To determine whether a change in cochlear implant technology and electrode array design affects electrophysiological, behavioral, and functional measures of audition in pediatric cochlear implant users.
Prospective nonrandomized control study over 6 months postimplantation.
Tertiary referral pediatric hospital.
A total of 115 children using unilateral cochlear implants were included in this study. Subjects were divided into 3 groups: 1) 38 using the Nucleus 24M straight array device, 2) 20 using the perimodiolar Nucleus 24RCS Contour array, and 3) 57 using the perimodiolar Nucleus 24RE array with advance off stylet insertion. The mean ages at implantation were 4.85 ± 4 (24M), 3.88 ± 3.4 (24RCS), and 5.41 ± 4.36 years (24RE; not significant, p > 0.05).
The electrically evoked compound action potential (ECAP) and the electrically evoked stapedius reflex and behavioral measures of stimulation threshold were evoked by stimulation of basal, mid, and apical electrodes. These measures were completed at regular intervals over 6 to 12 months of implantation. Age-appropriate speech perception skills were also assessed during this period.
The 24RE array group had significantly lower ECAP and behavioral thresholds compared with the 24M and 24RCS array groups. The largest reductions of ECAP thresholds in the precurved array group were observed upon apical and basal electrode stimulation. Electrically evoked stapedius reflex thresholds were significantly higher in the 24RE group as compared with 24M and 24RCS groups. Comparing age-matched groups, open- and closed-set speech perception test scores were significantly higher in the 24RE array group.
The precurved Freedom 24RE cochlear implant potentially provides a wider range of stimulation levels and better functional results than the straight electrode 24M and the precurved 24RCS devices in profoundly hearing impaired children.
*Department Otolaryngology-Head and Neck Surgery; and †The Cochlear Implant Lab, The Hospital for Sick Children, Toronto, Ontario, Canada
Address correspondence and reprint requests to Arie Gordin, M.D., Department of Otolaryngology-Head and Neck Surgery, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada; E-mail: firstname.lastname@example.org