Pulsatile Tinnitus Caused by a Dilated Mastoid Emissary Vein
A 44-yr-old female with tinnitus in the form of a high-pitched, 'whooshing' sound in the left ear visited our tinnitus clinic on April 11, 2012. The patient had a 6-month history of ear-ringing synchronous with the heart beat during physically stressful conditions such as fatigue, exhaustion, and emotional upset. It was heard about 50% of the time during the day and became louder when she experienced fatigue at her job in accounting. The patient described attenuation of tinnitus by manual compression of the left posterior auricular area. The patient did not complain of hearing impairment, fullness in the ear, hyperacusis, dizziness, or headache. She had no past head or neck trauma, no exposure to ototoxic drugs or extremely loud noise, chronic medical illness, or neuropsychiatric condition. The tinnitus was not audible even with a stethoscope around the left ear and mastoid area. The patient described that the Valsalva maneuver, or manual compression of the left internal jugular vein, reduced the loudness of the tinnitus, but it was unaffected by head position or compression of the right neck. The otoscopic examination and pure-tone audiogram were normal.\nAn axial temporal bone computed tomography with contrast enhancement revealed that the left MEV had a prominent opening to the sigmoid sinus and the large canal of the vein crossing the mastoid bone to the soft tissue, without other accessory MEVs (). The outer foramen of the MEV was located on the posterior-superior mastoid region. The diameter of the inner foramen (at the sinus side) of the left MEV was approximately 4.5 mm whereas that of the right MEV was 1.3 mm. The magnetic resonance image (MRI, Gyroscan, Philips, the Netherlands) of the posterior fossa with contrast enhancement showed an outstanding figure of the MEV enhanced together with the sigmoid sinus, also demonstrated on an MR-venogram where no other significant abnormality was found in the venous structures except a size discrepancy between the left internal jugular vein and the right, with the left being slightly larger ().\nDoppler of the left mastoid region detected the origin of the pulsatile tinnitus and displayed pulsating outward venous flow (from the sigmoid sinus to the scalp) with approximately 0.5 m/s of peak velocity at the orifice of the MEV (). However, no turbulence was detected by the Doppler waveform (confirmed by two professional sonographers) and the flow inside the mastoid bone was also not visible due to bony opacity. However, the Doppler recording seemed to be identical to the patient's tinnitus, which showed synchrony with her heartbeat and attenuation of the flow-signal by the Valsalva maneuver, which matched the timing of tinnitus-reduction described by the patient ().\nAlthough transfemoral venous embolization was recommended to obliterate the MEV, the patient preferred to adapt to the tinnitus and successfully modified her life style by avoiding stressful conditions and distracting attention from the tinnitus.