Prevention of cochlear implant electrode damage.
OBJECTIVE
As the current trend in cochlear implantation is to prescribe cochlear implants for patients with residual hearing and to use electroacoustic stimulation, cochlear implant damage must be prevented. This article summarizes current research endeavors to prevent electrode insertion trauma and resulting hearing loss.


RESULTS
Alteration in surgical technique is necessary with each new electrode design. Nontraumatic surgical technique also requires minimizing acoustic trauma due to drilling the cochleostomy, mechanical damage from electrode insertion, potential infection, and fibrosis of the cochlea. The pattern of hearing loss following electrode insertion trauma is an immediate loss that results from direct trauma to the macroscopic elements of the cochlea and a delayed loss that may reflect the activation of inflammatory and cell death pathways. Therapies under investigation include glucocorticoids, inhibitors of cell death pathways, and hypothermia.


CONCLUSIONS
Electrode insertion trauma-induced hearing loss involves multiple mechanisms ranging from mechanical insertion trauma to activation of inflammatory and cell death pathways. The macroscopic mechanical damage to the cochlea may be prevented by improvement of electrode design and surgical technique. The molecular damage needs further studies to assess the efficacy of novel therapeutic strategies in preserving functional residual hearing.
Eshraghi
Adrien A
AA
University of Miami Ear Institute, Department of Otolaryngology, University of Miami, Miller School of Medicine, Miami, Florida 33136, USA. Aeshraghi@med.miami.edu
D000818:Animals; D001309:Auditory Threshold; D019929:Cochlear Implantation / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design / Q000639:trends; D005938:Glucocorticoids / Q000627:therapeutic use; D034381:Hearing Loss / Q000517:prevention & control* / Q000534:rehabilitation; D006801:Humans; D007036:Hypothermia, Induced; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors; D023421:Models, Animal; D009925:Organ of Corti / Q000293:injuries; D010455:Peptides / Q000627:therapeutic use; D014947:Wounds and Injuries / Q000517:prevention & control
D005938:Glucocorticoids; D010455:Peptides; D048670:MAP Kinase Kinase 4; C478085:D-JNKI-1