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PubMed1996

Clinical interest of brainstem auditory evoked potentials in 72 children with inadequate language development.

The present study is of brainstem auditory evoked potentials (BAEP) in 72 children, of 2 to 13 years of age, showing inadequate language development. The age of the children was mainly below the age of 4 (39 cases = 54%), peaking between 3 and 4 years of age (33 cases = 46%). Even so, 82% of our patients were 3 years old or over: 64% were boys, 36% girls, the proportion of boys falling off with age 26% (19 cases) of BAEPs recorded were normal, 74% (53 cases) pathological. High prevalence of undiagnosed hearing loss was found. Physiopathological BAEP classification showed endocochlear impairment in 68% (36 cases), conductive impairment in 21% (11 cases) and retrocochlear impairment in 11% (6 cases) of subjects. Unilateral impairment (20 cases = 28%) cannot account for inadequate language development; but, in the 8 cases (11%) of total bilateral hearing loss, and the 15 cases (21%) of partial bilateral impairment, hearing loss more or equal to 50 dB HL, impaired hearing would play a role in the retardation.

Aging↗
PubMed1981

Clinical application of nonacoustic middle ear muscle stimulation.

Several clinical situations exist when only nonacoustic stimuli will provide data necessary for the correct neuro-otologic diagnosis. The tactile stapedius and the orbital air-jet reflexes have been used to aid in detecting the middle ear status in severe hearing losses, retrocochlear hearing losses, ossicular fixation, and facial paralysis. These reflexes also are useful in localization in some cranial nerve disorders. The equipment required to elicit these reflexes is inexpensive, and the test can be performed rapidly. Some pitfalls in interpretation are caused by the lack of precise correlative data. When properly used, performed, and interpreted, nonacoustic reflex response data supply information to the clinician that is otherwise unobtainable.

Cranial Nerve Diseases↗
PubMed1993

Acoustic neuroma and non-tumour retrocochlear patients: audiological features.

Seventeen surgically confirmed acoustic neuroma subjects and seventeen radiologically confirmed non-tumour subjects with retrocochlear pathology of unknown aetiology were selected to investigate retrospectively the diagnostic yield of basic audiological test procedures. Puretone audiometry, tympanometry, reflexometry and auditory brainstem response audiometry were used in the identification of acoustic neuromas versus non-tumour retrocochlear disorders. All subjects had been referred originally for neuroaudiological assessment because of suspected acoustic neuroma and had been found to have a range of abnormal ABR findings consistent with retrocochlear pathology. Detailed retrospective analysis of audiological results following surgical and radiological classification showed subject similarities for most parameters of the individual audiological tests for both acoustic neuroma and non-tumour groups. A significant difference was noted, however, between the two clinical populations for the ABR Wave V absolute interaural latency difference parameter.

Acoustic Impedance Tests↗
PubMed1988

Screening for retrocochlear pathology.

In 1982, 135 patients were screened for possible retrocochlear pathology, by means of an investigation protocol consisting of caloric test, impedance audiometry and brainstem response audiometry (BRA). A combination of the first two of these procedures had an unacceptably low prognostic accuracy. BRA indicated retrocochlear pathology in 8 and was inconclusive in 4 cases. Enhanced computer tomography revealed an intracranial tumour in 4 of the former, while no space-occupying lesion could be demonstrated in the remainder nor in the 4 patients with inconclusive BRA. BRA is the best single test for screening of this patient category.

Acoustic Impedance Tests↗
PubMed2005

Electrically evoked hearing perception by functional neurostimulation of the central auditory system.

Perceptional benefits and potential risks of electrical stimulation of the central auditory system are constantly changing due to ongoing developments and technical modifications. Therefore, we would like to introduce current treatment protocols and strategies that might have an impact on functional results of auditory brainstem implants (ABI) in profoundly deaf patients. Patients with bilateral tumours as a result of neurofibromatosis type 2 with complete dysfunction of the eighth cranial nerves are the most frequent candidates for auditory brainstem implants. Worldwide, about 300 patients have already received an ABI through a translabyrinthine or suboccipital approach supported by multimodality electrophysiological monitoring. Patient selection is based on disease course, clinical signs, audiological, radiological and psycho-social criteria. The ABI provides the patients with access to auditory information such as environmental sound awareness together with distinct hearing cues in speech. In addition, this device markedly improves speech reception in combination with lip-reading. Nonetheless, there is only limited open-set speech understanding. Results of hearing function are correlated with electrode design, number of activated electrodes, speech processing strategies, duration of pre-existing deafness and extent of brainstem deformation. Functional neurostimulation of the central auditory system by a brainstem implant is a safe and beneficial procedure, which may considerably improve the quality of life in patients suffering from deafness due to bilateral retrocochlear lesions. The auditory outcome may be improved by a new generation of microelectrodes capable of penetrating the surface of the brainstem to access more directly the auditory neurons.

