Wang Cheng-Ping, Hsu Wei-Chung, Young Yi-Ho
Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan.
Ann Otol Rhinol Laryngol. 2005 Jan;114(1 Pt 1):69-73. doi: 10.1177/000348940511400113.
Neurofibromatosis 2 (NF2) is characterized by bilateral vestibular neurofibromas. Although the facial nerve, the cochlear nerve, and the superior division of the vestibular nerve can be evaluated before surgery, whether the inferior division of the vestibular nerve is affected remains undetermined without an operation. A total of 7 patients with NF2 (2 men and 5 women) underwent pure tone audiometry, caloric testing, vestibular evoked myogenic potential (VEMP) testing, and magnetic resonance imaging. Audiometry revealed mean hearing levels of less than 26 dB for 1 ear, 26 to 70 dB for 8 ears, 71 to 90 dB for 3 ears, and more than 90 dB for 2 ears. Caloric testing revealed an absent response in 71% of the 14 ears. Seven ears underwent VEMP testing, and only 1 ear (14%) displayed absent VEMPs. Magnetic resonance imaging depicted space-occupying lesions in all 14 auditory canals: small tumors in 3 ears, medium tumors in 7 ears, and large tumors in 4 ears. The tumor size of NF2 is related to the caloric response, but is unrelated to the mean hearing level or VEMPs. In conclusion, NF2 originates from the superior vestibular nerve more often than the inferior vestibular nerve. It more often infiltrates the cochlear nerve than the inferior vestibular nerve.
神经纤维瘤病2型（NF2）的特征是双侧前庭神经纤维瘤。虽然在手术前可以评估面神经、耳蜗神经和前庭神经上支，但在未进行手术的情况下，前庭神经下支是否受影响仍无法确定。共有7例NF2患者（2例男性和5例女性）接受了纯音听力测定、冷热试验、前庭诱发肌源性电位（VEMP）测试和磁共振成像检查。听力测定结果显示，1只耳平均听力水平低于26dB，8只耳为26至70dB，3只耳为71至90dB，2只耳超过90dB。冷热试验显示，14只耳中有71%无反应。7只耳接受了VEMP测试，只有1只耳（14%）VEMP缺失。磁共振成像显示所有14个耳道均有占位性病变：3只耳为小肿瘤，7只耳为中等肿瘤，4只耳为大肿瘤。NF2的肿瘤大小与冷热反应有关，但与平均听力水平或VEMP无关。总之，NF2更多起源于前庭上神经而非前庭下神经。与前庭下神经相比，它更常侵犯耳蜗神经。
