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Results for “Retrocochlear Diseases”

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PubMed1992

Specificity of auditory brainstem response audiometry criteria in acoustic neuroma screening as a function of deviations of reference values in patients with cochlear hearing loss.

On the basis of 79 patients with cochlear hearing loss, the statistical distribution of two criteria commonly used in auditory brainstem response audiometry (ABR) was analyzed: the interaural V latency difference (ILD V) and the interaural difference of I-V interpeak interval (ID I-V). The distribution of both criteria was Gaussian. By evaluating their standard deviations the percentages of statistical false-positives were estimated. The estimated results were 24% false-positive findings using the decision criterion ILD V greater than 0.2 ms and 5.4% false-positive findings using ID I-V greater than 0.3 ms. This corresponds closely to the actual false-positive ABR rates obtained in this sample: 21.5% and 6.3%, respectively. In a separate series of 301 unselected cases with asymmetric sensorineural hearing loss, 29 ABRs were suspect for retrocochlear pathology. In 20 patients, ABRs were absent due to severe hearing loss. Retrocochlear pathology could be confirmed in only 2 cases (both from the group with ABR present). Thus, 47 ABRs (15.7% of 299) were false-positive.

Cochlear Diseases↗

PubMed1985

Combined electrophysiological and autoradiographic delimitation of retrocochlear dysfunction in a mouse mutant.

The hereditary retrocochlear dysfunction in the quivering (qv) mouse was investigated with autoradiography and single unit recordings. Whilst the cochlea appears to function normally, earlier studies had indicated some single unit dysfunction detectable at the level of the cochlear nucleus (CN) and abnormality of auditory evoked potentials recorded at the inferior colliculus (IC). The present study investigated the possibility of progressive deterioration of function at successive higher levels in the auditory system. The 2-deoxyglucose technique illustrated auditory activity in the CN of quivering mice similar to that seen in normally-hearing control animals. There was only a slight increment in metabolic activity detectable at the level of the IC. Electrophysiology demonstrated that this minimal IC activity was the result of abnormally raised thresholds associated with all single units recorded, rather than of activity in a few normally responding cells. There was no evidence from autoradiography for any enhanced auditorily evoked metabolic activity in either the superior olivary complex or the lateral lemniscus. This study suggests that the retrocochlear dysfunction in quivering mice is due to a specific abnormality at a low stage in the auditory pathway rather than being non-specific and cumulative over stages.

Animals↗

PubMed1977

Use of performance-intensity functions for diagnosis.

Performance-intensity (PI) functions for phonetically balanced (PB) word lists were obtained for a group of normal listeners (27 ears), and for two groups of patients with cochlear (89 ears) and retrocochlear disorders (eight ears). Listeners with normal hearing or cochlear disorders exhibited mild to moderate reductions in discrimination score as the speech level was raised above the PB maximum. In contrast, patients with retrocochlear disorders showed a pronounced rollover phenomenon, characterized by a rapid decline in performance as the speech level was raised above the maximum discrimination score.

Audiometry↗

PubMed1982

[Hearing disorders in industrial workers: clinical analysis of the cases observed in the audiological laboratory of the Lódź Institute of Occupational Medicine during the years 1976-1980].

The documentation of 697 cases with suspected, as suggested by regional health service units, occupational aetiology, was analysed. Within consultation those cases underwent complex audiological evaluation at the Laboratory of Audiology, using following examinations: pure tone threshold and suprathreshold audiometry, malingering tests, speech audiometry and electronystagmographic tests. The findings revealed that only 30% of subjects confirmed noise-induced hearing loss. 65.2% of those subjects exhibited cochlear localization, whereas in the remaining 34.8% the results of audiological tests showed retrocochlear impairment. The calculated mean hearing losses were characterized by symmetrical changes both in the right and left ear, as well as by directly proportional dependence on subjects' duration and exposure and age, men having more advanced hearing loss than women, despite identical mean parameters of age and exposure of both sexes. In 70% cases hearing losses were not regarded as occupational diseases, which resulted from: functional disturbances found in form of aggravation and simulation (15.3%), the presence of hearing loss lesser than the one specified by the certification rule (15.1%), post--inflammatory and adhesional changes in the middle ear (12.3%) and lack of significant exposure to noise (8.3%). It has been settled that the major causes of the diagnostic errors that we had detected were: deficient audiometric apparatus, erroneous technics of hearing measurements (among others--without masking), lack of the determination of hearing thresholds for bone conduction, drawing conclusions from single examinations, giving up simulating tests, improper evaluation of the data on occupational exposure. The considerations summing up the results of analysis include an optimum methodology of audiological studies, required standard conditions of audiometry and principles of differential diagnostics as indispensable elements of proper certification procedures in setting up the hearing impairments etiology in industrial workers.

