Audiometry Brainstem Research Articles

Limitations of Modern Imaging Techniques in Detection of Parotid Carcinoma

Most peripheral facial paralysis is of unknown cause and labeled as idiopathic or Bell's palsy. Only for about 20% of peripheral facial paralysis cases can a specific cause be identified.1 The common diagnostic workup of peripheral facial nerve palsies includes routine investigations, such as a neurologic examination and a complete neuro-otologic screening (pure tone audiometry, caloric vestibular and stapedial reflex testing, Schirmer tear test, gustometry, serologic examination to rule out viral or bacterial infections, and brainstem audiometry in cases of equivocal findings),2 as well as electromyography of the facial muscles.

Potencial evocado auditivo de tronco encefálico como auxílio diagnóstico de morte encefálica

brainstem auditory evoked potentials in brain death. to verify the agreement between the response in the auditory brainstem audiometry and the clinical outcome, analyzing the pattern of responses to electric stimulation. a cross-sectional study performed in 30 patients with Glasgow coma score of 3, submitted to the auditory brainstem audiometry and followed up until their clinical outcome: recovery or death. The test was considered positive to brain death when there was no registry of waves or when there was only the registry of wave I; and negative when there were two or more waves, independently of their latencies. Among the patients who presented positive results for brain death (86.66%), all died; the only patient who recovered presented a negative result, indicating a specificity of 100%. Internal consistency of data was also observed, with an intraclass correlation coefficient of 0.562, obtained using the Cronbach s test; and a significant agreement between the test and the clinical outcome using the Kappa s test, with a confidence interval of 95% (K = 0.545; p = 0.015). in the present study, the brainstem auditory evoked potential demonstrated to be highly specific in death prediction of patients in Glasgow coma score of 3, and was useful in assisting the diagnosis of brain death.

Frühkindliche Hörstörung - eine interdisziplinäre Aufgabe

The increasing specialization in medicine, technology, therapy and educational sciences for the handicapped gave us more knowledge and understanding for patients with hearing disorders but also may cause more problems and confuse the parents of these children. Early diagnosis of hearing deficits is of utmost importance. The high plasticity of the brain during the first year of life offers the best possibilities for therapy and rehabilitation at this early stage. The automatic measuring of otoacoustic emissions and automatic brainstem audiometry are two methods with high sensitivity and specifity for screening of neonates. Screening only makes sense if followed by tracking, confirmation diagnosis, therapy and rehabilitation. These steps are discussed in the paper. Diagnosis, therapy and early rehabilitation needs multidisciplinary cooperation of doctors, audiologists, therapists and teachers for the handicapped to optimise the work with children with communication disorders and their parents. The situation has improved in Germany; however there is not a general screening and tracking in the country. The children do not yet get the support needed for the development of their communicative abilities.

Monitoring residual hearing during cochlear implantation by intra-operative brainstem audiometry

Objective Aim of this paper is to prove the applicability of intra-operative recordings of auditory brainstem responses during cochlear implantation. Methods The clinical practicability of intra-operative monitoring of hearing thresholds (Notched-Noise BERA, Amplitude Modulation Following Response [AMFR]) is presented in the respective case. The recordings were performed prior to the cochlear implantation and were compared with those obtained during and after cochlear implantation. Results It is demonstrated that the patient's cochlear function can be monitored; residual hearing is available after surgery. Conclusion The possibility of monitoring of hearing thresholds may add some security to the concept of electric-acoustic stimulation.

Melatonin is a Useful Alternative to Sedation in Children Undergoing Brainstem Audiometry with an Age Dependent Success Rate - A Field Report of 250 Investigations

Though brainstem audiometry is one of the most important investigations in pediatric audiology, it often necessitates sedation or general anaesthetics, especially in newborns and infants. Melatonin, inducing natural sleep without the risks of sedation, has been successfully used to induce sleep prior to EEG investigations. 250 children (142 male, 108 female) with suspected hearing loss underwent ABR (auditory brainstem responses) tests in melatonin-induced sleep. Click-induced and notched-noise ABR tests were performed. Click tests were successfully performed in 216 of 249 children or 86.7% (123 male, 93 female), notched-noise tests in 115 of 155 children or 74.2%. Failure rates showed an age dependence increasing from 4% in children <1 year to 25%>3 years, but no gender difference. In conclusion, melatonin-induced sleep is a good alternative to sedation, especially in children younger than 3 years. This method is widely accepted by parents and permits earlier diagnosis of hearing impairment in a routine clinical setting. The number of children undergoing general anaesthesia for ABR investigation was reduced from over 60 per year in 2000-2002 to 12 in 2005, which means >80% less general anaesthesia.

