Department of Otolaryngology-Head and Neck Surgery, Division of Facial Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Otol Neurotol. 2013 Jun;34(4):762-5. doi: 10.1097/MAO.0b013e31827f1909.
Synkinetic facial movement after facial nerve regeneration is a well-documented phenomenon. Rarely, patients recovering from facial nerve injury report feelings of auditory ringing, fullness, and a sensation of ear tightness as a result of stapedial muscle involvement. It is exceedingly rare for such synkinesis to produce perceivable changes in hearing threshold. We report a unique case of stapedial synkinesis causing pure-tone changes in hearing threshold with activation of the facial musculature.
A single patient is presented who developed stapedial synkinesis after suboccipital resection of a unilateral acoustic neuroma.
Despite facial nerve sparing, surgery resulted in House-Brackmann grade V/VI right facial nerve paralysis that improved to Grade III/VI after 7 months. Synkinesis developed that caused eye closure with puckering of the lips. Puckering of the lips likewise caused decreased hearing in the right ear, corresponding to a measured decrease of 10 dB in the PTA. Over the next several months, facial motion continued to improve, and hearing changes became less bothersome, so no intervention was undertaken.
The changes presented in the hearing threshold fit within the classically described 15-dB attenuation provided by the stapedial reflex. Although no intervention was undertaken in this particular case, some patients with unremitting stapedial synkinesis might benefit from sectioning of the stapedial muscle. Thus, consideration should be made for audiometric evaluation with and without facial muscle contraction in the evaluation of individuals with synkinetic facial movement.
面肌协同运动是面神经再生后一种有据可查的现象。面神经损伤恢复的患者很少会因镫骨肌受累而出现听觉鸣响、饱满感和耳紧感等感觉。这种面肌协同运动极少见会导致听力阈值发生可察觉的变化。我们报告了一例罕见的因镫骨肌协同运动导致纯音听阈改变的病例，其特征是面肌活动时出现这种改变。
报告了一例单侧听神经瘤枕下切除术后发生镫骨肌协同运动的患者。
尽管面神经得到保留，但手术导致右侧面神经House-Brackmann 分级 V/VI 瘫痪，7 个月后改善至 III/VI 级。出现了协同运动，导致闭眼时嘴唇噘起。嘴唇噘起同样导致右耳听力下降，相应的纯音听阈测试（PTA）下降了 10dB。在接下来的几个月里，面部运动继续改善，听力变化也不那么麻烦了，因此没有进行干预。
听力阈值的变化符合经典描述的镫骨肌反射提供的 15dB 衰减。虽然在这个特定的病例中没有进行干预，但一些持续存在镫骨肌协同运动的患者可能会受益于切断镫骨肌。因此，在评估具有面肌协同运动的个体时，应考虑进行听力评估，并在评估时考虑面肌收缩的情况。