Auditory Perception↗
PubMed1982

The SISI test: a review. Part II.

This is the second of two papers reviewing the SISI test. In this paper we discuss modifications of SISI, and the effects of contralateral masking and tone decay. We also compare SISI to other psychoacoustic site of lesion tests and discuss the implications of the results obtained in SISI. The following conclusions are drawn: (1) SISI performed at high levels appears powerful in detecting retrocochlear impairments. (2) Contralateral masking is advisable when cross-hearing cues are present. The masking level should be minimized and a noise level 10 dB below the level of the contralaterilized tone provides sufficient masking. (3) SISI remains valid despite the presence of tone decay. (4) High SISI scores in cochlearly impaired listeners do not indicate improved auditory acuity.

Audiometry, Pure-Tone↗
PubMed2000

Pure tone audiogram and speech audiometry in patients with hereditary motor and sensory neuropathy.

The goal of our work was to determine hearing thresholds in patients with hearing impairment due to hereditary motor and sensory neuropathy (HMSN I). In assessment of auditory function we used two methods: pure tone and speech audiometry. Pure tone audiometry was performed using air and bone conducted signals. Speech comprehension was defined with a test battery of monosyllabic words unknown to the patient. By comparing the results of these methods we were able to differentiate whether the hearing loss was of cochlear or retrocochlear origin. We tested 5 patients with HMSN I associated with difficulty in speech understanding. The tests showed mild to severe elevation of pure tone thresholds but no speech perception in any of tested patients. We suggest that this type of hearing impairment be due to the disorder of the auditory nerve function--a neuropathy of the auditory nerve as part of HMSN.

Adolescent↗
PubMed1999

Lesion site in sudden deafness: study with electrocochleography and transiently evoked otoacoustic emission.

We examined electrocochleogram (ECochG) and transiently evoked otoacoustic emission (TEOAE) on five cases of sudden sensorineural hearing loss which had no abnormalities detected on diagnostic imagings and showed complete recovery of hearing. At the initial examination, three cases showed a broadened wave 1 with prolonged latency in the auditory brainstem response (ABR) at 90 dB HL. The ECochG AP showed a broad waveform, low amplitude, and high threshold. CM threshold, although increased, was relatively well preserved compared with hearing threshold measured with conventional pure-tone audiometry. The thresholds in TEOAE examination were similar to those for CM and preserved better when compared with pure-tone audiometric thresholds. These findings suggest that the location of the disorder in these three cases involved not only the cochlea but also the retrocochlear auditory pathway. The other two cases showed normal ABR waveforms at 90 dB HL at the initial examinations. ECochG examination showed that a normal AP in one case and a smaller amplitude AP, an elevated threshold, and normal waveform of AP in the other ear. CM thresholds coincided with the conventional audiometry thresholds. These findings suggest that hearing loss in these two cases involved primarily the sensory hair cells.

Acoustic Stimulation↗
PubMed1996

Prevalence and mechanisms of hearing loss in patients with resistance to thyroid hormone.

Hearing impairment was anecdotally reported in resistance to thyroid hormone (RTH), a condition caused by mutations in the beta-thyroid hormone receptor (beta TR) gene. Because of its ontogenic distribution in the cochlea, the beta TR may have a pivotal role in the development of auditory function. To assess the prevalence and mechanisms of hearing impairment in RTH, 82 RTH-positive (RTH+) patients and 55 unaffected relatives (RTH-) underwent systematic audiological examination, including puretone and speech reception thresholds, and tests studying middle ear (tympanometry and acoustic reflexes), cochlear (otoacoustic emissions), and retrocochlear integrity (brain stem auditory evoked potentials). Significant hearing loss was present in 21% of RTH+ patients vs. none in RTH- patients. More RTH+ patients had abnormal tympanometry (34% vs. 12%) and abnormal acoustic reflexes (39% vs. 19%). Isolated conductive deficit was found in 7 of 17 RTH+ patients with hearing loss, isolated sensorineural deficit in 7 cases, and mixed deficit in 3 cases. Cochlear dysfunction was found in 50% of all RTH+ patients, with or without hearing loss. Retrocochlear function was normal. No morphological cochlear abnormalities were detected on computed tomography of the temporal bone. In conclusion, hearing loss is a significant problem in RTH, with an equal frequency of conductive (probably related to the frequent ear infections) and sensorineural deficits. Abnormal otoacoustic emissions suggest that the mutant beta TR has a specific negative impact on cochlear function.

