[Evaluation of superior semicircular canal dehiscence in patients with vertigo and tinnitus].

OBJECTIVES

The aim of the study was to investigate the presence of superior semicircular canal dehiscence (SSC) in patients with unknown etilogy of vertigo/tinnitus.

PATIENTS AND METHODS

This study was performed prospectively between December 2007 and March 2008. Fifty five patients (23 males, 32 females; mean age 44.5; range 36 to 74 year) with complaints of vertigo and/or tinnitus, of which we couldn,t establish the etiologies, were included in the study. Control group was consisted of 15 patients who didn,t have complaints of vertigo and/or tinnitus. A high resolution temporal bone computed tomograpy (CT) scan (1 mm slice thickness) was performed in all study groups (patients and controls).

RESULTS

Thirty nine subjects (72%) had normal odiometric findings. Mild conductive hearing loss was present in 12 (22%) subjects. Two (3%) of the patients had moderate conductive hearing loss and the other two subjects (3%) had mixed type hearing loss. High resolution temporal bone CT scan revealed that 35 (65%) subjects had dehissence around SSC otic capsule whereas 20 (35%) remaining patients yielded no dehissence. Twenty one of 35 patients (60%) with dehissence at SSC had minimum defect and 14 patients (40%) had significant defect. Bilateral defect was present in nine (64%) of 14 patients with significant defect but none of the subjects with minimum defect showed bilateral involvement. None of the control subjects exhibited SSC dehissence with CT imaging.

CONCLUSION

Semicircular canal dehissence was found in 65% of the patients with unknown etiology of the vertigo and tinnitus. Physicians should evaluate the SSC dehissence in patients with vertigo and tinnitus as an etiologic factor.