Can an Arteriovenous Malformation Cause Intermittent Pulsatile Tinnitus?
Yes, arteriovenous malformations (AVMs) are a recognized cause of pulsatile tinnitus, though the symptom is typically continuous rather than intermittent. AVMs create abnormal high-flow vascular connections that generate turbulent blood flow audible to the patient's auditory system 1.
How AVMs Cause Pulsatile Tinnitus
AVMs produce pulsatile tinnitus through abnormal arteriovenous shunting that creates turbulent flow patterns synchronized with the cardiac cycle, which the auditory system perceives as rhythmic sound 1, 2.
Both intracranial and extracranial AVMs can present with pulsatile tinnitus, including those located in the parotid region, external ear, and skull base 3, 4, 5.
The mechanism involves direct arteriovenous communication without normal capillary connections, resulting in high-flow turbulence that transmits sound to the inner ear structures 5.
Clinical Presentation Patterns
Pulsatile tinnitus from AVMs is typically continuous rather than intermittent, as the abnormal vascular flow is constant 1.
If your patient describes truly intermittent symptoms, consider alternative diagnoses such as positional venous abnormalities (sigmoid sinus diverticulum, jugular bulb variants) or intermittent flow changes from other vascular causes 1, 2.
AVMs most commonly present with hemorrhage (>50% of cases), followed by seizures (20-25%), headaches (15%), and less commonly with pulsatile tinnitus 1.
Critical Diagnostic Considerations
Dural arteriovenous fistulas (AVF) are more common than AVMs as a cause of pulsatile tinnitus, accounting for 8% of pulsatile tinnitus cases, and represent a life-threatening condition requiring urgent identification 1, 2.
The distinction between AVM and dural AVF is critical because dural AVF can lead to hemorrhagic or ischemic stroke if untreated, and both require catheter angiography for definitive diagnosis 1, 6.
Recommended Diagnostic Approach
Order CT angiography (CTA) of the head and neck with contrast as the first-line imaging study when suspecting AVM or dural AVF as the cause of pulsatile tinnitus 1, 2.
If CTA is negative but clinical suspicion remains high, proceed to MRI with MR angiography (MRA) to evaluate for vascular malformations not identified on initial imaging 1, 2.
Reserve catheter angiography for cases with objective pulsatile tinnitus, inconclusive noninvasive imaging, or for definitive characterization of suspected dural AVF or AVM identified on CTA/MRA 1, 6.
Do not rely on carotid duplex ultrasound alone, as it only evaluates extracranial carotid stenosis and will miss intracranial AVMs or dural AVF 1.
Important Clinical Pitfalls
Missing a dural AVF is the most dangerous pitfall, as it can present with isolated pulsatile tinnitus before catastrophic hemorrhage occurs 2.
AVMs carry a 2-3% annual hemorrhage risk, with 10-30% mortality from first hemorrhage, making timely diagnosis essential even when the presenting symptom is only tinnitus 1.
Atherosclerotic carotid artery disease is actually the most common cause of pulsatile tinnitus (17.5% of cases), so don't anchor on AVM without appropriate vascular imaging to exclude more common etiologies 2.
Idiopathic intracranial hypertension is the second most common cause and should be considered, particularly in young overweight women with headaches, as missing this can lead to vision loss 2.