听力正常单侧耳鸣的双侧ABR结果比较及临床意义

摘要

目的 听力正常单侧耳鸣患者的双侧听性脑干反应(ABR)的结果比较及临床意义进行探讨,阐明听力正常耳鸣的可能发病机制.方法 对20例听力正常的单侧耳鸣患者,常规进行耳专科检查及声导抗检查,排除外中耳病变.分别记录双侧纯音测听、耳声发射(DPOAE)及ABR,将耳鸣侧与非耳鸣侧的ABR结果进行对比分析.结果 耳鸣侧与非耳鸣侧在纯音听阈、声导抗、DPOAE及ABR阈值上均表现正常,无统计学差异,但耳鸣侧ABR的I波幅度0.19uV,V波幅度0.24uV,V/I比值为1.31;非耳鸣侧ABR的I波幅度0.14uV,V波幅度0.26uV,V/I比值为2.19.结论 虽然单侧耳鸣患者耳鸣侧未发现听阈提高,但其V/I比值明显较非耳鸣侧下降(V/I比值为1.31vs2.19),提示在中脑传入信号减少,在听觉中枢维持内环境神经平衡的机制作用下导致听觉皮层神经元兴奋性增强,可能是耳鸣产生的原因之一.%Objective Comparison the bilateral auditory brainstem response ( ABR ) results of unilateral tinnitus patients with normal hearing and analysis clinical significance,discussed the possible mechanism of tinnitus with normal hearing. Methods 20 cases of unilateral tinnitus patients with normal hearing were documented bilateral audiometry, otoacoustic emission ( DPOAE ) and ABR, comparative analysis the ABR results of the side with the tinnitus and non-tinnitus side.Results The pure tone audiometry, DPOAE and ABR threshold showed normal, no statistical difference, but the tinnitus side I wave amplitude is 0.19uV,V wave amplitude is 0.24uV, V/I ratio is 1.31; but the non-tinnitus side I wave amplitude is 0.14uV, V wave amplitude is 0.26uV,V/I ratio is 2.19. Conclusion Although unilateral tinnitus patients with tinnitus side did not found threshold increase, but the V/I ratio was significantly decreased than the non-tinnitus side (V/I is 1.31vs 2.19), prompting in the midbrain afferent signal is reduced, in the central auditory system of maintaining inner environment nervous balance mechanism maybe cause the excitability of auditory cortex to enhance, may is one of the possible causes of tinnitus generation.