Superior semicircular canal dehiscence with concomitant otosclerosis—A literature review and case discussion

Abstract

Key Clinical MassageComputed tomography scan should be performed as a routine before every stapes surgery, in order to exclude concomitant superior semicircular canal dehiscence, since no other clinical, audiological, or electro‐physiological criteria are available to exclude concomitant superior semicircular canal dehiscence in the otosclerotic temporal bone.

One Genetic Defect and Two Related Entities in Monozygotic Twins: Otosclerosis and Superior Semicircular Canal Near Dehiscence Syndrome

“…Although the coexistence of otosclerosis and SSCD or SSCND findings is rarely seen in the literature, it has been reported that the underlying pathogeneses are different and it is coincidental that they are found simultaneously in the same patient [ 7 , 8 ]. The prevalence of concomitant otosclerosis and SSCD findings has been reported to be 6 to 8 per 100,000 [ 8 ].…”

“…Although the coexistence of otosclerosis and SSCD or SSCND findings is rarely seen in the literature, it has been reported that the underlying pathogeneses are different and it is coincidental that they are found simultaneously in the same patient [ 7 , 8 ]. The prevalence of concomitant otosclerosis and SSCD findings has been reported to be 6 to 8 per 100,000 [ 8 ]. It is known that there may be congenital or acquired causes in the development of SSCD, but congenital causes are prominent, and familial cases of SSCD syndrome have been reported [ 9 ].…”

Imaging Studies in Otosclerosis: An Up-to-date Comprehensive Review

“…In cases in which otosclerosis and SSCD occur simultaneously, the preoperative radiological diagnosis of both conditions can also be beneficial, as this particular situation increases the risk of unsatisfactory surgical outcomes. 44 The presence of diverticula from the internal auditory canal (IAC), usually in the anteroinferior wall, (►Fig. 7) is more frequently observed in individuals with otosclerosis.…”

Response to Letter to the Editor: “Outcomes of Stapedotomy in Patients With Concomitant Otosclerosis and Superior Semicircular Canal Dehiscence: Should a Radiographic Third-Window Be a Contraindication to Stapes Surgery?”

“…Although SCDS cannot exist without SCD, the presence of a radiographic dehiscence may simply be apparent because of inadequate slice thickness or visualization in the proper planes to give a false impression of a dehiscence when in fact a thin plate of bone remains intact. Even some patients with a true bony dehiscence may remain asymptomatic (2). Furthermore, SCDS, the physiologically active clinical syndrome caused by the bony dehiscence, can present anywhere from a mild nuisance to debilitating symptoms.…”

“…When the question of an active dehiscence arises, we agree that vestibular-evoked myogenic potential (VEMP) testing may be useful; however, results can be difficult to interpret because of unpredictable stimulation of the third window due to the effect of otosclerosis (2). As expected, air conduction VEMPs may be absent in more than 75% of cases because of inefficient transmission of acoustic energy to the inner ear, whereas even bone conduction VEMPs may be absent in nearly a quarter of patients with otosclerosis, more so for those with a greater degree of hearing loss (3).…”