PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Retrocochlear Diseases”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

[Stapedial reflex in nontumor retrocochlear pathology].

The authors study the different parameters of the stapedius reflex on a 55 patients group with retrocochlear and non tumoral diagnostic is assess by electrophysiologic (BERA, Electrocochleography) and neuroradiologic explorations (TAC), Meato-cisternography, NMR). We realise an comparative study between the results of this group and the results of 2 other groups (98 acoustic neuromas and 104 endocochlear diseases). The test has a moderate sensibility and none specificity in this kind of pathology, because the high percent of false negative (30%), and the positivity on 95% of acoustic neuromas and on 74% of endocochlear diseases.

Acoustic Impedance Tests↗
PubMed1996

[Otoacoustic emission and auditory efferent function testing in normal subjects and patients with sensori-neural hearing loss].

OBJECTIVE: To examine the role of otoacoustic emission and function test of the auditory efferent system in evaluating of auditory functional status in both normal and diseased conditions. METHODS: Spontaneous and transient evoked otoacoustic emission and efferent function in terms of contralateral white noise induced transient evoked otoacoustic emission suppressions were tested and cross compared in 32 normal ears, 24 ears with cochlear hearing loss and 16 ears with retrocochlear hearing loss. RESULTS: Transient evoked otoacoustic emission amplitude and contralateral suppression, spontaneous otoacoustic emission incidence, peaks and frequency range were significantly reduced in cochlear hearing loss, while in retrocochlear hearing loss transient evoked otoacoustic emission and spontaneous otoacoustic emission levels were significantly higher than in cochlear hearing loss group and showed no suppression. CONCLUSION: Contralateral acoustic stimulation induced transient evoked otoacoustic emission suppression as an index of efferent function is clinically feasible. Combined otoacoustic emission and efferent tests are of great significance in evaluating cochlea status and auditory central mechanisms. Auditory efferent function is weakened in cochlear lesions and severely damaged in retrocochlear lesions.

Acoustic Impedance Tests↗
PubMed1997

Otoacoustic emission and auditory efferent function testing in patients with sensori-neural hearing loss.

OBJECTIVE: To examine the role of otoacoustic emissions and auditory efferent system function in evaluating auditory functional status in both normal and diseased conditions. METHODS: Spontaneous and transient evoked otoacoustic emissions and efferent function in terms of contralateral white noise induced transient evoked otoacoustic emission suppressions were tested and cross compared in 32 normal ears, 24 ears with cochlear hearing loss and 16 ears with retrocochlear hearing loss. RESULTS: Transient evoked otoacoustic emission amplitude and contralateral suppression, spontaneous otoacoustic emission incidence, peaks and frequency range were significantly reduced in cochlear hearing loss while in retrocochlear hearing loss transient evoked otoacoustic emission and spontaneous otoacoustic emission levels were significantly higher than in cochlear hearing loss group and showed no suppression. CONCLUSIONS: Contralateral acoustic stimulation induced transient evoked otoacoustic emission suppression as an index of efferent function is clinically feasible. Combined otoacoustic emission and efferent tests are of great significance in evaluating cochlea status and auditory central mechanisms. Auditory efferent function is weakened in cochlear lesions and severely damaged in retrocochlear lesions.

Adolescent↗
PubMed1996

Brain stem auditory-evoked potentials of mice with experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE) is an experimental model for multiple sclerosis. In order to study autoimmune retrocochlear hearing loss, we performed brain stem auditory-evoked potential (BAEP) studies on EAE mice. The EAE was induced in B10.PL and (PL/J x SJL)F1 mice. In the BAEP study, all of the peak and interpeak latencies were prolonged significantly in the diseased mice. Hearing thresholds were slightly elevated in the immunized mice during the acute phase. Inflammatory and phagocytic cell infiltration, demyelination, and V beta 8.1, 8.2 T-cell receptor-positive cells were observed in the cochlear nerves or their proximity by histologic study. It is suggested that immunologic reactions identified with EAE also occurred in the cochlear nerve, and that these reactions were responsible for the hearing problems. It appears that EAE is a useful model system for studying autoimmune insults on the neural portion of the auditory system.

Animals↗
PubMed1983

Relationships among auditory brain stem responses, masking level differences and the acoustic reflex in multiple sclerosis.

We report the results of a study in which we compared auditory brain stem responses (ABR), the binaural masking level difference (MLD) for a 500-Hz pure tone and acoustic reflexes in 20 patients with confirmed multiple sclerosis. Our intent was to determine whether abnormalities in the three measures were related or whether they varied independently. The results indicated that the size of the MLD varied with the integrity of wave III of the ABR. When the ABR was abnormal to the extent of lacking wave III on one or both ears, there was no release from masking and the crossed acoustic reflex was abnormal, as well. The sensitivity of the MLD to retrocochlear disorder was comparable to that of ABR, and was greater than that provided by speech audiometry or acoustic reflexes.

