Yokota Chieko, Koda Yuki, Kajimoto Yasuyuki, Shimono Taro, Sunami Kishiko
Otolaryngology - Head and Neck Surgery, Osaka Metropolitan University, Osaka, JPN.
Radiology, Osaka Metropolitan University, Osaka, JPN.
Cureus. 2025 Mar 31;17(3):e81488. doi: 10.7759/cureus.81488. eCollection 2025 Mar.
Facial nerve abnormalities and congenital middle ear malformations originate in similar developmental stages and are often concomitant. Preoperative recognition of such a condition is desirable to prevent any damage, but it is often difficult. Here, we report two cases of middle ear malformations associated with facial nerve abnormalities, describe the computed tomography (CT) appearance, and discuss its preoperative detectability. Case 1 was a 40-year-old female with a facial nerve abnormality associated with stapes ankylosis. She underwent stapes surgery. The facial nerve was hanging over the footplate of the stapes. Case 2 was a 32-year-old female with a facial nerve abnormality associated with stapes ankylosis. She underwent an exploratory tympanotomy. The facial nerve was branched. The branches emerged from the incudo-malleolar joint, ran between the chorda tympani nerve and the incus, and ran into the temporal bone inside the canaliculus chorda tympani. For both cases, the facial nerve branches were detectable with high-resolution CT (HRCT) in the mastoid segment and were confirmed during surgery. For Case 2, the facial nerve was also visible with HRCT as soft tissue shadows in the tympanic portion on the lateral side of the stapes. These two cases highlighted the critical role of preoperative CT imaging in detecting subtle features of facial nerve anomalies, such as nerve branching in the mastoid segment or soft tissue shadows around ossicles.
面神经异常和先天性中耳畸形起源于相似的发育阶段，且常相伴发生。术前识别这种情况有助于预防任何损伤，但往往很困难。在此，我们报告两例与面神经异常相关的中耳畸形病例，描述计算机断层扫描（CT）表现，并讨论其术前可检测性。病例1是一名40岁女性，患有与镫骨固定相关的面神经异常。她接受了镫骨手术。面神经悬于镫骨足板上方。病例2是一名32岁女性，患有与镫骨固定相关的面神经异常。她接受了探查性鼓室切开术。面神经出现分支。分支从砧镫关节发出，走行于鼓索神经与砧骨之间，然后进入鼓索小管内的颞骨。对于这两个病例，面神经分支在乳突段通过高分辨率CT（HRCT）均可检测到，并在手术中得到证实。对于病例2，面神经在HRCT上也表现为镫骨外侧鼓室部分的软组织阴影。这两个病例突出了术前CT成像在检测面神经异常细微特征方面的关键作用，如乳突段神经分支或听小骨周围的软组织阴影。
