Sass K, Densert B, Magnusson M
Department of Otolaryngology, University of Lund, Sweden.
Audiol Neurootol. 1997 Nov-Dec;2(6):391-402. doi: 10.1159/000259264.
An objective method for the pre-operative diagnosis and the post-operative assessment of a presumed perilymphatic fistula (PLF) using transtympanic electrocochleography is presented. Three cases are reported in which the history of the disease and the symptoms strongly suggested the presence of a PLF. Pre-operative transtympanic electrocochleography (TT ECoG) recordings at rest showed changes similar to those of endolymphatic hydrops and signs of instability of the inner ear hydrodynamic system during raised intrathoracic pressure. Surgery revealed a visible leak in two of the three cases. Both windows were repaired in all the patients. All patients were relieved from their vestibular symptoms at the time when the post-operative TT ECoG was conducted 3-6 months later. The post-operative recordings were stable during raised intrathoracic pressure and the previously elevated summating potentials decreased which was interpreted as an objective indication of the recovery of the hydrodynamic system. However, later one of the patients again developed recurrent vertigo. Twenty patients with well-documented Ménière's disease were used as a control group. TT ECoG was conducted during raised intrathoracic pressure. The Ménière patients showed stable recordings. It is suggested that among patients with suspected PLF and signs of hydrops in TT ECoG, a dependence on the intrathoracic pressure reflected in the recordings may indicate a possible fistula.
本文介绍了一种使用经鼓膜电耳蜗图对疑似外淋巴瘘（PLF）进行术前诊断和术后评估的客观方法。报告了3例病例，其疾病史和症状强烈提示存在外淋巴瘘。术前静息状态下的经鼓膜电耳蜗图（TT ECoG）记录显示出与内淋巴积水相似的变化，以及在胸内压升高时内耳流体动力系统不稳定的迹象。手术发现3例中有2例可见瘘管。所有患者均修复了两个窗。3至6个月后进行术后TT ECoG时，所有患者的前庭症状均得到缓解。术后记录在胸内压升高时稳定，先前升高的总和电位降低，这被解释为流体动力系统恢复的客观指标。然而，后来其中1例患者再次出现复发性眩晕。将20例有充分记录的梅尼埃病患者作为对照组。在胸内压升高时进行TT ECoG。梅尼埃病患者的记录显示稳定。提示在疑似PLF且TT ECoG有积水迹象的患者中，记录中反映的对胸内压的依赖性可能表明存在瘘管。
