Combined with other techniques like lip reading, though, they can make a big difference in understanding and communication.
Hildeana can distinguish sounds like a barking dog or a fire truck, but she understands very little speech with the implant alone. And with lip reading alone, she understands about 25 percent. But with the ABI and lip reading combined, she boosts her understanding of words and sentences up to about 90 to 100 percent.
The team has since implanted two more patients, one by Dr. Telischi and Dr. Jacques Morcos, director of skull base tumour surgery, and another by Dr. Dinh and Dr. Michael Ivan, skull base neurosurgeon and director of brain tumour research. “Every week we all meet, ten specialists under one roof that intersect over the disease of a given patient,” says Dr. Morcos. “This is personalised medicine at its best.”