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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
years; range 36 to 74 years) 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.