Quantitative interpretation of audiological test battery. I. A comparison with ABR in 97 cases of unilateral sensorineural hearing loss

A retrospective study was made of 97 patients with unilateral sensorineural hearing loss who underwent an audiological test battery and ABR during a 2 1/2-year period. The test battery included tone- and speech audiometry, Békésy audiometry, loudness balance test, tone decay test and impedance measurements (reflex thresholds and reflex decay). A quantitative interpretation of each audiological test was tried out and a mean value of included tests (audiological test score ATS), was compared with results of ABR. The audiological test score showed the same predictive value as ABR for detection of acoustic neurinomas. Among the auditory tests, Békésy audiometry had the lowest sensitivity. Eight patients with neurinomas were found in the series. Retrocochlear test results prevailed in another 23 ears, most often in combined hearing loss and vestibular dysfunction and in insidious or longstanding hearing loss. Quantitative interpretation of the audiological test battery is valuable for uniformity in classification of sensorineural hearing loss, and will facilitate extended studies on aetiology and course in auditory dysfunction.     

感音神经性聋患儿客观测听评估与特征分析

目的：综合评估低龄感音神经性聋患儿蜗性及蜗后病变的临床听力学特点及其与中枢性神经系统病变的关系;并对比观察不同客观测听技术的特征。方法：选取1998－2000年间资料完整的感音神经性聋患儿共310例（500耳）,年龄1个月－6岁,平均年龄24．23个月。根据神经康复科的专科评估,分为伴随中枢神经系统病变听力障碍组和不伴随中枢神经系统病变听力障碍组;前者又根据中枢性病变的病理特征及发病特征分为核黄疸－脑瘫,外部性脑积水和其它中枢性病变3小组。设立同年龄段对照组60例（104耳）。每一组组员同时检测听性脑干反应（auditory brainstem responses,ABR)和畸变产物耳声发射（distortion product otoacoustic emissions,DPOAE),对此观察不同组别间ABR波V阈值及DPOAE各自的特点,同一组间不同ABR波V阈值耳DPOAE的变化特征。结果：（1）低龄感音神经性聋患儿中伴随有中枢神经系统病变者比例高（41％）。（2）伴随有中枢神经系统病变的患儿中,核黄疸－脑瘫常导致严重的蜗后性听力损失,耳蜗功能也轻度受累;外部性脑积水仅导致轻度蜗后听力损失;其它以大脑皮层受累为主的中枢性病变一般不累及耳蜗功能,（3）蜗性听力损失者,ABR波V阈值达60dB nHL时,DPOAE幅值明显下降,达70dB nHL以上者,DPOAE幅值严重下降或消失。结论：感音神经性聋患儿常伴有中枢性神经系统病变,并表现出听力障碍特征的多样性,因此,在临床上需进行跨学科多手段的综合评估。才能作出客观正确的诊断。     

畸变产物耳声发射对侧抑制效应的临床应用价值

目的：为观察畸变产物耳声发射（ＤＰＯＡＥ）对侧抑制效应的临床应用价值。方法：研究以白噪声为对侧声刺激,对１７例正常人（３４耳）,１３例蜗性聋（１３耳）,９例蜗后聋（９耳）进行了ＤＰＯＡＥ及其对偶抑制效应测试。结果：蜗性聋耳的ＤＰＯＡＥ幅值较正常耳显著下降（Ｐ〈０．０１）,对偶抑制效应减弱,但与正常人差异无统计学意义（Ｐ〉０．０５）,蜗后聋耳ＤＰＯＡＥ幅值高于正常耳（Ｐ〉０．０５）,对侧抑制效应显著     

Audiological investigation of chronic alcoholics

Pure tone audiometry performed on 67 alcoholics showed a sensorineural hearing loss in 70% of the ears examined. The prevalence of the hearing loss was related to the duration of heavy drinking. Twenty-two subjects with hearing loss were evaluated using impedance audiometry, SISI test, tone decay test and fixed frequency Békésy recording. The results of these tests are suggestive of a retrocochlear lesion in chronic alcoholics.     

The effects of tocainide on audiological and electrophysiological responses in humans

This study reports on the systematic audiological evaluation of 18 cardiac patients receiving tocainide, an orally administered cardiac antiarrhythmic agent. The results of an audiological site of lesion test battery were compared with auditory brain stem response (ABR) measures. Of 35 ears tested, 17 (48%) presented ABR findings consistent with retrocochlear pathology. Audiological signs of retrocochlear pathology occurred less frequently and often in patients in whom ABR results suggested normal hearing or cochlear hearing loss. These data demonstrate that an extraneous agent, in this case tocainide, can affect ABR transmission times and that it is important to recognize such possible effects in order to interpret ABR data appropriately.     

