Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan.
Ear Hear. 2010 Apr;31(2):289-95. doi: 10.1097/AUD.0b013e3181c5b743.
Click and galvanic stimulations of vestibular-evoked myogenic potential (c-VEMP and g-VEMP) were applied to measure the interaural difference (IAD) of saccular responses in patients with acute low-tone sensorineural hearing loss (ALHL). This study intended to explore the relationship between saccular asymmetry and final hearing recovery. We hypothesize that greater extent of saccular dysfunction may be associated with lesser hearing recovery.
Twenty-one patients with unilateral ALHL were prospectively enrolled to receive c-VEMP and g-VEMP tests in a random sequence. The IAD of the saccular responses for each patient was measured using three parameters-the raw and corrected amplitudes of c-VEMP, and corrected c-VEMP to g-VEMP amplitude ratio (C/G ratio). The IAD for each parameter was classified as depressed, normal, or augmented by calculating the difference between the affected and unaffected ears and dividing by its sum for both ears.
After 3 consecutive months of oral medication and follow-up, 19 patients displayed a hearing recovery of >50%; only two had a recovery of <50%. The significant correlation between the IAD of corrected C/G ratios and hearing recovery demonstrated that subjects with depressed responses had a worse hearing outcome (percent recovery: 51% [45-80%], median [minimum-maximum]), compared with those with normal responses, who exhibited the best recovery (87% [56-100%]), whereas patients with augmented response showed an intermediate recovery (67% [54-100%]; p = 0.02, Kruskal-Wallis test). On the contrary, the raw and corrected amplitudes of c-VEMP did not reveal a significantly different hearing recovery among the three groups of saccular responses.
The extent of saccular dysfunction in ALHL might be better explored by combining the results of c-VEMP and g-VEMP. Outcome analysis indicated that the corrected C/G ratio might be a promising prognostic factor for hearing recovery in ALHL.
通过对前庭诱发肌源性电位（c-VEMP 和 g-VEMP）的点击和电刺激，测量急性低频感音神经性听力损失（ALHL）患者的囊状反应的耳间差异（IAD）。本研究旨在探讨囊状反应不对称与最终听力恢复之间的关系。我们假设囊状功能障碍的程度越大，听力恢复的可能性越小。
前瞻性纳入 21 例单侧 ALHL 患者，按随机顺序接受 c-VEMP 和 g-VEMP 测试。使用三个参数- c-VEMP 的原始和校正幅度，以及校正后的 c-VEMP 与 g-VEMP 幅度比（C/G 比），测量每个患者囊状反应的 IAD。通过计算受影响和未受影响耳之间的差异并除以双耳之和，将每个参数的 IAD 分类为抑郁、正常或增强。
在连续 3 个月的口服药物治疗和随访后，19 例患者的听力恢复>50%；只有 2 例患者的听力恢复<50%。校正 C/G 比的 IAD 与听力恢复之间的显著相关性表明，反应抑郁的患者听力预后较差（恢复百分比：51%[45-80%]，中位数[最小-最大]），与反应正常的患者相比，反应正常的患者听力恢复最佳（87%[56-100%]），而反应增强的患者听力恢复居中（67%[54-100%]；p=0.02，Kruskal-Wallis 检验）。相反，c-VEMP 的原始和校正幅度在囊状反应的三组之间没有显示出明显不同的听力恢复。
通过结合 c-VEMP 和 g-VEMP 的结果，可以更好地探索 ALHL 中囊状功能障碍的程度。结果分析表明，校正后的 C/G 比可能是 ALHL 听力恢复的一个有前途的预后因素。