Adult↗
PubMed1984

Reverse frequency-sweep audiometry in patients with retrocochlear and cochlear deafness.

The material consisted of 21 patients with surgically confirmed eighth-nerve tumour and 107 patients with cochlear deafness. 13 (62%) of the patients with eighth-nerve tumour showed separated forward-backward tracings in sweep-frequency audiometry. One of the 13 patients gave an initially normal result but after the test ear had been exposed to 80 dB HL white noise for 3 min, the curves separated. Only 2 (1.9%) of the 107 patients with cochlear deafness had separated curves. Tone decay test revealed a pathological result in 67% of the patients with eighth-nerve tumour and in 26% of the cases with cochlear hearing loss. There is no single pathognomonic test for the diagnosis of retrocochlear and cochlear deafness. Diagnosis must be based on a whole battery of several tests, and among these, reverse frequency-sweep audiometry seems to be a suitable additional adaptation test. If an abnormal result is found in forward-backward sweep-frequency audiometry, a retrocochlear lesion is very probable.

Audiometry↗
PubMed2000

Otoacoustic emissions in central auditory disorders.

Otoacoustic emissions are sounds produced by outer hair cells of cochlea. It is known that they may be useful in assessing hearing loss. The aim of our study was to evaluate their diagnostic capability in separating sensory from neural hearing impairment. Transiently evoked otoacoustic emissions (TOAE) and distortion-product emissions (DP) were measured in 14 patients with sensorineural hearing loss. The results showed DP to be present in 12 patients and in 8 of them TOAE were detected despite the mild to severe hearing loss, thus indicating the lesion should be retrocochlear. The recording of otoacoustic emissions appears to be a technique for precise etiological diagnosis of hearing impairment.

Adolescent↗
PubMed1985

Rollover measurements with Auditec NU-6 word lists.

Auditec cassette tape recordings of NU-6 word lists were used to obtain performance-intensity functions for phonetically balanced words (PI-PB) from 25 subjects with normal hearing, 19 subjects with presumed cochlear disorders, and 9 subjects with confirmed retrocochlear lesions. A rollover index greater than .35 differentiated retrocochlear hearing loss from cochlear hearing loss, although some retrocochlear subjects scored well below that level. Factors that may contribute to differences among PI-PB studies are discussed.

Adolescent↗
PubMedDate not supplied

Stapedial reflex decay in retrocochlear and cochlear lesions. Review of procedures and methods for conducting SRD tests.

The procedures for conducting and interpreting Stapedial Reflex Decay (SRD) are discussed. A modification of currently used procedures and interpretations in which testing is conducted at 750 and 1500 Hz as well as 500, 1000 and 2000 Hz is also discussed. Abnormal decay is defined as fatigue to half-life in less than 6.2 seconds. The SRD test patterns of 464 ears with cochlear lesions and 68 ears with retrocochlear lesions are presented and discussed. The findings are strongly supportive of SRD testing using the proposed procedures and interpretations.

Auditory Threshold↗
PubMed1994

Frequency selectivity in patients with acoustic neuroma.

Frequency selectivity was compared in subjects with hearing loss due to acoustic neuroma and cochlear pathology, and normal listeners. A particular interest was the role of probe tone parameters on the shape of the tuning curve. Psychophysical tuning curves (PTCs) were measured for each of two equal energy 2000-Hz probe tones (10 dB SL/300 msec and 17 dB SL/60 msec), using simultaneous 1/3-octave narrow-band noise maskers centered at 1, 1.25, 1.6, 2.5, 3.15, and 4 kHz. The results showed that the critical masker levels obtained for impaired listeners were significantly greater than those from normal subjects. The slope of the low-frequency limb of the PTC was steeper for normal compared to hearing-impaired listeners but there was no difference due to site of lesion. In all three groups, the critical masker levels obtained with the short probe were significantly greater than those for the long probe, negating the hypothesis that equal energy probes would yield the same outcomes. Tuning in listeners with hearing loss was highly correlated with audiometric threshold but not with tumor size, width of the internal auditory canal, or tumor location within the cerebellopontine angle. The main conclusion was that cochlear and retrocochlear hearing loss are similar with respect to their effect on frequency selectivity.

Acoustic Stimulation↗
PubMed1986

[Hearing disorders in Paget's disease].

The audiometric data of 41 patients with Paget's disease of the bone show that hearing loss exceeds the age-related presbycusis in patients with deformities of the temporal bone as demonstrated by X-ray (27%). The usual type of hearing loss is a sensorineural one. 80% of these patients showed hair cell damage, 32% of them a retrocochlear lesion, depending on the degree of deformity of the temporal bone. Conductive hearing loss of the otosclerosis type was found in only 20%. The Paget-related hearing loss can be regarded as a consequence of the deformation occurring both at the bone surrounding the cochlea and at the internal auditory canal.

Acoustic Impedance Tests↗
PubMed2000

Magnetic resonance imaging of the internal auditory canal.

