Focal defect of mastoid bone shell in the region of the transverse-sigmoid junction: a new cause of pulsatile tinnitus

Abstract

OBJECTIVE: Pulsatile tinnitus usually originates from vascular structures, causing an arterial or venous bruit. We report a new cause of pulsatile tinnitus: a focal defect of the mastoid bone shell in the region of the transverse-sigmoid junction, with a normal transverse-sigmoid sinus. PARTICIPANTS AND INTERVENTION: Three patients complained of unilateral, pulsatile tinnitus present for many years. They were identified as having a focal defect of the mastoid bone shell in the region of the transverse-sigmoid junction. The patients underwent transmastoid reconstruction of the mastoid bone shell overlying the transverse-sigmoid sinus. RESULTS: All three patients reported immediate resolution of their symptoms, and were asymptomatic at final follow up. CONCLUSION: A focal defect of the mastoid bone shell overlying the transverse-sigmoid sinus, with no abnormality of the sinus itself, may be a new cause of pulsatile tinnitus. Surgical reconstruction of the mastoid bone shell overlying the transverse-sigmoid sinus can provide lasting symptom relief for patients with pulsatile tinnitus and computed tomographic evidence of the defect.