scholarly journals Unilateral Auditory Neuropathy Caused by Cochlear Nerve Deficiency

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Cheng Liu ◽  
Xingkuan Bu ◽  
Feiyun Wu ◽  
Guangqian Xing
Keyword(s):  
Otoacoustic Emissions ◽  
Internal Auditory Canal ◽  
Auditory Brainstem ◽  
Auditory Neuropathy ◽  
Cochlear Nerve ◽  
Auditory Brainstem Responses ◽  
Maximum Output ◽  
Neural Responses ◽  
Ear Effusion ◽  
Cochlear Nerve Deficiency

Objective. To explore possible corelationship between the cochlear nerve deficiency (CND) and unilateral auditory neuropathy (AN).Methods. From a database of 85 patients with unilateral profound sensorineural hearing loss, eight who presented with evoked otoacoustic emissions (EOAEs) or cochlear microphonic (CM) in the affected ear were diagnosed with unilateral AN. Audiological and radiological records in eight patients with unilateral AN were retrospectively reviewed.Results. Eight cases were diagnosed as having unilateral AN caused by CND. Seven had type “A” tympanogram with normal EOAE in both ears. The other patient had unilateral type “B” tympanogram and absent OAE but CM recorded, consistent with middle ear effusion in the affected ear. For all the ears involved in the study, auditory brainstem responses (ABRs) were either absent or responded to the maximum output and the neural responses from the cochlea were not revealed when viewed by means of the oblique sagittal MRI on the internal auditory canal.Conclusion. Cochlear nerve deficiency can be seen by electrophysiological evidence and may be a significant cause of unilateral AN. Inclined sagittal MRI of the internal auditory canal is recommended for the diagnosis of this disorder.

scholarly journals Auditory neuropathy in a patient exposed to xylene: case report

2008 ◽  
Vol 123 (4) ◽  
pp. 462-465 ◽  
Author(s):  
T H J Draper ◽  
D-E Bamiou
Keyword(s):  
Case Report ◽  
Otoacoustic Emissions ◽  
Auditory Pathway ◽  
Auditory Brainstem ◽  
Auditory Neuropathy ◽  
Auditory Brainstem Responses ◽  
Test Results ◽  
Solvent Exposure ◽  
Complex Sounds ◽  
Acoustic Reflexes

AbstractObjective:To report the case of an adult patient who developed auditory complaints following xylene exposure, and to review the literature on the effects of solvent exposure on hearing.Case report:The patient presented with a gradual deterioration in his ability to hear in difficult acoustic environments and also to hear complex sounds such as music, over a 40-year period. His symptoms began following exposure to the solvent xylene, and in the absence of any other risk factor. Our audiological investigations revealed normal otoacoustic emissions with absent auditory brainstem responses and absent acoustic reflexes in both ears, consistent with a diagnosis of bilateral auditory neuropathy. Central test results were also abnormal, indicating possible involvement of the central auditory pathway.Conclusions:To our knowledge, this is the first report of retrocochlear hearing loss following xylene exposure. The test results may provide some insight into the effect of xylene as an isolated agent on the human auditory pathway.

Newborn Hearing Screening with Combined Otoacoustic Emissions and Auditory Brainstem Responses

2004 ◽  
Vol 15 (06) ◽  
pp. 414-425 ◽  
Author(s):  
James W. Hall ◽  
Steven D. Smith ◽  
Gerald R. Popelka
Keyword(s):  
Auditory Brainstem Response ◽  
Otoacoustic Emissions ◽  
Auditory Brainstem ◽  
Hearing Screening ◽  
Auditory Neuropathy ◽  
Diagnostic Evaluation ◽  
Auditory Brainstem Responses ◽  
Conductive Loss ◽  
Brainstem Response ◽  
Screening Measures

Accurate assessment of neonatal hearing screening performance is impossible without knowledge of the true status of hearing, a prohibitive requirement that necessitates a complete diagnostic evaluation on all babies screened. The purpose of this study was to circumvent this limitation by integrating two types of screening measures obtained near simultaneously on every baby. Peripheral auditory function was defined by otoacoustic emission results. A complete diagnostic evaluation was performed on every baby who received a "Refer" outcome for auditory brainstem response screening. The integrated results for auditory brainstem response screening in an unselected group of 300 newborns estimated sensitivity at 100%, specificity at 99.7%, overall referral rate at 2.0%, and a positive predictive value of 83.3%. Conductive loss associated with amniotic fluid in the middle ear can persist several weeks after birth; conductive loss can produce a "Refer" outcome for auditory brainstem response screening; and auditory neuropathy can be detected with screening measures. Prevalence results were consistent with the published literature. The implications of this study are that otoacoustic emissions and auditory brainstem measures provide much more information than either alone and that both are needed for a comprehensive hearing screening program.

