Alballaa A, Aschendorff A, Arndt S, Hildenbrand T, Becker C, Hassepass F, Laszig R, Beck R, Speck I, Wesarg T, Ketterer M C
Klinik für Hals‑, Nasen‑, Ohrenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert-Ludwigs-Universität Freiburg, Killianstraße 5, 79106, Freiburg, Deutschland.
Department of Otolaryngology, King Abdulaziz University Hospital, King Abdullah Ear Specialist Center (KAESC), College of Medicine, King Saud University, Riyadh, Saudi Arabia.
HNO. 2019 Oct;67(10):760-768. doi: 10.1007/s00106-019-00733-y.
Incomplete partition type III (IP III) is defined by a missing lamina cribrosa between the cochlea and the internal auditory canal (IAC). Cochlear implantation (CI) may result in an insertion of the electrode array into the IAC. The aim of this study is to evaluate CI surgery protocols, long-term audiological outcome, mapping and electrophysiological data after CI in IP III patients.
Nine IP III patients were implanted with perimodiolar electrode arrays between 1999 and 2014; eight of them were included in this study. We evaluated mapping data, stapedius reflexes, electrode impedances and ECAP thresholds. We matched them with 3 CI patients each with normal cochlear morphology regarding sex, age, side, implant type and surgical date. Speech discrimination was evaluated with the Oldenburger sentence test for adults, Göttingen audiometric speech test for children and the Freiburger monosyllabic word test.
3 years after CI IP III patients showed a significant increase in pulse width, calculated electric load and electrode impedances in basal electrodes. Intraoperative electrically-evoked stapedius reflexes could be measured in all patients. Speech recognition scores were lower than average scores for matched patients, but without statistical significance.
The significant increase of pulse width, electric load and electrode impedances of basal electrodes over time seem to be characteristic for IP III patients probably occurring due to fibrosis and neurodegeneration of the cochlear nerve. The long term audiological results are stable. Intraoperative imaging and stapedius reflexes are highly recommended to control the right position of the electrode array.
III型不完全分隔（IP III）的定义是耳蜗与内耳道（IAC）之间缺少筛板。人工耳蜗植入（CI）可能会导致电极阵列插入内耳道。本研究的目的是评估IP III患者人工耳蜗植入手术方案、长期听力结果、调机情况及电生理数据。
1999年至2014年间，9例IP III患者植入了鼓阶电极阵列；其中8例纳入本研究。我们评估了调机数据、镫骨肌反射、电极阻抗和电刺激听神经复合动作电位（ECAP）阈值。我们将他们与3例耳蜗形态正常的人工耳蜗植入患者在性别、年龄、患侧、植入类型和手术日期方面进行匹配。使用成人奥尔登堡句子测试、儿童哥廷根听力言语测试和弗赖堡单音节词测试评估言语辨别能力。
人工耳蜗植入3年后，IP III患者基底电极的脉宽、计算出的电负荷和电极阻抗显著增加。所有患者术中均能测量到电诱发镫骨肌反射。言语识别得分低于匹配患者的平均得分，但无统计学意义。
随着时间的推移，基底电极的脉宽、电负荷和电极阻抗显著增加似乎是IP III患者的特征，可能是由于耳蜗神经的纤维化和神经变性所致。长期听力结果稳定。强烈建议术中进行影像学检查和镫骨肌反射检查，以控制电极阵列的正确位置。
