Oct 2019 Mlive.com
Shawn Macauley, 55, is the eighth person in the world to receive the vestibular implant.
The vestibular implant is a device similar to the cochlear implant, which is used for people who have hearing loss. But it serves a different purpose -- to restore balance when people have the lost the function of their inner ears. The vestibular implant has three electrodes that connect to the semicircular canals, the fluid-filled tubes in the ear that maintain balance. The electrodes send signals from an external gyroscope, a magnetic attachment placed on the outside of the head, to the ear, where those signals will be interpreted as head motion. The ear then sends signals to the eyes and muscles to anticipate and coordinate movement.
Physicians, researchers and medical engineers from all over the world are working at Johns Hopkins Hospital in Baltimore to develop this experimental technology. Their next trial patient is 55-year old Shawn Macauley. For the last 23 years, Macauley has been struggling with his balance. After having some dental work back in 1996, he got an infection. A doctor prescribed too much of the antibiotic gentamicin and as a side effect, Macauley’s inner ears were “destroyed,” and with that, his balance, he said. “For the next nine years, I was on total disability,” Macauley said. “I had to learn how to walk again and drive again and, basically, live again.” What most people don’t know, Macauley said, is that your ear has a lot to do with your balance. According to Johns Hopkins Medicine, the vestibular part of the ear senses head tilt and rotation when moving. Without the vestibules in the ear telling the eyes, brain and limbs how to react, people who have lost vestibular sensation suffer from imbalance, dizziness and blurred or unsteady vision with head movement.
Years of therapy helped Macauley, who now uses a walker, get used to the feelings of dizziness and nausea so that he can function somewhat normally. He is back to work as a professor of anatomy at Muskegon Community College, and he can get around walking and driving. “When I walk now, I can’t see,” Macauley said. “Everything blurs, everything moves, I’m always sort of in this dizzy state.” While Macauley can mask it well at this point, he’s had people think he’s intoxicated when he stumbles in public. People have approached him at movie theatres, parks and he has even been denied getting on an airplane because people accused him of being drunk. “People, rather than trying to be empathetic, are talking behind my back or steering away from me," Macauley said. “You get tired of the looks. You get tired of people whispering.”
Macauley just recently got the internal magnetic pieces of the experimental implant surgically put into his head, and effectively lost his hearing in his right ear, the side where everything originated. He said loss of hearing in his ear is a definite risk to getting the implant, but he’s willing to take that chance to regain his sense of balance. “I want to get better myself,” Macauley said. “If I can help the technology get better, if I can help move this field further, then that’s worth it.”
Over 300 people applied to participate in the trial, although some of those may be repeat applications. The U.S. Food and Drug Administration, FDA, approved this trial through a strictly regulated Investigational Device Exemption. Macauley faces a unique risk that his balance won’t be restored because he’s had vestibular dysfunction for 23 years. The longest any of the other patients with the device had gone with the dysfunction was 12 years, so there is a chance Macauley’s body will have a harder time adapting, he said.
Taking the lead in the work is Dr. Charley Della Santina, who runs the Johns Hopkins Vestibular NeuroEngineering Lab that is overseeing the study. He also is the principal investigator on the grant that is funding the study and is the CEO of Labyrinth Devices, one of the companies creating the implant device. “Other than doing rehabilitation exercises, we really don’t have anything to offer patients who’ve lost inner ear balance function,” Della Santina said. Della Santina added that about 60,000 to 100,000 people in the U.S. and about one million people in the word suffer loss of vestibular function.
A professor of anatomy himself, Macauley uses himself as an example to his students who are medical and nursing majors. “As a healthcare professional, if something doesn’t seem right, you say something, and you keep saying it,” Macauley said. “The second lesson is before you take a drug be fully aware of the possible complications and ask questions.” This coming week, Macauley will travel back to Maryland to get the outer part of the implant installed in his head. He’s hoping his hearing will come back, but there’s no guarantee, as the device is still being developed.
All medical, travel and lodging expenses have been covered by Johns Hopkins, Macauley said. Otherwise, his insurance would not have covered it because it’s experimental work.
Della Santina said he hopes the development of the vestibular implant can be similar to the cochlear implant, which has been used for decades by modern medicine. “Our immediate goal is to try to get the best possible outcome for subjects in this trial, while at the same time using this experience to learn what works best, what doesn’t work well,” Della Santina said. “How to optimise the hardware, the surgery, the stimulus parameters, our approach to programming devices, so we can get our patients the best possible outcome.”