Auditory neuropathy in a patient with mitochondrial myopathy and multiple mtDNA deletions

2006 ◽  
Vol 120 (10) ◽  
pp. 888-891 ◽  
Author(s):  
F Forli ◽  
M Mancuso ◽  
A Santoro ◽  
M T Dotti ◽  
G Siciliano ◽  
...  
Keyword(s):  
Hair Cells ◽  
Otoacoustic Emissions ◽  
Mitochondrial Myopathy ◽  
Spiral Ganglion ◽  
Mitochondrial Diseases ◽  
Auditory Brainstem ◽  
Auditory Neuropathy ◽  
Auditory Brainstem Responses ◽  
Common Symptom ◽  
First Case

Auditory neuropathy (AN) is a hearing disorder characterized by the absence or severe distortion of the auditory brainstem responses, in the presence of preserved otoacoustic emissions. This peculiar combination suggests the presence of a defect impinging upon the functional complex formed by inner hair cells, the primary afferents (spiral ganglion neurones) and the first order synapses between hair cells and the cochlear nerve. Typically, AN patients show a severe speech perception impairment, which appears reduced out of proportion to pure tone threshold, but the clinical presentation of AN is quite complex.Hearing loss is a common symptom associated with mitochondrial diseases; however, AN has only rarely been reported in these disorders.Here we report a rare association, the first case observed in Italy, in a patient with autosomal recessive mitochondrial myopathy and mitochondrial DNA multiple deletions, and a hearing deficit with the audiological and electrophysiological features of AN.

Audiological findings in glomus tumours

1997 ◽  
Vol 111 (3) ◽  
pp. 218-222 ◽  
Author(s):  
William W. Qiu ◽  
Shengguang S. Yin ◽  
Fred J. Stucker ◽  
Mardjohan Hardjasudarma
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Auditory System ◽  
Middle Ear ◽  
Otoacoustic Emissions ◽  
Cerebellopontine Angle ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

AbstractGlomus tumours involving the middle ear and the cerebellopontine angle are reported with emphasis on audiological findings. Magnetic resonance imaging (MRI), angiographic and pathological results are presented. Audiological tests, including impedance audiometry, evoked otoacoustic emissions and auditory brainstem responses, are valuable in evaluation of the effect of glomus tumours on the auditory system as well as their pathological extent.

Μελέτη των παραγόντων υψηλού κινδύνου για εμφάνιση βαρηκοΐας σε νεογνά της μονάδας εντατικής νοσηλείας

2016 ◽  
Author(s):  
Εμμανουήλ Νησωτάκης
Keyword(s):  
Otoacoustic Emissions ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Transiently Evoked Otoacoustic Emissions

