Audiological Evaluation of Vestibular Schwannoma Patients with Normal Hearing

2019 ◽  
Vol 24 (3) ◽  
pp. 117-126 ◽  
Author(s):  
Nervana Salem ◽  
Ahmed Galal ◽  
Valentina Mastronardi ◽  
Mohamed Talaat ◽  
Ossama Sobhy ◽  
...  

Objective: To evaluate the audiological aspects of vestibular schwannoma (VS) patients with normal hearing. Study Design: Retrospective study. Setting: Quaternary referral center for skull base pathologies. Patients: The records on 4,000 patients who had been diagnosed with VS between 1986 and December 2017 were retrospectively reviewed. The patients included in the study were the ones who complied with the strict audiological normality criteria, as follows: a pure tone hearing threshold (at the 6-octave-spaced frequencies from 250 to 8,000 Hz) ≤25 dBHL; a word recognition score >90%; and interaural differences ≤10 dB at each frequency. Interventions: Auditory brainstem response (ABR) testing and radiological imaging. Main Outcome Measures: The incidence of normal objective hearing among VS patients, and the diagnostic utility of the ABR and the effect of tumor size and site on the response. Results: The incidence of normal hearing among VS patients was 4.2%. Tinnitus and vertigo were the most common symptoms across tumor grades; 5.6% of the tumors were large and giant tumors. The ABR yielded a sensitivity of 73.6%, with a false negative rate of 26.3% using a cutoff point of 0.2 ms for interaural latency differences. Conclusions: The diagnosis of VS should not be based on audiometric thresholds alone. Alarming signs of VS should be clear to the physician in order not to miss or delay the diagnosis of the disease. The ABR is useful in the diagnosis of VS, but normal results do not exclude the occurrence of the disease in patients with normal hearing.

2000 ◽  
Vol 122 (2) ◽  
pp. 157-162 ◽  
Author(s):  
Daniel D. Magdziarz ◽  
Richard J. Wiet ◽  
Elizabeth A. Dinces ◽  
Lois C. Adamiec

Although several studies have previously reported on patients presenting with “normal” audiologic parameters in acoustic neuroma, the present study is, to our knowledge, the first to exclusively examine in detail cases involving exceptionally stringent objective audiometric features. Of 369 patients with acoustic neuroma who were operated on between April 1980 and April 1997 by our group, 10 had strictly normal hearing, defined as follows: (1) pure-tone average < 20 dB; (2) speech discrimination score > 90%; and (3) interaural differences < 10 dB at every hertz level. A high level of audiologic functioning was found to significantly lower the sensitivity of auditory brainstem response in the detection of acoustic neuroma. Magnetic resonance imaging was the only preoperative test exhibiting 100% sensitivity in this setting. Thus, a high level of clinical suspicion appears warranted in any case involving unexplained unilateral audio-vestibular symptoms—including those instances in which strictly normal hearing parameters exist and are associated with negative auditory brainstem response findings.


2021 ◽  
pp. 1-8
Author(s):  
Jae-Hun Lee ◽  
Sang Hee Ji ◽  
Jae Yun Jung ◽  
Min Young Lee ◽  
Chi-Kyou Lee

Introduction: Diabetes mellitus (DM) is a systemic disease characterized by hyperglycemia and several pathological changes. DM-related hearing dysfunctions are associated with histological changes. Here, we explore hearing function and synaptic changes in the inner hair cells (IHCs) of rats with streptozotocin (STZ)-induced diabetes. Methods: STZ was injected to trigger diabetes. Rats with DM were exposed to narrow-band noise (105 dB SPL) for 2 h, and hearing function was analyzed 1, 3, 7, and 14 days later. Both the hearing threshold and the peak 1 amplitude of the tone auditory brainstem response were assessed. After the last functional test, animals were sacrificed for histological evaluation. Results: We found no changes in the baseline hearing threshold; however, the peak 1 amplitude at the low frequency (4 kHz) was significantly higher in both DM groups than in the control groups. The hearing threshold had not fully recovered at 14 days after diabetic rats were exposed to noise. The peak 1 amplitude at the higher frequencies (16 and 32 kHz) was significantly larger in both DM groups than in the control groups. The histological analysis revealed that the long-term DM group had significantly more synapses in the 16 kHz region than the other groups. Conclusions: We found that high blood glucose levels increased peak 1 amplitudes without changing the hearing threshold. Diabetic rats were less resilient in threshold changes and were less vulnerable to peak 1 amplitude and synaptic damage than control animals.


2019 ◽  
Vol 2 (1) ◽  
pp. 17-21
Author(s):  
Adil Munir ◽  
Nazia Mumtaz ◽  
Ghulam Saqulain ◽  
Munir Ahmad

Objective: Hearing loss (HL) with a local prevalence of 5.7%, is the commonest childhood disability, requiring Early Hearing Detection and Intervention (EHDI) programs to reduce the disability burden. Knowing the degree, type and configuration of HL is prerequisite for appropriate amplification, with Automated Auditory Brainstem Responses (ABR) being commonly used for this purpose, however Auditory Steady State Response (ASSR) has been recently introduced in the region. This study was conducted to compare ABR to ASSR, as an early diagnostic tool in children under five years of age. Methodology: This cross-sectional comparative study was performed at the Auditory Verbal Institute of Audiology and Speech (AVIAS) clinics in Rawalpindi and Islamabad, from December 2016 to September 2017. It included thirty-two cases (n=32) who visited AVIAS clinics for hearing assessment and conformed to the investigative protocol using non probability convenient sampling technique, and subjected to both ABR and ASSR for comparative purposes. Correlations were calculated between the thresholds obtained by ABR and ASSR. Results: N=32 children (64 ears) with male female ratio of 2.2:1 and mean age of 33.50±17.73 months were tested with ABR and ASSR for hearing thresholds and correlation coefficient between 2KHz, 4KHz ASSR and average of both with ABR was calculated to be 0.92 and 0.90 and 0.94 respectively. Conclusion: ASSR provides additional frequency specific hearing threshold estimation compared to C-ABR, essentially required for proper setting of amplification devices. 


2019 ◽  
Vol 80 (01) ◽  
pp. e1-e9 ◽  
Author(s):  
Anand Kasbekar ◽  
Yu Chuen Tam ◽  
Robert Carlyon ◽  
John Deeks ◽  
Neil Donnelly ◽  
...  

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.


2010 ◽  
Vol 124 (9) ◽  
pp. 950-956 ◽  
Author(s):  
A A Emara ◽  
T A Gabr

AbstractReview:Auditory neuropathy is a disorder characterised by preservation of outer hair cell function, with normal otoacoustic emissions and/or cochlear microphonics, but an absent or distorted auditory brainstem response.Purpose:This study aimed to objectively assess hearing thresholds in patients with auditory neuropathy, using the auditory steady state response.Materials and methods:Thirteen patients with auditory neuropathy and 15 normal hearing subjects were examined. Audiological evaluation included basic audiological tests, otoacoustic emissions, auditory brainstem response and auditory steady state response.Results:In the auditory neuropathy patients, the auditory brainstem response was absent in 11 patients, while the auditory steady state response was absent in only three.Conclusion:The auditory steady state response may serve as a valuable objective measure for assessing the hearing threshold across different frequencies in patients with auditory neuropathy. We recommend that auditory steady state response be used to complete the evaluation of patients with auditory neuropathy.


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