Peters B Robert, Litovsky Ruth, Parkinson Aaron, Lake Jennifer
Dallas Otolaryngology Cochlear Implant Program, Dallas, TX 75230, USA.
Otol Neurotol. 2007 Aug;28(5):649-57. doi: 10.1097/01.mao.0000281807.89938.60.
Clinical trials in which children received bilateral cochlear implants in sequential operations were conducted to analyze the extent to which bilateral implantation offers benefits on a number of measures. The present investigation was particularly focused on measuring the effects of age at implantation and experience after activation of the second implant on speech perception performance.
Thirty children aged 3 to 13 years were recipients of 2 cochlear implants, received in sequential operations, a minimum of 6 months apart. All children received their first implant before 5 years of age and had acquired speech perception capabilities with the first device. They were divided into 3 age groups on the basis of age at time of second ear implantation: Group I, 3 to 5 years; Group II, 5.1 to 8 years; and Group III, 8.1 to 13 years. Speech perception measures in quiet included the Multisyllabic Lexical Neighborhood Test (MLNT) for Group I, the Lexical Neighborhood Test (LNT) for Groups II and III, and the Hearing In Noise Test for Children (HINT-C) sentences in quiet for Group III. Speech perception in noise was assessed using the Children's Realistic Intelligibility and Speech Perception (CRISP) test. Testing was performed preoperatively and again postactivation of the second implant at 3, 6, and 12 months (CRISP at 3 and 9 mo) in both the unilateral and bilateral conditions in a repeated-measures study design. Two-way repeated-measures analysis of variance was used to analyze statistical significance among device configurations and performance over time.
US Multicenter.
Results for speech perception in quiet show that children implanted sequentially acquire open-set speech perception in the second ear relatively quickly (within 6 mo). However, children younger than 8 years do so more rapidly and to a higher level of speech perception ability at 12 months than older children (mean second ear MLNT/LNT scores at 12 months: Group I, 83.9%; range, 71-96%; Group II, 59.5%; range, 40-88%; Group III, 32%; range, 12-56%). The second-ear mean HINT-C score for Group III children remained far less than that of the first ear even after 12 months of device use (44 versus 89%; t, 6.48; p<0.001; critical value, 0.025). Speech intelligibility for spondees in noise was significantly better under bilateral conditions than with either ear alone when all children were analyzed as a single group and for Group III children. At the 9-month test interval, performance in the bilateral configuration was significantly better for all noise conditions (13.2% better for noise at first cochlear implant, 6.8% better for the noise front and noise at second cochlear implant conditions, t=2.32, p=0.024, critical level=0.05 for noise front; t=3.75, p<0.0001, critical level=0.05 for noise at first implant; t=2.73, p = 0.008, critical level=0.05 for noise at second implant side). The bilateral benefit in noise increased with time from 3 to 9 months after activation of the second implant. This bilateral advantage is greatest when noise is directed toward the first implanted ear, indicating that the head shadow effect is the most effective binaural mechanism. The bilateral condition produced small improvements in speech perception in quiet and for individual Group I and Group II patient results in noise that, in view of the relatively small number of subjects tested, do not reach statistical significance.
Sequential bilateral cochlear implantation in children of diverse ages has the potential to improve speech perception abilities in the second implanted ear and to provide access to the use of binaural mechanisms such as the head shadow effect. The improvement unfolds over time and continues to grow during the 6 to 12 months after activation of the second implant. Younger children in this study achieved higher open-set speech perception scores in the second ear, but older children still demonstrate bilateral benefit in noise. Determining the long-term impact and cost-effectiveness that results from such potential capabilities in bilaterally implanted children requires additional study with larger groups of subjects and more prolonged monitoring.
开展了关于儿童接受序贯式双侧人工耳蜗植入手术的临床试验，以分析双侧植入在多项指标上的获益程度。本研究特别关注测量植入时的年龄以及激活第二枚植入体后的使用经验对言语感知表现的影响。
30名年龄在3至13岁的儿童接受了2枚人工耳蜗植入，手术为序贯式，间隔至少6个月。所有儿童在5岁前接受了第一枚植入体，并已通过该装置获得了言语感知能力。根据第二耳植入时的年龄，将他们分为3个年龄组：第一组，3至5岁；第二组，5.1至8岁；第三组，8.1至13岁。安静环境下的言语感知测量中，第一组采用多音节词汇邻域测试（MLNT），第二组和第三组采用词汇邻域测试（LNT），第三组安静环境下采用儿童噪声中听力测试（HINT-C）句子。使用儿童现实可懂度和言语感知（CRISP）测试评估噪声环境下的言语感知。在重复测量研究设计中，于术前以及激活第二枚植入体后的3、6和12个月（CRISP在3和9个月时）在单侧和双侧条件下进行测试。采用双向重复测量方差分析来分析装置配置和随时间变化的表现之间的统计学显著性。
美国多中心。
安静环境下的言语感知结果表明，序贯植入的儿童在第二耳相对较快地（6个月内）获得了开放式言语感知能力。然而，8岁以下儿童在12个月时比年龄较大的儿童获得开放式言语感知能力的速度更快，且达到更高的水平（12个月时第二耳的平均MLNT/LNT分数：第一组，83.9%；范围为71 - 96%；第二组，59.5%；范围为40 - 88%；第三组，32%；范围为12 - 56%）。即使在使用装置12个月后，第三组儿童第二耳HINT-C的平均分数仍远低于第一耳（44%对89%；t值为6.48；p < 0.001；临界值为0.025）。当将所有儿童作为一个整体分析以及单独分析第三组儿童时，噪声环境下双音节词的言语可懂度在双侧条件下显著优于单耳。在9个月的测试间隔时，双侧配置在所有噪声条件下的表现均显著更好（第一枚人工耳蜗处噪声时提高13.2%，第二枚人工耳蜗处噪声及前方噪声时提高6.8%，第一枚人工耳蜗处噪声时t = 2.32，p = 0.024，前方噪声临界水平 = 0.05；第一枚人工耳蜗处噪声时t = 3.75，p < 0.0001，临界水平 = 0.05；第二枚人工耳蜗侧噪声时t = 2.73，p = 0.008，临界水平 = 0.05）。激活第二枚植入体后3至9个月，双侧在噪声环境下的获益随时间增加。当噪声指向第一枚植入耳时，这种双侧优势最大，表明头部阴影效应是最有效的双耳机制。双侧条件在安静环境下对言语感知有小幅改善，对于第一组和第二组个体患者在噪声环境下的结果，鉴于测试的受试者数量相对较少，未达到统计学显著性。
不同年龄段儿童序贯式双侧人工耳蜗植入有潜力提高第二枚植入耳的言语感知能力，并能利用双耳机制如头部阴影效应。这种改善随时间推移而显现，并在激活第二枚植入体后的6至12个月内持续增强。本研究中年龄较小的儿童在第二耳获得了更高的开放式言语感知分数，但年龄较大的儿童在噪声环境下仍表现出双侧获益。确定双侧植入儿童这种潜在能力所带来的长期影响和成本效益需要对更大规模的受试者群体进行更多长期监测的进一步研究。
