Sennaroglu Levent, Saatci Isil, Aralasmak Ayse, Gursel Bulent, Turan Ergin
Department of Otolaryngology-Head and Neck Surgery, Hacettepe University, Turkey.
J Laryngol Otol. 2002 Oct;116(10):804-10. doi: 10.1258/00222150260293619.
Recent reports indicate that the cochlear nerve may be absent in some cases of congenital sensorineural hearing loss. The aim of this prospective study was to determine the incidence of cochlear nerve anomaly in cochlear implant candidates with congenital hearing loss using magnetic resonance imaging (MRI). Twenty-seven patients with congenital profound bilateral sensorineural hearing loss who were being evaluated for the cochlear implant procedure were studied. These patients had high-resolution computerized tomography (CT), through the petrous bone in axial sections. MRI examinations consisted of T1 and turbo spin echo (TSE) T2-weighted 3 mm axial images, and additional 3D Fourier Transform T2-weighted TSE sequences obtained on three different planes (axial, perpendicular and parallel to the internal auditory canal (IAC) i.e. oblique sagittal and coronal, respectively) for the purpose of cochlear nerve demonstration. Results showed that all of the 14 patients with normal CT of the temporal bone, had four distinct nerves in the distal part of the IAC on TSE-MRI. Thirteen patients demonstrated various bony malformations of the cochleovestibular system on CT. MRI revealed the absence of the cochleovestibular nerve in four patients where the IAC was very narrow or completely absent on CT. One patient with severe Mondini malformation who had an enlarged IAC demonstrated an isolated absent cochlear nerve.
近期报告表明，在某些先天性感音神经性听力损失病例中可能不存在蜗神经。这项前瞻性研究的目的是使用磁共振成像（MRI）确定先天性听力损失的人工耳蜗植入候选者中蜗神经异常的发生率。对27例正在接受人工耳蜗植入手术评估的先天性双侧重度感音神经性听力损失患者进行了研究。这些患者进行了通过颞骨岩部的轴向高分辨率计算机断层扫描（CT）。MRI检查包括T1加权和快速自旋回波（TSE）T2加权3毫米轴向图像，以及在三个不同平面（分别为轴向、垂直于内耳道（IAC）和平行于内耳道，即斜矢状面和冠状面）获得的额外三维傅里叶变换T2加权TSE序列，以显示蜗神经。结果显示，14例颞骨CT正常的患者在TSE-MRI上IAC远端均有四条不同的神经。13例患者在CT上显示蜗前庭系统存在各种骨质畸形。MRI显示，4例患者的IAC非常狭窄或在CT上完全缺失，蜗前庭神经缺如。1例患有严重Mondini畸形且IAC扩大的患者显示孤立的蜗神经缺如。