Εισαγωγή Η συγγενής βαρηκοΐα είναι ίσως η πιο συχνή αισθητηριακή βλάβη της νεογνικής ηλικίας. Τα νοσηλευόμενα στη ΜΕΝΝ νεογνά θεωρείται ότι διατρέχουν μεγαλύτερο κίνδυνο για εμφάνιση είτε νευροαισθητήριας βαρηκοΐας είτε ακουστικής νευροπάθειας. Η σοβαρότητα της απώλειας ακοής κατά τη διάρκεια της πρώιμης κρίσιμης περιόδου ανάπτυξης του λόγου καθορίζει την απόκτηση επαρκούς γλωσσικής ικανότητας γι’ αυτό και είναι σημαντική η έγκαιρη διάγνωση και αντιμετώπιση κάθε υποκείμενης ακουστικής διαταραχής.Στη μελέτη αυτή εστιάζουμε στην παρουσία ακοολογικών παραγόντων κινδύνου και προσπαθούμε να διευκρινίσουμε την συσχέτισή τους με την εμφάνιση συγγενούς βαρηκοΐας, συμπεριλαμβανομένης και της ακουστικής νευροπάθειας, στον πληθυσμό των νεογνών της ΜΕΝΝ του νοσοκομείου μας.Ασθενείς και ΜέθοδοςΣτην παρούσα προοπτική μελέτη κοόρτης μελετήθηκαν 453 νεογνά τα οποία εισήχθησαν στη ΜΕΝΝ για περισσότερο από 24 ώρες μεταξύ 2012 και 2016 και εμφάνιζαν έναν ή περισσότερους παράγοντες κινδύνου. Όλα τα νεογνά υποβλήθηκαν σε ακοολογικό έλεγχο με χρήση αυτοματοποιημένων προκλητών δυναμικών του εγκεφαλικού στελέχους (automated Auditory Brainstem Responses – aABRs) σε συνδυασμό με παροδικά προκλητές ωτοακουστικές εκπομπές (Transiently Evoked OtoAcoustic Emissions – TEOAEs) τουλάχιστον 48 ώρες μετά τη γέννησή τους. Τα νεογνά που απέτυχαν στην αρχική εξέταση επανεξετάζονταν πριν τον πρώτο μήνα ζωής κι επί αποτυχίας παραπέμπονταν στο ιατρείο παιδικής βαρηκοΐας για πλήρη ακοολογικό έλεγχο. ΑποτελέσματαΑπό τον συνολικό αριθμό των 453 νεογνών 71 απέτυχαν στον αρχικό ακοολογικό έλεγχο. Μόνο 49 προσήλθαν για επανεξέταση και τελικά 8 νεογνά (1.8%) απέτυχαν τόσο στα a-ABRs όσο και στις TEOAEs και διαγνώσθηκαν με πιθανή νευροαισθητήρια βαρηκοΐα, ενώ σε επίσης 8 νεογνά (1.8%) οι TEOAEs εκλύθηκαν φυσιολογικά αλλά απέτυχαν στα a-ABRs οπότε διαγνώσθηκαν με πιθανή ακουστική νευροπάθεια. Από τους 13 ανεξάρτητους παράγοντες κινδύνου που ελέγχθηκαν η ωτοτοξικότητα των χορηγούμενων φαρμάκων, η μηχανική υποστήριξη της αναπνοής, το χαμηλό βάρος γέννησης και η υπερχολερυθριναιμία ήταν οι πιο συχνά εμφανιζόμενοι. Η πλειοψηφία των νεογνών (48%) εμφάνιζε ταυτόχρονα δύο παράγοντες κινδύνου. Το χαμηλό βάρος γέννησης βρέθηκε να συσχετίζεται με την εμφάνιση πιθανής νευροαισθητήριας βαρηκοΐας (p=0.002), ενώ οι κρανιοπροσωπικές ανωμαλίες και οι λοιμώξεις της ομάδας TORCH παρουσίασαν στατιστικά σημαντική συμμετοχή (p=0.03 και p=0.05 αντίστοιχα) στην ανάπτυξη πιθανής απώλειας ακοής συμπεριλαμβανομένης και της ακουστικής νευροπάθειας.ΣυμπεράσματαΤα προκλητά δυναμικά του εγκεφαλικού στελέχους (ABRs) και οι ωτοακουστικές εκπομπές (OAEs) αποτελούν τους θεμέλιους λίθους του καθολικού νεογνικού ελέγχου ακοής στη ΜΕΝΝ καθώς σημαντικός αριθμός παιδιών μπορεί να πάσχει από ακουστική νευροπάθεια. Η συνεχής επανεξέταση των παραγόντων κινδύνου και της συμβολής τους στην εμφάνιση βαρηκοΐας κρίνεται απαραίτητη καθώς αυτοί μεταβάλλονται. Απαιτείται ένα αποδοτικό σύστημα γραμματειακής υποστήριξης προκειμένου να ελαττωθεί το ποσοστό των νεογνών που δεν προσέρχονται για επανεξέταση.

The Nervus Intermedius in Children with Cochlear Nerve Deficiency Submitted to Auditory Brainstem Implantation

2014 ◽  
Vol 151 (1_suppl) ◽  
pp. P93-P93
Author(s):  
Giacomo Colletti ◽  
Marco Mandala ◽  
Liliana Colletti ◽  
Vittorio Colletti
Keyword(s):  
Auditory Brainstem ◽  
Cochlear Nerve ◽  
Cochlear Nerve Deficiency ◽  
Nervus Intermedius

scholarly journals Intraoperative Monitoring of the Cochlear Nerve during Neurofibromatosis Type-2 Vestibular Schwannoma Surgery and Description of a “Test Intracochlear Electrode”

2019 ◽  
Vol 80 (01) ◽  
pp. e1-e9 ◽  
Author(s):  
Anand Kasbekar ◽  
Yu Chuen Tam ◽  
Robert Carlyon ◽  
John Deeks ◽  
Neil Donnelly ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Vestibular Schwannoma ◽  
Intraoperative Monitoring ◽  
Neurofibromatosis Type ◽  
Auditory Brainstem ◽  
Cochlear Nerve ◽  
Auditory Brainstem Responses ◽  
Tertiary Referral Center ◽  
Objective Evidence ◽  
Brainstem Response

