Piecuch Anna K, Cywka Katarzyna B, Skarżyński Piotr H, Skarżyński Henryk
Oto-Rhino-Laryngology Surgery Clinic, Institute of Physiology and Pathology of Hearing - World Hearing Center, Kajetany, Poland.
Department of Teleaudiology and Screening, Institute of Physiology and Pathology of Hearing - World Hearing Center, Kajetany, Poland.
Am J Case Rep. 2025 Sep 5;26:e947791. doi: 10.12659/AJCR.947791.
BACKGROUND Duplicated internal auditory canal (dIAC) is a rare congenital temporal bone anomaly associated with ipsilateral sensorineural hearing loss (SNHL). The Bonebridge bone conduction implant has a magnet, an internal transducer, and an external audio processor. This report is of a 14-year-old girl with unilateral SNHL and vestibulocochlear nerve (VIII cranial nerve) aplasia due to dIAC who was treated with a Bonebridge bone conduction implant. CASE REPORT A 14-year-old girl was diagnosed with unilateral hearing loss during a school health check. Her hearing screening at birth was normal. Pure-tone audiometry revealed unilateral deafness in the right ear. CT scan showed a separate canal for the facial and vestibulocochlear nerves. MRI suggested unilateral aplasia of the right nerve VIII. The patient was implanted with a Bonebridge 602 implant in the right ear as a CROS (contralateral routing of signal). During implant activation in the Matrix test with the Bonebridge implant (in SSD configuration), the patient achieved SRT=-10.3 dB SNR. The results of the APHAB questionnaire indicated improvements in hearing. CONCLUSIONS Duplication of the internal auditory canal is pathognomonic for severe cochlear nerve hypoplasia or aplasia. It is important to perform an imaging study before deciding on implantation, as a hearing screening test at birth may not detect congenital hearing loss (embryogenesis of the inner ear and the internal auditory canal occurs independently). In the case of a unilateral anomaly with no hearing impairment on the opposite side, bone conduction implantation should be considered as a CROS.
背景 重复内耳道（dIAC）是一种罕见的先天性颞骨异常，与同侧感音神经性听力损失（SNHL）相关。骨桥骨传导植入物有一个磁铁、一个内部换能器和一个外部音频处理器。本报告介绍了一名14岁女孩，因dIAC导致单侧SNHL和前庭蜗神经（第八颅神经）发育不全，接受了骨桥骨传导植入物治疗。病例报告 一名14岁女孩在学校健康检查中被诊断为单侧听力损失。她出生时听力筛查正常。纯音听力测试显示右耳单侧耳聋。CT扫描显示面神经和前庭蜗神经有单独的管道。MRI提示右侧第八神经单侧发育不全。患者右耳植入了骨桥602植入物作为对侧信号路由（CROS）。在使用骨桥植入物进行矩阵测试（SSD配置）激活植入物时，患者的言语识别阈（SRT）=-10.3 dB信噪比。APHAB问卷结果表明听力有所改善。结论 内耳道重复是严重耳蜗神经发育不全或发育不全的特征性表现。在决定植入前进行影像学检查很重要，因为出生时的听力筛查测试可能无法检测出先天性听力损失（内耳和内耳道的胚胎发生是独立的）。在单侧异常且对侧无听力障碍的情况下，应考虑将骨传导植入作为CROS。
