Clinical Characteristics of Posterior and Lateral Semicircular Canal Dehiscence

Spasić, Marko; Trang, Andy; Chung, Lawrance K.; Ung, Nolan; Thill, Kimberly; Zarinkhou, Golmah; Gopen, Quinton; Yang, Isaac

doi:10.1055/s-0035-1551667

Cited by 26 publications

(17 citation statements)

References 35 publications

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“…Often this is an incidental finding but some patients pre sent with sensorineural hearing loss from dehiscence into the IAC or posterior SCC, or Ménière's syndrome from encroachment into the endolymphatic sac. 16,36,41,43 Jugular bulb diverticulum is best seen on HRCT or CT as a wellcorticated polypoid projection from the jugular bulb itself, commonly projecting superomedially into the petrous bone medial to the labyrinth and partly covered by the dense otic capsule. HRJBs can pose some surgical challenges when a transotic approach is planned for treating skull base pathologies.…”

Section: Jugular Bulb Distension Diverticulum Dehiscence and Pseudmentioning

confidence: 99%

Jugular bulb and skull base pathologies: proposal for a novel classification system for jugular bulb positions and microsurgical implications

Manjila

Bazil

Kay

et al. 2018

Neurosurgical Focus

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OBJECTIVEThere is no definitive or consensus classification system for the jugular bulb position that can be uniformly communicated between a radiologist, neurootologist, and neurosurgeon. A high-riding jugular bulb (HRJB) has been variably defined as a jugular bulb that rises to or above the level of the basal turn of the cochlea, within 2 mm of the internal auditory canal (IAC), or to the level of the superior tympanic annulus. Overall, there is a seeming lack of consensus, especially when MRI and/or CT are used for jugular bulb evaluation without a dedicated imaging study of the venous anatomy such as digital subtraction angiography or CT or MR venography.METHODSA PubMed analysis of “jugular bulb” comprised of 1264 relevant articles were selected and analyzed specifically for an HRJB. A novel classification system based on preliminary skull base imaging using CT is proposed by the authors for conveying the anatomical location of the jugular bulb. This new classification includes the following types: type 1, no bulb; type 2, below the inferior margin of the posterior semicircular canal (SCC), subclassified as type 2a (without dehiscence into the middle ear) or type 2b (with dehiscence into the middle ear); type 3, between the inferior margin of the posterior SCC and the inferior margin of the IAC, subclassified as type 3a (without dehiscence into the middle ear) and type 3b (with dehiscence into the middle ear); type 4, above the inferior margin of the IAC, subclassified as type 4a (without dehiscence into the IAC) and type 4b (with dehiscence into the IAC); and type 5, combination of dehiscences. Appropriate CT and MR images of the skull base were selected to validate the criteria and further demonstrated using 3D reconstruction of DICOM files. The microsurgical significance of the proposed classification is evaluated with reference to specific skull base/posterior fossa pathologies.RESULTSThe authors validated the role of a novel classification of jugular bulb location that can help effective communication between providers treating skull base lesions. Effective utilization of the above grading system can help plan surgical procedures and anticipate complications.CONCLUSIONSThe authors have proposed a novel anatomical/radiological classification system for jugular bulb location with respect to surgical implications. This classification can help surgeons in complication avoidance and management when addressing HRJBs.

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Section: Jugular Bulb Distension Diverticulum Dehiscence and Pseudmentioning

confidence: 99%

Jugular bulb and skull base pathologies: proposal for a novel classification system for jugular bulb positions and microsurgical implications

Manjila

Bazil

Kay

et al. 2018

Neurosurgical Focus

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“…[53][54][55] For cases of superior semicircular canal dehiscence, surgical plugging of the pathologic osseous defect can be completed, either via a middle cranial fossa craniotomy or transmastoid approach. 55,56 Alternatively, the round window can be targeted; surgeons may reinforce the round window with overlying tissue (eg, fascia, cartilage, fat) or occlude the round window niche (Fig 12). 55,[57][58][59][60] Currently, most authors favor the former approach over the latter; although round window occlusion is considered low-risk, this strategy may induce conductive hearing loss.…”

Section: Surgical Considerationsmentioning

confidence: 99%

The Forgotten Second Window: A Pictorial Review of Round Window Pathologies

Benson

Diehn

Passe

et al. 2019

AJNR Am J Neuroradiol

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The round window serves to decompress acoustic energy that enters the cochlea via stapes movement against the oval window. Any inward motion of the oval window via stapes vibration leads to outward motion of the round window. Occlusion of the round window is a cause of conductive hearing loss because it increases the resistance to sound energy and consequently dampens energy propagation. Because the round window niche is not adequately evaluated by otoscopy and may be incompletely exposed during an operation, otologic surgeons may not always correctly identify associated pathology. Thus, radiologists play an essential role in the identification and classification of diseases affecting the round window. The purpose of this review is to highlight the developmental, acquired, neoplastic, and iatrogenic range of pathologies that can be encountered in round window dysfunction. ABBREVIATIONS: LO 4 labyrinthitis ossificans; RW 4 round windowIndicates open access to non-subscribers at www.ajnr.org http://dx.

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“…The pathophysiological explanation of dehiscence syndromes refers to 2 already known phenomena: the Tullio phenomenon (vertigo and nystagmus symptoms caused by noise [ 175 ], [ 176 ], [ 177 ]) and the Hennebert’s sign (syn: fistula sign; vertigo caused by pressure increase [ 178 ]). Meanwhile, also dehiscence syndromes have been described for the posterior and lateral semicircular canals as well as synchronous dehiscences of different semicircular canals [ 179 ], [ 180 ], [ 181 ], [ 182 ], [ 183 ]. The dehiscence of the lateral semicircular canal mostly occurs in relation with chronic otitis media (cholesteatoma) and is discussed in chapter 4 as labyrinth fistula.…”

Section: Dehiscence Syndromesmentioning

confidence: 99%