Functional benefits of sequential bilateral cochlear implantation in children with long inter-stage interval between two implants

• Published in: International journal of pediatric otorhinolaryngology 2013-02, Vol.77 (2), p.162-169
• Main Authors: Kim, Jeong-Seo, Kim, Lee-Suk, Jeong, Sung-Wook
• Format: Article
• Language: English
• Subjects: Adolescent; Bilateral; Child; Children; Cochlear Implantation - methods; Cochlear Implants; Female; Hearing; Hearing Tests; Humans; Inter-stage interval; Male; Otolaryngology; Pediatrics; Signal-To-Noise Ratio; Speech Perception; Time Factors; Treatment Outcome
• ISSN: 0165-5876; 1872-8464
• DOI: 10.1016/j.ijporl.2012.10.010

Abstract Objectives Older children are increasingly deriving binaural benefits from sequential bilateral cochlear implantation, and this procedure should be considered by experienced cochlear implant centers. This study aimed to identify the influence of a long inter-stage interval between two implants in older children. Speech perception and everyday listening performance were investigated and analyzed according to the length of the inter-stage interval. Study design and settings Forty-two children who received sequential bilateral cochlear implantation participated in this study. Their average ages at the first and second implantation were 4.2 and 9.7 years, respectively. All subjects acquired excellent speech performance from their first implant, and the mean inter-stage interval was 5.5 years. Speech perception in quiet was assessed by formal speech measures, and postoperative performance using the second implant only was compared with the preoperative performance. Speech perception in noise test was administered using three noise directions with noise (+10 dB signal-to-noise ratio) from front and 90° to each side, and the change in performance using the first implant only and both implants were analyzed across the three noise directions. Subjects were divided into three groups according to their inter-stage interval (group I, 3–4.9 years; group II, 5–6.9 years; and group III, 7–9.9 years), and the test results were compared between the groups. Functional hearing benefits in daily life were measured by a questionnaire before and after bilateral cochlear implantation. Results The speech perception abilities in quiet using the second implant only improved quickly and were similar to those using the first implant only within 1 year after the second implantation. The scores for the monosyllabic word test (phoneme: p = 0.052; word: p = 0.125) and common phrases sentence test ( p = 0.062) 6 month after the second implantation, and the Categories of Auditory Performance score ( p = 1.000) 1 year after the second implantation using the second implant only did not differ significantly from those using the first implant only. Speech perception was significantly better using both implants than using the first implant in all three noise conditions (speech and noise in front: p = 0.004; speech in front and noise to the first implant: p = 0.003; speech in front and noise to the second implant: p < 0.001), and the effect of noise direction was negligibly small. No sa