title: Evolution of cochlear implant arrays result in changes in behavioral and physiological responses in children.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Prospective nonrandomized control study over 6 months postimplantation.
  
  
  METHODS
  Tertiary referral pediatric hospital.
  
  
  METHODS
  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).
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department Otolaryngology-Head and Neck Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada. ariegor@hotmail.com
authors.forename: Arie
authors.initials: A
authors.lastname: Gordin
authors.forename: Blake
authors.initials: B
authors.lastname: Papsin
authors.forename: Adrian
authors.initials: A
authors.lastname: James
authors.forename: Karen
authors.initials: K
authors.lastname: Gordon
mesh_terms: D001309:Auditory Threshold; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D003056:Cochlear Nerve / Q000502:physiology; D004558:Electric Stimulation / Q000295:instrumentation; D005072:Evoked Potentials, Auditory; D005260:Female; D034381:Hearing Loss / Q000503:physiopathology* / Q000523:psychology* / Q000534:rehabilitation / Q000628:therapy*; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D011571:Psychoacoustics; D012022:Reflex, Acoustic; D013067:Speech Perception; D013198:Stapedius / Q000502:physiology