scholarly journals Posterior semicircular canal dehiscence: a diagnostic and surgical conundrum

2019 ◽  
Vol 12 (7) ◽  
pp. e229573 ◽  
Author(s):  
Ajay Philip ◽  
Manju Deena Mammen ◽  
Anjali Lepcha ◽  
Anu Alex
Keyword(s):  
Conservative Management ◽  
Semicircular Canal ◽  
Posterior Semicircular Canal ◽  
Superior Semicircular Canal Dehiscence ◽  
Bony Labyrinth ◽  
Abnormal Pressure ◽  
Vestibular Symptoms ◽  
Inner Ear Fluids ◽  
Tullio’S Phenomenon ◽  
Canal Dehiscence

Third window defects have increasingly been identified as a cause of vertigo. These defects are bony dehiscences that occur in the bony labyrinth, resulting in abnormal pressure gradient in the inner ear fluids leading to sound (Tullio’s phenomenon) or pressure (Hennebert’s sign) induced vertigo. The superior semicircular canal dehiscence syndrome is a well-described entity in this regard, however defects of the posterior semicircular canal are rare and may have overlapping symptomatology. We describe the history, clinical profile and management of a patient who had importunate symptoms despite being on conservative management for a year and had resolution of vestibular symptoms following surgical management.

scholarly journals A Third Labyrinthine Window: An Overview of Perilymph and Labyrinthine Fistulae and Superior Semicircular Canal Dehiscence

2012 ◽  
Vol 4 (2) ◽  
pp. 100-105 ◽  
Keyword(s):  
Inner Ear ◽  
Semicircular Canal ◽  
Membranous Labyrinth ◽  
Superior Semicircular Canal Dehiscence ◽  
Bony Labyrinth ◽  
Superior Semicircular Canal ◽  
Inner Ear Fluids ◽  
Canal Dehiscence

ABSTRACT The membranous labyrinth is contained within the bony labyrinth and surrounded by perilymph. The only two ‘potentially yielding’ parts of the otherwise solid bony labyrinth are the oval and round windows, which by their relative movements, pressure differentials and resilience are responsible for all the functions attributed to the inner ear. In pathologies, such as trauma, infection or occasionally congenital dehiscence, there may develop a ‘third window’ that may serve as an abnormal communication for the inner ear fluids and manifest with audiovestibular symptoms. Three such distinct entities have been identified, namely ‘superior semicircular canal dehiscence syndrome, perilymphatic fistulae and labyrinthine fistulae’. This overview intends to discuss these above-mentioned entities, as regards their characteristic presentations and principles of management. How to cite this article Hathiram BT, Khattar VS. A Third Labyrinthine Window: An Overview of Perilymph and Labyrinthine Fistulae and Superior Semicircular Canal Dehiscence. Otorhinolaryngol Clin Int J 2012;4(2):100-105.

Bilateral superior semicircular canal dehiscence: bilateral conductive hearing loss with subtle vestibular symptoms

2020 ◽  
Vol 13 (3) ◽  
pp. e233042
Author(s):  
Diogo Pereira ◽  
Abílio Leonardo ◽  
Delfim Duarte ◽  
Nuno Oliveira
Keyword(s):  
Hearing Loss ◽  
Semicircular Canal ◽  
Conductive Hearing Loss ◽  
Vestibular Evoked Myogenic Potentials ◽  
Caucasian Woman ◽  
Superior Semicircular Canal Dehiscence ◽  
Superior Semicircular Canal ◽  
Vestibular Symptoms ◽  
Conductive Hearing ◽  
Canal Dehiscence

Superior semicircular canal dehiscence is caused by a bone defect on the roof of the superior semicircular canal. The estimated prevalence when unilateral varies between 0.4% and 0.7% and is still unknown when bilateral. Patients may present with audiologic and vestibular symptoms that may vary from asymptomatic to disabling. We report a case of a 72-year-old Caucasian woman presented to otolaryngology department reporting imbalance, bilateral pulsatile tinnitus, hypoacusis while being very sensitive to certain sounds. Physical examination was unremarkable, except for the Rinne test that was negative in both sides. The patient underwent an audiometry revealing a mild bilateral conductive hearing loss. A temporal bone CT scan was performed which evidenced bilateral superior semicircular canal dehiscence. Cervical vestibular evoked myogenic potentials and electrocochleography confirmed diagnosis. Although rare, superior semicircular canal dehiscence shall be considered in conductive hearing loss with vestibular symptoms.

