Hearing Loss Associated with Xylene Exposure in a Laboratory Worker

2012 ◽  
Vol 23 (10) ◽  
pp. 824-830 ◽  
Author(s):  
Adrian Fuente ◽  
Bradley McPherson ◽  
Linda J. Hood
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Otoacoustic Emissions ◽  
Outer Hair Cell ◽  
Cell Damage ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Auditory Brainstem Responses ◽  
Initial Assessment ◽  
Laboratory Worker

Background: Xylene is an organic solvent, widely used in histology laboratories and other occupational settings. Research in animals has demonstrated that xylene induces outer hair cell damage. Evidence regarding the effects of xylene in humans is only available from studies investigating workers exposed to mixtures of solvents containing xylene. These data indicate that mixtures of solvents containing xylene may induce hearing loss and central auditory dysfunction. Purpose: To comprehensively evaluate the peripheral and central auditory system of a histology laboratory worker exposed to xylene, who had presented with bilateral mild sensorineural hearing loss at an initial assessment. Research Design: A case report of a male histology laboratory worker who has been exposed to xylene for over 20 yr. Results: A diagnosis of bilateral mild sensorineural hearing loss of cochlear origin was made on the basis of otological, neuroimaging, and audiological examinations. Results indicating the absence of transient-evoked otoacoustic emissions, and auditory brainstem responses as expected for a mild cochlear hearing loss, were obtained. Conclusions: The observed bilateral mild sensorineural hearing loss was considered to have been induced by xylene exposure, due to the absence of any other etiological factors related to the onset of hearing loss. The results found in this patient are in agreement with animal data indicating xylene-induced ototoxicity. Xylene-exposed individuals should be audiologically monitored on a regular basis.

Hearing recovery from deafness caused by bromate intoxication

2018 ◽  
Vol 132 (11) ◽  
pp. 1039-1041 ◽  
Author(s):  
J Suzuki ◽  
Y Takanashi ◽  
A Koyama ◽  
Y Katori
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Pure Tone ◽  
Pure Tone Audiometry ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Auditory Brainstem Responses ◽  
Common Symptom ◽  
Hearing Recovery ◽  
Continuous Haemodiafiltration

AbstractObjectivesSodium bromate is a strong oxidant, and bromate intoxication can cause irreversible severe-to-profound sensorineural hearing loss. This paper reports the first case in the English literature of bromate-induced hearing loss with hearing recovery measured by formal audiological assessment.Case reportA 72-year-old woman was admitted to hospital with complaints of profound hearing loss, nausea, diarrhoea and anuria after bromate ingestion in a suicide attempt. On admission, pure tone audiometry and auditory brainstem responses showed profound bilateral deafness. Under the diagnosis of bromate-induced acute renal failure and sensorineural hearing loss, continuous haemodiafiltration was performed. When dialysis was discontinued, pure tone audiometry and auditory brainstem responses showed partial threshold recovery from profound deafness.ConclusionSevere-to-profound sensorineural hearing loss is a common symptom of bromate intoxication. Bromate-induced hearing loss may be partially treated, and early application of continuous haemodiafiltration might be useful as a treatment for this intractable condition.

scholarly journals Enhancing the sensitivity of the envelope-following response for cochlear synaptopathy screening in humans: the role of stimulus envelope

2020 ◽  
Author(s):  
Viacheslav Vasilkov ◽  
Markus Garrett ◽  
Manfred Mauermann ◽  
Sarah Verhulst
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Sensorineural Hearing Loss ◽  
Auditory Nerve ◽  
Outer Hair Cell ◽  
Cell Damage ◽  
Modulation Depth ◽  
Auditory Evoked Potential ◽  
Sensorineural Hearing ◽  
Age Related