Importance of vestibulography in the acoustic neurinoma test battery

Vestibular, audiological and X-ray findings on 25 surgically confirmed neurinoma cases were reviewed to determine the diagnostic sensitivity of each in the neurinoma test battery. A comprehensive, retrocochlear audiological and vestibular work-up was run. X-ray procedures included posterior fossa myelograms in all but one instance, with all of the patients complaining of some auditory difficulties; progressive hearing loss and tinnitus were the most common complaints with tinnitus as the earliest symptom. Thirty-six percent of the cases had a retrocochlear audiological pattern, while 60 percent manifested a mixed cochlear and retrocochlear pattern, the remaining 4 percent presented cochlear findings. A correlation between audiological findings and standard X-ray views revealed that 32 percent of the cases presented equivocal audiometric and negative X-ray findings, while myelogram were performed on 24 percent of the patients, and all but two. cases were positive. One of these cases revealed negative findings, and the other was equivocal. Our clinical findings indicated that a routine vestibular work-up provided the indication for a more progressive neurinoma evaluation.     

Audiological assessment in Ramsay Hunt syndrome.

Ramsay Hunt syndrome is known to cause symptoms and signs of vestibulocochlear dysfunction, including sensorineural hearing loss. The present study investigates the audiological features of a group of 15 patients with this syndrome. A complete otolaryngological, neurologic, and audiological workup was performed in every patient, including auditory brain stem response measurements and recording of transiently evoked otoacoustic emissions. In most patients, some degree of hearing loss was evident, and abnormal latencies and interpeak latencies of the auditory brain stem response, or even absence of the waves, were observed. Transiently evoked otoacoustic emissions were present in only 6 cases, and caloric tests showed unilateral weakness in the majority of the patients. In all of the performed tests, abnormalities were present only on the affected side. The audiological data suggested cochlear or retrocochlear involvement or involvement at more than one site along the auditory pathway.     

Critical bandwidth in patients with acoustic neuroma

Eleven patients with verified acoustic neuroma had critical band estimation performed by the method of loudness summation using noise bands centered around 1 kHz. The normal loudness difference between broad band noise and narrow band noise was reduced at all levels except the highest. Judged as single individuals, 9 of the 11 patients had a normal critical band. The pooled data indicated a normal critical band, both in patients with hearing loss less than 50 dB HL and in patients with hearing loss greater than or equal to 50 dB HL. The results are similar to those obtained in patients with Ménière's disease (Bonding, 1978c) and thus CB-measurements cannot be utilized for differentiating between cochlear and retrocochlear lesions. However, at the highest test levels applied the loudness difference between broad band noise and narrow band noise appeared to have some correlation to the presence or absence of recruitment.     

Safety and clinical performance of acoustic reflex tests

OBJECTIVE: Safety and effectiveness of acoustic reflex tests are important issues because these tests are widely applied to screen for retrocochlear pathology. Previous studies have reported moderately high sensitivity and specificity for detection of acoustic neuroma. However, there have been reports of possible iatrogenic hearing loss resulting from acoustic reflex threshold (ART) and decay (ARD) tests. This study assessed safety and clinical performance of ART tests for detection of acoustic neuroma. DESIGN: We report a case in which ARD testing resulted in a significant bilateral permanent threshold shift. This case was the impetus for us to investigate the clinical utility of ART and ARD tests. We analyzed sensitivity and specificity of ART, as well as asymmetry in pure-tone thresholds (PTT) for detection of acoustic neuroma in 56 tumor and 108 non-tumor ears. RESULTS AND CONCLUSIONS: Sensitivity and specificity were higher for PTT asymmetry than for ART. Ipsilateral ART at 1000 Hz had poor sensitivity and specificity for detection of acoustic neuroma, and involves some potential risk to residual hearing for presentation levels higher than 115 dB SPL. Approximately half of the acoustic neuroma group had ipsilateral ARTs that would require administration of ARD tests at levels exceeding 115 dB SPL. Therefore, we conclude that PTT asymmetry is a more effective test for detection of acoustic neuroma, and involves no risk to residual hearing. Future studies of contralateral reflex threshold and ARD in combination with PTT asymmetry are recommended.     

