Auditory Midbrain Implant: Alternative Solution for Patients with Neural Deafness

Introduction: Patients with neural deafness do not benefit from a cochlear implant. Some of them due to cerebral damage at the brainstem, for example, tumor, trauma, or tumor removal. Many patients cannot benefit even from an Auditory Brainstem Implant (ABI). Therefore, electrical stimulation of the auditory midbrain in the inferior colliculus is another option for hearing restoration.

Concept of AMI: Auditory Midbrain Implant (AMI) is a penetrating single or double shank electrode to stimulate the frequency layers at the inferior colliculus. This allows for frequency-specific stimulation along the tonotopic axis.

Patients: Patients with neurofibromatosis type 2 and poor results with ABI have been selected for clinical study. They were implanted with a single shank electrode.

Results: Auditory perception is possible. Patients show hearing improvement over time for several years up to the level of limited speech test understanding. Results are comparable with that of the ABI.

Conclusion: The AMI is an alternative to ABI in cases where severe damage to the brainstem reduces the success of ABI functioning.