eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > Audiology

Auditory Neuropathy: Differential Diagnoses & Workup

Author: Wayne T Shaia, MD, Consulting Staff, Department of Otology/Neurotology, Medical College of Virginia
Coauthor(s): Dennis I Bojrab, MD, Chairman of Otolaryngology, William Beaumont Hospital; Director of Skull Base Surgery, Providence Hospital; Professor, Department of Otolaryngology-Head and Neck Surgery, Department of Neurosurgery, Wayne State University; Jason G May, MD, Staff Physician, Department of Otolaryngology Head and Neck Surgery, Harper Hospital/Wayne State University School of Medicine
Contributor Information and Disclosures

Updated: Aug 27, 2009

Differential Diagnoses

Other Problems to Be Considered

Ototoxicity
Auditory dyssynchrony
Central auditory processing deficits
Hyperbilirubinemia

Workup

Laboratory Studies

No hematologic workup is necessary to diagnose auditory neuropathy/auditory dyssynchrony (AN/AD). History and audiologic testing establish the diagnosis (see History and Other Tests).

Imaging Studies

  • Imaging studies are not necessary in the newborn period.
  • Once the diagnosis is made correctly, conservative treatment can be initiated. If the parents choose surgical intervention, high-resolution computed tomography scanning of the temporal bones should be performed. This test helps the otologist or neurootologist determine the possibilities of inner ear malformations that might contribute to the disorder. In addition, the inner ear can be visualized and preparations for cochlear implantation can be made.
  • Typically, magnetic resonance imaging (MRI) has no role in AN/AD.

Other Tests

  • The most pertinent audiologic tests for auditory neuropathy/auditory dyssynchrony (AN/AD) are briefly summarized, as follows:
    • Pure tone audiogram testing: This is a graphic plot of a patient's thresholds of auditory sensitivity for pure tone (sine wave) stimuli. It does not test a patient's ability to process sound. This test shows only the patient's ability to hear sounds or tones.
    • Speech audiometry: These tests use spoken words and sentences rather than pure tones. Tests are designed to assess sensitivity (threshold) or understanding (intelligibility) of speech.
    • Acoustic reflex (AR) measures: This measures the contraction of the stapedius muscle in the middle ear. Deviation from the normal threshold on AR testing indicates potential abnormalities of the hearing nerve and auditory system.
    • Otoacoustic emissions (OAEs): These are measured by the presentation of a series of clicks to the ear through a probe inserted in the ear canal. This test measures the integrity of the outer hair cells of the cochlea and cochlear function. Cochlear microphonics (CMs) tests the function of the cochlea similarly.
    • Auditory brainstem responses (ABRs): This test uses scalp electrodes to measure electrical activity in response to sound clicks. Abnormal results of ABR testing indicate that the hearing nerve, as well as the brainstem nuclei, may not correctly process the sounds.
  • Criteria for the diagnosis of AN/AD are as follows:
    • With the advent of newborn hearing screens, children with auditory detriments are being identified and treated at increasingly earlier ages. All of the following must be present in newborns to diagnose AN/AD:
      • Absent or severely abnormal ABR test results at maximal stimulus (100 dBnHL)
      • Normal outer hair cell function as determined by OAEs or CMs
      • Absent or elevated stapedial reflex thresholds
    • Suspect AN/AD in older children or adults with the following audiologic findings:
      • Pure tone thresholds are abnormal. The entire range of abnormalities, from near-normal to profound, may be seen. A more severe loss is usually displayed in the lower frequency thresholds.
      • Poor speech discrimination scores are out of proportion with the level of loss suspected based on the pure tone average.
      • The audiogram findings may vary some, but the overall milieu usually remains unchanged.

More on Auditory Neuropathy

Overview: Auditory Neuropathy
Differential Diagnoses & Workup: Auditory Neuropathy
Treatment & Medication: Auditory Neuropathy
Follow-up: Auditory Neuropathy
Multimedia: Auditory Neuropathy
References
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References

  1. Berlin CI, Hood L, Rose K. On renaming auditory neuropathy as auditory dys-synchrony. Auditory Today. 2002;13:15-17.

  2. Buchman CA,, Roush PA,, Teagle HF et al. Auditory neuropathy characteristics in children with cochlear nerve deficiency. Ear Hear. 2006;Aug;27(4):399-408. [Medline].

  3. Buss E, Labadie RF, Brown CJ, et al. Outcome of cochlear implantation in pediatric auditory neuropathy. Otol Neurotol. May 2002;23(3):328-32. [Medline].

  4. Colletti V, Fiorino FG, Carner M, et al. Auditory brainstem implant as a salvage treatment after unsuccessful cochlear implantation. Otol Neurotol. Jul 2004;25(4):485-96; discussion 496. [Medline].

  5. Conlee JW, Shapiro SM. Morphological changes in the cochlear nucleus and nucleus of the trapezoid body in Gunn rat pups. Hear Res. Dec 1991;57(1):23-30. [Medline].

  6. Harrison RV. An animal model of auditory neuropathy. Ear Hear. Oct 1998;19(5):355-61. [Medline].

  7. Kraus N, Ozdamar O, Stein L, Reed N. Absent auditory brain stem response: peripheral hearing loss or brain stem dysfunction?. Laryngoscope. Mar 1984;94(3):400-6. [Medline].

  8. Madden C, Hilbert L, Rutter M, et al. Pediatric cochlear implantation in auditory neuropathy. Otol Neurotol. Mar 2002;23(2):163-8. [Medline].

