Auditory brainstem implant

Auditory Brainstem Implant (ABI) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf, due to injury or disease affecting the cochlear nerve. The ABI is designed to stimulate the cochlear nucleus (CN), a nucleus that is part of the auditory brainstem.

History

The first auditory brainstem implant was developed by William F. House and William E. Hitselberger at the House Ear Institute in Los Angeles in 1979. The device was initially used to help patients with neurofibromatosis type II (NF2), a rare genetic condition that causes tumors to grow on the nerves used for hearing and balance.

Procedure

The ABI procedure involves the surgical implantation of an electrode array onto the surface of the cochlear nucleus in the brainstem. This is connected to a receiver and stimulator that is implanted under the skin behind the ear. The receiver is then connected to a speech processor, which is worn externally and converts sound into electrical signals that are sent to the brain.

Candidates for ABI

Candidates for an ABI are typically individuals who cannot benefit from a cochlear implant due to damage or absence of the cochlear nerve or inner ear. This includes individuals with NF2, certain forms of severe inner ear malformations, and those who have experienced trauma to the inner ear.

Benefits and Risks

The benefits of an ABI can vary greatly among individuals. Some may gain awareness of environmental sounds, while others may achieve some degree of speech recognition. However, the ABI also carries risks, including the risks associated with brain surgery, such as infection, bleeding, and changes in sensation or movement.

See Also

• Cochlear implant
• Neurofibromatosis type II
• Hearing loss