When should a patient with 9 months of pulsatile tinnitus be evaluated by an ear, nose, and throat (ENT) specialist or a neurologist?

Immediate Evaluation Required for Pulsatile Tinnitus

A patient with 9 months of pulsatile tinnitus should have already been evaluated urgently—this represents a significant delay, and imaging workup must be initiated immediately because pulsatile tinnitus indicates an underlying vascular or structural abnormality in over 70% of cases, with potentially life-threatening causes including dural arteriovenous fistula and arterial dissection that can result in catastrophic hemorrhage or stroke. 1

Why This Is Urgent

• Pulsatile tinnitus is fundamentally different from common nonpulsatile tinnitus and almost always requires imaging evaluation, regardless of duration. 1
• The American Academy of Otolaryngology guidelines specify imaging for tinnitus that is unilateral, pulsatile, or associated with focal neurological abnormalities—pulsatile tinnitus meets these criteria automatically. 2
• Missing dural arteriovenous fistula is a life-threatening pitfall, as it can present with isolated pulsatile tinnitus before catastrophic hemorrhage, accounting for 8% of cases. 1
• Arterial dissection is another potentially fatal condition requiring urgent identification. 1

Immediate Clinical Assessment Required

The ENT specialist or neurologist should perform the following targeted evaluation:

• Determine if the tinnitus is truly synchronous with heartbeat (pulsatile) versus other rhythmic sounds, as this distinction fundamentally changes the diagnostic approach. 1
• Perform otoscopic examination to identify vascular retrotympanic masses (paragangliomas appear as vascular masses and account for 16% of pulsatile tinnitus cases). 1
• Assess for objective versus subjective tinnitus—if the examiner can hear it (objective), this strongly suggests vascular pathology requiring immediate workup. 1
• Test carotid and jugular compression—relief with compression suggests venous etiology (sigmoid sinus abnormalities) or arterial dissection. 1
• Auscultate the neck, periauricular region, and temporal area for bruits if pulsatile tinnitus is present. 3
• Perform cranial nerve examination focusing on hearing (CN VIII) and looking for focal neurological abnormalities. 3

Required Audiologic Testing

• Obtain comprehensive audiologic examination including pure tone audiometry, speech audiometry, and acoustic reflex testing, as this patient has persistent tinnitus (≥6 months). 2, 3
• Document any asymmetric hearing loss, which would require different imaging protocols. 1

First-Line Imaging Strategy

The American College of Radiology provides clear guidance on imaging selection:

• Order CT angiography (CTA) of head and neck with contrast as first-line when suspecting dural arteriovenous fistulas, arterial dissection, atherosclerotic carotid artery disease (most common cause at 17.5%), sigmoid sinus diverticulum/dehiscence, or arteriovenous malformations. 1
• Alternatively, order high-resolution CT temporal bone (non-contrast) as first-line for evaluating paragangliomas, glomus tumors, jugular bulb abnormalities, superior semicircular canal dehiscence, and aberrant vascular anatomy. 1
• CTA source images can be reconstructed to create dedicated temporal bone CT images without additional radiation exposure. 1

When to Escalate Imaging

• Reserve MRI with contrast and MR angiography for suspected cerebellopontine angle lesions, vascular malformations not identified on CT/CTA, contraindications to iodinated contrast, or when CT/CTA are negative but clinical suspicion remains high. 1
• Consider digital subtraction angiography (DSA) if initial vascular imaging is negative and a vascular etiology is strongly suspected. 4

Critical Pitfalls to Avoid

• Dismissing pulsatile tinnitus as benign is the most dangerous error—identifiable causes exist in >70% of cases. 1, 5
• Inadequate otoscopic examination can lead to delayed diagnosis of vascular retrotympanic masses (paragangliomas). 1
• Overlooking intracranial hypertension (second most common cause), particularly in young, overweight women with headaches, can lead to vision loss. 1
• Failing to recognize that bilateral pulsatile tinnitus still requires imaging, unlike bilateral nonpulsatile tinnitus. 1

Common Etiologies by Frequency

Based on diagnostic series:

• Atherosclerotic carotid artery disease: 17.5% of cases (turbulent flow). 1
• Highly vascularized skull base tumors (paragangliomas, glomus tumors): 16% of cases. 1, 6
• Idiopathic intracranial hypertension: Second most common cause overall. 1
• Venous normal variants and anomalies: 14% of cases. 6
• Dural arteriovenous fistulas: 8% of cases (can cause stroke). 1, 6

Timeline Context

At 9 months duration, this patient has already exceeded the 6-month threshold that defines "persistent" tinnitus in the American Academy of Otolaryngology guidelines. 2 However, the pulsatile nature—not the duration—is what mandates urgent imaging evaluation. 1 This evaluation should have occurred at initial presentation, not after 9 months of observation.