Seltzer S, Mark A S
Department of Radiology, George Washington University, Washington, DC 20052.
AJNR Am J Neuroradiol. 1991 Jan-Feb;12(1):13-6.
The sudden onset of hearing loss and vertigo presents a difficult diagnostic problem. We describe the finding of labyrinthine enhancement on MR images in five patients with sudden unilateral hearing loss or vertigo or both and correlate the MR findings with audiologic and electronystagmographic studies. All patients were studied with T2-weighted axial images through the whole brain, contrast-enhanced 3-mm axial T1-weighted images through the temporal bone, and enhanced T1-weighted sagittal images through the whole brain. Cochlear enhancement, on the side of hearing loss only, was found in all five patients. The presence of associated vestibular enhancement correlates with objective measures of vestibular function on the electronystagmogram. In two patients, the resolution of symptoms 4-6 months later correlated with resolution of the enhancement on gadopentetate dimeglumine-enhanced MR images. Two patients had luetic labyrinthitis. No labyrinthine enhancement was seen in a series of 30 control subjects studied with gadopentetate dimeglumine-enhanced MR using the same protocol. Labyrinthine enhancement in patients with auditory and vestibular symptoms is a new finding and is indicative of labyrinthine disease. While abnormalities on electronystagmograms and audiograms are nonspecific and indicate only a sensorineural problem, gadopentetate dimeglumine-enhanced MR may separate patients with retrocochlear lesions, such as acoustic neuromas, from those in whom the abnormal process is in the labyrinth or is intraaxial. This group of patients underscores the importance of identifying and commenting on the structures of the membranous labyrinth when evaluating MR studies of the internal auditory canal and the cerebellopontine angle in individuals with hearing loss.
突发性听力损失和眩晕的突然发作带来了一个棘手的诊断问题。我们描述了5例单侧突发性听力损失或眩晕或两者皆有的患者在磁共振成像（MR）上出现迷路强化的情况，并将MR表现与听力学和眼震电图研究结果相关联。所有患者均接受了全脑T2加权轴位成像、颞骨3毫米对比增强T1加权轴位成像以及全脑增强T1加权矢状位成像检查。在所有5例患者中均发现仅在听力损失侧出现耳蜗强化。伴有前庭强化与眼震电图上前庭功能的客观指标相关。在2例患者中，4 - 6个月后症状的缓解与钆喷酸葡胺增强MR图像上强化的消退相关。2例患者患有梅毒性迷路炎。在按照相同方案进行钆喷酸葡胺增强MR检查的30例对照受试者中未发现迷路强化。有听觉和前庭症状患者的迷路强化是一项新发现，提示迷路疾病。虽然眼震电图和听力图上的异常是非特异性的，仅表明存在感音神经性问题，但钆喷酸葡胺增强MR可能有助于将患有蜗后病变（如听神经瘤）的患者与病变位于迷路或脑内的患者区分开来。这组患者强调了在评估听力损失患者的内耳道和小脑脑桥角的MR检查时，识别并描述膜迷路结构的重要性。
