Department of Otolaryngology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.
Ear Hear. 2019 May/Jun;40(3):577-591. doi: 10.1097/AUD.0000000000000630.
Variability in speech perception outcomes with cochlear implants remains largely unexplained. Recently, electrocochleography, or measurements of cochlear potentials in response to sound, has been used to assess residual cochlear function at the time of implantation. Our objective was to characterize the potentials recorded preimplantation in subjects of all ages, and evaluate the relationship between the responses, including a subjective estimate of neural activity, and speech perception outcomes.
Electrocochleography was recorded in a prospective cohort of 284 candidates for cochlear implant at University of North Carolina (10 months to 88 years of ages). Measurement of residual cochlear function called the "total response" (TR), which is the sum of magnitudes of spectral components in response to tones of different stimulus frequencies, was obtained for each subject. The TR was then related to results on age-appropriate monosyllabic word score tests presented in quiet. In addition to the TR, the electrocochleography results were also assessed for neural activity in the forms of the compound action potential and auditory nerve neurophonic.
The TR magnitude ranged from a barely detectable response of about 0.02 µV to more than 100 µV. In adults (18 to 79 years old), the TR accounted for 46% of variability in speech perception outcome by linear regression (r = 0.46; p < 0.001). In children between 6 and 17 years old, the variability accounted for was 36% (p < 0.001). In younger children, the TR accounted for less of the variability, 15% (p = 0.012). Subjects over 80 years old tended to perform worse for a given TR than younger adults at the 6-month testing interval. The subjectively assessed neural activity did not increase the information compared with the TR alone, which is primarily composed of the cochlear microphonic produced by hair cells.
The status of the auditory periphery, particularly of hair cells rather than neural activity, accounts for a large fraction of variability in speech perception outcomes in adults and older children. In younger children, the relationship is weaker, and the elderly differ from other adults. This simple measurement can be applied with high throughput so that peripheral status can be assessed to help manage patient expectations, create individually-tailored treatment plans, and identify subjects performing below expectations based on residual cochlear function.
人工耳蜗植入患者的言语感知结果存在很大差异，但其原因仍未得到充分解释。最近，电 Cochleography（或响应声音的 Cochlear 潜力测量）已用于评估植入时的残余 Cochlear 功能。我们的目的是描述所有年龄段患者植入前的潜在记录，并评估包括对神经活动的主观估计在内的反应与言语感知结果之间的关系。
在北卡罗来纳大学（10 个月至 88 岁）的人工耳蜗植入候选者前瞻性队列中记录电 Cochleography。为每个受试者获得称为“总反应”（TR）的残余 Cochlear 功能测量值，该值是响应不同刺激频率的音调的频谱分量大小的总和。然后，将 TR 与在安静环境下呈现的适合年龄的单音节单词得分测试的结果相关联。除了 TR 之外，还评估了 Cochlear 图形动作电位和听觉神经神经声音等电 Cochleography 结果的神经活动。
TR 幅度从约 0.02µV 的几乎可检测到的响应到超过 100µV 不等。在成年人（18 至 79 岁）中，线性回归（r = 0.46；p < 0.001）解释了言语感知结果的 46%的变异性。在 6 至 17 岁的儿童中，变异性占 36%（p < 0.001）。在年龄较小的儿童中，TR 解释的变异性较小，为 15%（p = 0.012）。与年轻成年人相比，6 个月测试间隔时，80 岁以上的受试者的 TR 表现更差。与主要由毛细胞产生的 Cochlear 微音组成的 TR 相比，主观评估的神经活动并没有增加信息量。
听觉外围的状态，特别是毛细胞而不是神经活动，解释了成人和大龄儿童言语感知结果的很大一部分变异性。在年龄较小的儿童中，这种关系较弱，老年人与其他成年人不同。这种简单的测量可以高通量应用，以便评估外围状态，帮助管理患者的期望，制定个性化的治疗计划，并根据残余 Cochlear 功能识别表现低于预期的患者。
