Posterior semicircular canal dehiscence in asymptomatic ears

Conclusions: This study revealed that, in the adult population, the final diagnosis of this entity can only be made by combining imaging with clinical tests. Objective: We developed the largest temporal bone multislice computed tomography (CT) scan study so far by including 410 cases to investigate the prevalence of posterior semicircular canal dehiscence in patients with symptoms unrelated to the inner ear. Methods: A prospective study was performed in 410 consecutive adult individuals who underwent temporal bone multislice CT scan examinations. Results: The prevalence of posterior semicircular canal dehiscence was determined to be 1.2%. No superior or lateral semicircular canal defect was detected in these five patients. All cases with posterior semicircular canal defect were male. In two cases the canal was located unilaterally, while in three cases the defects were present bilaterally. Otological examination and audiovestibular tests revealed no abnormal findings in any of the individuals.