Adult↗
PubMed1998

ABR disturbances in children with insulin dependent diabetes mellitus.

A number of papers present the research on hearing disturbances in the course of diabetes mellitus. Some authors report the damage of inner ear cells, whereas others maintain that it is located in the retrocochlear part of the hearing pathway. The objective of the paper was to find the location of the auditory pathway disturbances in children suffering from diabetes mellitus. The analysis concerns 37 insulin treated children aged 6-18 years. The following audiometric methods were applied: pure-tone audiometry, impedance audiometry as well as auditory brainstem response (ABR). We observed conduction disturbances within the stem in ABR, in the children without hearing loss in pure-tone audiometry.

Acoustic Impedance Tests↗
PubMed1990

The use of diagnostic testing in asymmetric sensorineural hearing loss.

The etiology of an asymmetric sensorineural hearing loss can often be difficult to determine. Because a wide variety of pathologic processes may be responsible for the hearing loss, numerous diagnostic tests are usually used in the initial evaluation, including pure-tone audiometry, acoustic reflex testing, imaging, serologic testing, and auditory brainstem response testing. The diagnostic evaluations of 225 consecutive cases of asymmetric sensorineural hearing loss are reviewed. A cochlear site-of-lesion was demonstrated in the majority (194) of patients. Because all retrocochlear lesions (31) were associated with an abnormal auditory brainstem response, imaging should be performed in that group of patients. Magnetic resonance imaging offers greater specificity than computed tomography. Reflex decay, acoustic reflex testing, and rollover were all associated with a high false-negative rate. Whereas serologic testing for syphilis yielded several cases of otosyphilis, thyroid function testing was of little value. A diagnostic protocol for asymmetric sensorineural hearing loss is presented.

Adolescent↗
PubMed1988

Central vestibulocochlear pathology: role of MRI and CT.

Hearing loss, tinnitus, dizziness and disequilibrium are frequent complaints of patients with labyrinthine and retrolabyrinthine lesions. The objective of a neurotological examination is to establish the presence and location of a lesion, whether it is labyrinthine (cochlear or vestibular) or intracranial. On the basis of neurotological and vestibular results, provided by neurotologist or otolaryngologist, if a retrocochlear or retrovestibular lesion is suspected, a magnetic resonance imaging (MRI) or computed tomography (CT) study of the head is obtained with particular attention to the acoustic nerve and posterior fossa. MR and CT are exceedingly helpful to identify the extraaxial and intra-axial lesions involving the vestibulocochlear nerves and their central pathways. The appearances on MR and CT scans of varied pathological entities involving the central vestibulocochlear pathways are reviewed and illustrated.

Cochlear Nerve↗
PubMed1993

Effectiveness of acoustic reflex threshold criteria in the diagnosis of retrocochlear pathology.

This study examines the acoustic reflex threshold criteria, derived from a large group of patients with cochlear hearing loss proposed by Cohen & Prasher (1992), in order to evaluate their effectiveness in differentiating between cochlear and retro-cochlear lesions. This criterion was tested on 63 patients with surgically confirmed cerebello-pontine angle (CPA) lesions. The false results obtained with this and other criteria were compared. The best balance between the false positive and negative results in the cochlear and retrocochlear group is provided by the criterion of any two adjacent test frequencies (proposed in the companion paper) having an upper limit of 105 dB for hearing below 60 dB and 110 dB for hearing over 60 dB. This study has also singled out the interaural difference criterion as the best diagnostic indicator with the lowest false results with only 1 false negative from 63 CPA cases and 3 false positive cases from 61 cochlear lesions with hearing thresholds over 55 dB.

Acoustic Stimulation↗
PubMed2001

Cerebro-oculo-facio-skeletal syndrome as a human example for accelerated cochlear nerve degeneration.

