What is the diagnosis for a patient presenting with unilateral tinnitus characterized by a pulsatile sound, accompanied by headache, dizziness, and potentially elevated blood pressure, with a possible history of hypertension, diabetes, or previous vascular events?

Pulsatile Tinnitus with Headache and Dizziness

This patient has pulsatile tinnitus, and the most likely diagnosis is atherosclerotic carotid artery disease (17.5% of cases) or idiopathic intracranial hypertension (second most common cause), though life-threatening conditions like dural arteriovenous fistula, arterial dissection, or arteriovenous malformation must be urgently excluded through immediate imaging. 1

Immediate Diagnostic Approach

Order CT angiography (CTA) of the head and neck with contrast as the first-line imaging study. 1 This single study captures both arterial and venous pathology and can identify:

• Dural arteriovenous fistulas (8% of cases, can cause hemorrhagic or ischemic stroke if missed) 1
• Arterial dissection (life-threatening, requires urgent identification) 1
• Atherosclerotic carotid disease (most common cause at 17.5%) 1
• Arteriovenous malformations (high-flow lesions with 2-3% annual hemorrhage risk) 1
• Sigmoid sinus diverticulum or dehiscence 1
• Venous sinus abnormalities associated with intracranial hypertension 1

Critical Clinical Features Supporting This Diagnosis

Unilateral pulsatile tinnitus has a higher likelihood of identifiable structural or vascular cause compared to bilateral presentation. 1 The combination of:

• Pulsatile quality (synchronous with heartbeat) 1
• Unilateral presentation 1
• Associated headache and dizziness 1
• "Washing" or pulse-like sound 1

This constellation mandates urgent imaging because over 70% of pulsatile tinnitus cases have identifiable causes, and missing life-threatening etiologies can result in catastrophic hemorrhage or stroke. 1

High-Risk Conditions to Exclude Immediately

Dural Arteriovenous Fistula

• Accounts for 8% of pulsatile tinnitus cases 1
• Can present with isolated pulsatile tinnitus before catastrophic hemorrhage 1
• Requires high index of suspicion and appropriate vascular imaging 1
• Missing this diagnosis is a life-threatening pitfall 1

Arterial Dissection

• Potentially life-threatening condition requiring urgent identification 1
• Can present with pulsatile tinnitus, headache, and dizziness 1
• May be relieved by carotid compression 1

Idiopathic Intracranial Hypertension

• Second most common cause of pulsatile tinnitus 1
• Associated with sigmoid sinus wall abnormalities 1
• Can lead to vision loss if missed 1
• Particularly suspect in young, overweight women with headaches 1

Physical Examination Maneuvers

Perform these specific assessments:

• Carotid/jugular compression test: Tinnitus relieved by compression suggests venous etiology (sigmoid sinus abnormalities, jugular bulb variants) or arterial dissection 1
• Otoscopic examination: Look for vascular retrotympanic masses (paragangliomas appear as red pulsatile masses behind tympanic membrane) 1
• Auscultation: Attempt to hear objective tinnitus (audible to examiner), which strongly suggests vascular pathology requiring immediate workup 1

Risk Factors and Associated Conditions

The patient's potential history of hypertension and diabetes are relevant:

• Hypertension prevalence is 44.4% in tinnitus patients versus 31.4% in controls 2
• Hypertension is particularly associated with pulsatile tinnitus in older patients 2
• Diabetes causes microangiopathy of the inner ear and increases tinnitus likelihood 3
• Both conditions can cause cochlear microcirculation changes 4, 5

However, these systemic conditions are more commonly associated with non-pulsatile tinnitus. The pulsatile nature of this patient's tinnitus indicates a structural vascular abnormality that requires imaging regardless of comorbidities. 1

If Initial CTA is Negative

Proceed to MRI brain with contrast and MR angiography (MRA) if CTA is negative but clinical suspicion remains high. 1 This evaluates for:

• Cerebellopontine angle lesions 1
• Vascular malformations not identified on CT/CTA 1
• Subtle venous sinus abnormalities 1

Common Pitfalls to Avoid

• Never dismiss pulsatile tinnitus as benign - it almost always requires imaging evaluation due to identifiable causes in >70% of cases 1
• Do not perform inadequate otoscopic examination - this leads to delayed diagnosis of vascular retrotympanic masses (paragangliomas) 1
• Do not miss dural AVF - requires high index of suspicion as it can present with isolated pulsatile tinnitus before catastrophic hemorrhage 1
• Do not overlook intracranial hypertension - particularly in young, overweight women with headaches, as this can lead to vision loss 1

Audiometric Testing

Order comprehensive audiologic examination including pure tone audiometry, speech audiometry, and acoustic reflex testing. 6 This is recommended for all unilateral or persistent tinnitus to document asymmetric hearing loss, which would require different imaging protocols. 1, 6