An accurate, cost-effective approach for diagnosing retrocochlear lesions utilizing the T2-weighted, fast-spin echo magnetic resonance imaging scan

Radiographic findings in young adults with asymmetric sensorineural hearing loss

PURPOSE

To evaluate radiographic findings in US Navy recruits found to have asymmetric sensorineural hearing loss (ASNHL) during routine medical screening.

MATERIALS AND METHODS

Retrospective analysis of US Navy recruits receiving screening audiometry and medical suitability evaluation from January 2011 to October 2016. Single-institution, institutional review board-approved study of US Navy recruits screened for hearing loss over a six-year period. All recruits with ASNHL were evaluated by an otolaryngologist and received diagnostic radiographic evaluation. Audiometric and imaging results were retrospectively reviewed for this population and compared to common screening criteria.

RESULTS

ASNHL was identified in 674 of 228,504 total recruits screened. This population was 91% male and between 17 and 29 years old (mean age 21.1). Six-hundred fifty-three (97%) met criteria for further ASNHL evaluation. Subjective hearing loss was reported in only 6% of patients. Six-hundred sixty-one (99%) received magnetic resonance imaging of the internal auditory canals. Intracranial pathology was identified in 43 (6.3%) patients and 2 (0.3%) had a causative intracranial lesion corresponding to ASNHL. No patients were found to have a vestibular schwannoma.

CONCLUSIONS

In a population of healthy young adults with audiometric proven ASNHL, 0.3% had radiographic proven intracranial pathology explaining the hearing loss. Intracranial masses may be less likely to cause ASNHL in this population; further research is needed to determine appropriate MRI screening methods for young adults with ASNHL.

Respuesta evocada auditiva de tronco en el schwannoma del VIII par: correlación anatomofisiológica y funcional. Nuestra experiencia

INTRODUCTION

Schwannomas are tumors charasteristically originated from the nerve sheath. They expande eccentrically from the nerve promoting a disturbance in the neural function either due to vascular compresion or to the effect of the tumor itself on the nerve, disturbance that can be evidenced with the Auditory-evoked Brainstem Response (ABR), fact that constituted the base for their diagnosis in the past. The new radiological techniques developed over the last decades have made possible an earlier diagnosis, and therefore changed their prognosis in terms of nerve function. Diagnosis is more certain today with these techniques so it could seem that ABR may not have any longer a role in the management of this condition.

OBJECTIVE

To describe the most frequent ABR patterns in those patients suffering from acoustic schwannoma related to the size of the tumour and the remanent audition thresholds, and to determine the value of this test in our practice.

MATERIAL AND METHODS

We describe the ABR features found in our series of 72 patients. Whose diagnosis was done between 1997 and 2003 in relation to the size of the tumour and the residual auditory function.

RESULTS AND CONCLUSIONS

ABR has a good sensibility for detection of acoustic schwannoma. This sensibility decreases in small-sized tumours, specially in intracanalicular ones. ABR patterns do not relate to the size of the tumour but they do to the auditory function. The authors defend ABR to be a very valuable test due to the information and accesibility they provide.

Chronic Pachymeningitis Presenting as Asymmetric Sensorineural Hearing Loss

OBJECTIVE

The objective of this study was to characterize the auditory dysfunction associated with chronic pachymeningitis (inflammation of the dura mater).

STUDY DESIGN AND SETTING

We conducted a university-based retrospective review.

RESULTS

Three patients were identified who were diagnosed with chronic pachymeningitis after being referred for asymmetric sensorineural hearing loss. All patients were found to have other neurologic symptoms and signs during careful neurotologic evaluation. Two varieties of chronic pachymeningitis exist: a hypertrophic mass lesion and a linear dural thickening. Although the hypertrophic variety could be easily detectable by noncontrast magnetic resonance imaging (MRI), the linear form is only visible with the use of gadolinium enhancement.

CONCLUSION

Chronic pachymeningitis is a rare form of sensorineural hearing loss that could portend an underlying disease of greater concern. Extensive evaluation is needed to exclude identifiable causes of chronic pachymeningitis, including infectious, neoplastic, and autoimmune diseases.

SIGNIFICANCE

The clinician should be aware that the evaluation of a patient with asymmetric sensorineural hearing loss involves more than simply ruling out an acoustic neuroma. Fast-spin echo MRI techniques without the use of gadolinium contrast could miss a number of potentially treatable diseases such as chronic pachymeningitis. Patients with asymmetric sensorineural hearing loss should be carefully evaluated for other neurologic findings, and imaging with enhanced MRI is recommended.

Diagnostic imaging

Imaging technology continues to advance and simplify the diagnosis of neurotologic pathology. Namely, high-resolution magnetic resonance imaging has provided detailed evaluation of the internal auditory canal and membranous labyrinth. Conversely, the role of high-resolution magnetic resonance imaging as a screening tool remains controversial. Functional imaging studies, such as functional magnetic resonance imaging and single photon emission computed tomography are beginning to find significant roles in the evaluation of patients with cochlear implants. General imaging principles and imaging strategies for specific pathologic conditions of the temporal bone are also discussed.

Diagnostic imaging

Imaging technology continues to advance and simplify the diagnosis of neurotologic pathology. Namely, high resolution magnetic resonance imaging has provided detailed evaluation of the internal auditory canal and membranous labyrinth. Conversely, the role of high resolution magnetic resonance imaging as a screening tool remains controversial. Functional imaging studies such as functional magnetic resonance imaging and single photon emission computed tomography are beginning to find significant roles in the evaluation of cochlear implant patients. General imaging principles and imaging strategies for specific temporal bone pathologies are also discussed.

Accuracy of terminology and methodology in economic analyses in otolaryngology

OBJECTIVE

Economic studies increasingly guide health care resource allocation decisions. Because rigorous adherence to accepted definitions and research techniques is critical to ensure accuracy, we evaluated the terminology and methods of otolaryngology economic analyses.

STUDY DESIGN

A total of 71 articles published from 1990 to 1999 in 6 peer-reviewed otolaryngology journals with terms such as "cost-effective" in their title or representing economic analyses were reviewed for terminology and use of established methodology guidelines.

RESULTS

Over half (35 of 66) of terms such as "cost-effective" were used incorrectly, and 60% of articles (39 of 64) confused "charge" and "cost" data. Eleven percent (7 of 64) of papers specified the perspective of their analysis. About half (17 of 30) reported a summary measure such as a cost-effectiveness ratio. Only one third (23 of 63) performed sensitivity analyses.

CONCLUSION

Adherence to accepted definitions and research methods is inconsistent, although we did note moderate improvements in making the distinction between costs and charges, defining of study perspective, and performing sensitivity analysis.

SIGNIFICANCE

Greater attention to both terminology and methodology can enhance the quality of economic analyses and ultimately improve certain resource allocation decisions.

Vertigo and dysequilibrium with associated hearing loss

There are numerous disorders that can present with hearing loss and vertigo or dysequilibrium. The combination of vertigo and imbalance associated with hearing loss are symptoms suggestive of a peripheral vestibular disorder. This article summarizes presentation, diagnosis, and treatment of the various common and rare peripheral vestibular disorders that can present with these symptoms.