Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Superior Canal Dehiscence

  • Author: Wayne T Shaia, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
 
Updated: Feb 01, 2016
 

Background

Superior canal dehiscence syndrome (SCDS) is a newly described condition in which vestibular symptoms are elicited by sound or pressure secondary to a dehiscent superior semicircular canal. More than 70 years have passed since Tullio and Hennebert described their findings of sound-induced and pressure-induced vestibular activation.[1]

Since then, the Tullio phenomenon, wherein vestibular symptoms are induced by loud sounds, has been associated with syphilis, perilymphatic fistula, congenital deafness, Ménière disease, head trauma, Lyme disease, cholesteatomas with labyrinthine fistula, and fenestration operations. The Hennebert sign of vestibular symptoms due to changes in external auditory canal pressure is frequently found in conjunction with the Tullio phenomenon (as in perilymphatic fistula, syphilis, Ménière disease).

In 2000, Minor found a series of patients with positive Tullio and Hennebert signs.[2] He was the first to relate these positive findings directly to an anatomical defect of the superior semicircular canal that was detected with high-resolution computed tomography (HRCT). Minor theorized that, when the bone over the canal becomes thin or dehiscent, it acts as an additional window for the vestibular system, allowing pressure and noise changes to induce vestibular activity. SCDS, as it has become known, is now recognized and treated by otolaryngologists and neurotologists throughout the world.

Next

Pathophysiology

The cochleovestibular system has 2 functional windows. The oval window, which houses the footplate of the stapes, allows sound to enter the inner ear (vestibule) and to be carried via hydroacoustic waves through the perilymph. This allows the mechanical wave to be transduced into neural activity, and, thus, sound is perceived.

The function of the round window is more controversial. It is thought to have several roles. Its first role is thought to involve the release of sound and mechanical energy from the scala tympani. Another proposed role is its participation in the secretion and absorption of substances in the inner ear. The round window may also play a role as a defense mechanism of the inner ear.

These 2 windows of the inner ear work together to regulate hearing and balance. When a dehiscence in the superior semicircular canal is created, a third-window effect is thought to take place. As a result, endolymph within the labyrinthine system continues to move in relation to sound or pressure, which causes an activation of the vestibular system. The intracranial pressure transmission to the round window may also result in increased compliance of the inner ear from stretching of the round window membrane. This pressure transmission may also result in a frank round window (or oval window) fistula.

Previous
Next

Epidemiology

Frequency

United States

The true incidence of persons with symptomatic SCDS is currently unknown. One study of 1000 cadaveric temporal bones revealed that a dehiscence of bone that overlies the superior canal was present in approximately 0.5% of temporal bone specimens. In an additional 1.4% of the specimens, the bone was markedly thin (≤ 0.1 mm) compared with the normal bone.

Race

SCDS has no racial bias.

Sex

SCDS appears to affect males and females equally.

Age

In 2000, Minor reported that, in his original series of 17 patients, the median age at diagnosis was 40 years (range, 27-70 y).[2]

Previous
 
 
Contributor Information and Disclosures
Author

Wayne T Shaia, MD Director, The Balance and Ear Center

Disclosure: Nothing to disclose.

Coauthor(s)

Jack M Kartush, MD Clinical Professor, Department of Otolaryngology, Wayne State University School of Medicine; Professor Emeritus, Michigan Ear Institute at Providence Hospital; Clinical Professor, Oakland University William Beaumont School of Medicine

Jack M Kartush, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Otological Society, American Neurotology Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Gerard J Gianoli, MD Clinical Associate Professor, Departments of Otolaryngology-Head and Neck Surgery and Pediatrics, Tulane University School of Medicine; President, The Ear and Balance Institute; Board of Directors, Ponchartrain Surgery Center

Gerard J Gianoli, MD is a member of the following medical societies: American Otological Society, Society of University Otolaryngologists-Head and Neck Surgeons, Triological Society, American Neurotology Society, American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Vesticon<br/>Received none from Vesticon, Inc. for board membership.