Adult↗

PubMed1998

Field sensitivity of targeted neonatal hearing screening using the Nottingham ABR Screener.

OBJECTIVE: A population of children having bilateral moderate to profound hearing impairment was investigated to find out the number who passed (false negatives) and who failed (true positives) a screening test based on the auditory brain stem response (ABR). DESIGN: This study of the ABR is a parallel report to Lutman, Davis, Fortnum, and Wood (1997), where the transient evoked otoacoustic emission was examined on a similar but not identical population of at-risk neonates. Hearing screening was undertaken in at-risk neonates (targeted screening) at seven hospitals in the UK using the Nottingham ABR Screener. During the period from January 1988 to December 1993, a total of 6983 neonates had been tested. Assessment of audiological records from the participating centers ascertained that 201 children born between January 1988 and December 1993 had hearing threshold levels in both ears of 50 dB or more, averaged over the speech frequencies 0.5, 1, 2, and 4 kHz. Of these, 51 had completed the ABR screening test. Examination of the ABR records, which included both machine and visual scoring, indicated whether they had passed or failed the screening test. RESULTS: Forty-six of the 51 hearing impaired babies failed the neonatal ABR screen either on one or both ears (five false negatives), and 42 failed the test on both ears (nine false negatives). This resulted in field sensitivities of 90% and 82%, respectively. Two cases of suspected progressive hearing loss have been included in the numbers of false negative results. The percentage of babies passing the screen on both ears and subsequently having normal hearing (specificity) is typically 93%. CONCLUSIONS: Neonatal hearing screening in an at-risk population using a highly automated ABR test is a viable and effective tool for identification of hearing impairment. Although the field sensitivity of the test is high, it is unable to identify all babies with a criterion level of hearing loss. There are a number of possible explanations as to the origin of false negative results: configuration of the pure-tone audiogram, a progressive hearing loss, acquired sensorineural or conductive loss, retrocochlear deafness, or an incorrect interpretation of the screening test. Passing a neonatal screening test, therefore, does not exclude the possibility of subsequent hearing impairment and highlights the need for further surveillance.

Auditory Threshold↗

PubMed1979

Histopathology of 30 non-operated acoustic schwannomas.

Thirty of 1720 temporal bones from the Wittmaack's Collection contain nonoperated acoustic neuromas, 22 of them large tumors. Histologically, each tumor has to be considered as an individual. Most of the tumors show a mixture of Antoni type A and B. Tumor vascularization is pronounced in half the cases. Vessels of the internal acoustic meatus are found in all cases. Protein contents of the perilymphatic spaces is medium to pronounced in 23 of 30 cases in comparison to the small protein contents of the healthy side. Ganglion geniculi is invaded in 11 cases (9 von Recklinghausen's disease), Ganglion Scarpae in 26 cases (9 von Recklinghausen's disease), and Ganglion spirale in 9 cases (7 von Recklinghausen's disease). Cochlear and vestibular nerve fibers within the internal auditory meatus were affected by the tumor in 28 of 30 cases, the facial nerve only in 11 cases, among them 9 cases of von Recklinghausen's disease. Twenty-six of 30 schwannomas have a portion within the cribriform area of the cochlea fundus, which explains the limitation to radical tumor surgery without damage of the cochlear nerve. These histological findings explain the site of damage of hearing to expand between the cochlea to the auditory brain stem nuclei, and support the audiological experience that a correlation of "acoustic neuroma" and "retrocochlear lesion" is often not correct.

