Auditory Brainstem Implants
University Hospitals Offers Innovative Surgical Technique To Treat NF2
University Hospitals Neurofibromatosis 2 (NF2) Center is one of a select few programs in the United States offering auditory brainstem implants (ABI) counseling and treatment as a surgical solution to patients suffering from hearing loss due to NF2. Our team includes surgeons who specialize in cochlear and brainstem implants and work with a neurosurgeon to perform the procedure.
An ABI is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf due to illness or injury damaging the cochlea or auditory nerve, such as from tumors brought on by NF2.
Because of the location of NF2 tumors, the auditory nerve is at risk of being severed during surgery. When the nerve is severed, a cochlear implant cannot be used because the auditory nerve cannot carry signals from the cochlea to the brainstem. However, an ABI is designed to stimulate the auditory area of the cochlear nucleus in the brainstem and send sound signals directly to the brain. In certain cases in which small tumors have been removed and the auditory nerve remains in tact or when the tumor has been treated with X-ray therapy, a cochlear implant may be beneficial.
ABI uses technology similar to a cochlear implant except that the electrical stimulation is focused on the brainstem instead of the cochlea. The implant consists of a tiny microphone placed near the ear, a decoder and number of electrodes implanted on the brainstem. The microphone picks up sounds and digitally transmits them to the decoding chip. The chip stimulates the electrodes on the brainstem, allowing the patient to hear a variety of sounds.
After surgery, several follow-up sessions with an audiologist are held to test and adjust the sound on the ABI and to learn to interpret new sounds. The ABI doesn't always provide a full range of hearing but allows for increased awareness of sounds and noise. The degree and quality of hearing can vary from patient to patient.