5Recognising Pulsatile Tinnitus

FA symptom that changes the whole story

Most tinnitus is a steady tone or hiss with no rhythm. Pulsatile tinnitus is different: patients describe a whooshing, swishing or thumping that beats in time with their pulse. It accounts for roughly one in ten tinnitus presentations, and unlike ordinary subjective tinnitus it frequently has an identifiable, sometimes treatable, and occasionally dangerous structural cause [2003].

The single most useful question is whether the sound is synchronous with the heartbeat. Ask the patient to take their own pulse while listening: true pulsatile tinnitus keeps step beat for beat. A rhythmic sound that does not match the pulse — a rapid clicking or fluttering — points instead toward middle-ear myoclonus, a quite different problem.

TArterial or venous? Listening to the clues

The history itself often separates arterial from venous origins. A venous hum tends to be a low, continuous machinery-like sound that the patient can abolish or soften by turning the head toward the affected side or by gentle pressure over the ipsilateral neck (light jugular compression). It may worsen with exertion or lying down and is the typical sound of a high-riding jugular bulb, sigmoid sinus dehiscence, or raised intracranial pressure [2013].

An arterial bruit is sharper and may be associated with a carotid stenosis, an aberrant internal carotid artery, a persistent stapedial artery, or a dural arteriovenous fistula. It is generally not abolished by venous compression and may instead be exacerbated by the cardiac output of exercise. These manoeuvre-based clues are imperfect but they shape the imaging request that follows [2003].

CPutting the stethoscope to work

Pulsatile tinnitus is one of the rare tinnitus complaints where the examiner can sometimes hear what the patient hears. Auscultate over the periauricular region, the mastoid, the orbit and along the carotid in the neck; an audible bruit makes the tinnitus objective and strongly implies a vascular generator. Note whether light compression of the ipsilateral internal jugular vein changes the sound — abolition favours a venous source, while persistence keeps an arterial or fistulous cause in play [2008].

Examine the tympanic membrane too: a reddish or bluish retrotympanic mass that pulses or blanches may betray a glomus tumour or an aberrant carotid. The bedside findings do not make the final diagnosis, but they classify the patient and justify the imaging that does.

CWhy recognition changes the work-up

Recognising pulsatile tinnitus matters because it reroutes the evaluation entirely. Ordinary subjective tinnitus is investigated with audiometry and managed with sound and counselling; pulsatile tinnitus demands a search for a structural vascular cause and a low threshold for dedicated imaging, because the differential includes conditions — dural arteriovenous fistula, carotid dissection, idiopathic intracranial hypertension, paraganglioma — that carry real risk if missed [2013].

The detailed radiology (CT angiography, MR venography, catheter angiography and their imaging signatures) belongs to a later chapter on investigation. The clinical skill emphasised here is recognition and triage: identify pulse-synchrony, characterise the sound and its response to manoeuvres, auscultate, and escalate. Get that right and the imaging chapter has a clear question to answer [2013].