Adolescent↗

PubMedDate not supplied

Sudden deafness: a retrospective evaluation of dextran therapy.

A retrospective evaluation was performed in 112 patients treated during a 10-year period as inpatients with the diagnosis idiopathic sudden hearing loss. Excluding all patients in whom later other diagnosis were established, like Ménière's disease, collagenoses, mumps etc., 101 patients remained. 80 of them had been treated consistently according to a protocol as having idiopathic sudden hearing loss. These patients had all 5-day treatment with low molecular weight dextran and nicotinic acid and vitamin B during 1 month. 68% did completely recover or were markedly improved (> 30 dB), another 19% were fairly improved (10-30 dB). Statistical analysis showed that all retrocochlear signs or nystagmus made the prognosis less favorable. To wake up with the hearing loss was more favorable than a daytime debut. A mid-frequency loss had always a good prognosis. Because no untreated controls were included in the study, it was not possible to evaluate the specific effect of the treatment. The results obtained from this study have changed the treatment policy in our clinic.

Adult↗

PubMedDate not supplied

The auditory brain stem response I-V amplitude ratio in normal, cochlear, and retrocochlear ears.

The auditory brain stem response I-V amplitude ratio was measured for 25 normal, 25 cochlear, and 25 retrocochlear ears. Results indicated that amplitude ratios of less than 1.00 seldom occurred in the normal or cochlear ears. However, 44% of the retrocochlear ears revealed an amplitude ratio of less than 1.00. Details of this analysis and discussion of the clinical implications of these results are presented.

Adolescent↗

PubMed1983

Lateralization, impedance, auditory brain stem response and synthetic sentence audiometry in brain stem disorders.

Applied individually, the conventional audiometric tests are unsatisfactory in the diagnosis of retrocochlear disorders. An accurate identification of a retrocochlear lesion, however, is not always possible using a single test, and only an appropriate test battery provides the basis for correct prediction of a retrocochlear lesion. Because of this observation, lateralization tests, impedance studies, auditory brain stem responses and speech audiometry with synthetic sentences have been applied to patients affected with retrocochlear disorders (acute nucleoreticular vestibular syndrome, multiple sclerosis and focal lesions). Analysis of the results has demonstrated the value of the tests employed, but the various tests were not strongly correlated and are therefore complementary.

Acoustic Impedance Tests↗

PubMed2006

Audiovestibular manifestations of sarcoidosis: a review of the literature.

OBJECTIVE/HYPOTHESIS: Sarcoidosis is a multisystem disease of unknown etiology. Audiovestibular involvement is rare but has been reported in a number of cases. The objective of this review is to provide an evidence-based summary of the audiovestibular manifestations of sarcoidosis by collating the findings of these case reports. STUDY DESIGN: Retrospective review of 48 published case reports and 2 cases recently encountered in audiovestibular medicine clinics. METHODS: Case reports were identified using a key word search of Medline database. Clinical details, audiovestibular test results, and radiological findings were recorded for each patient when available. RESULTS: When type of hearing loss (HL) was recorded, all losses were sensorineural, with only two patients found to have an additional conductive loss. The severity of HL ranged from mild to profound. Median thresholds were moderately raised. The HL was bilateral in 75% of patients and asymmetrical in 75% of these cases. Seventy percent of HLs demonstrated some recovery. Many of the patients with recovery were treated with corticosteroids, but no statistically significant association between treatment and HL outcome was observed. Symptoms of vestibular impairment were common. Vestibular testing was performed in 24 cases and was abnormal in 23. Eighty-one percent of patients had additional features of neurosarcoidosis. Six patients had radiological evidence of a retrocochlear lesion. CONCLUSION: In taking into account the evidence from the clinical features, audiovestibular testing, radiological investigations, and postmortem findings, it is concluded that the audiovestibular manifestations of sarcoidosis are likely to be primarily a result of vestibulocochlear nerve neuropathy.

Adolescent↗

PubMed1979

[On the audiology of multiple sclerosis (author's transl)].

