Degree of modiolar coiling, electrical thresholds, and speech perception after cochlear implantation.

OBJECTIVE

Perimodiolar electrode arrays were developed to improve stimulation of specific neural populations and to decrease power consumption. Postoperative radiographs suggest that some arrays are more tightly coiled than others. The purpose of this study was to evaluate whether the degree of modiolar coil correlates with electrical threshold and/or performance measures postimplantation with the Nucleus CI24RCS (Contour) device.

STUDY DESIGN

Retrospective review.

SETTING

Cochlear implant center and a tertiary care hospital.

PATIENTS

Twenty-eight adult cochlear implant recipients with normal cochlear anatomy who underwent implantation with the Nucleus C124RCS perimodiolar electrode and are at least 1 year postimplantation.

INTERVENTIONS

Therapeutic.

MAIN OUTCOME MEASURES

Radiologic degree of perimodiolar electrode placement (determined by a computer algorithmic analysis) compared with electrical thresholds and standard speech perception outcome measures at 1 year postcochlear implantation.

RESULTS

No significant correlations were found between the degree of modiolar coiling of the electrode array and electrical thresholds and speech perception outcome measures at 1 year postcochlear implantation.

CONCLUSIONS

The degree of coiling of a modiolar hugging electrode array was not directly correlated with the level of electrical thresholds or postoperative speech perception outcome measures. Appearance of coil tightness on postoperative radiographs could reflect either differences in array placement or intrinsic variations in cochlear anatomy, and variations in speech perception performance can be influenced by other factors, including length of deafness.