Lee Yi-Fang, Lee Cheng-Chia, Wang Mao-Che, Liu Kang-Du, Wu Hsiu-Mei, Guo Wan-Yuo, Shiao An-Suey, Pan David Hung-Chi, Chung Wen-Yuh, Hsu Sanford P C
Department of Otolaryngology, Taipei Veterans General Hospital, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Auris Nasus Larynx. 2015 Aug;42(4):265-70. doi: 10.1016/j.anl.2015.01.004. Epub 2015 Feb 7.
Gamma-knife radiosurgery (GKS) for vestibular schwannomas (VSs) has become popular during the last two decades, and a promising tumor control rate has been reported. Therefore, the evaluation and preservation of auditory-vestibular nerve function after GKS have become more and more important in these patients with long-term survival. We have traditionally used pure-tone audiometry (PTA) for evaluation of auditory nerve function, and the caloric test for superior vestibular nerve function. Vestibular-evoked myogenic potential (VEMP) has recently emerged from various neurophysiological examinations for assessment of the integrity of the inferior vestibular nerve function. This novel tool has been established to represent a sacculo-collic reflex. By using these three tools, the auditory-vestibular nerve function of VS patients can be evaluated and monitored before and after GKS.
Fourteen patients with unilateral VS that underwent GKS were prospectively recruited. All of them received a battery of auditory-vestibular function tests including PTA, caloric, and cVEMP tests before and after GKS at each time point (1, 6, and 12 months). Our data also included the tumor volumes and their relationship with the PTA, caloric, and cVEMP test results.
The PTA, caloric, and cVEMP tests showed abnormal results before GKS in 85.7%, 78.6% and 78.6% of our VS patients, respectively. The PTA, caloric, and cVEMP results did not show strong correlations between each other. However, there was a tendency that when the tumor grew larger, the auditory-vestibular function deficits became more severe. The PTA and cVEMP test results remained stable during the 1-year follow-up after GKS. However, the caloric test showed transient deterioration at the 6th month follow-up, which then recovered by the 1-year follow-up.
The combination of these three tests can help us diagnose VS and assess the change in auditory-vestibular nerve function during the post-GKS follow-up period. The results of these three tests were independent for smaller tumors, but all tests may show abnormal findings with larger tumors. Although the study is still ongoing, the preliminary data showed that GKS treatment would not affect the auditory-vestibular nerve function within a 1-year follow-up period.
在过去二十年中，伽玛刀放射外科治疗（GKS）前庭神经鞘瘤（VSs）已变得流行，并且已有报道显示其具有可观的肿瘤控制率。因此，对于这些长期存活的患者，评估和保留GKS后的听觉 - 前庭神经功能变得越来越重要。我们传统上使用纯音听力测定（PTA）来评估听觉神经功能，使用冷热试验来评估前庭上神经功能。最近，前庭诱发肌源性电位（VEMP）已从各种神经生理学检查中脱颖而出，用于评估前庭下神经功能的完整性。这种新工具已被确立为代表球囊 - 颈反射。通过使用这三种工具，可以在GKS前后对VS患者的听觉 - 前庭神经功能进行评估和监测。
前瞻性招募了14例接受GKS治疗的单侧VS患者。他们在GKS前后的每个时间点（1、6和12个月）均接受了一系列听觉 - 前庭功能测试，包括PTA、冷热试验和颈肌前庭诱发肌源性电位（cVEMP）测试。我们的数据还包括肿瘤体积及其与PTA、冷热试验和cVEMP测试结果的关系。
在我们的VS患者中，PTA、冷热试验和cVEMP测试在GKS前分别有85.7%、78.6%和78.6%的结果异常。PTA、冷热试验和cVEMP结果之间没有很强的相关性。然而，存在一种趋势，即当肿瘤增大时，听觉 - 前庭功能缺损会变得更严重。GKS后1年随访期间，PTA和cVEMP测试结果保持稳定。然而，冷热试验在随访第6个月时显示短暂恶化，然后在1年随访时恢复。
这三种测试的组合可以帮助我们诊断VS，并评估GKS后随访期间听觉 - 和前庭神经功能的变化。对于较小的肿瘤，这三种测试的结果是独立的，但对于较大的肿瘤，所有测试可能都会显示异常结果。虽然研究仍在进行中，但初步数据显示，在1年随访期内，GKS治疗不会影响听觉 - 前庭神经功能。
