Cochlear Implantation Outcome in Patients with Common Cavity Deformity

Abstract

Objectives: (1) Analyze our own cases and those in published reports involving cochlear implantation (CI). (2) Determine the factors affecting outcome in patients with common cavity (CC) deformity. Methods: We reviewed the English and Japanese literature published from January 1995 to December 2013 using the keywords “CC,” “CI,” and “cochlear malformation.” We included cochlear implanted CC patients whose records on occurrence of cerebral spinal fluid (CSF) gusher, facial nerve stimulation (FNS), number of inserted and actively used electrodes, or hearing levels before or after CI were available. Results: A total of 72 cochlear implanted CC patients were identified from 11 reports, including 5 patients from our institution. Individual hearing results as monosyllable and word scores were reported in 9 and 15 patients, respectively. Monosyllable hearing levels were greater in patients inserted with ≥20 electrodes and in those younger at time of CI. CSF gusher occurred in 18 (32%) of 57 patients, and FNS occurred in 12 (44%) of 27 patients. Conclusions: Individual data are important in assessing the outcome after CI in patients with CC because the outcomes vary significantly. Although there have been several reports, only a few have reported efficient data to discuss the propriety of each operation. Younger age at CI and greater number of inserted electrodes were associated with better outcome following CI in patients with CC. However, additional data are needed to confirm our findings.