The paper reports about a female patient who developed an uncommon, unilateral, reversible hearing defect while suffering from multiple sclerosis. The tone audiogram showed a break in the hearing threshold curve down to values no longer measurable, progressing from the high to the low frequencies. There were all symptoms of a retrocochlear hearing defect. After about a month a restitutio ad integrum was achieved. The paper continues with discussions on the seat of the focus of demyelinisation with particular reference to the central part of the N. acusticus, whose myelin sheaths are formed by glia cells.

Adult↗

PubMed1982

Sudden hearing loss in the contralateral ear in postoperative acoustic tumor: three case reports.

Careful presurgical otologic assessment of the contralateral ear in acoustic tumor patients is essential, not only to establish baseline data but more importantly to resolve the intense patient anxiety that arises almost immediately when the diagnosis is presented. Any subsequent reduction in hearing acuity in the contralateral ear after the tumor ear has been deafened, poses serious psychological, socio-economic and medical problems. Three detailed case reports of sudden hearing loss in the contralateral ear of postoperative acoustic tumor patients are presented. The lesion sites include: the middle ear, cochlear, and retrocochlear. In each case, hearing returned to its previous or near-previous levels. Allergic factors were implicated in two cases.

Adult↗

PubMed2006

[Facial palsy as the first syndrome of multiple sclerosis in 16 years old girl].

INTRODUCTION: Multiple sclerosis (MS) is demyelinating disease characterized by scattered neurologic deficits the central nervous system. The large number of scattered lessions produce many clinical symptoms. Facial palsy is rarely ascribed to multiple sclerosis as first syndrome. MATERIAL AND METHODS: 16-years old girl with sequence of features: 1. facial palsy, 2. transitional sudden hearing loss 3. transitory vertigo is presented. In audiologic examination pure tone audiogram, impedance audiometry, ABR and ENG were done. Air and bone thresholds were normal, stapedial reflex was absent and ABR suggested retrocochlear involvement in affected ear. RESULTS: In this case after MRI examination multiple sclerosis was diagnosed. CONCLUSION: ENT specialists should considered MS like a reason of facial palsy.

Adolescent↗

PubMed1983

Prognosis and pathogenesis of sudden deafness with scaling out.

Recovery of hearing in sudden deafness is said to be such that the severer the hearing loss and the longer the period from the disease onset to the start of treatment, the poorer the recovery of hearing. However, the prognosis of the so-called scaling out cases has not yet been fully studied. We have therefore studied 96 patients with severest sudden deafness who consulted us within 14 days after disease onset and who had scaling out in all the frequencies. We evaluated the extent to which recovery of hearing could be expected and whether any characteristics are seen in pathogenesis, etc. The results showed that there was no patient who experienced complete recovery, even when treatment was started as early as within 4 days. Recovery of hearing was better in low frequencies than in high frequencies. The site of the lesion was the inner ear in many cases, and some had retrocochlear lesions. Concerning pathogenesis, we think the difference in degree of lesion should be considered important, rather than there may be a substantial difference, compared to that of slight deafness.

Adolescent↗

PubMed1999

[A case of superficial siderosis of the central nervous system--findings of the neuro-otological tests and evoked potentials].

We report a 57-year-old woman with superficial siderosis of the central nervous system. On physical examination, sensorineural hearing impairment, cerebellar ataxia, pyramidal tract signs, dysarthria, and neurogenic bladder were seen. Brain and spinal cord MRI (T2 and proton weighted images) revealed cerebellar atrophy and marginal hypointensity of the Sylvian fissure and brain stem, cerebellum and spinal cord. We diagnosed this patient as superficial siderosis because of the clinical course and specific findings on MRI. We consider this case idiopathic superficial siderosis because the source of the bleeding was unknown. Neuro-otological tests and BAEP disclosed retrocochlear deafness. Her central motor conduction time on MEP was delayed. We discussed the pathogenic mechanism of these conditions, and we concluded that we must take notice of myelinopathy in superficial siderosis and that MEP was useful for detecting them.

Audiometry, Evoked Response↗

PubMedDate not supplied

Hyperintensity of the middle cerebellar peduncles on fluid-attenuated inversion recovery imaging: variation with age and implications for the diagnosis of multiple system atrophy.