Cochlear Findings in VIIIth Nerve Tumors

We have been particularly concerned with the large number of patients with confirmed retrocochlear lesions who have demonstrated cochlear test results on audiological evaluation. The literature is replete with information suggesting that the patient with a tumor of the VIIIth nerve will demonstrate the classical signs of significant reduction in auditory speech discrimination, abnormal tone decay, lack of loudness recruitment, negative SISI scored and Békésy tracings classifiable as either type III or type IV. We feel it is safe to say that one rarely encounters such a clearcut picture.

In this paper we discuss the audiologic data for a series of patients recently evaluated in our department. All these patients demonstrated only cochlear findings on audiological evaluation, yet all patients had surgically confirmed VIIIth nerve tumors.     

Clinical application of brain-stem audiometry

Based on the examination of 249 consecutive patients, the usefulness of brain-stem response audiometry in a major audiological clinic was evaluated. Auditory brain-stem responses were performed either for hearing threshold determination (67 patients) or for assessment of retrocochlear hearing loss (182 patients). The results demonstrate that ABR is a reliable method for the estimation of hearing thresholds in non-cooperative subjects. The rate of false positives was 5% and no false negatives were found. In combination with caloric testing, ABR is considered a valuable testing procedure in the audiological clinic and it may form the basis for submission to brain imaging examination when a suspicion of retrocochlear hearing disorder is raised. Concerning the diagnosis of retrocochlear hearing disorder, no false negatives have yet been found, while a rate of 13% of false positives has been indicated.     

The Stapedius Reflex Tests in Retrocochlear Hearing Disorders

The commonly used parameters of the stapedius reflex responses in the diagnosis of sensorineural hearing disorders are the reflex threshold level and the persistence of the reflex response on prolonged stimulation, i.e., the reflex decay test. With the object of establishing the sensitivity of these reflex parameters to identify tumours affecting the eighth nerve in the early stages, a series of 97 such cases were examined. The mean hearing loss of the affected ears was 32 dB; 28 of the cases still had normal thresholds of hearing; 95 of the ears demonstrated elevated reflex thresholds and/or pathologic reflex decay. To check the specificity of the test, a control series with sensorineural hearing loss and reflex threshold elevation or pathologic reflex decay was analysed with respect to clinical diagnoses. In every third case of reflex threshold elevation and in every second case of reflex decay, the medical diagnosis confirmed a disease known to be associated with retrocochlear dysfunction. It was also noted that none of the cases with brain stem lesion demonstrated reflex decay - an observation which supports the idea of the reflex decay phenomenon as specifically associated with eighth-nerve lesions.     

Verhalten des Stapediusreflexes bei akustischer Langzeitstimulation

Summary The present examination shows the action of the acoustic reflex from stimulation with a pure tone of 500 cps which lies 10 dB above the reflex threshold by impedance measurement. The duration of stimulation lasts 5 min. The test results of persons with normal hearing, persons with cochlear, and retrocochlear lesions were measured following the amount, the duration, the beginning, and the speed of reflex decay. The preliminary results permit the following conclusions:Persons with noise induced hearing loss shows no reflex decay for the entire duration of stimulation.Persons with normal hearing show a minimal reflex decay after 2 min. after another 90 s a constant reflex amplitude is attained. Subjects with cochlear lesions which are not caused by noise and the subjects with noise induced lesions includeing degenarative tendencies, shows similar reflex behavior. The amount of decay is larger, and the decay begins earlier.Persons with retrocochlear lesions show heterogeneous results, but the average amplitudinal decay is rapid and exceeds 50%.     

Auditory brainstem response testing in neurodiagnosis: structure versus function

This case report describes a 44-yr-old female referred by an outside facility who presented with progressive hearing loss in her left ear. Magnetic resonance imaging (MRI) results were normal, but a battery of audiological tests suggested neural hearing loss in the left ear. Following diagnosis of left neural hearing loss, the patient was successfully fit with a hearing aid on the left ear. This case report underlines the importance of using a battery of medical, radiologic, and audiological tests in the accurate determination of hearing loss site of lesion. Obvious retrocochlear dysfunction was revealed via auditory brainstem response (ABR) testing. MRI did not reveal underlying structural abnormality. Without the addition of the ABR to the diagnostic test battery, a cochlear hearing loss site of lesion would most likely have been diagnosed. Accurate diagnosis of hearing loss site of lesion is critical for patient counseling and treatment as well as for patient follow-up and monitoring.     

