Pulsatile tinnitus caused by a dilated mastoid emissary vein

Abstract

Although pulsatile tinnitus can be audible, objective demonstration of this heartbeat-synchronous sound has rarely been successful. We report a rare case of pulsatile tinnitus in a 44-yr-old female patient, which was induced by a large mastoid emissary vein (MEV) and objectively documented by Doppler sonography of the left posterior auricular region. The tinnitus was intermittent and the patient could adapt to the tinnitus without intervention on the mastoid emissary vein. These findings suggest that a single large MEV can cause pulsatile tinnitus in the absence of other vascular abnormalities, and imaging studies of the posterior fossa and Doppler ultrasonography can aid the diagnosis in such cases.

Keywords: Mastoid Vein; Pulsatile Tinnitus.

Fig. 1

Imaging studies revealing the large mastoid emissary vein (MEV). The patient's temporal bone CT scan showed a prominent orifice of the large left MEV (black arrow), with a diameter of 4.5 mm at the inner foramen, abnormally larger than the other side (dotted arrow) (A). The enhanced MRI and MR venogram showed blood flow of the left MEV draining into the sigmoid sinus (white arrows) (B, C).

Fig. 2

Doppler sonogram of the pulsating flow in the mastoid emissary vein (MEV), correlating to the pulsatile tinnitus. Doppler sonography identified the location of the outer foramen of the MEV and the pulsating venous blood flow draining into the sigmoid sinus (A, B). The patient recognized reduction of the pulsatile tinnitus synchronously with the decrease of the flow-signal by compression of the left jugular vein (C) and the Valsalva maneuver (D). Arrows: starting points of compression of the left jugular vein and the Valsalva maneuver, respectively.