Pulsatile tinnitus: imaging and differential diagnosis

Abstract

Background: Pulsatile tinnitus, unlike idiopathic tinnitus, usually has a specific, identifiable cause. Nonetheless, uncertainty often arises in clinical practice about the findings to be sought and the strategy for work-up.

Methods: Selective literature review and evaluation of our own series of patients.

Results: Pulsatile tinnitus can have many causes. No prospective studies on this subject are available to date. Pulsatile tinnitus requires both a functional organ of hearing and a genuine, physical source of sound, which can, under certain conditions, even be objectified by an examiner. Pulsatile tinnitus can be classified by its site of generation as arterial, arteriovenous, or venous. Typical arterial causes are arteriosclerosis, dissection, and fibromuscular dysplasia. Common causes at the arteriovenous junction include arteriovenous fistulae and highly vascularized skull base tumors. Common venous causes are intracranial hypertension and, as predisposing factors, anomalies and normal variants of the basal veins and sinuses. In our own series of patients, pulsatile tinnitus was most often due to highly vascularized tumors of the temporal bone (16%), followed by venous normal variants and anomalies (14%) and vascular stenoses (9%). Dural arteriovenous fistulae, inflammatory hyperemia, and intracranial hypertension were tied for fourth place (8% each).

Conclusion: The clinical findings and imaging studies must always be evaluated together. Thorough history-taking and clinical examination are the basis for the efficient use of imaging studies to reveal the cause of pulsatile tinnitus.

Figure 1

Bilateral carotid dissection in a 41-year-old woman. Clinical symptoms: bilateral pulsatile tinnitus, pain in the back of the neck, and weakness in both arms. Axial T1-weighted MRI showed direct evidence of intramural hematoma (arrow)

Figure 2

Digital subtraction angiography (DSA) of a direct arteriovenous short-circuit (arrow) between the vertebral artery and the vertebral venous plexus. Subsequent closure with a detachable balloon led to immediate, long-term cessation of the tinnitus, which had been unbearable

Figure 3

Diverticulum of the right transverse sinus (arrow)

Figure 4

Dehiscence of the posterior portion of the anterior semicircular canal to the superior petrosal sinus (arrow). Clinical symptoms: right-sided pulsatile tinnitus, unpleasant perception of the patient’s own footsteps

Dural arteriovenous fistula, MRA showed only subtle alterations as a result of atypical flows in the right transverse sinus (arrow).