The ototoxic interaction of styrene and noise

The interaction between noise and inhaled styrene on the structure and function of the auditory organ of the male Wistar rat was studied. The animals were exposed either to 600 ppm, 300 ppm or 100 ppm styrene (12 h/day, 5 days/week, for 4 weeks) alone or in combination with a simultaneous 100–105 dB industrial noise stimulant. Auditory sensitivity was tested by auditory brainstem audiometry at 1.0, 2.0, 4.0 and 8.0 kHz frequencies. Inner ear changes were studied by light microscopy. Exposure to 600 ppm styrene alone caused a 3 dB hearing loss only at the highest test frequency (8 kHz). Quantitative morphological analysis of cochlear hair cells (cytocochleograms) showed a severe outer hair cell (OHC) loss particularly in the third OHC row of the upper basal and lower middle coil. Exposure to noise alone caused only a mild hearing loss (2–9 dB), and only an occasional loss of OHCs (<1% missing). Exposure to the combination of noise and 600 ppm styrene caused a moderate flat hearing loss of 23–27 dB. The cytocochleograms showed a more severe damage of the OHCs than after exposure to 600 ppm styrene alone. The inner hair cells were found to be destroyed in some animals in the upper basal turn only after the combination exposure. Only in combination with noise exposure, the lower styrene concentrations (100 and 300 ppm) induced a hearing loss which was equivalent to that seen after exposure to noise alone. We conclude that: (1) There is an ototoxic interaction between styrene and noise. (2) Synergism is manifested only if styrene is applied in concentrations above the critical level (between 300 and 600 ppm in this study).

Distortion evoked otoacoustic emission using GSI 70 analyzer for neonatal screening

Objective: Following the recommendation of the United State National Institute of Health Consensus Conference in 1993, otoacoustic emissions (OAE) are now used internationally for hearing screening. The GSI 70 OAE screener provides the means for carrying out OAE recordings within a short period of time and includes an automatic evaluation of results. The aim of this study was to determine the reliability of recordings in comparison with available standards in brainstem audiometry. Method: OAE recorded in 29 hearing-impaired suspected infants and young children (aged 1 months–7 years old) in order to compare the result of the GSI 70 screener with the result of ABR. This study was conducted in the outpatient clinic of the Tokyo University Hospital. Result: Our study showed that the GSI 70 screener has higher false negative rate compared with ABR results ( P<0.01). Consequently, an OAE measuring method, is also provides high sensitivity and easy to use. However, there was no trend toward increased refer rates with increased age. Conclusion: Our findings show that the GSI 70 screener can meet the demands of systematic hearing screening in infants and young children, although there is a tendency to miss cochlear impaired cases.

Functional and morphological effects of styrene on the auditory system of the rat.

The effect of inhaled styrene on the structure and function of the auditory organ of the male Wistar rat was studied. The animals were exposed either to 600, 300 or 100 ppm styrene (12 h/day, 5 days/week, for 4 weeks). Auditory sensitivity was tested prior to and after the exposure by auditory brain stem audiometry (ABR) at frequencies of 1.0, 2.0, 4.0 and 8.0 kHz. Inner ear morphological changes were studied by light- and electron-microscopy. Exposure to 600 ppm styrene caused a 3 dB hearing loss only at the highest test frequency (8 kHz). Quantitative morphological analysis of cochlear hair cells (cytocochleograms) showed that 600 ppm styrene caused a severe outer hair cell (OHC) loss particularly in the third OHC row of the upper basal and lower middle coil. The inner hair cells were usually intact. Exposure to lower styrene concentrations (100 and 300 ppm) caused no unequivocal functional deficit or hair cell damage. We conclude that there appears to be a concentration threshold for styrene ototoxicity in rats (between 300 and 600 ppm).

Evaluation of the use of a questionnaire to detect hearing loss in babies in China

A questionnaire was used to screen hearing of 1020 babies 6–8 months in China. All babies failing the questionnaire and 10% of those who passed were tested using auditory brainstem audiometry (ABR). Babies with unilateral or bilateral hearing thresholds 30 dBnHL or more were investigated to determine the cause of the hearing impairment. Sixty-seven failing the questionnaire were tested and 23 were confirmed to have a hearing loss, 20 with bilateral hearing impairment. The causes were: 13 otitis media with effusion (OME), one hypoxia, one genetic and five unknown. One child with an OME related hearing loss passed the screen. The sensitivity of the questionnaire was estimated to be 70%, specificity 96%.

Fast spin echo magnetic resonance imaging: clinical application in screening for acoustic neuroma.