Chief Editor

Arlen D Meyers, MD, MBA Professor of Otolaryngology, Dentistry, and Engineering, 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, American Head and Neck Society

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Cerescan;RxRevu;SymbiaAllergySolutions<br/>Received income in an amount equal to or greater than $250 from: Symbia<br/>Received from Allergy Solutions, Inc for board membership; Received honoraria from RxRevu for chief medical editor; Received salary from Medvoy for founder and president; Received consulting fee from Corvectra for senior medical advisor; Received ownership interest from Cerescan for consulting; Received consulting fee from Essiahealth for advisor; Received consulting fee from Carespan for advisor; Received consulting fee from Covidien for consulting.

Additional Contributors

Robert A Battista, MD, FACS Assistant Professor of Otolaryngology, Northwestern University, The Feinberg School of Medicine; Physician, Ear Institute of Chicago, LLC

Robert A Battista, MD, FACS is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, Illinois State Medical Society, American Neurotology Society, American College of Surgeons

Disclosure: Nothing to disclose.

Acknowledgements

Angela Shu-Yuen Peng, MD Resident Physician, Department of Otolaryngology/Head and Neck Surgery, Virginia Commonwealth University Medical Center

Angela Shu-Yuen Peng, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Medical Association, and Virginia Society of Otolaryngology-Head and Neck Surgery

Disclosure: Nothing to disclose.

References
  1. Chilvers G, McKay-Davies I. Recent advances in superior semicircular canal dehiscence syndrome. J Laryngol Otol. 2015 Mar. 129 (3):217-25. [Medline].

  2. Minor LB. Superior canal dehiscence syndrome. Am J Otol. 2000 Jan. 21(1):9-19. [Medline].

  3. Tsunoda A, Terasaki O. Dehiscence of the bony roof of the superior semicircular canal in the middle cranial fossa. J Laryngol Otol. 2002 Jul. 116(7):514-8. [Medline].

  4. Brantberg K, Verrecchia L. Testing vestibular-evoked myogenic potentials with 90-dB clicks is effective in the diagnosis of superior canal dehiscence syndrome. Audiol Neurootol. Sep 2009. 14(1):54-8. [Medline].

  5. Verrecchia L, Westin M, Duan M, Brantberg K. Ocular vestibular evoked myogenic potentials to vertex low frequency vibration as a diagnostic test for superior canal dehiscence. Clin Neurophysiol. 2016 Jan 12. [Medline].

  6. White JA, Hughes GB, Ruggieri PN. Vibration-induced nystagmus as an office procedure for the diagnosis of superior semicircular canal dehiscence. Otol Neurotol. 2007 Oct. 28(7):911-6. [Medline].

  7. Lee GS, Zhou G, Poe D, Kenna M, Amin M, Ohlms L, et al. Clinical experience in diagnosis and management of superior semicircular canal dehiscence in children. Laryngoscope. 2011 Oct. 121(10):2256-61. [Medline].

  8. Brantberg K, Bergenius J, Mendel L, Witt H, Tribukait A, Ygge J. Symptoms, findings and treatment in patients with dehiscence of the superior semicircular canal. Acta Otolaryngol. 2001 Jan. 121(1):68-75. [Medline].

  9. Kartush JK. Superior Canal Dehiscence Syndrome symptoms resolved by reinforcement of the oval and round windows. Unpublished data. 2002.

  10. Silverstein et al. Round Window Reinforcement for Superior Canal Dehiscence. Oto-HNS. Sept 2012. 147:93.

  11. Silverstein H, Kartush JM, Parnes LS, Poe DS, Babu SC, Levenson MJ. Round window reinforcement for superior semicircular canal dehiscence: A retrospective multi-center case series. Am J Otolaryngol. 2014 May-Jun. 35(3):286-93. [Medline].

  12. Barber SR, Cheng YS, Owoc M, et al. Benign paroxysmal positional vertigo commonly occurs following repair of superior canal dehiscence. Laryngoscope. 2015 Dec 15. [Medline].

