Medical team performs auditory brainstem implant surgery on child

Summarized by Rachel Janis, staff writer

For the first time, sound registered in a deaf Canadian boy’s brain after doctors activated a hearing device that had been surgically placed in his brainstem, said a team of scientists and surgeons from Keck Medicine of USC, Children’s Hospital Los Angeles (CHLA) and Huntington Medical Research Institutes (HMRI).

His name is Auguste Majkowski, who is three years old and the first child in the United States to undergo an auditory brainstem implant (ABI) surgery as part of a National Institutes of Health (NIH)-funded study. The device was activated at a Keck Medicine of USC clinic six weeks after surgery at CHLA. Auguste showed positive results.

The child’s mother Sophie Gareau reflects: “It was magical… He’s a tough kid.”

The surgery, along with device activation and future studies, is part of a five-year clinical trial funded by NIH, where ten devices will be implanted in deaf children who are under five; the children will be studied over the course of three years. This study, under audiologist Laurie Eisenberg and surgeon Eric Wilkinson, is the only one in the U.S. to be supported by the NIH.

“Our Los Angeles-based team has been at the forefront of ABI technology development since it came into use in the late 1970s for adults, so it is especially gratifying to help break the ‘sound barrier’ once again; this time, for children who previously could not hear,” stated Eisenberg, who is a professor of otolaryngology at the Keck School of Medicine of USC. “Surgeons outside the United States have been doing ABI surgeries in children for 10 years, but there has never been a formal safety or feasibility study under regulatory oversight. Our team is writing the manuals for all the procedures for this technology, and we have a top-notch multidisciplinary team in place to carry out the research.”

Wilkinson was part of the surgical team at CHLA, along with research scientist and neurosurgeon Marc Schwartz, pediatric neurosurgeon Mark Krieger, and CHLA’s Billy and Audrey Wilder Chair, Division of Neurosurgery. Vittorio Colletti of the University of Verona Hospital in Italy was present at the surgery; Colletti has performed the most ABI surgeries on children overseas and collaborated on the study.

Once the surgery is approved for children in the United States, doctors will use the established safety protocols and research procedures of this surgery to aid them in future surgeries.

“Hundreds of children in the U.S. can benefit from ABI surgery,” said Krieger, also an associate professor of clinical neurosurgery at the Keck School of Medicine. “These children would otherwise never hear or develop verbal speech in their lives.”

Auguste was the first one to be accepted into this Los Angeles study. Audiologists Margaret Winter and Jamie Glater of the USC Center for Childhood Communication activated the device that was implanted in the boy’s brainstem thirty-six days after the surgery. Auguste responded to the tiny pulses of electric current to the electrodes in his brain by lifting his head.

The boy has been deaf since he was born. He underwent a bilateral cochlear implant when he was twenty-two months. The cochlear implant uses electrodes to stimulate auditory nerves, but it didn’t affect Auguste’s hearing because he doesn’t have a cochlear nerve. He and his parents came from Montreal to Los Angeles to be participants of the clinical trial. The NIH grant covered the costs of the device, procedure, and future testing. Participants must prove that standard treatment, like hearing aids and cochlear implants, did not work.

It was a six-hour surgery in May where the doctors removed his right cochlear implant and then implanted the ABI device on his brainstem. This device has external and internal parts. An external processor, consisting of a microphone and transmitter, transforms sound into electrical signals and then sends the signals to an internal receiver that is a part of the electrode array. This electrode array is implanted on the cochlear nucleus of the brainstem. This surgery is revolutionary because it stimulates the neurons directly at the brainstem, avoiding the inner ear completely.

In the United States, the device is FDA-approved only in patients twelve years or older with neurofibromatosis type II, which is a disease that causes a non-threatening brain tumor on the hearing nerve. Scientists believe the device is more effective in young children rather than adults since their brains are more likely to adapt to the device.

The clinical trial wants to prove that the surgery is safe in young children. Researchers desire to study how the brain will develop over time and how it learns to hear sound and develop speech. Professor Robert Shannon, an investigator for this trial and a scientist in the ABI technology field since 1989, said, “The children in this study are under 5 years of age… When a child is born, their ear is hard-wired for sound, but the brain has to learn how to perceive sound and speech from the information coming up the hearing pathway. If the ear is not providing sound information to the brain, the hearing part of the brain doesn’t develop properly. The ABI provides sound to these pathways so they grow and develop with the child.”

If the trial and the subsequent research are successful, children across the United States will be able to benefit from the techniques and protocols constructed in the study. 

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