Dr. Dornhoffer’s surgery was in August of 2015, but his hearing loss journey began when he was a second grader.
At that time, he was diagnosed with an autosomal dominant, progressive, sensorineural hearing loss. He wore hearing aids until his hearing got worse. Eventually, it was bad enough that even with the strongest behind-the-ear aids, he was unable to adequately understand speech.
By the time he was 50, he could only understand speech with low tones. This meant that he was mostly hearing only vowel sounds. As he wrote in JAMA, he was able to use lip reading and other strategies to get by. He was definitely experiencing a diminished quality of life.
He had the same concerns as other CI recipients. Losing residual hearing and relying on an external device were main concerns. But because he’s also an otologist, he knew too much. He was all too aware of the variability in implant performance.
Eventually, the difficulties he experienced as a result of his hearing loss meant that it was time to consider an implant.
Dornhoffer wanted to preserve as much of his residual hearing as possible. He opted to have the longest electrode available completely inserted. The end of the cochlea is where the low tones are stimulated, so this way it would be reached.
“My surgical experience implanting long, straight electrodes showed preservation of residual hearing in a high percentage of patients,” Dornhoffer wrote in JAMA. “If this were the case with my own implant, I would be able to use my preserved low tones until I could no longer hear these tones acoustically, at which time the deeper electrodes would be stimulated (via programming).”
Interestingly, while he experienced the usual reduction in hearing, it wasn’t due to the expected sensorineural loss. Instead, it was an inner ear conductive loss. Conductive is usually related to problems with the middle ear and conduction from the eardrum to the cochlea, Dornhoffer explains. There’s a phenomenon called inner ear conductive loss. This is when the sound isn’t conducted to the fluids of the cochlea for whatever reason.
“We do not know the reason why a cochlear implant can cause an inner ear conduction problem, but I speculate that having the electrode in the scala tympani of the inner ear is impeding movements of the fluid of the inner ear and resulting in decreased basilar membrane moves,” he told HearingLikeMe.
This scenario, he says, is being investigated and could have implications for future electrode design.
Dornhoffer acknowledged in his essay that any implant surgeon knows the true work begins after the surgery, in the audiologist’s office. Indeed, when Dornhoffer was activated, he struggled with the beeps, whistles, and distortion that he heard. He described himself as being vigilant with rehabilitation. One of the frustrating things for him was when the audiologist asked how a particular program sounded.
“It is difficult for someone who has not heard in a long time to answer this question,” he wrote in JAMA.
In his quest to improve his sound input, Dornhoffer stumbled upon a winning programming strategy. He asked the audiology team to program every frequency straight across at 30 dB, since that’s how the normal cochlea works. Four years later, this program remains. He hasn’t adjusted it at all.
A month or two after the final programming, his ability to perceive low tones returned.
“Since this change happened without any additional programming, I began to believe that outcome in cochlear implantation is more related to neuroplasticity of the brain than to the device or to the cochlea,” he wrote in JAMA. “And I was amazed how fast it all happened once it began.”
Another interesting development was discovering that wearing his hearing aid helped. Many surgeons tell recipients to only use the implanted ear to hear. Dornhoffer tried this for a while, but wearing a hearing aid in his other ear helped his implanted ear to reprogram to the right frequency.
Once he adjusted to the cochlear implant, about three or four months after activation, Dornhoffer stopped wearing the hearing aid.
“It just wasn’t strong enough and I liked getting that earpiece out of my ear canal for comfort,” he said.
Dornhoffer also had lifelong tinnitus. When he first got the implant, his tinnitus worsened. Once his brain adapted to the low tones, however, the tinnitus went away. After about six months, it was “nearly completely suppressed,” he says.
Now, he says, when he takes his implant off, within two to three minutes, the tinnitus returns. But it’s not as loud as before and goes away when the implant is back on.
“My theory is that the electrical stimulation from the cochlea reverses some of the mal-adaptive sensory reorganization that occurs in the brain that causes the tinnitus,” Dornhoffer wrote in JAMA. “Continuous electrical stimulation from the cochlea, when the implant is on, is necessary for more complete resolution of the tinnitus.”
When asked if he has any plans for a second implant, Dornhoffer told HLM he’ll get one at some point.
He still has some low tone hearing, which means he can still hear some environmental noises when his implant is off. This comes in handy when he’s in the water or when it’s nighttime.
“The prospect of going totally deaf and having no connection to environmental noise without the implant is more frightening than I had anticipated, so I am in no rush,” he says.
At the end of his published essay, Dornhoffer described his journey as one of the most fascinating experiences he’s ever had. Both personally and professionally.
“I have learned more from this one cochlear implant in my head than the 1,000 plus devices I have implanted in others,” he said.
“I have learned more from this one cochlear implant in my head than the 1,000 plus devices I have implanted in others.”
He now has many questions arising from the amazing neuroplasticity of the brain. They include: Why do the neuroplastic changes not happen in everyone with similar auditory profiles? Should routine assessments of cognitive function be included for candidates?
Dornhoffer told HLM he plans to use high-density EEG to correlate changes in the brain that occur during the neuroplastic changes after programming.
“This process is extremely important for success of the implanted patient, and it is poorly understood,” he says. “If we can understand what mechanisms occur and where in the brain they occur, we can perhaps manipulate these areas with non-invasive measures such as trans cranial magnetic stimulation. The variability and performance and patience with cochlear implants is frustrating and related to this mechanism.”
Dornhoffer’s colleagues have been extremely supportive of his plans. As for his patients, his experience has helped them ask him questions and advice about the process. It also encourages them to see him perform well in nearly every environment. He acknowledged this could lead to frustrations because some of them don’t perform as well.
The quality of sound through his implant is better than expected. He’s still working on trying to understand music.
In the meantime, he says, “Empathy is one of those words we throw around a lot in medicine, but really it almost has to come from experiencing the condition.”
What cochlear implant advances would you like to see? Let us know in the comments!