AbstractAuditory de-afferentation, a permanent reduction in the number of innerhair-cells and auditory-nerve synapses due to cochlear damage or synaptopathy, can reliably be quantified using temporal bone histology and immunostaining. However, there is an urgent need for non-invasive markers of synaptopathy to study its perceptual consequences in live humans and to develop effective therapeutic interventions. While animal studies have identified candidate auditory-evoked-potential (AEP) markers for synaptopathy, their interpretation in humans has suffered from translational issues related to neural generator differences, unknown hearing-damage histopathologies or lack of measurement sensitivity. To render AEP-based markers of synaptopathy more sensitive and differential to the synaptopathy aspect of sensorineural hearing loss, we followed a combined computational and experimental approach. Starting from the known characteristics of auditory-nerve physiology, we optimized the stimulus envelope to stimulate the available auditory-nerve population optimally and synchronously to generate strong envelope-following-responses (EFRs). We further used model simulations to explore which stimuli evoked a response that was sensitive to synaptopathy, while being maximally insensitive to possible co-existing outer-hair-cell pathologies. We compared the model-predicted trends to AEPs recorded in younger and older listeners (N=44, 24f) who had normal or impaired audiograms with suspected age-related synaptopathy in the older cohort. We conclude that optimal stimulation paradigms for EFR-based quantification of synaptopathy should have sharply rising envelope shapes, a minimal plateau duration of 1.7-2.1 ms for a 120-Hz modulation rate, and inter-peak intervals which contain near-zero amplitudes. From our recordings, the optimal EFR-evoking stimulus had a rectangular envelope shape with a 25% duty cycle and a 95% modulation depth. Older listeners with normal or impaired audiometric thresholds showed significantly reduced EFRs, which were consistent with how (age-induced) synaptopathy affected these responses in the model.Significance StatementCochlear synaptopathy was in 2009 identified as a new form of sensorineural hearing loss (SNHL) that also affects primates and humans. However, clinical practice does not routinely screen for synaptopathy, and hence its consequences for degraded sound and speech perception remain unclear. Cochlear synaptopathy may thus remain undiagnosed and untreated in the aging population who often report self-reported hearing difficulties. To enable an EEG-based differential diagnosis of synaptopathy in humans, it is crucial to develop a recording method that evokes a robust response and emphasizes inter-individual differences. These differences should reflect the synaptopathy aspect of SNHL, while being insensitive to other aspects of SNHL (e.g. outer-hair-cell damage). This study uniquely combines computational modeling with experiments in normal and hearing-impaired listeners to design an EFR stimulation and recording paradigm that can be used for the diagnosis of synaptopathy in humans.

scholarly journals Auditory Brainstem Responses in Cases with Sensorineural Hearing Loss in Low Frequency Tones.

1994 ◽  
Vol 37 (2) ◽  
pp. 136-141
Author(s):  
Toshifumi Sakata ◽  
Akihide Imamura ◽  
Nobuhide Imamura ◽  
Yuji Suoya ◽  
Kimio Shiraishi ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Low Frequency ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Auditory Brainstem Responses

scholarly journals Towards a differential diagnosis of cochlear synaptopathy and outer-hair-cell deficits in mixed sensorineural hearing loss pathologies

2019 ◽  
Author(s):  
Viacheslav Vasilkov ◽  
Sarah Verhulst
Keyword(s):  
Hearing Loss ◽  
Differential Diagnosis ◽  
Hair Cell ◽  
Sensorineural Hearing Loss ◽  
Noise Exposure ◽  
Outer Hair Cell ◽  
Cell Damage ◽  
Sensorineural Hearing ◽  
Inner Hair Cell ◽  
Hearing Thresholds

AbstractDamage to the auditory periphery is more widespread than predicted by the gold-standard clinical audiogram. Noise exposure, ototoxicity and aging can destroy cochlear inner-hair-cell afferent synapses and result in a degraded subcortical representation of sound while leaving hearing thresholds unaffected. Damaged afferent synapses, i.e. cochlear synaptopathy, can be quantified using histology, but a differential diagnosis in living humans is difficult: histology cannot be applied and existing auditory evoked potential (AEP) metrics for synaptopathy become insensitive when other sensorineural hearing impairments co-exist (e.g., outer-hair-cell damage associated with elevated hearing thresholds). To develop a non-invasive diagnostic method which quantifies synaptopathy in humans and animals with normal or elevated hearing thresholds, we employ a computational model approach in combination with human AEP and psychoacoustics. We propose the use of a sensorineural hearing loss (SNHL) map which comprises two relative AEP-based metrics to quantify the respective degrees of synaptopathy and OHC damage and evaluate to which degree our predictions of AEP alterations can explain individual data-points in recorded SNHL maps from male and female listeners with normal or elevated audiometric thresholds. We conclude that SNHL maps can offer a more precise diagnostic tool than existing AEP methods for individual assessment of the synaptopathy and OHC-damage aspect of sensorineural hearing loss.Significance StatementHearing loss ranks fourth in global causes for disability and risk factors include noise exposure, ototoxicity and aging. The most vulnerable parts of the cochlea are the inner-hair-cell afferent synapses and their damage (cochlear synaptopathy) results in a degraded subcortical representation of sound. While synaptopathy can be estimated reliably using histology, it cannot be quantified this way in living humans. Secondly, other co-existing sensorineural hearing deficits (e.g., outer-hair-cell damage) can complicate a differential diagnosis. To quantify synaptopathy in humans and animals with normal or elevated hearing thresholds, we adopt a theoretical and interdisciplinary approach. Sensitive diagnostic metrics for synaptopathy are crucial to assess its prevalence in humans, study its impact on sound perception and yield effective hearing restoration strategies.