The advent of magnetic resonance imaging has greatly improved our ability to diagnose acoustic tumors, but it is a relatively expensive imaging modality. In the present climate of medical cost restraints, methods that reduce costs but maintain quality are extremely desirable. We report a new magnetic resonance imaging technique that uses fast spin echo without gadolinium. It provides ultrahigh-resolution images of the internal auditory canal and cerebellopontine angle. The sensitivity of this technique for the detection of acoustic tumors is equivalent to conventional gadolinium-enhanced magnetic resonance imaging, but the global cost is comparable with that of brain stem audiometry. In our practice fast spin echo magnetic resonance imaging has replaced brain stem audiometry as a screening modality to evaluate most acoustic tumor suspects. Also, the intricate detail of the internal auditory canal anatomy provided by this technique is useful in planning surgical removal of acoustic tumors.

Fast spin echo magnetic resonance imaging: Clinical application in screening for acoustic neuroma

The advent of magnetic resonance imaging has greatly improved our ability to diagnose acoustic tumors, but it is a relatively expensive imaging modality. In the present climate of medical cost restraints, methods that reduce costs but maintain quality are extremely desirable. We report a new magnetic resonance imaging technique that uses fast spin echo without gadolinium. It provides ultrahigh-resolution images of the internal auditory canal and cerebellopontine angle. The sensitivity of this technique for the detection of acoustic tumors is equivalent to conventional gadolinium-enhanced magnetic resonance imaging, but the global cost is comparable with that of brain stem audiometry. In our practice fast spin echo magnetic resonance imaging has replaced brain stem audiometry as a screening modality to evaluate most acoustic tumor suspects. Also, the intricate detail of the internal auditory canal anatomy provided by this technique is useful in planning surgical removal of acoustic tumors. (Otolaryngol Head Neck Surg 1996;114:71-6.)

Evaluation of TEOAE and DPOAE measurements for the assessment of auditory thresholds in sensorineural hearing loss.

Transiently evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) can be quantified concerning their amplitude and frequency. They are known to be diminished or absent in sensorineural hearing loss. It is therefore of interest how TEOAE and DPOAE correlate with the auditory threshold and whether the auditory threshold can be predicted by these variables. In a cross sectional study of 61 patients (102 ears) with sensorineural hearing loss, auditory threshold, tympanometry, stapedius reflexes, TEOAE and DPOAE were measured. Correlation coefficients of the hearing loss (0.5-6 kHz) and the amplitude of the distortion product 2f1-f2 (0.46 4 kHz) respectively TEOAE amplitude (1-4 kHz) were computed. TEOAE showed lower correlation coefficients and less frequency specificity than DPOAE. In order to increase the correlations with the auditory threshold we fitted a multivariate linear regression model with TEOAE and DPOAE simultaneously as predictors for the auditory threshold gaining 95% prediction intervals of 19-39 dB depending on the frequency investigated. By restricting the hearing loss to a maximum of 70 dB HL the 95% prediction interval of the auditory threshold could be decreased to 18-26 dB. Further improvements can be expected if the high inter- and intraindividual variability of TEOAE and particularly DPOAE measurements can be reduced. The results allow us to use TEOAE and DPOAE in addition to click-evoked brainstem audiometry in order to provide more frequency specific information about the hearing loss in newborns, which is of the utmost importance for an ideal fitting of hearing aids.

Diagnostik intrameatal gelegener Akustikusneurinome - Die Rolle akustisch evozierter Hirnstammpotentiale und anderer otoneurologischer Untersuchungsverfahren*

Today intracanalicular acoustic neuromas are diagnosed very early by magnetic resonance imaging (MRI). The purpose of this study was to test the capability of brainstem evoked response audiometry (BERA) for detecting these small tumors. Seventeen of 91 consecutive cases with acoustic neuromas treated at our department suffered from purely intracanalicular tumors. For these 17 patients we reviewed their medical history, clinical otoneurologic examination, audiometry, auditory evoked brainstem audiometry, electronystagmography, and MRI studies. In 13 of 17 patients (76.5%) auditory evoked brainstem audiometry was indicative of a suspected retrocochlear lesion, whereas in 4 cases BERA did not indicate such a lesion. The symptoms of these patients are described in detail. The role of auditory evoked brainstem audiometry and other otoneurologic test methods for detection of intracanalicular acoustic neuromas will be discussed.

Clinical Electrocochleography and Brainstem Audiometry

Educational objectives: To order the proper audiometric studies for neurotologic diagnosis and to understand the basics of electrocochleography and brain stem audiometry for neurotologic diagnosis.