BACKGROUND AND PURPOSE: T2 hyperintensity of the middle cerebellar peduncle (MCP) is described in a number of diseases, including multiple system atrophy (MSA). We hypothesize that mild MCP hyperintensity on fluid-attenuated inversion recovery (FLAIR) imaging can be a normal finding. To our knowledge, a detailed study of the prevalence of this finding in various age groups with the FLAIR sequence has not been described. METHODS: One hundred twenty-two patients underwent an axial FLAIR examination of the brain as part of either a hearing loss or tinnitus work-up (ie, to exclude an acoustic neuroma or a retrocochlear cause). Subjects aged 15-78 years were included to reflect an even spread through the decades and were divided into 6 age groups. A radiologist and an MR imaging fellow graded the examinations subjectively, blinded to age: 0 for normal or 1 for the presence of MCP hyperintensity if the increased signal intensity was greater than that of adjacent pons and cerebellar white matter. Spearman rank correlation test of MCP hyperintensity with age and analysis of variance (ANOVA) were performed. RESULTS: Of 122 patients, we identified 17 with MCP FLAIR hyperintensity. None of these patients had a clinical condition that could cause MCP hyperintensity. MCP hyperintensity did not show a statistically significant correlation with age (r = 0.05, P = .62). Patients were divided into 6 age groups, and ANOVA showed no statistically significant difference in the incidence of MCP hyperintensity between different age groups (P = .95). However, results were highly reproducible with excellent interobserver correlation (r = 0.97, P < .001). CONCLUSIONS: Mild MCP FLAIR hyperintensity can occur normally, and this finding shows no relationship with age.

Adolescent↗

PubMedDate not supplied

Transtympanic and surface recordings in the diagnosis of retrocochlear disorders.

A series of patients presenting with subsequently surgically confirmed central tumour involving the auditory pathways were investigated using both transtympanic electrocochleography (TT ECochG) and surface recordings of brainstem evoked responses (BER). While ECochG allows a detailed study of peripheral function, BER allow the investigation of neural conduction up to the level of the inferior colliculus. Valuable information can be obtained from: (1) comparison of the amplitudes of the sensory and neural components of the ECochG; (2) comparison of ECochG, BER and auditory thresholds; (3) time interval measurements between the auditory nerve response (N1 on the ECochG) and the inferior colliculus (wave P4-5 on BER); (4) contralateral comparisons. Similar measurements performed in pure cochlear pathologies, mainly in Meniere's disease, yielded very significant differences.

Audiometry↗

PubMed2004

Temporal resolution and speech recognition ability of patients with retrocochlear auditory dysfunction.

OBJECTIVE: To study the effect of temporal resolution measured by gap detection tasks on the speech recognition ability of patients with retrocochlear auditory dysfunction. MATERIAL AND METHODS: The gap detection thresholds (GDTs) for dichotic stimuli were measured for 23 patients with retrocochlear auditory dysfunction confirmed by abnormal auditory brainstem responses the relationship between GDTs and maximum speech recognition scores (max. SRSs) in quiet was examined. In gap detection testing, narrow-band noises of the five center frequencies of 0.25, 0.5, 1.0, 2.0, 4.0 kHz were used as leading and trailing markers. Each of these two marker sounds was presented to the opposite ear at 20 dBSL with various gap durations between them. RESULTS: Abnormal GDTs were observed at one or more test frequencies in 17 of 23 patients. In 12 patients, abnormal GDTs were found at four or five test frequencies. These 12 patients included 4 patients with poor max. SRS less than 30%. However, no tendency was found for max. SRSs to be poorer as abnormal GDTs were observed for more test frequencies. CONCLUSION: Temporal resolution measured by gap detection for dichotic stimuli was frequently reduced in patients with retrocochlear auditory dysfunction, and this reduction appeared to spread over a wide frequency range when speech recognition had markedly deteriorated. However, it also appeared that reduced temporal resolution for dichotic stimuli might not necessarily imply poor speech recognition in quiet.

Acoustic Stimulation↗