Eklöf Martin, Smeds Henrik, Karltorp Eva, Wales Jeremy
Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
Section for Hearing Implants, Department of Otorhinolaryngology, Karolinska University Hospital, Stockholm, Sweden.
Ear Hear. 2025;46(2):353-360. doi: 10.1097/AUD.0000000000001584. Epub 2024 Sep 12.
Patients with X-linked incomplete partition type III (IP3) deafness treated with cochlear implants exhibit higher "Most Comfortable Loudness" (MCL) levels of stimulation and more electrode deactivation than patients with normal morphology. We endeavored to analyze the progression of the MCL levels and electrode deactivation over time and assess those factors that could have led to deactivation. Furthermore, we aimed to assess whether speech perception was affected by a progressive loss of neural contact.
All 13 patients with the IP3 malformation in our clinical database were analyzed retrospectively with regard to impedance, stimulation levels, deactivated electrodes, and speech perception. A control group of patients with normal anatomy was included.
MCL levels increased over time by 2.5 charge units (qu) per year, which was not seen in the control group. Electrode deactivation was more common in IP3 malformation, and it was estimated that 25% of electrodes would be deactivated by 15 years of age. Impedance was stable but higher in the study population. Speech perception was lower in IP3 malformation generally and was correlated to the number of deactivated electrodes.
Patients diagnosed with IP3 malformation deafness may suffer a greater risk of cochlear implant discontinuation compared with those with normal anatomy. A progressive loss of sensitivity to electrical stimulation may indicate a form of neural degradation in the abnormal cochlea. With time, patients in this group, even with cochlear implant technology, may experience gradual deterioration of speech perception. This has clinical implications for the counseling of parents.
与正常形态的患者相比，接受人工耳蜗植入治疗的X连锁不完全分隔III型（IP3）耳聋患者表现出更高的“最舒适响度”（MCL）刺激水平和更多的电极失活。我们试图分析MCL水平和电极失活随时间的进展情况，并评估可能导致失活的因素。此外，我们旨在评估言语感知是否受到神经接触逐渐丧失的影响。
对我们临床数据库中所有13例IP3畸形患者的阻抗、刺激水平、失活电极和言语感知进行回顾性分析。纳入解剖结构正常的患者作为对照组。
MCL水平随时间每年增加2.5个电荷单位（qu），对照组未出现这种情况。电极失活在IP3畸形中更为常见，据估计，到15岁时25%的电极会失活。研究人群的阻抗稳定但更高。IP3畸形患者的言语感知总体较低，且与失活电极数量相关。
与解剖结构正常的患者相比，被诊断为IP3畸形耳聋的患者人工耳蜗停用风险可能更大。对电刺激敏感性的逐渐丧失可能表明异常耳蜗中存在一种神经退化形式。随着时间的推移，即使采用人工耳蜗技术，该组患者的言语感知也可能逐渐恶化。这对向家长提供咨询具有临床意义。
