A Cohort Study Comparing Importance of Clinical Factors in Determining Diagnosis and Treatment for Superior Semicircular Canal Dehiscence Syndrome

Objective: To determine which clinical factors have the strongest impact on determining diagnosis and decision for surgical repair for superior semicircular canal dehiscence syndrome (SCDS).

Patients: A total of 81 patients presented with a suspicion for SCDS between October 2017 and October 2018. 38 patients ultimately were diagnosed with SCDS, and 28 chose surgical repair.

Methods: Clinical factors of subjective patient symptoms (autophony, sensitivity to loud sounds, vertigo induced by loud sounds, dizziness, hearing their own heartbeats or other visceral organs) and audiogram findings (low frequency conductive hearing loss [CHL], bone-conduction hyperacusis, low cVEMP threshold [<80 db nHL], increased oVEMP [>17 μV] amplitudes) were analyzed with logistic regression to identify factors that predicted those who would ultimately be diagnosed with SCDS and those who would have surgical repair. Preoperative high-resolution CT imaging was performed on all patients.

Results: Significant predictors of presence of SCDS from logistic regression included low frequency CHL and increased oVEMP amplitude (p = 0.002 [OR 40, 95%CI 3.8-413], p = 0.001 [OR 93, 95%CI 6.8-1267], respectively). These were also significant predictors of individuals who chose to have surgical repair (p = 0.004 [OR 47, 95%CI 3.5-620], p = 0.001 [OR 126, 95%CI 8.2-1941], respectively). Area under the receiver operating characteristic curve (ROC curve) for these two variables are 93% for diagnosing SCDS and 94% for predicting choice for surgical repair.

Conclusions: Low frequency CHL and increased oVEMP amplitude are the strongest predictive factors for making a diagnosis of SCDS and for choosing surgical repair.