  13. Gianoli GJ, Soileau JS. The dehiscent middle fossa: prevalence, manifestations, associated findings and results of 24 surgical explorations for superior semicircular canal dehiscence. Publication pending: presented as triologic thesis, 2005.

  14. Banerjee A, Whyte A, Atlas MD. Superior canal dehiscence: review of a new condition. Clin Otolaryngol. 2005. Feb 30(1):9-15. [Medline].

  15. Brantberg K, Ishiyama A, Baloh RW. Drop attacks secondary to superior canal dehiscence syndrome. Neurology. 2005 Jun 28. 64(12):2126-8. [Medline].

  16. Deutschländer A, Strupp M, Jahn K, Jäger L, Quiring F, Brandt T. Vertical oscillopsia in bilateral superior canal dehiscence syndrome. Neurology. 2004 Mar 9. 62(5):784-7. [Medline].

  17. Hennebert C. A new syndrome in hereditary syphilis of the labyrinth. Presse Med Belg Brux. 1911. 63:467.

  18. Hillman TA, Kertesz TR, Hadley K, Shelton C. Reversible peripheral vestibulopathy: the treatment of superior canal dehiscence. Otolaryngol Head Neck Surg. 2006 Mar. 134(3):431-6. [Medline].

  19. Martin JE, Neal CJ, Monacci WT, Eisenman DJ. Superior semicircular canal dehiscence: a new indication for middle fossa craniotomy. Case report. J Neurosurg. 2004 Jan. 100(1):125-7. [Medline].

  20. Merchant SN, Rosowski JJ, McKenna MJ. Superior semicircular canal dehiscence mimicking otosclerotic hearing loss. Adv Otorhinolaryngol. 2007. 65:137-45. [Medline].

  21. Mikulec AA, McKenna MJ, Ramsey MJ, Rosowski JJ, Herrmann BS, Rauch SD. Superior semicircular canal dehiscence presenting as conductive hearing loss without vertigo. Otol Neurotol. 2004 Mar. 25(2):121-9. [Medline].

  22. Mikulec AA, Poe DS, McKenna MJ. Operative management of superior semicircular canal dehiscence. Laryngoscope. 2005. Mar 115(3):501-7. [Medline].

  23. Minor LB. Clinical manifestations of superior semicircular canal dehiscence. Laryngoscope. 2005. Oct 15(10):1717-27. [Medline].

  24. Minor LB, Carey JP, Cremer PD, Lustig LR, Streubel SO, Ruckenstein MJ. Dehiscence of bone overlying the superior canal as a cause of apparent conductive hearing loss. Otol Neurotol. 2003 Mar. 24(2):270-8. [Medline].

  25. Minor LB. Clinical manifestations of superior semicircular canal dehiscence. Laryngoscope. 2005. Oct;115(10):1717-27. [Medline]. [Full Text].

  26. Streubel SO, Cremer PD, Carey JP, Weg N, Minor LB. Vestibular-evoked myogenic potentials in the diagnosis of superior canal dehiscence syndrome. Acta Otolaryngol Suppl. 2001. 545:41-9. [Medline].

  27. Teixido MT, Artz GJ, Kung BC. Clinical experience with symptomatic superior canal dehiscence in a single neurotologic practice. Otolaryngol Head Neck Surg. Sep 2008. 139(3):405-13. [Medline].

  28. Tullio P. Das Ohr und die Entstehung der Sprache und Schrift Berlin. Urban & Schwarzenberg,. 1929.

  29. [Guideline] Vlastarakos PV, Proikas K, Tavoulari E, Kikidis D, Maragoudakis P, Nikolopoulos TP. Efficacy assessment and complications of surgical management for superior semicircular canal dehiscence: a meta-analysis of published interventional studies. Eur Arch Otorhinolaryngol. 2009 Feb. 266 (2):177-86. [Medline].

 
Previous
Next
 
Coronal high-resolution computed tomography scan (1-mm sections) that demonstrates the presence of the superior semicircular canal (figure A, black arrow). As the scan is followed posteriorly (figures B, C, D), the bony dehiscence over the superior canal (black arrow) becomes more apparent.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.