Clinical Utility of the Standardized Word Recognition Score.

OBJECTIVES: An unexpectedly low word recognition (WR) score may be taken as evidence of increased risk for retrocochlear tumor. We sought to develop evidence for or against using a standardized WR (sWR) score in detecting retrocochlear tumors. The sWR is a z score expressing the difference between an observed WR score and a Speech Intelligibility Index-based predicted WR score. We retrospectively compared the sensitivity and specificity of pure-tone asymmetry-based logistic regression models that incorporated either the sWR or the raw WR scores in detecting tumor cases. Two pure-tone asymmetry calculations were used: the 4-frequency pure-tone asymmetry (AAO) calculation of the American Academy of Otolaryngology-Head and Neck Surgery and a 6-frequency pure-tone asymmetry (6-FPTA) calculation previously optimized to detect retrocochlear tumors. We hypothesized that a regression model incorporating the 6-FPTA calculation and the sWR would more accurately detect retrocochlear tumors. DESIGN: Retrospective data from all patients seen in the audiology clinic at Mayo Clinic in Florida in 2016 were reviewed. Cases with retrocochlear tumors were compared with a reference group with noise- or age-related hearing loss or idiopathic sensorineural hearing loss. Two pure-tone-based logistic regression models were created (6-FPTA and AAO). Into these base models, WR variables (WR, sWR, WR asymmetry [WRΔ], and sWR asymmetry [sWRΔ]) were added. Tumor detection performance for each regression model was compared twice: first, using all qualifying cases (61 tumor cases; 2332 reference group cases), and second, using a data set filtered to exclude hearing asymmetries greater than would be expected from noise-related or age-related hearing loss (25 tumor cases; 2208 reference group cases). The area under the curve and the DeLong test for significant receiver operating curve differences were used as outcome measures. RESULTS: The 6-FPTA model significantly outperformed the AAO model-with or without the addition of WR or WRΔ variables. Including sWR into the AAO base regression model significantly improved disease detection performance. Including sWR into the 6-FPTA model significantly improved disease detection performance when large hearing asymmetries were excluded. In the data set that included large pure-tone asymmetries, area under the curve values for the 6-FPTA + sWR and AAO + sWR models were not significantly better than the base 6-FPTA model. CONCLUSIONS: The results favor the superiority of the sWR computational method in identifying reduced WR scores in retrocochlear cases. The utility would be greatest where undetected tumor cases are embedded in a population heavily representing age- or noise-related hearing loss. The results also demonstrate the superiority of the 6-FPTA model in identifying tumor cases. The 2 computational methods may be combined (ie, the 6-FPTA + sWR model) into an automated tool for detecting retrocochlear disease in audiology and community otolaryngology clinics. The 4-frequency AAO-based regression model was the weakest detection method considered. Including raw WR scores into the model did not improve performance, whereas including sWR into the model did improve tumor detection performance. This further supports the contribution of the sWR computational method for recognizing low WR scores in retrocochlear disease cases.

Cochlear Mechanisms and Otoacoustic Emission Test Performance.

