The first successful case of hearing produced by electrical stimulation of the human midbrain.
OBJECTIVE
Electrical stimulation of the inferior colliculus in the midbrain can provide a safe and efficacious alternative to auditory brainstem implants (ABIs).


BACKGROUND
Patients with neurofibromatosis type 2 (NF2) receive limited speech recognition with ABIs. Some ABI patients without NF2 can achieve excellent speech understanding, suggesting that the limited NF2 performance is due to brainstem damage from the tumor and its removal.


METHODS
An array of electrodes (Med-El ABI) was placed on the dorsal surface of the inferior colliculus in the midbrain of a human volunteer as an auditory prosthesis via an infratentorial supracerebellar median surgical approach. Electrophysiological responses, psychophysical responses, and speech recognition were measured.


RESULTS
Electrical stimulation produced auditory sensations on all 12 electrodes with no nonauditory sensations. Auditory threshold levels indicated the stability of the electrode array over time. Electrophysiological measures showed activation in the contralateral auditory cortex but none in ipsilateral cortex. All electrodes demonstrated a full range of loudness sensation and electrode-specific pitch sensations. Speech recognition was significant, but limited in the first month after surgery.


CONCLUSIONS
This approach may provide advantages for patients with brainstem damage.
Colletti
Vittorio
V
ENT, University of Verona, Verona, Italy.
Shannon
Robert
R
Carner
Marco
M
Sacchetto
Luca
L
Turazzi
Sergio
S
Masotto
Barbara
B
Colletti
Lilliana
L
D000328:Adult; D038263:Auditory Brain Stem Implantation; D001303:Auditory Cortex / Q000502:physiology; D001309:Auditory Threshold / Q000502:physiology; D003638:Deafness / Q000601:surgery; D004558:Electric Stimulation / Q000295:instrumentation; D004567:Electrodes, Implanted; D006801:Humans; D007245:Inferior Colliculi / Q000601:surgery*; D008297:Male; D016518:Neurofibromatosis 2; D013067:Speech Perception / Q000502:physiology*; D013997:Time Factors; D016896:Treatment Outcome