Preoperative imaging of sensorineural hearing loss in pediatric candidates for cochlear implantation.

Cochlear implantation is the only U.S. Food and Drug Administration-approved treatment for children with marked bilateral sensorineural hearing loss. It provides auditory benefits that range from simple sound detection to substantial word understanding. Improved hearing through cochlear implantation has been demonstrated to enhance the rate of language acquisition, enable development of spoken language, and advance literacy in deaf children. Magnetic resonance imaging and computed tomography both have roles in the preoperative assessment of inner-ear abnormalities, cochlear nerve deficiency, and variant anatomy that may affect the decision to implant and the prognosis for auditory improvement and increase the risk for complications. Most cochlear abnormalities may be successfully treated with cochlear implantation, but the presence of a cochlear malformation may increase the risk for intraoperative cerebrospinal fluid leakage and postoperative bacterial meningitis. Eighth-nerve deficiency correlates with poor auditory outcomes and may affect eligibility for cochlear implantation. Another important consideration for implantation is the presence of labyrinthitis ossificans in some children with deafness resulting from bacterial meningitis, which may cause obstruction that limits electrode insertion. Anatomic variations of the facial nerve or middle-ear cavity, which are more common in syndromic patients, may also affect the surgical approach and make implantation difficult.