OBJECTIVES: This study aims to determine the impact of controlling cochlear-source mechanism on the accuracy with which auditory status is identified using otoacoustic emissions (OAEs) in two groups of subjects with normal hearing (NH) and subjects with mild to moderate hearing loss. DESIGN: Data were collected from 212 subjects with NH and with mild to moderate hearing loss who fell into two categories based on a distortion product OAE (DPOAE) screening protocol: the uncertain-identification group (where errors were likely) and the certain-identification group (where errors were unlikely). DPOAE fine-structure patterns were recorded at intervals surrounding f2 = 1, 2 and 4 kHz (f2/f1 ratio = 1.22), with L2 = 35, 45, and 55 dB SPL (L1/L2 ratio = 10 dB). The discrete cosine transform was used to smooth fine structure, limiting the source contribution to the distortion source only. Reflection-source OAEs were also recorded using amplitude-modulated stimulus frequency OAEs (AM-SFOAE). Area under the relative operating characteristic (AROC) curve was used to quantify test accuracy when the source contribution was controlled versus the condition where both sources contribute. Additionally, failure rate, fixed at 5% for NH ears, as a function of behavioral-threshold category was evaluated. RESULTS: When data for the entire subject group were examined, reducing the reflection-source contribution to the DPOAE did not result in better test performance than the best control condition at any frequency tested. When the subjects with NH were restricted to those with confirmed fine structure, AROC analyses indicated that reducing the reflection-source contribution resulted in several small increases in the accuracy (2%-5%) with which auditory status was identified relative to the best control condition. This improvement was observed for the lowest stimulus levels (i.e., L2 = 35 or 45 dB SPL). In this subset of subjects, distortion-source DPOAEs resulted in more accurate identification of mild hearing loss for a fixed false-positive rate of 5% in NH ears at lower L2's, conditions with poor accuracy in the larger group of subjects. The impact of controlling the source contribution on the identification of moderate losses was less clear in the reduced subject group, with some conditions where the distortion-source DPOAE was more accurate than the control condition and other conditions where there was no change. There was no evidence that reflection-source AM-SFOAEs more accurately identified ears with hearing loss when compared to any of the DPOAE conditions in either the large or reduced group of subjects. CONCLUSION: While improvements in test accuracy were observed for some subjects and some conditions (e.g., mild hearing losses and low stimulus levels in the reduced subset of subjects), these results suggest that restricting cochlear source contribution by "smoothing" DPOAE fine structure is not expected to improve DPOAE test accuracy in a general population of subjects. Likewise, recording reflection-source OAEs using the AM-SFOAE technique would not be expected to more accurately identify hearing status compared to mixed- or single-source DPOAEs.

Auditory function in normal-hearing, noise-exposed human ears.

OBJECTIVES: To determine whether suprathreshold measures of auditory function, such as distortion-product otoacoustic emissions (DPOAEs) and auditory brainstem responses (ABRs), are correlated with noise exposure history in normal-hearing human ears. Recent data from animal studies have revealed significant deafferentation of auditory nerve fibers after full recovery from temporary noise-induced hearing loss. Furthermore, these data report smaller ABR wave I amplitudes in noise-exposed animal ears when compared with non-noise-exposed control animals or prenoise exposure amplitudes in the same animal. It is unknown whether a similar phenomenon exists in the normal-hearing, noise-exposed human ear. DESIGN: Thirty normal-hearing human subjects with a range of noise exposure backgrounds (NEBs) participated in this study. NEB was quantified by the use of a noise exposure questionnaire that extensively queried loud sound exposure during the previous 12 months. DPOAEs were collected at three f2s (1, 2, and 4 kHz) over a range of L2s. DPOAE stimulus level began at 80 dB forward-pressure level and decreased in 10 dB steps. Two-channel ABRs were collected in response to click stimuli and 4 kHz tone bursts; one channel used an ipsilateral mastoid electrode and the other an ipsilateral tympanic membrane electrode. ABR stimulus level began at 90 dB nHL and was decreased in 10 dB steps. Amplitudes of waves I and V of the ABR were analyzed. RESULTS: A statistically significant relationship between ABR wave I amplitude and NEB was found for clicked-evoked ABRs recorded at a stimulus level of 90 dB nHL using a mastoid recording electrode. For this condition, ABR wave I amplitudes decreased as a function of NEB. Similar systematic trends were present for ABRs collected in response to clicks and 4 kHz tone bursts at additional suprathreshold stimulation levels (≥70 dB nHL). The relationship weakened and disappeared with decreases in stimulation level (≤60 dB nHL). Similar patterns were present for ABRs collected using a tympanic membrane electrode. However, these relationships were not statistically significant and were weaker and more variable than those collected using a mastoid electrode. In contrast to the findings for ABR wave I, wave V amplitude was not significantly related to NEB. Furthermore, there was no evidence of a systematic relationship between suprathreshold DPOAEs and NEB. CONCLUSIONS: A systematic trend of smaller ABR wave I amplitudes was found in normal-hearing human ears with greater amounts of voluntary NEB in response to suprathreshold clicks and 4 kHz tone bursts. These findings are consistent with the data from previous work completed in animals, where the reduction in suprathreshold responses was a result of deafferentation of high-threshold/low-spontaneous rate auditory nerve fibers. These data suggest that a similar mechanism might be operating in human ears after exposure to high sound levels. However, evidence of this damage is only apparent when examining suprathreshold wave I amplitude of the ABR. In contrast, suprathreshold DPOAE level was not significantly related to NEB. This was expected, given noise-induced auditory damage findings in animal ears did not extend to the outer hair cells, the generator for the DPOAE response.