Magnetic resonance imaging (MRI) is presently the study of choice for assessment of the internal auditory canal (IAC). MRI provides excellent assessment of the IAC and the bony changes occurring in the canal walls, and it provides excellent demonstration of the content of the canal. Pathological processes arising within the IAC are well visualized by various MR sequences. The possibility of demonstrating masses as small as 2 mm has propelled MRI into the leading role for diagnosis of vestibular schwannoma. Unfortunately, the high cost of MR has been a limiting factor in its use as a screening test for patients with sensorineural hearing loss (SNHL) of unknown origin. Auditory brain stem response has been widely used as a screening procedure, but this test fails to recognize small lesions and cannot be used whenever hearing loss is severe. In this article, we will discuss our approach to assessment of the IAC in patients with retrocochlear SNHL or vestibular symptoms of central origin, review the pathological processes involving the IAC walls or arising within the canal, emphasizing the appropriate MRI sequences used for diagnosis.

Ear Diseases↗
PubMed2003

Cochlear implantation in a patient with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes syndrome.

OBJECTIVE: The aim of this study was to investigate the usefulness of a Nucleus C124M cochlear implant in a patient with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome. MATERIAL AND METHODS: A 29-year-old woman with MELAS syndrome presented with sensorineural hearing loss and diabetes mellitus and underwent multichannel cochlear implantation. The follow-up period was 10 months. The case history, assessment of mitochondrial disease, indications for the cochlear implant and the benefits of cochlear implantation were evaluated. RESULTS: Nine months after the surgery the patient could use the telephone and was quite satisfied with the improvement in communication due to the cochlear implant. CONCLUSION: Cochlear implantation can be recommended for patients with MELAS syndrome if they have residual retrocochlear function. Single photon emission computerized tomography was found to be very useful for evaluating retrocochlear function.

Adult↗
PubMed1988

The immune system in hearing disorders.

Cellular and humoral immune reactions may play a role in the ethiopathogenesis of audiovestibular dysfunction. Immune-mediated inner ear disorders can be of cochlear and retrocochlear origin. Autoimmunity plays a certain role, but is certainly not obligatory. Anti-inflammatory treatment remains the mainstay of therapy. Such hearing disorders can further be looked upon as 'experiments of nature'.

Autoimmune Diseases↗
PubMed1999

Clinical relevance of medial efferent auditory pathways.

Evoked otoacoustic emissions have been shown to be suppressed by sounds applied in the contralateral ear and this effect can be largely explained by the involvement of medial olivocochlear efferent fibers. Thus, EOAE recording during contralateral stimulation provides a non-invasive means of investigating auditory efferent system functioning in humans. The question remains, however, as to whether this test provides a tool, which could be useful in a variety of clinical applications. This review describes current clinical applications for this test, showing that it may prove useful for improving identification of retrocochlear pathologies. Some new areas are also identified. Methodological topics are discussed and suggestions for maximizing the value of this test are proposed.

Adult↗
PubMedDate not supplied

Intratympanic gentamicin therapy for vertigo in nonserviceable ears.

PURPOSE: Intratympanic ototoxic agents have become a widely accepted means of managing vertigo in patients with Meniere's disease while preserving residual hearing. We investigated expanding the indications for intratympanic gentamicin to include control of vertigo in patients without serviceable hearing in the involved ear caused by a variety of end-organ pathologies. MATERIALS AND METHODS: We present a retrospective series of 6 patients suffering from vertigo caused by end-organ disease, in an ear without serviceable hearing. Two patients suffered from delayed endolymphatic hydrops, 3 from Meniere's disease, and 1 from poststapedectomy vertigo. These patients chose unilateral vestibular ablation with serial intratympanic gentamicin injection rather than labyrinthectomy for a variety of reasons. Conventional electronystagmography (ENG) testing and audiometry were completed on all patients. The ENG testing included bithermal calorics and rotational testing. All patients had a magnetic resonance image with gadolinium to exclude retrocochlear or central pathology. Rotational testing was repeated before each injection and at the conclusion of therapy to assess changes in the peripheral vestibular response. The patients' subjective response to therapy was followed. RESULTS: Follow-up has been 10 to 69 months with successful control of vertigo in all patients. CONCLUSIONS: Intratympanic gentamicin therapy offers a minimally invasive, ambulatory, low morbidity, cost-effective means of managing vertigo in patients with nonserviceable hearing.

Adult↗
PubMed1977

[The differential diagnosis of cochlear, retrocochlear and central hearing disorders, and the limitations of conventional audiometry (author's transl)].

A review is made of the difficulties of audiometric diagnosis resulting from inadequate anatomical, physiological and pathological knowledge of the auditory system and from discrepancies in audiometric technique. Even with a broad battery of tests there is in 20-40% of cases an inconsistent audiometric pattern, which differs from the expected and typical cochlear eighth nerve, brain stem and cortical responses. These are demonstrated in presbyacusis, Meniere's disease, acoustic tumours, brainstem disorders and temporal lobe disease.

Audiometry↗