Accuracy of intraoperative electrophysiological testing in confirming correct cochlear implant electrode positions.

Objective: To investigate the accuracy of intraoperative electrophysiological studies in detecting incorrectly positioned electrodes in cochlear implant surgery. Study design: A retrospective chart review. Setting: Tertiary referral centre. Patients: In total, 104 consecutive patients with a mean age of 5 years underwent cochlear implant surgery at our centre between January 2012 and December 2013. All patients were implanted with Cochlear Nucleus Freedom implants. Method: A retrospective study to compare intraoperative neural response telemetry (NRT), impedance and electrode position using Stenver's transorbital plain X-ray view. Results: Intraoperative electrophysiological tests for patients with Cochlear Nucleus Freedom implants showed 97% sensitivity and 100% specificity compared with postoperative X-ray imaging. Conclusion: NRT results for the position of cochlear implants were very accurate when checked by X-ray imaging showing that this technique is sufficient in most cases. Stenver's plain X-ray view is needed in complicated cases with abnormal NRT testing or difficult electrode insertion.