Hyperviscosity Syndrome Induced Bilateral Visual and Auditory Impairment in Therapy Resistant Waldenström Macroglobulinemia with MYD88 and CXCR4 Mutations.

Hyperviscosity syndrome (HVS) is an emergent complication of Waldenström macroglobulinemia (WM) characterized by visual, neurologic, and rarely auditory impairment. We report a 69-year-old female with MYD88 and CXCR4-mutant WM who developed HVS resulting in bilateral blindness and deafness associated with neurologic manifestations including confusion, severe generalized weakness, and imbalance. Ophthalmologic evaluation revealed bilateral central retinal vein occlusion (CRVO), diffuse retinal hemorrhages, macular edema, and serous macular detachments (SMD). Magnetic resonance imaging of the brain showed bleeding in the inner ears. Management was challenging as her WM was resistant to systemic therapies including bendamustine + rituximab (BR) and rituximab + bortezomib + dexamethasone (RVD). Bruton's tyrosine kinase inhibitors could not be used initially due to ongoing lower gastrointestinal bleeding. She required five total sessions of plasma exchange and was finally initiated on zanubrutinib, achieving a partial response. She also received intravitreal bevacizumab with rapid resolution of the retinal hemorrhages but with little improvement of the SMD. She had partial restoration of her hearing in the right ear and only slight improvement in her bilateral visual deficits. The management of HVS in frail, elderly patients with therapy-resistant WM can be challenging. In these cases, plasma exchange is required until an effective systemic therapy can be safely instituted. Genomic profiling is important in the management of WM as it can predict treatment resistance and guide therapeutic decisions.

Sensorineural Hearing Loss and Wernicke Encephalopathy: A Case Report and Literature Review.

Sensorineural hearing loss (SNHL) is seldom associated with Wernicke encephalopathy (WE) or thiamine deficiency. While thiamine deficiency and repletion are often considered prior to dextrose infusions in patients with chronic alcohol abuse to prevent WE, they are often overlooked in non-alcoholic patients who are also at risk for malnutrition. In this paper we describe a case of a non-alcoholic 28-year-old female status post-sleeve gastrectomy who developed SNHL in the setting of thiamine deficiency and WE, with ongoing hearing impairment requiring hearing aids despite thiamine repletion.

Safety of audiology direct access for medicare patients complaining of impaired hearing.

BACKGROUND: Allowing Medicare beneficiaries to self-refer to audiologists for evaluation of hearing loss has been advocated as a cost-effective service delivery model. Resistance to audiology direct access is based, in part, on the concern that audiologists might miss significant otologic conditions. PURPOSE: To evaluate the relative safety of audiology direct access by comparing the treatment plans of audiologists and otolaryngologists in a large group of Medicare-eligible patients seeking hearing evaluation. RESEARCH DESIGN: Retrospective chart review study comparing assessment and treatment plans developed by audiologists and otolaryngologists. STUDY SAMPLE: 1550 records comprising all Medicare eligible patients referred to the Audiology Section of the Mayo Clinic Florida in 2007 with a primary complaint of hearing impairment. DATA COLLECTION AND ANALYSIS: Assessment and treatment plans were compiled from the electronic medical record and placed in a secured database. Records of patients seen jointly by audiology and otolaryngology practitioners (Group 1: 352 cases) were reviewed by four blinded reviewers, two otolaryngologists and two audiologists, who judged whether the audiologist treatment plan, if followed, would have missed conditions identified and addressed in the otolaryngologist's treatment plan. Records of patients seen by audiology but not otolaryngology (Group 2: 1198 cases) were evaluated by a neurotologist who judged whether the patient should have seen an otolaryngologist based on the audiologist's documentation and test results. Additionally, the audiologist and reviewing neurotologist judgments about hearing asymmetry were compared to two mathematical measures of hearing asymmetry (Charing Cross and AAO-HNS [American Academy of Otolaryngology-Head and Neck Surgery] calculations). RESULTS: In the analysis of Group 1 records, the jury of four judges found no audiology discrepant treatment plans in over 95% of cases. In no case where a judge identified a discrepancy in treatment plans did the audiologist plan risk missing conditions associated with significant mortality or morbidity that were subsequently identified by the otolaryngologist. In the analysis of Group 2 records, the neurotologist judged that audiology services alone were all that was required in 78% of cases. An additional 9% of cases were referred for subsequent medical evaluation. The majority of remaining patients had hearing asymmetries. Some were evaluated by otolaryngology for hearing asymmetry in the past with no interval changes, and others were consistent with noise exposure history. In 0.33% of cases, unexplained hearing asymmetry was potentially missed by the audiologist. Audiologists and the neurotologist demonstrated comparable accuracy in identifying Charing Cross and AAO-HNS pure-tone asymmetries. CONCLUSIONS: Of study patients evaluated for hearing problems in the one-year period of this study, the majority (95%) ultimately required audiological services, and in most of these cases, audiological services were the only hearing health-care services that were needed. Audiologist treatment plans did not differ substantially from otolaryngologist plans for the same condition; there was no convincing evidence that audiologists missed significant symptoms of otologic disease; and there was strong evidence that audiologists referred to otolaryngology when appropriate. These findings are consistent with the premise that audiology direct access would not pose a safety risk to Medicare beneficiaries complaining of hearing impairment.

