多频稳态诱发电位测试对中重度以下听力损失的评估价值

背景:多频稳态诱发电位测试是近年来应用于临床的客观听力检查方法。与以往的听性脑干诱发电位检查比较,多频稳态诱发电位测试具有频率特异性。目的:了解多频稳态诱发电位测试在客观听力评价中的准确性。设计:病例-对照观察。单位:中山大学附属第一医院耳鼻咽喉科。对象:听力正常组为在校大学学生21人42耳,无任何耳科疾病症状,无噪声暴露史及前庭系统疾病,耳镜检查正常。感音神经性聋患者均为在中山大学附属第一医院耳鼻咽喉科门诊和住院部求治的病例,均行磁共振检查排除中枢性病变;疾病种类主要为:突发性耳聋6例耳、老年性耳聋8例耳,其他不明原因的感音神经性耳聋20例耳,按纯音测听结果均为平坦型或渐降型听力图,按听力损害程度分3组,轻度聋组13例耳、中度聋组9例耳和中重度聋组12例耳。方法:①在隔音室内采用纯音测听检查,测试方法按0.125～8000Hz各倍频程的纯音测听,听力正常者的听阈级符合GB-7583-87期望值分布标准。感音神经性聋病例的纯音测听气导听力阈值取0.5,1,2和4kHz4个频率的均值。②在声电磁屏蔽室内进行多频稳态诱发电位检查,采用双耳同一刺激强度、相同4个载频音0.5,1,2和4kHz共8个点同步刺激模式。③在声电磁屏蔽室内进行听性脑干诱发电位检查,采用刺激声为疏波短声,使用插入式耳机,阈值结果判定按取可辨别出Ⅴ波的最小刺激声强度。④以纯音测听结果和听性脑干诱发电位检查结果为参照对比,将不同听力水平组的多频稳态诱发电位测试结果进行方差分析、Bayers准则下分类资料的多类判别分析和q检验。主要观察指标:纯音测听阈值、频稳态诱发电位测试阈值和听性脑干诱发电位检查阈值,Bayers准则下多类判别分析的正确率。结果:正常听力组42例耳及轻度聋组13例耳、中度聋组9例耳和中重度聋组12例耳均测出各项指标,全部进入结果分析。①听性脑干反应值与实际听力水平相符合,与多频稳态诱发电位1.0～2.0kHz的阈值最为接近;不同频率的多频稳态诱发电位的引出率随着听力损害的加重而逐渐降低熏听力正常或轻度聋者多频稳态诱发电位的引出率均为100%,而中度、中重度聋组的引出率有所下降(0.5kHz时,分别为77.8%和92.8%;4kHz时,分别为88.9%和85.7%)。不同频率时,中重度聋组的多频稳态诱发电位阈值显著高于听力正常组,差异有显著性意义(P<0.05);0.5kHz及4kHz时中重度聋组的多频稳态诱发电位阈值显著高于轻度聋组,差异有显著性意义(P<0.05);2kHz时轻度聋组的多频稳态诱发电位阈值显著高于听力正常组,差异均有显著性意义(P<0.05);4kHz时中度聋组的多频稳态诱发电位阈值显著高于听力正常组和轻度聋组,差异均有显著性意义。②由多频稳态诱发电位检查结果和实际纯音测听的组别经交互聚类判别纯音测听结果所犯的判断错误,听力正常组的判别符合正确率为100%;轻度聋组12例中仅有1例错判,正确率为92%;中度聋组9例中1例错判,正确率为89%,中重度聋组判别正确率为83%。结论:由多频稳态诱发电位测试结果可推测以纯音测听结果为标准的客观听力状况所犯的判别错误,多频稳态诱发电位测试在客观听力评价中对轻度聋以上的有较好的准确率,在实际应用中有较好应用前景。

Auditory steady-state response measurement in evaluating hearing loss milder than moderate to severe level