Objectives A decision on whether to insert a cochlear implant can be made in neurofibromatosis 2 (NF2) if there is objective evidence of cochlear nerve (CN) function post vestibular schwannoma (VS) excision. We aimed to develop intraoperative CN monitoring to help in this decision. Design We describe the intraoperative monitoring of a patient with NF2 and our stimulating and recording set up. A novel test electrode is used to stimulate the CN electrically. Setting This study was set at a tertiary referral center for skull base pathology. Main outcome measure Preserved auditory brainstem responses leading to cochlear implantation. Results Electrical auditory brainstem response (EABR) waveforms will be displayed from different stages of the operation. A cochlear implant was inserted at the same sitting based on the EABR. Conclusion Electrically evoked CN monitoring can provide objective evidence of CN function after VS excision and aid in the decision-making process of hearing rehabilitation in patients who will be rendered deaf.

scholarly journals Selective Removal of Lateral Olivocochlear Efferents Increases Vulnerability to Acute Acoustic Injury

2007 ◽  
Vol 97 (2) ◽  
pp. 1775-1785 ◽  
Author(s):  
Keith N. Darrow ◽  
Stéphane F. Maison ◽  
M. Charles Liberman
Keyword(s):  
Brain Stem ◽  
Otoacoustic Emissions ◽  
Outer Hair Cells ◽  
Cochlear Nerve ◽  
Sensory Cells ◽  
Neural Responses ◽  
Distortion Product ◽  
Auditory Brain Stem ◽  
Pharmacological Studies

Cochlear sensory cells and neurons receive efferent feedback from the olivocochlear (OC) system. The myelinated medial component of the OC system and its effects on outer hair cells (OHCs) have been implicated in protection from acoustic injury. The unmyelinated lateral (L)OC fibers target ipsilateral cochlear nerve dendrites and pharmacological studies suggest the LOC's dopaminergic component may protect these dendrites from excitotoxic effects of acoustic overexposure. Here, we explore LOC function in vivo by selective stereotaxic destruction of LOC cell bodies in mouse. Lesion success in removing the LOC, and sparing the medial (M)OC, was assessed by histological analysis of brain stem sections and cochlear whole mounts. Auditory brain stem responses (ABRs), a neural-based metric, and distortion product otoacoustic emissions (DPOAEs), an OHC-based metric, were measured in control and surgical mice. In cases where the LOC was at least partially destroyed, there were increases in suprathreshold neural responses that were frequency- and level-independent and not attributable to OHC-based effects. These interaural response asymmetries were not found in controls or in cases where the lesion missed the LOC. In LOC-lesion cases, after exposure to a traumatic stimulus, temporary threshold shifts were greater in the ipsilateral ear, but only when measured in the neural response; OHC-based measurements were always bilaterally symmetric, suggesting OHC vulnerability was unaffected. Interaural asymmetries in threshold shift were not found in either unlesioned controls or in cases that missed the LOC. These findings suggest that the LOC modulates cochlear nerve excitability and protects the cochlea from neural damage in acute acoustic injury.

Differences in Responses from the Cochleae and Central Nervous Systems of Females with Low versus High Acceptable Noise Levels

2006 ◽  
Vol 17 (09) ◽  
pp. 667-676 ◽  
Author(s):  
Ashley W. Harkrider ◽  
Joanna W. Tampas
Keyword(s):  
Auditory System ◽  
Background Noise ◽  
Otoacoustic Emissions ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Intersubject Variability ◽  
Hearing Sensitivity ◽  
Central Regions ◽  
Central Nervous Systems ◽  
Medial Olivocochlear

Studies of acceptable noise level (ANL) consistently report large intersubject variability in acceptance of background noise while listening to speech. This variability is not related to age, gender, hearing sensitivity, type of background noise, speech perception in noise performance, or efferent activity of the medial olivocochlear pathway. An exploratory study was conducted to determine if differences in aggregate responses from the peripheral and central auditory system can account for intersubject variability in ANL. Click-evoked otoacoustic emissions (CEOAEs), binaural auditory brainstem responses (ABRs), and middle latency responses (MLRs) were measured in females with normal hearing with low (n = 6) versus high (n = 7) ANLs. Results of this preliminary study indicate no differences between the groups for CEOAEs or waves I or III of the ABR. Differences between the two groups emerge for the amplitudes of wave V of the ABR and for the Na-Pa component of the MLR, suggesting that physiological variations arising from more central regions of the auditory system may mediate background noise acceptance.

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