Why pulsatile tinnitus is different
Most tinnitus is a continuous, non-rhythmic sound with no structural cause found. Pulsatile tinnitus is different: a whooshing or thumping sound in time with the heartbeat. It reflects turbulent blood flow being transmitted to the inner ear, and in a substantial proportion of patients a specific structural cause can be identified. That matters for two reasons: some causes are dangerous if missed, and many are treatable, with treatment often curing the sound entirely.
Vascular causes
- Dural arteriovenous fistula (dAVF): an abnormal connection between arteries and the venous sinuses. The most important diagnosis to exclude, as some fistulae carry a risk of haemorrhage, and most are treatable with endovascular embolisation.
- Venous sinus stenosis and idiopathic intracranial hypertension (IIH): narrowing of the large draining veins, often associated with raised intracranial pressure and headache; treatable with venous sinus stenting in selected patients.
- Sigmoid sinus wall anomalies (dehiscence, diverticulum): a common and correctable venous cause.
- Carotid disease: stenosis or dissection of the carotid artery can present with pulsatile tinnitus.
- Vascular tumours (such as glomus/paraganglioma) and other arterial anomalies.
How the workup proceeds
Assessment starts with the history and examination (including whether the sound is audible on auscultation, and whether it changes with neck pressure or position), followed by dedicated imaging: typically high-resolution CT of the temporal bones with CT angiography and venography, or MRI with MRA and MRV. Protocol selection matters, as the appropriate sequences materially change the diagnostic yield.
Where non-invasive imaging is negative or equivocal and suspicion remains, particularly for dural fistula, which may not be visible on standard sequences, catheter cerebral angiography (DSA) remains the reference standard. Interventional neuroradiology contributes at both stages: the diagnostic angiogram and, where a treatable cause is found, the treatment.
Persistent unilateral pulsatile tinnitus should not be dismissed as ordinary tinnitus. It warrants structured vascular imaging, and in selected cases catheter angiography, because an identified cause is frequently a treatable one.
Treatment
Treatment depends on the cause: embolisation for dural fistulae, venous sinus stenting for symptomatic sinus stenosis with raised pressure, management of carotid disease, or reassurance where a benign flow-related cause is confirmed. Assessment commonly proceeds alongside ENT and neurology colleagues, and patients are referred back with a clear plan.