BACKGROUND: Auditory steady-state responses (ASSR) is an objective method of hearing examination in clinic in recent years. ASSR has the frequency specificity as compared with previous auditory brainstem responses (ABR).OBJECTIVE: To investigate the accuracy of ASSR in objective hearing assessment.DESIGN: A case-control observation.SETTING: Department of Otorhinolaryngology, the First Affiliated Hospital of Sun Yat-sen University.PARTICIPANTS: The subjects in the normal hearing group were the 21 undergraduates (42 ears) were enrolled, they all had not any symptoms of ear disease, without history of noise exposure and disease of vestibule system, and they were normal in otoscopy. The outpatients and inpatients with neurosensory deafness were selected from the Department of Otorhinolaryngology, the First Affiliated Hospital of Sun Yat-sen University. All the children cases worn hearing aids, and had the speech ability, and cooperated in the examination. The main types included 6 ears of sudden deafness,8 ears of presbycusis, and 20 ears of neurosensory deafness due to other unknown causes. Central lesions were excluded by MR examination, and all the patients agreed with the enrollment. The results of pure-tone audiometry were all flat or descending audiogram. According to the severity of hearing damage, the patients were divided into mild deafness group (13ears), moderate deafness group (9 ears) and moderate-to-severe deafness group (12 ears).METHODS: ① The pure-tone audiometry was performed at the frequencies of 0.125-8 000 Hz in a sound insulation room. The auditory threshold grades of the subjects with normal hearing all accorded with the standards of GB-7583-87 expected value distribution. The average value of air-conduction auditory thresholds of pure-tone audiometry at the frequencies of 0.5, 1, 2 and 4 kHz was calculated. ② ASSR measurement was performed with the synchronous stimulation pattern in a sound and electromagnetic shielding room, including 8 points for both ears of the same stimulation intensity and the carrier frequency tones of 0.5, 1, 2 and 4 kHz respectively.③ ABR examination was performed by click sounds with sparse waves in a sound and electromagnetic shielding room, and insert earphones were used.The threshold results were judged according to the minimal stimulation sound intensity of the distinguishable Ⅴ wave. ③ The results of pure-tone audiometry were compared with those of ABR examination, and the results of ASSR measurement in different hearing groups were processed with analysis of variance, multi-classification discrimination based Bayes standard and q test.MAIN OUTCOME MEASURES: The thresholds of pure-tone audiometry, ASSR measurement and ABR examination, and the correct rate analyzed by the multi-classification discrimination based Bayes standard were mainly observed.RESULTS: The indexes of the 42 ears in the normal hearing group, 13, 9 and 12 ears in the mild, moderate and moderate-to-severe deafness groups were all involved in the analysis of results. ① The ABR values were accorded with the actual hearing levels, and the closest to the ASSR thresholds at 1-2 kHz; ASSR reflected induction rates at different frequencies were gradually decreased with the aggravation of hearing damage, and that at each frequency varied with the changes of hearing level, the induction rates of ASSR responses were all 100% for the subjects with normal hearing and patients with mild deafness, but those for the patients with moderate and moderate-to-severe deafness were decreased (0.5 kHz: 77.8%,92.8%; 4 kHz: 88.9%, 85.7%). At different frequencies, the ASSR thresholds in the moderate-to-severe deafness group were significantly higher than those in the normal hearing group (P ＜ 0.05). The ASSR thresholds at 0.5 and 4 kHz in the moderate-to-severe deafness group were significantly higher than those in the mild deafness group (P ＜ 0.05). The ASSR threshold at 2 kHz in the mild deafness group was significantly higher than that in the normal hearing group (P ＜ 0.05). The ASSR thresholds at 4 kHz in the everedeafness group were significantly higher than those in the normal hearing group and mild deafness group. ② The incorrect discriminations of actual pure-tone audiometry were analyzed with the interactive clustering discriminant analysis of ASSR measurement and actual pure-tone audiometry, and the results showed that the correct rate of discrimination was 100% in the normal hearing group; Only 1 of the 12 cases in the mild deafness group was incorrectly judged, and the correct rate was 92%; Only 1 of the 19 cases in the moderate deafness group was incorrectly judged, and the correct rate was 89%; the correct rate in the moderateto-severe deafness group was 83%.CONCLUSION: The results of ASSR measurement can detect the incorrect discrimination of objective hearing condition by taking the results of pure-tone audiometry as the standards. ASSR has an acceptable accuracy for deafness higher than mild level in estimating objective hearing, and it has a better prospect of application in practice.