听神经病与前庭上、下神经损害的关系

The Relationship Between Auditory Neuropathy and Superior and Inferior Vestibular Nerve Impairment

目的观察听神经病(auditory neuropathy,AN)患者伴发前庭上、下神经损害的特点,分析其与AN的关系。方法检测70例AN患者的眼震电图(electronystagmography,ENG)及前庭诱发肌源性电位(vestibular evoked myo-genic potential,VEMP),观察VEMP波形、潜伏期及振幅,并与对照组比较,分析前庭神经受损与AN患者听力损害程度、年龄及病程的关系。结果70例(139耳)AN患者中VEMP引出38耳(27.3%),未引出101耳(72.7%),ENG冷热试验半规管功能正常106耳(76.3%),异常33耳(23.7%),两种检测结果差异有显著统计学意义(P<0.01)。VEMP引出的38耳中,左、右耳的潜伏期均值P13为24.54±5.388及25.17±6.068ms,N23为31.38±5.766及32.02±6.058ms,对照组P13为17.04±1.781及17.49±2.291ms;N23为25.05±2.864及25.81±3.273ms,两组差异有显著统计学意义(P<0.01);左、右耳的振幅均值为60.16±34.732及43.83±31.288μV,对照组为147.16±50.026及135.66±54.737μV,两组差异有显著统计学意义(P<0.01)。AN患者VEMP是否引出与听力损害程度有相关性(P<0.05),与年龄及病程无相关性(P>0.05)。AN患者ENG的半规管功能是否正常与病程有相关性(P<0.05),与听力损害程度及年龄无相关性(P>0.05)。结论AN患者伴发前庭下神经损害的几率远大于前庭上神经,表现为VEMP波形未引出或潜伏期延长、振幅低;VEMP是否引出与听力损害程度有相关性,ENG的半规管功能异常与病程有相关性,提示AN患者听神经病变极易累及前庭下神经及其终器球囊;VEMP与ENG联合应用可对AN伴发前庭神经病变的范围作出较全面可靠的评估,应作为AN诊断常规检查项目之一。

Objective To investigate the characteristics of superior vestibular nerve （SVN） and inferior vestibular nerve （IVN） lesion in auditory neuropathy（AN）, and to explore the relationship between AN and vestibular nerve lesion.Methods Electronystagmography （ENG） and vestibular- evoked myogenic potential（VEMP） were observed in 70 patients（ 139 ears） with AN, and compared with control group. The relationship between the extent of vestibular involvement and the status of hearing loss, age and course were analyzed in patients with AN. Flesults The statistical analysis showed the absent VEMP in 101 ears and the abnormality of ENG in 38 ears, latencies P13 of VEMP in left and right ears （24.54 ± 5.388 ms and 25.17 ± 6.068 ms） and N23 of VEMP （31. 38 ±5.766 ms and 32.02±6.058 ms） compared with control group. P13：17.04 ± 1.781 ms and 17.49 ±2.291 ms,N23：25.05 ± 2.864 ms and 25.81± 3.273 ms respectively ）were noticeably prolonged（ P 〈 0.01）.The amplitudes of VEMP in 38 ears of AN （60.16 ± 34.732 μV and 43.83 ± 31.288 μV） were notable lower（ P 〈 0.01 ） compared with control group （ 147.16 ± 50. 026 μV and 135.66 ± 54.737 μV）. Significant relationship between VEMP and the degree of hearing loss （ P 〈 0.05） was observed while there was no relationship between VEMP and age, course （ P 〉 0.05） in patients with AN . There was significant relationship between ENG induced by caloric testing and the course （ P 〈0.05）,and no relationship between ENG and degree of hearing loss,age （ P 〉 0.05） in patients with AN. Conclusion IVN dysfunction accompanying AN were more common than SVN. VEMP showed no response, nor prolonged latencies and reduced amphtudes, because of the neuropathy involving the IVN and/or its end organ, the saccule. There was significant relationship between VEMP and the degree of hearing loss, and between ENG and the course in patients with AN. VEMP applied with ENG had important clinic significance to assess AN patients with involvement of different parts of the inner ear and its innervations. It was suggested that VEMP and ENG should be a routine test to diagnose of AN.