  9. Madden C, Rutter M, Hilbert L, et al. Clinical and audiological features in auditory neuropathy. Arch Otolaryngol Head Neck Surg. Sep 2002;128(9):1026-30. [Medline].

  10. Merchan-Perez A, Liberman MC. Ultrastructural differences among afferent synapses on cochlear hair cells: correlations with spontaneous discharge rate. J Comp Neurol. Jul 22 1996;371(2):208-21. [Medline].

  11. Narne VK, Vanaja CS. Perception of envelope-enhanced speech in the presence of noise by individuals with auditory neuropathy. Ear Hear. Feb 2009;30(1):136-42. [Medline].

  12. Peterson A, Shallop J, Driscoll C, et al. Outcomes of cochlear implantation in children with auditory neuropathy. J Am Acad Audiol. May-Jun 2003;14(4):188-201. [Medline].

  13. [Best Evidence] [Guideline] Sanyelbhaa Talaat H, Kabel AH, Samy H, Elbadry M. Prevalence of auditory neuropathy (AN) among infants and young children with severe to profound hearing loss. Int J Pediatr Otorhinolaryngol. Jul 2009;73(7):937-9. [Medline].

  14. Schmiedt RA, Okamura HO, Lang H, Schulte BA. Ouabain application to the round window of the gerbil cochlea: a model of auditory neuropathy and apoptosis. J Assoc Res Otolaryngol. Sep 2002;3(3):223-33. [Medline].

  15. Shaia WT, Shapiro SM, Heller AJ, et al. Immunohistochemical localization of calcium-binding proteins in the brainstem vestibular nuclei of the jaundiced Gunn rat. Hear Res. Nov 2002;173(1-2):82-90. [Medline].

  16. Shaia WT, Shapiro SM, Spencer RF. The jaundiced gunn rat model of auditory neuropathy/dyssynchrony. Laryngoscope. 2005;115(12):2167-73. [Medline].

  17. Shallop JK, Peterson A, Facer GW, et al. Cochlear implants in five cases of auditory neuropathy: postoperative findings and progress. Laryngoscope. Apr 2001;111(4 Pt 1):555-62. [Medline].

  18. Sininger YS, Trautwein P. Electrical stimulation of the auditory nerve via cochlear implants in patients with auditory neuropathy. Ann Otol Rhinol Laryngol Suppl. May 2002;189:29-31. [Medline].

  19. Spencer RF, Shaia WT, Gleason AT, et al. Changes in calcium-binding protein expression in the auditory brainstem nuclei of the jaundiced Gunn rat. Hear Res. Sep 2002;171(1-2):129-141. [Medline].

  20. Starr A, Picton TW, Sininger Y, et al. Auditory neuropathy. Brain. Jun 1996;119 (Pt 3):741-53. [Medline].

  21. Sutton G, Gravel J, Hood L, et al. Assessment and Management of Auditory Neuropathy/Auditory Dys-synchrony. UK Newborn Hearing Screening. 2005;1-13. [Full Text].

  22. Worthington DW, Peters JF. Quantifiable hearing and no ABR: paradox or error?. Ear Hear. Sep-Oct 1980;1(5):281-5. [Medline].

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Further Reading

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Keywords

auditory neuropathy, auditory dyssynchrony, AD, AN, AN/AD, AD/AN, central processing disorder, pediatric hearing loss, hearing loss, cochlear implants, otoacoustic emissions, Friedrich ataxia, Stevens-Johnson syndrome, Ehlers-Danlos syndrome, Charcot-Marie-Tooth syndrome, hyperbilirubinemia, anoxia, hypoxia

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Contributor Information and Disclosures

Author

Wayne T Shaia, MD, Consulting Staff, Department of Otology/Neurotology, Medical College of Virginia
Disclosure: Nothing to disclose.

Coauthor(s)

Dennis I Bojrab, MD, Chairman of Otolaryngology, William Beaumont Hospital; Director of Skull Base Surgery, Providence Hospital; Professor, Department of Otolaryngology-Head and Neck Surgery, Department of Neurosurgery, Wayne State University
Dennis I Bojrab, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Medical Association, American Otological Society, and North American Skull Base Society
Disclosure: Nothing to disclose.

Jason G May, MD, Staff Physician, Department of Otolaryngology Head and Neck Surgery, Harper Hospital/Wayne State University School of Medicine
Jason G May, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Otolaryngology-Head and Neck Surgery
Disclosure: Nothing to disclose.

Medical Editor

Michael E Hoffer, MD, Director, Spatial Orientation Center, Department of Otolaryngology, Naval Medical Center of San Diego
Michael E Hoffer, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery
Disclosure: American biloogical group Royalty Other

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Gerard J Gianoli, MD, Clinical Associate Professor, Department of Otolaryngology-Head and Neck Surgery, Tulane University School of Medicine; Vice President, The Ear and Balance Institute; Chief Executive Officer, Ponchartrain Surgery Center
Gerard J Gianoli, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons, American Neurotology Society, American Otological Society, Society of University Otolaryngologists-Head and Neck Surgeons, and Triological Society
Disclosure: Nothing to disclose.

CME Editor

Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders
Christopher L Slack, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine
Arlen D Meyers, MD, MBA is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Head and Neck Society
Disclosure: Covidien Corp Consulting fee Consulting; US Tobacco Corporation unstricted gift unknown; Axis Three Corporation Ownership interest Consulting; Omni Biosciences Ownership interest Consulting; Sentegra Ownership interest Board membership; Syndicom Ownership interest Consulting; Oxlo  Consulting; Medvoy Ownership interest Management position

 
 
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