Morita Takeshi, Naito Yasushi, Tsuji Jun, Nakamura Teruko, Yamaguchi Shinobu, Ito Juichi
Department of Otolaryngology--Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Acta Otolaryngol Suppl. 2004 Mar(551):56-9. doi: 10.1080/03655230310016708.
This study aimed to evaluate the relationship between the diameters of the auditory and eighth cranial nerves and improvements in post-implant performance. Twenty prelingually deafened children (aged from 2.0 to 6.0 years) who received the Nucleus 24 cochlear implant participated in this study. All subjects had used their implant for at least 1 year after device connection. The diameters of cochlear and eighth cranial nerves were retrospectively measured on preoperative T2-weighted axial magnetic resonance image (MRI). In 17 of 20 subjects, the cochlear and eighth cranial nerves could be identified on MRI. The mean diameter of the cochlear and eighth cranial nerves were 0.9 +/- 0.2 mm and 1.2 +/- 0.3 mm, respectively. In the remaining three subjects, the cochlear and eighth cranial nerves could not be identified on MRI. These three subjects had significantly lower scores in the Infant-Toddler-Meaningful Auditory Integration Scale (IT-MAIS) than the other 17 subjects at 12 months post-implant. There was no significant correlation among the maximal diameters of the nerves and age, ECAP thresholds and IT-MAIS scores. A sufficient outcome from cochlear implantation can be expected when cochlear and eighth cranial nerves are depicted on MRI, regardless of the nerve diameters.
本研究旨在评估听神经和第八颅神经直径与植入后性能改善之间的关系。20名接受Nucleus 24人工耳蜗植入的语前聋儿童（年龄在2.0至6.0岁之间）参与了本研究。所有受试者在设备连接后使用其植入物至少1年。在术前T2加权轴向磁共振成像（MRI）上回顾性测量耳蜗神经和第八颅神经的直径。在20名受试者中的17名中，MRI上可以识别出耳蜗神经和第八颅神经。耳蜗神经和第八颅神经的平均直径分别为0.9±0.2毫米和1.2±0.3毫米。在其余三名受试者中，MRI上无法识别出耳蜗神经和第八颅神经。这三名受试者在植入后12个月时，婴幼儿有意义听觉整合量表（IT-MAIS）的得分明显低于其他17名受试者。神经的最大直径与年龄、电刺激听觉脑干反应（ECAP）阈值和IT-MAIS得分之间无显著相关性。当MRI上显示出耳蜗神经和第八颅神经时，无论神经直径如何，人工耳蜗植入都有望获得足够的效果。