Noise Exposure Questionnaire: A Tool for Quantifying Annual Noise Exposure.

BACKGROUND: Exposure to both occupational and nonoccupational noise is recognized as a risk factor for noise-induced hearing loss (NIHL). Although audiologists routinely inquire regarding history of noise exposure, there are limited tools available for quantifying this history or for identifying those individuals who are at highest risk for NIHL. Identifying those at highest risk would allow hearing conservation activities to be focused on those individuals. PURPOSE: To develop a detailed, task-based questionnaire for quantifying an individual's annual noise exposure (ANE) arising from both occupational and nonoccupational sources (aim 1) and to develop a short screening tool that could be used to identify individuals at high risk of NIHL (aim 2). RESEARCH DESIGN: Review of relevant literature for questionnaire development followed by a cross-sectional descriptive and correlational investigation of the newly developed questionnaire and screening tool. STUDY SAMPLE: One hundred fourteen college freshmen completed the detailed questionnaire for estimating ANE (aim 1) and answered the potential screening questions (aim 2). An additional 59 adults participated in data collection where the accuracy of the screening tool was evaluated (aim 2). DATA COLLECTION AND ANALYSIS: In study aim 1, all participants completed the detailed questionnaire and the potential screening questions. Descriptive statistics were used to quantify participant participation in various noisy activities and their associated ANE estimates. In study aim 2, linear regression techniques were used to identify screening questions that could be used to predict a participant's estimated ANE. Clinical decision theory was then used to assess the accuracy with which the screening tool predicted high and low risk of NIHL in a new group of participants. RESULTS: Responses on the detailed questionnaire indicated that our sample of college freshmen reported high rates of participation in a variety of occupational and nonoccupational activities associated with high sound levels. Although participation rates were high, ANE estimates were below highest-risk levels for many participants because the frequency of participation in these activities was low in many cases. These data illustrate how the Noise Exposure Questionnaire (NEQ) could be used to provide detailed and specific information regarding an individual's exposure to noise. The results of aim 2 suggest that the screening tool, the 1-Minute Noise Screen, can be used to identify those participants with high- and low-risk noise exposure, allowing more in-depth assessment of noise exposure history to be targeted at those most at risk. CONCLUSIONS: The NEQ can be used to estimate an individual's ANE and the 1-Minute Noise Screen can be used to identify those participants at highest risk of NIHL. These tools allow audiologists to focus hearing conservation efforts on those individuals who are most in need of those services.

Bilateral multicanal benign paroxysmal positional vertigo coexisting with a vestibular schwannoma: case report.

We describe a rarely encountered case of coexisting bilateral multicanal benign paroxysmal positional vertigo (BPPV) and vestibular schwannoma in a 56-year-old woman. The patient had presented with a 10-year history of dizziness and imbalance, and her vestibular findings were perplexing. We decided on a working diagnosis of BPPV and began treatment. After several months of canalith repositioning maneuvers had failed to resolve her symptoms, we obtained magnetic resonance imaging, which revealed the presence of the vestibular schwannoma. This case serves as a reminder of the importance of differentiating between central and peripheral vestibular disorders, as well as central and anterior canal BPPV-induced down-beating nystagmus in order to establish the correct diagnosis and initiate appropriate treatment.