title: [A longitudinal study of electrode impedance in nucleus 24M cochlear implant users].
abstract: OBJECTIVE
  The primary goal of this study was to examine changes that may occur in electrode impedance over time in cochlear implant users. Secondary goal was to determine the timetable of mapping for patients who were cooperative quite well in psychophysical test.
  
  
  METHODS
  Sixteen patients implanted with Nucleus CI24M participated in this study. The impedance of electrode was measured intra-operatively, at initial stimulation, and at each mapping visits. Statistical analysis was conducted to assess how the changes occurring over time.
  
  
  RESULTS
  There was a significant increase in electrode impedance from the intra-operative test to initial stimulation, and a significant decrease in impedance from initial stimulation to the following visit. The impedance values remained stable for approximately 2-4 months after initial stimulation.
  
  
  CONCLUSIONS
  The results suggest that electrode-tissue interface gradually tend to remain stable. If a patient cooperates quite well in psychophysics test, the psychophysical levels for the map should be stable after 2 to 4-month mapping.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Chinese PLA General Hospital, Beijing 100853.
authors.forename: Xin
authors.initials: X
authors.lastname: Xi
authors.forename: Dongyi
authors.initials: D
authors.lastname: Han
authors.forename: Deliang
authors.initials: D
authors.lastname: Huang
authors.forename: Weiyan
authors.initials: W
authors.lastname: Yang
authors.forename: Mengdi
authors.initials: M
authors.lastname: Hong
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000503:physiopathology*; D003054:Cochlear Implants; D017097:Electric Impedance; D004566:Electrodes; D005500:Follow-Up Studies; D034381:Hearing Loss / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D011184:Postoperative Period