Cho Jiwon, Cheon Hanjae, Park Jung Hye, Lee Hyo-Jeong, Kim Hyung-Jong, Choi Hyo Geun, Koo Ja-Won, Hong Sung Kwang
Department of Otorhinolaryngology-Head and Neck Surgery, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea.
Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Anyang, Republic of Korea.
PLoS One. 2017 Oct 4;12(10):e0186038. doi: 10.1371/journal.pone.0186038. eCollection 2017.
Although recent advances in magnetic resonance imaging (MRI) techniques have contributed to the detection of tiny lesions in the internal auditory canal (IAC) that may be responsible for sudden sensorineural hearing loss (SSNHL), there have been relatively few studies on the clinical characteristics of intra-labyrinthine hemorrhage (ILH) and labyrinthitis versus those regarding IAC tumors. Our purpose was to investigate the frequency of those IAC lesions on MRI and their clinical characteristics. Initial MRIs of 200 patients with SSNHL (93 men, 107 women; mean age = 48.61 years, range: 18-84 years), as well as detailed clinical histories, audiological examinations, and thyroid function, lipid battery, and serological tests (for viral agents and autoimmune disease), were performed. All patients were hospitalized at the time of diagnosis of SSNHL and were administered the same treatment protocol. Patients were divided into idiopathic and secondary groups according to their MRI results. After discharge, they underwent follow-up audiometry and clinical examination at predetermined intervals (2 weeks, 1, 2, 4, and 6 months, and 1 and 2 years). Propensity score-matching and receiver operating characteristics curves of the initial parameters were used for estimating clinical characteristics. Of the 200 patients, 25 (12.55%) who had abnormal findings suggesting inner ear lesions on MRI were assigned to the secondary SSNHL group; within this group, 10 patients (10/200, 5%) had a tumor invading the IAC, 7 (7/200, 3.5%) had ILH, 6 (6/200, 3%) had labyrinthitis, and 2 (1%) had a structural deformity of the IAC. The secondary group showed significantly poor recovery of hearing function compared with that in the idiopathic group. Patients with ILH or labyrinthitis showed prognoses that were equally poor as those of patients with tumors in the secondary group. Additionally, patients with such lesions showed significant canal paresis on the lesion side at an early stage and a high prevalence of benign paroxysmal positional vertigo (BPPV). In conclusion, the prevalence of non-tumorous lesions on MRI represents common findings and showed a poorer treatment response than that of vestibular Schwannoma in patients with SSNHL. Abnormal canal paresis (cut-off value of 35% on the lesioned side, sensitivity 65.2% and specificity 67%), spontaneous nystagmus directed to the contralesional side, and positional vertigo would be the clinical presentation of SSNHL with IAC lesions, in which the presence of acute prolonged vertigo or positional vertigo compatible with BPPV suggests the possibility of a non-tumorous lesion, such as ILH or a labyrinthitis rather than an IAC tumor.
尽管磁共振成像（MRI）技术的最新进展有助于检测内耳道（IAC）中可能导致突发性感音神经性听力损失（SSNHL）的微小病变，但关于迷路内出血（ILH）和迷路炎与IAC肿瘤的临床特征的研究相对较少。我们的目的是研究MRI上这些IAC病变的发生率及其临床特征。对200例SSNHL患者（93例男性，107例女性；平均年龄=48.61岁，范围：18 - 84岁）进行了初始MRI检查，以及详细的临床病史、听力学检查、甲状腺功能、血脂全套和血清学检查（针对病毒病原体和自身免疫性疾病）。所有患者在诊断为SSNHL时均住院，并接受相同的治疗方案。根据MRI结果将患者分为特发性和继发性两组。出院后，他们在预定的时间间隔（2周、1、2、4和6个月以及1和2年）接受随访听力测定和临床检查。使用初始参数的倾向得分匹配和受试者操作特征曲线来评估临床特征。在200例患者中，25例（12.55%）MRI显示有提示内耳病变的异常发现，被归入继发性SSNHL组；在该组中，10例患者（10/200，5%）有肿瘤侵犯IAC，7例（7/200，3.5%）有ILH，6例（6/200，3%）有迷路炎，2例（1%）有IAC结构畸形。与特发性组相比，继发性组的听力功能恢复明显较差。ILH或迷路炎患者的预后与继发性组中的肿瘤患者同样差。此外，有此类病变的患者在早期病变侧显示明显的管轻瘫，且良性阵发性位置性眩晕（BPPV）的患病率较高。总之，MRI上非肿瘤性病变的发生率代表了常见发现，并且在SSNHL患者中显示出比特发性前庭神经鞘瘤更差的治疗反应。异常管轻瘫（病变侧截断值为35%，敏感性65.2%，特异性67%）、指向对侧的自发性眼球震颤和位置性眩晕将是伴有IAC病变的SSNHL的临床表现，其中存在与BPPV相符的急性持续性眩晕或位置性眩晕提示可能存在非肿瘤性病变，如ILH或迷路炎而非IAC肿瘤。