Superior semicircular canal dehiscence syndrome

2004 ◽  
Vol 100 (1) ◽  
pp. 123-124 ◽  
Author(s):  
Mitchell J. Ramsey ◽  
Michael J. McKenna ◽  
Fred G. Barker
Keyword(s):  
Semicircular Canal ◽  
Chronic Otitis Media ◽  
Middle Cranial Fossa ◽  
Content Type ◽  
Superior Semicircular Canal Dehiscence ◽  
Superior Semicircular Canal ◽  
Cranial Fossa ◽  
Vestibular Symptoms ◽  
Fine Print ◽  
Canal Dehiscence

✓ The authors present the case of a man who had superior semicircular canal dehiscence syndrome in addition to chronic otitis media. This case is atypical because the patient coincidentally had middle ear and mastoid disease, which previously had been treated surgically. The prior ear surgery delayed the diagnosis of superior semicircular canal dehiscence syndrome and increased the complexity of the repair of the superior semicircular canal dehiscence. Superior semicircular canal dehiscence syndrome is a recently recognized syndrome resulting in acute or chronic vestibular symptoms. The diagnosis is made using history, vestibular examination, and computerized tomography studies. Neurosurgeons should be aware that patients with superior semicircular canal dehiscence syndrome who experience disabling chronic or acute vestibular symptoms can be treated using a joint neurosurgical—otological procedure through the middle cranial fossa.

scholarly journals The Supine Superior Semicircular Canal Dehiscence Test

2021 ◽  
pp. 1-6
Author(s):  
Carrie W. Hoppes ◽  
Karen H. Lambert ◽  
Chris Zalewski ◽  
Robin Pinto ◽  
Holly Burrows ◽  
...  
Keyword(s):  
Dura Mater ◽  
Semicircular Canal ◽  
False Negative ◽  
New Method ◽  
Superior Semicircular Canal Dehiscence ◽  
Bony Labyrinth ◽  
Superior Semicircular Canal ◽  
Potential Benefits ◽  
Canal Dehiscence

Purpose The purpose of this clinical focus article is to describe a new method for assessment of superior semicircular canal dehiscence by laying the patient supine during Valsalva-induced nystagmus testing. Method The traditional Valsalva-induced nystagmus test is described, followed by a new method for assessment of superior semicircular dehiscence conducted by laying the patient supine during testing. A case study is presented to illustrate this new testing technique known as the Supine Superior Semicircular Canal Dehiscence Test. Results It is hypothesized that during Valsalva-induced nystagmus testing performed in the upright, seated position, the dura mater could potentially seal the superior semicircular canal fistula, thereby concealing a defect in the bony labyrinth and yielding a false-negative test. To circumvent this, the patient should be placed in the supine position during Valsalva-induced nystagmus testing in order to prevent the dura mater from inadvertently sealing itself against the petrous portion of the temporal bone. The Supine Superior Semicircular Canal Dehiscence Test may reveal the defect in the bony labyrinth and improve the sensitivity of the Valsalva-induced nystagmus test. Conclusions The Supine Superior Semicircular Canal Dehiscence Test may be more sensitive for identifying superior semicircular canal dehiscence in patients with traditional symptoms and a negative Valsalva-induced nystagmus test in the seated position. While a case study is presented to illustrate the potential benefits of including the Supine Superior Semicircular Canal Dehiscence Test in the battery of diagnostic tests, further research is needed in larger samples.

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