Database for vertigo

An interactive database has been developed to assist the diagnostic procedure for vertigo and to store the data. The database offers a possibility to split and reunite the collected information when needed. It contains detailed information about a patient's history, symptoms, and findings in otoneurologic, audiologic, and imaging tests. The symptoms are classified into sets of questions on vertigo (including postural instability), hearing loss and tinnitus, and provoking factors. Confounding disorders are screened. The otoneurologic tests involve saccades, smooth pursuit, posturography, and a caloric test. In addition, findings from specific antibody tests, clinical neurotologic tests, magnetic resonance imaging, brain stem audiometry, and electrocochleography are included. The input information can be applied to workups for vertigo in an expert system called ONE. The database assists its user in that the input of information is easy. If not only can be used for diagnostic purposes but is also beneficial for research, and in combination with the expert system, it provides a tutorial guide for medical students.

Database for vertigo

An interactive database has been developed to assist the diagnostic procedure for vertigo and to store the data. The database offers a possibility to split and reunite the collected information when needed. It contains detailed information about a patient's history, symptoms, and findings in otoneurologic, audiologic, and imaging tests. The symptoms are classified into sets of questions on vertigo (including postural instability), hearing loss and tinnitus, and provoking factors. Confounding disorders are screened. The otoneurologic tests involve saccades, smooth pursuit, posturography, and a caloric test. In addition, findings from specific antibody tests, clinical neurotologic tests, magnetic resonance imaging, brain stem audiometry, and electrocochleography are included. The input information can be applied to workups for vertigo in an expert system called ONE. The database assists its user in that the input of information is easy. It not only can be used for diagnostic purposes but is also beneficial for research, and in combination with the expert system, it provides a tutorial guide for medical students. (OTOLARYNGOL HEAD NECK SURG 1995;112:383-90.)

Influence of myelography on the developmental curve of auditory brainstem responses and hearing loss.

Auditory threshold and auditory brainstem response studies were conducted in 50 patients before and after myelography. Analysis of amplitudes and latencies of auditory brainstem measurements demonstrated significant disorders of function of the cochlea and auditory pathway. The Jewett I wave showed a prolongation of latency from 1.92 to 1.98 ms using an average of all repetition rates. The Jewett III wave showed prolongation from 4.01 to 4.14 ms and the Jewett V wave prolongation from 6.01 to 6.16 ms. At the same time average amplitudes for Jewett III and V decreased. In most of the patients these disorders of function were found to be subclinical. However, 12 patients had changes ranging from a subjectively slight hearing loss to an audiometrically defined acute hearing loss. The reasons for these disorders could not be clarified. An open cochlear aqueduct through which perilymph can enter the subarachnoid space, leading to secondary endolymphatic hydrops, was suggested as the cause for the losses found. Changes in brainstem audiometry were also explained by changes in osmolality of inner ear fluids, leading to the development of an endolymphatic hydrops.

Computer assisted data collection in vestibular disorders.

We have developed an interactive database for vertigo than can be used to assist in the diagnostic procedure and to store the data in a form of a database. The database offers the possibility to split and reunite the collected information in a desired way. The database contains detailed information about patient history, symptoms and findings in neurotological, audiological and imaging tests. The symptoms are classified into three sets of questions: vertigo (including postural instability), hearing loss and tinnitus, and provoking factors. Confounding disorders are screened. The neurotological tests involve saccades, smooth pursuit, posturography and caloric test. In addition, findings in specified antibody testing, clinical neurotological tests. MRI, brain stem audiometry and electrocochleography are included. The input information can be applied in an expert system ONE for vertigo work-up. The database is user-friendly. Besides diagnostic purposes the database is excellent for research purposes, and combined with the expert system it works as a tutorial guide for medical students.

Drug points: Hearing loss and tinnitus with carbimazole

We present a previously undocumented complication of carbimazole treatment occurring in a 28 year old woman with Graves' disease. Four months after starting carbimazole (40 mg, dropping to 20 mg daily after six weeks) she developed left sided otalgia and presented with high pitched tinnitus. An audiogram showed a unilateral 25 dB high frequency loss which could not be accounted for by family or occupational history. Brain stem audiometry showed no evidence of an acoustic neuroma; …

A study on the otoscopical and audiological findings in patients with Down's syndrome in Greece

One hundred and twenty patients (children) with Down's Syndrome were examined by the Audiological Dept. at ‘Aghia Sophia’ Children's Hospital during the period 1988–1990. Of these 73 (60.8%) were boys and 47 (37.2%) were girls. Their ages varied from 7–18 years of age with an average age of 14.8 years. Physical examination included otoscopy, tympanometry, and in some cases auditory brainstem audiometry. It is worth noting that a high percentage of these patients were unable to cooperate in this study, therefore making it obligatory to utilize objective measures for hearing evaluation.