Abstract
A cochlear implant (CI) is a surgically implanted device for the treatment of severe
to profound sensorineural hearing loss in children and adults. It works by transducing
acoustic energy into an electrical signal, which is used to stimulate surviving spiral
ganglion cells of the auditory nerve. The past 2 decades have witnessed an exponential
rise in the number of CI surgeries performed. Continual developments in programming
strategies, device design, and minimally traumatic surgical technique have demonstrated
the safety and efficacy of CI surgery. As a result, candidacy guidelines have expanded
to include both pre and postlingually deaf children as young as 1 year of age, and
those with greater degrees of residual hearing. A growing proportion of patients are
undergoing CI for off-label or nontraditional indications including single-sided deafness,
retrocochlear hearing loss, asymmetrical sensorineural hearing loss (SNHL) in adults
and children with at least 1 ear that is better than performance cut-off for age,
and children less than 12 months of age. Herein, we review CI design, clinical evaluation,
indications, operative technique, and outcomes. We also discuss the expanding indications
for CI surgery as it relates to lateral skull base pathology, comparing CI to auditory
brainstem implants, and address the concerns with obtaining magnetic resonance imaging
(MRI) in CI recipients.
Keywords
cochlear implantation - hearing loss - auditory prosthesis - electric stimulation
- auditory nerve - auditory brainstem implant