Idiopathic sudden sensorineural hearing loss: prognostic factors

2006 ◽  
Vol 120 (9) ◽  
pp. 718-724 ◽  
Author(s):  
J Xenellis ◽  
I Karapatsas ◽  
N Papadimitriou ◽  
T Nikolopoulos ◽  
P Maragoudakis ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Auditory Brainstem ◽  
Sudden Sensorineural Hearing Loss ◽  
Sensorineural Hearing ◽  
Auditory Brainstem Responses ◽  
Hearing Outcome ◽  
Younger Age ◽  
Hearing Recovery ◽  
One Year

Objectives: Sudden sensorineural hearing loss (SSHL) remains a challenge for the clinician. In the majority of cases, no definite cause can be found and the prognosis is variable.Methods: The present study assessed 114 patients suffering from idiopathic SSHL, with regard to the prognostic value of demographic, epidemiologic, neurotologic and audiometric factors. In addition, the relationship between the identification of wave V in auditory brainstem responses and the final hearing outcome was investigated. All patients received 75 mg/day intravenous prednisolone, divided into three daily doses, for 10 days, with gradual tapering of the dose over the next 10 days.Results: The results (after one year follow up) revealed the following factors to be related to a better hearing outcome: younger age; male sex; less time elapsed between the onset of hearing loss and the beginning of treatment; and an upward-sloping or cupeloid audiogram contour. The detection of wave V early in recovery and within the first month of medical treatment might also constitute a significant favourable factor in respect to hearing recovery.Conclusions: The present study revealed that there are certain factors that affect prognosis in idiopathic SSHL. This is very important in counselling patients and may affect current clinical practice.

scholarly journals Is undernutrition a risk factor for sensorineural hearing loss in early infancy?

2009 ◽  
Vol 103 (9) ◽  
pp. 1296-1301 ◽  
Author(s):  
Bolajoko O. Olusanya
Keyword(s):  
Hearing Loss ◽  
Nutritional Status ◽  
Sensorineural Hearing Loss ◽  
Otoacoustic Emissions ◽  
Auditory Brainstem ◽  
Sensorineural Hearing ◽  
Hearing Level ◽  
Visual Response ◽  
Brainstem Response ◽  
The Relationship

The present cross-sectional study set out to determine the nutritional status of infants aged 0–3 months with the WHO Multicentre Growth Reference (WHO-MGR) and examine the relationship between undernutrition and congenital or early-onset sensorineural hearing loss (CESHL) rarely reported for developing countries. The nutritional status of all infants attending community-based clinics for routine Bacille de Calmette-Guérin (BCG) immunisation from July 2005 to December 2006 was determined by weight-for-age, weight-for-length and BMI-for-age based on the WHO-MGR. Hearing loss status was determined by tympanometry, auditory brainstem response (ABR) and visual response audiometry after a two-stage screening with transient evoked otoacoustic emissions and automated ABR. The relationship between nutritional status and CESHL were explored after adjusting for potentially confounding maternal and infant characteristics using multivariable logistic regression analyses. Of the 3386 infants who completed the hearing evaluation protocol, seventy-one were confirmed with hearing loss (>30 dB hearing level). More than one-third (37·9 %) of all infants and over half (54·9 %) of those with CESHL were undernourished by at least one measure of growth. Stunting (35·3 %) was the most prevalent nutritional deficit in infants with CESHL. In the final logistic model, infants with any undernourished physical state were significantly likely to have CESHL (OR 1·67; 95 % CI 1·03, 2·77) and of a severe-to-profound degree (OR 3·92; 95 % CI 1·38, 11·17) compared with infants without any undernourishment. Prospective studies to establish the full spectrum of the relationship between undernutrition and CESHL, particularly in resource-poor countries, are therefore warranted.

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