特殊类型听性脑干反应波形诊断蜗神经发育不良的意义

Significance of Special Types in Auditory Brainstem Response Waveforms in Diagnosis of Cochlear Nerve Deficiency

目的分析听性脑干反应(ABR)测试时强声刺激在4 ms左右出现的特殊正向波对诊断蜗神经发育不良(cochlear nerve deficiency,CND)的临床意义。方法将磁共振成像(MRI)显示为蜗神经发育不良的患者56例(CND组103耳)作为研究对象,另选取50例(100耳)MRI提示蜗神经未见明显异常的极重度感音神经性聋患者作为对照组;两组均分别行ABR检测,分析ABR波形,判断强声刺激下4 ms左右是否记录到特殊正向波,并对此波形的特征进行分析。结果ABR特殊正向波仅在高强度刺激声下引出,在100 dB nHL刺激声下二组对象中共32耳引出该特殊正向波,平均潜伏期为4.22±0.24 ms,平均反应阈为94.68±5.98 dB nHL;CND组103耳中28耳记录到特殊正向波,占27.18%,对照组100耳中4耳记录到此特殊正向波,占4.00%,此特殊正向波诊断CND的敏感性为27.18%,特异性为96.00%。结论ABR测试在4 ms左右记录到的特殊正向波对诊断蜗神经发育不良的敏感性较低,但特异性极高,即出现此正向波可高度怀疑是CND,对CND的辅助诊断有重要作用。

Objective To study the clinical significance of the special positive wave in auditory brainstem response(ABR)test in the diagnosis of cochlear nerve deficiency(CND).Methods Fifty-six patients(103 ears)with cochlear nerve dysplasia on MRI were selected as the research subjects,and 50 patients(100 ears)with profound sensorineural hearing loss without obvious abnormality of cochlear nerve on MRI were selected as the control group.The ABR waveform of all patients were analyzed and judged whether a special positive wave was recorded at about 4 ms.The characteristics of this specific waveform were analyzed.Results The average latency of ABR special positive wave under 100 dB nHL stimulation was 4.22±0.24 ms.This wave was recorded only under high intensity stimulation,and the average response threshold was 94.68±5.98 dB nHL.This special positive wave were recorded in 28 of 103 ears in CND group,accounting for 27.18%,and were recorded in 4 ears of 100 ears in the control group,accounting for 4%.In all,the sensitivity and specificity of this special positive wave in diagnosis of CND were 27.18%and 96.00%.Conclusion The special positive wave recorded by ABR test at about 4 ms has low sensitivity but high specificity in the diagnosis of cochlear nerve dysplasia.That is,the presence of this positive wave can be highly suspected to be CND,which plays an important role in the auxiliary diagnosis of CND.