What could cause unilateral tinnitus with bilateral hearing loss in a 54‑year‑old woman?

Unilateral Tinnitus with Bilateral Hearing Loss: Differential Diagnosis

The combination of unilateral tinnitus with bilateral hearing loss in a 54-year-old woman is highly atypical and should immediately trigger urgent evaluation for serious underlying pathology, particularly vestibular schwannoma, brainstem stroke, autoimmune inner ear disease, or systemic conditions—this is NOT idiopathic sudden hearing loss. 1, 2

Why This Presentation is a Red Flag

The bilateral nature of hearing loss fundamentally changes the diagnostic approach:

• Bilateral sudden sensorineural hearing loss represents only 1.7% of all sudden hearing loss cases and mandates urgent investigation for serious systemic disease 3
• Idiopathic sudden hearing loss is rarely bilateral or recurrent and typically presents with unilateral symptoms 3
• The unilateral tinnitus suggests asymmetric pathology, which increases suspicion for retrocochlear lesions like acoustic neuroma 1, 4

Life-Threatening Causes That Must Be Excluded Immediately

Vestibular Schwannoma (Acoustic Neuroma)

• Every case of asymmetric hearing loss or unilateral tinnitus requires screening for vestibular schwannoma using MRI with dedicated internal auditory canal protocol 1
• Individuals with vestibular schwannoma almost always have tinnitus, and unilateral tinnitus with any hearing loss pattern should heighten suspicion 5, 4

Brainstem Stroke

• Acute brainstem stroke can present with sudden hearing loss and requires immediate neuroimaging to prevent irreversible damage 1
• Look for accompanying focal neurologic signs: dysarthria, hemiataxia, encephalopathy, severe headaches, focal weakness, diplopia, or downbeating/gaze-evoked nystagmus 6, 2
• The combination of bilateral hearing loss with any neurologic symptoms strongly suggests brainstem involvement and mandates immediate MRI 2

Autoimmune Inner Ear Disease

• Autoimmune inner ear disease may present initially with unilateral hearing loss that later becomes fluctuating and bilateral, often with vertigo 1
• Ask specifically about prior episodes of fluctuating hearing loss, as this feature should raise suspicion for Meniere disease, autoimmune inner ear disease, Cogan syndrome, or hyperviscosity syndromes 6
• Cogan syndrome causes nonsyphilitic interstitial keratitis, bilateral hearing loss, and vertigo—ask about recent eye pain, redness, lacrimation, and photophobia 6, 2

Meningitis

• Infectious, inflammatory, or neoplastic meningitis may manifest with unilateral or bilateral hearing loss accompanied by headache, fever, and possible cranial nerve deficits 1, 3

Other Important Causes to Consider

Ototoxic Medications

• Aminoglycoside antibiotics and cisplatin can cause bilateral sensorineural hearing loss, frequently with concurrent vestibular loss and oscillopsia 1, 2
• Review medication history carefully 3

Trauma

• Significant head trauma, basal skull fractures, or temporal bone fractures are recognized precipitants—ask about recent severe head trauma 1, 2
• Barotrauma from rapid pressure changes can also cause abrupt hearing loss 1

Systemic Autoimmune Disease

• Rheumatoid arthritis can cause autoimmune inner ear disease presenting as bilateral SNHL with tinnitus 7
• Recurrent episodes of sudden hearing loss are a red flag for autoimmune etiology 3

Mandatory Immediate Workup Algorithm

Step 1: Otoscopic Examination

• Remove impacted cerumen if present before establishing diagnosis—patients with sensorineural hearing loss will almost always have normal otoscopic examination 6
• Perform Weber and Rinne tuning fork tests to differentiate conductive from sensorineural loss 6

Step 2: Audiometric Confirmation

• Pure tone audiometry must be performed to confirm sensorineural hearing loss and identify patterns—diagnosis requires 30-dB hearing loss at 3 consecutive frequencies 2, 3
• Perform comprehensive audiometry within 14 days of symptom onset 3

Step 3: Urgent MRI

• MRI with dedicated internal auditory canal protocol is mandatory to exclude vestibular schwannoma, brainstem stroke, or structural lesions—do NOT order routine CT of the head 1, 2, 3
• MRI is rated "usually appropriate" for bilateral sudden hearing loss by the American College of Radiology 2

Step 4: Laboratory Workup

• Obtain antinuclear antibody (ANA) titer and syphilis serology 3
• Consider additional autoimmune markers if clinical features suggest systemic disease 3

Step 5: Immediate Treatment (If Within 2 Weeks of Onset)

• Initiate systemic corticosteroids immediately if within 2 weeks of onset while awaiting workup results 2, 3
• High-dose corticosteroids are first-line therapy for autoimmune inner ear disease 2

Critical Pitfalls to Avoid

• Do NOT assume this is benign cerumen impaction or idiopathic sudden hearing loss—new-onset ear fullness with bilateral hearing loss warrants immediate audiometric testing and imaging 1
• Do NOT treat bilateral sudden hearing loss with corticosteroids alone without comprehensive workup 3
• Do NOT delay MRI—unilateral tinnitus with bilateral hearing loss is NOT a typical presentation and requires urgent imaging 1, 4, 8

Specialist Referrals

• Otolaryngology referral should be made immediately/same day for bilateral sudden hearing loss 3
• Rheumatology referral within 1-2 weeks if autoimmune features are present (bilateral presentation, fluctuating hearing loss, recurrent episodes, or positive autoimmune markers) 3, 7
• Neurology referral if focal neurologic signs are present 2