What are the possible causes of left-sided unilateral tinnitus in a 54-year-old woman with a dull headache?

Unilateral Left-Sided Buzzing Tinnitus with Dull Headache in a 54-Year-Old Woman

This patient requires urgent imaging evaluation with either high-resolution CT temporal bone or CT angiography of the head and neck, because unilateral tinnitus combined with headache raises concern for serious vascular pathology (including arterial dissection, dural arteriovenous fistula, or intracranial hypertension), vestibular schwannoma, or other structural abnormalities that demand prompt identification. 1, 2

Critical Diagnostic Considerations

High-Priority Vascular and Structural Causes

The combination of unilateral tinnitus and headache creates a clinical picture that cannot be dismissed as benign:

• Idiopathic intracranial hypertension (IIH) is the second most common cause of pulsatile tinnitus and is particularly prevalent in middle-aged women with headaches, potentially causing permanent vision loss if missed 2
• Dural arteriovenous fistula accounts for 8% of pulsatile tinnitus cases and represents a life-threatening condition that can lead to hemorrhagic or ischemic stroke if untreated 2
• Arterial dissection is a potentially catastrophic vascular emergency requiring urgent identification 2
• Vestibular schwannoma (acoustic neuroma) almost always causes unilateral tinnitus with asymmetric hearing loss and must be excluded 3, 4
• Atherosclerotic carotid artery disease is the most frequent cause of pulsatile tinnitus (17.5% of cases), resulting from turbulent flow 2

Essential Clinical Characterization

First, determine if the tinnitus is pulsatile (synchronous with heartbeat) or non-pulsatile, as this fundamentally changes the diagnostic urgency and imaging strategy 2, 5:

• Pulsatile tinnitus has an identifiable structural or vascular cause in over 70% of cases and requires immediate vascular imaging 2
• Non-pulsatile buzzing is more commonly associated with sensorineural hearing loss but still requires investigation when unilateral 1, 4

Key history elements to elicit immediately 2, 6:

• Does the sound pulse with your heartbeat?
• Does jugular or carotid compression change the sound? (Relief suggests venous etiology or arterial dissection)
• Any vision changes, particularly transient visual obscurations? (Suggests IIH)
• Any hearing loss, fullness, or vertigo? (Suggests Meniere's disease or vestibular schwannoma)
• Does jaw movement or yawning worsen the tinnitus? (Suggests TMJ dysfunction or vascular abnormalities)

Immediate Diagnostic Workup

Required Initial Testing

Comprehensive audiologic examination within 4 weeks including pure tone audiometry, speech audiometry, and acoustic reflex testing is mandatory for any unilateral tinnitus 2, 4:

• Asymmetric hearing loss dramatically increases concern for vestibular schwannoma and changes the imaging protocol to MRI with contrast of the internal auditory canals 2, 3

Thorough otoscopic examination to identify 1, 2:

• Vascular retrotympanic masses (paragangliomas appear as reddish pulsatile masses behind the tympanic membrane)
• Cerumen impaction (simple reversible cause)
• Middle ear effusion or infection

Neurologic examination to detect focal deficits suggesting intracranial pathology 2, 4:

• Any focal neurologic abnormalities shift the evaluation away from tinnitus-specific protocols to emergent stroke/mass evaluation

Imaging Decision Algorithm

If tinnitus is pulsatile OR patient has headache with unilateral tinnitus 2:

1. First-line: CT angiography (CTA) of head and neck with contrast using mixed arterial-venous phase (20-25 seconds post-contrast) to capture both arterial and venous pathology in a single acquisition 2

   • This evaluates for: dural AVF, arterial dissection, atherosclerotic carotid disease, sigmoid sinus abnormalities, arteriovenous malformations
   • CTA source images can be reconstructed to create temporal bone CT images without additional radiation 2

2. Alternative first-line: High-resolution CT temporal bone (non-contrast) if suspecting 2:

   • Paragangliomas or glomus tumors
   • Jugular bulb abnormalities
   • Superior semicircular canal dehiscence
   • Sigmoid sinus diverticulum or dehiscence

If audiometry shows asymmetric hearing loss 2, 3:

• MRI of internal auditory canals with contrast becomes the priority imaging study to exclude vestibular schwannoma

If initial CT/CTA is negative but clinical suspicion remains high 2:

• Proceed to MRI brain with contrast and MR angiography/venography to evaluate for subtle vascular malformations, cerebellopontine angle lesions, or venous sinus abnormalities

Most Likely Etiologies in This Patient

Primary Differential Diagnoses

For non-pulsatile buzzing 3, 4, 5:

1. Sensorineural hearing loss (most common cause of subjective tinnitus, particularly in this age group with presbycusis risk)
2. Vestibular schwannoma (unilateral presentation is classic)
3. Meniere's disease (if accompanied by episodic vertigo and hearing loss)

For pulsatile component (if present) 2, 7:

1. Idiopathic intracranial hypertension (given middle-aged woman with headache)
2. Atherosclerotic carotid disease (age-appropriate risk)
3. Sigmoid sinus diverticulum or dehiscence
4. Dural arteriovenous fistula (life-threatening, cannot miss)

Headache-specific considerations 2:

• The combination of unilateral tinnitus and headache in a 54-year-old woman creates moderate-to-high pretest probability for IIH, which can cause permanent vision loss if untreated
• IIH-related tinnitus responds dramatically to treatment in nearly 100% of cases when truly pulsatile 2

Critical Pitfalls to Avoid

Never dismiss unilateral tinnitus as benign without proper evaluation, as treatable and life-threatening causes are common 2, 4:

• Pulsatile tinnitus almost always requires imaging due to identifiable causes in >70% of cases
• Missing dural AVF can result in catastrophic hemorrhage

Do not order imaging for bilateral, symmetric, non-pulsatile tinnitus without localizing features, but this patient's unilateral presentation does NOT fit that low-risk profile 1, 2

Do not delay audiometry waiting for arbitrary time periods—unilateral tinnitus warrants prompt comprehensive audiologic examination within 4 weeks 2, 4

Inadequate otoscopic examination can lead to delayed diagnosis of paragangliomas (vascular retrotympanic masses) that are visible on direct examination 2

Overlooking vision symptoms in a middle-aged woman with headache and tinnitus can result in permanent vision loss from untreated IIH 2

Management Approach Based on Findings

Treatment must target the underlying cause rather than just symptom management 6:

• Vestibular schwannoma: Surgical resection, radiation therapy, or observation depending on size
• IIH: Weight loss, acetazolamide, or surgical intervention (optic nerve sheath fenestration or CSF shunting)
• Paragangliomas: Surgical resection, radiation therapy, or observation 2
• Sigmoid sinus abnormalities: Surgical repair or stenting in severe cases 2
• Sensorineural hearing loss: Hearing aid evaluation provides significant relief even for mild or unilateral loss 2

Do not routinely recommend medications like antidepressants, anxiolytics, or dietary supplements (Ginkgo biloba, melatonin, zinc) as primary treatment without addressing the underlying cause 6, 4

Cognitive behavioral therapy is the only treatment proven to improve quality of life in patients with tinnitus, but only after excluding serious pathology 4