Clinical findings and diagnostic problems in sensorineural low frequency hearing loss

The otological and audiological findings in 39 patients with sensorineural low frequency hearing loss are reported. This type of perceptive hearing loss is difficult to distinguish from the true conductive hearing losses due to the air conduction audiogram shape and the invalidity of bone conduction determinations showing a false "air-bone gap". This may lead to surgical treatment of a perceptive hearing loss, as reported in the four case histories. By various audiological tests, contradictory information may be obtained. In our material, Bing's test and absent acoustic reflexes indicated a conductive disorder in 25% of the ears. The final differentiation may require cochleography. The hearing loss may be diagnosed as Meniere's disease. In our material only 17% complained of tinnitus and no patients had vertigo. Consequently, we find sensorineural low frequency hearing loss to differ from Meniere's disease. Our material comprises different etiological types of perceptive low frequency hearing loss. On type was inherited as an autosomal dominant trait, another type due to cochlear malformation probably also inherited, and a third group showing diverse audiological results. When the diagnosis is established, the patients may be treated successfully by specially constructed hearing aids.     

Neural networks applied to retrocochlear diagnosis.

Methodologies have been developed, based on insights from signal detection theory, to evaluate quantitatively the diagnostic performance of tests. Several studies have demonstrated that, in fact, performance of a test battery can be inferior to the best of the tests it includes. These studies have been quite persuasive in damping enthusiasm for the test battery approach. Because the results of all tests in a battery were weighted equally in these studies, it is not surprising that an individual test with good sensitivity and specificity is more effective diagnostically than a combination of tests with poorer sensitivity and specificity. The authors of many of these studies were well aware of the limitations of this approach. In the present study, neural networks were applied to evaluate audiological tests used to predict retrocochlear pathology by differentially weighting the results of the tests in the battery. This technique avoids some of the limitations of previous approaches. Of the audiological tests evaluated in the present analysis, the superiority of the auditory brainstem evoked response (ABR) in predicting retrocochlear disease was again demonstrated. However, the results also demonstrated that identification accuracy could be improved by combining the ABR with other tests (in this case contralateral acoustic reflex at 2000 Hz, ipsilateral acoustic reflex at 2000 Hz, tone decay, and word recognition score). Further, it was demonstrated that performance could be improved over that obtained using dichotomous test measures (i.e., positive or negative presence of pathology) by using raw test measures in conjunction with ABR.     

The role of brain stem evoked potentials in acoustic neuroma screening and diagnosis

For acoustic tumours > 2 cm the sensitivity of brainstem evoked auditory potentials (BAEP) to detect the retrocochlear lesions is 100 % as for magnetic resonance imaging (MRI). According to the literature the sensitivity for detection of retrocochlear pathology in tumours < 1 cm is estimated to be between 75 % and 95 %. In the MRI the sensitivity and specificity in such smaller tumours is reported to be 100 %. A normal result of the BAEP examination and for additional neurootologic tests helps to increase the rate of safe exclusion of retrocochlear pathology. By at this time not yet routinely available modifications of the BAEP examination and by additional neurootologic tests the sensitivity of the electrophysiological screening procedure can be brought up to nearly 100 %. Thereby their important role as the primary screening procedure can be re-established. Besides a possible detection of a retrocochlear lesion the BAEP together with the additional neurootologic test provide important information on the functional status of the hearing and equilibrium system. Possible safe indications for inclusion and for exclusion criteria of an MRI screening for individual patients will be provided and discussed.     

Audiological manifestations of Ramsay Hunt syndrome

Ramsay Hunt syndrome is known to cause audiological signs and symptoms, including sudden, unexpected hearing loss. We carried out a retrospective review of the audiological manifestations of 186 patients with Ramsay Hunt syndrome, measuring their hearing loss patterns, hyperacusis, tinnitus, herpetic rash, facial paralysis, pain and vertigo. Statistical correlations of these parameters were equated with prognosis. Prognosis for eventual hearing recovery is, in general, excellent. Prognostic indicators of poor hearing recovery include advanced age, retrocochlear hearing loss, male gender, vertigo, and speech frequency hearing loss.     

蜗后性听力减退29例病因分析

目的 探讨蜗后性低频听力减退的发病原因。方法 复习1988～2002年29例原因明确的蜗后性低频听力减退患者的临床特点和听力学检查结果。结果 头部外伤、听神经瘤、周围神经病、遗传性聋、多发性硬化和脑干疾病均可表现为蜗后性低频听力减退,其共同的特点是：低频听力减退,诱发性耳声发射正常或至少在部分频率正常,不受对侧噪声抑制,引不出镫骨肌反射,听性脑干反应(auditory能超群brainstem response,ABR)异常。结论 以耳声发射正常和ABR异常为主要特征的听功能障碍是一组症状群,可为不同病因引起的听神经和(或)听性脑干病变的表现,建议对这一组听力学表现称之为蜗后性低频听力减退。