BACKGROUND: Cerebro-oculo-facio-skeletal (COFS) syndrome is a rare autosomal-recessive disorder that includes microcephaly, severe mental retardation, and multiple congenital anomalies. Otologic findings are usually limited to descriptions of the auricles. PATIENT AND METHODS: The authors report inner ear histopathologic findings of a deceased 13-year-old patient with COFS. A histologic study of the inner ear in COFS syndrome has not yet been described. This patient was documented as having a profound bilateral sensorineural hearing loss at the age of 2 years. RESULTS: Histologic evaluation revealed accelerated neural and neuronal degeneration at the cochlear and retrocochlear levels. Remaining myelinated nerve fibers, counted in the spiral lamina, had degenerated by up to 97% when compared with normal innervation densities. Afferent nerve fibers innervating inner hair cells were completely absent, whereas medial efferent fibers to outer hair cells were found. Vestibular nerve fibers were less affected. CONCLUSION: The authors report inner ear findings that differ from animal models of primary cochlear neural degeneration and that resemble the pattern of hereditary cochlear nerve degeneration reported in Friedreich's ataxia.

Abnormalities, Multiple↗
PubMed1980

The negative acoustic reflex in retrocochlear disorders.

The most frequent impedance abnormality of an acoustic tumor is an absent reflex. However, this finding also occurs with middle ear disorders and is therefore nonspecific. This study recorded the contralateral acoustic reflex of human subjects suspected of having an acoustic tumor. Many tumor subjects, by visual inspection of the impedance bridge balance meter, appeared to have an absent reflex. Most of these subjects, in fact, had small amplitude negative reflexes by offline analysis on an averaging computer. Recognition of these negative reflexes increases the specificity and sensitivity of the reflex test for acoustic tumors. We recommend reflex testing with averaging computer monitoring to ensure their recognition.

Acoustic Impedance Tests↗
PubMed1979

A new acoustic reflex pattern.

A new crossed-vs-uncrossed acoustic reflex pattern has been observed in four patients with retrocochlear disorder. The new reflex pattern is characterized by a unique "uni-box" configuration. Reflexes are abnormal with sound to the affected ear on crossed stimulation only. In one additional patient, a variation of the uni-box pattern was found on suprathreshold reflex amplitude measures. WE observed a large ear difference between reflex amplitude functions in the crossed condition, but not in the uncrossed condition. This observation suggests that reflex amplitude measures may be a valuable addition to threshold measures in some patients.

Adolescent↗
PubMed1990

Acoustic reflex thresholds in normal and cochlear-impaired ears: effects of no-response rates on 90th percentiles in a large sample.

Ninetieth percentile cutoffs for acoustic reflex thresholds (ARTs) were determined for a sample of 2,748 ears of 1,374 subjects with normal hearing and sensorineural loss of cochlear origin. All subjects had measurable hearing (less than or equal to 110 dB HL, ANSI-1969) at all three activator frequencies (500, 1000, and 2000 Hz). Cutoff values including "no responses" ("absent" reflexes at 125 dB HL) were higher than those excluding no responses when hearing losses were greater than about 55 dB. The 90th percentiles including the effects of no responses identified ears with retrocochlear involvement for hearing losses as great as about 756 dB. For greater hearing losses at the activator frequency, the no-response rate for both cochlear and retrocochlear cases is too high to enable them to be differentiated by acoustic reflex thresholds. The 90th percentiles are derived at each activator frequency collapsed across ears. It is therefore necessary to determine the probabilities that normal or cochlear-impaired ears will have one, two, or three frequencies at which the ARTs exceed their respective 90th percentiles. It was found that among normal and cochlear-impaired ears, 12.2% have one ART elevated above the 90th percentile, but only 5.6% have two or three elevated ARTs. Clinical implications are discussed.

Adult↗
PubMed1981

Site of lesion testing findings in a routine test battery.

Audiologic test results in eight patients with confirmed retrocochlear lesions are cited and discussed with reference to reliability. Comparison as to diagnostic validity is made with older and more recent literature. Results suggest that standard test procedures of tone decay, threshold Bekesy audiometry, pure-tone configuration, and discrimination scores are the most consistent in routine audiologic examinations. Super Threshold Adoption Test (STAT), Stapedius Reflex Testing, Staggered Spondaic Word (SSW) testing, and PB Rollover were accurate in their test results. Other tests, including Alternate Binaural Loudness Balance (ABLB) and regular high level, Short Increment Sensitivity Index (SISI), were found to be less effective in routine site of lesion testing.

Audiometry, Pure-Tone↗