Tinnitus: Differential Diagnosis, Diagnostic Testing, and Treatment
Critical First Step: Classify the Tinnitus Type
The most important initial determination is whether tinnitus is pulsatile or non-pulsatile, as pulsatile tinnitus requires urgent imaging evaluation due to identifiable structural or vascular causes in over 70% of cases, including life-threatening conditions like dural arteriovenous fistulas and arterial dissection. 1, 2
Key Clinical Features to Determine:
- Pulsatile vs. non-pulsatile: Synchronous with heartbeat indicates vascular pathology 1, 2
- Objective vs. subjective: If audible to examiner (objective), this strongly suggests vascular pathology requiring immediate workup 2
- Unilateral vs. bilateral: Unilateral has higher likelihood of identifiable structural cause 2
- Recent onset (<6 months) vs. persistent (≥6 months): Determines urgency and intervention intensity 1, 3
- Associated hearing loss or difficulties: Guides need for audiometric testing 1
- Bothersome vs. non-bothersome: Prioritizes intervention 1, 3
Differential Diagnosis
Non-Pulsatile Tinnitus (Most Common)
- Sensorineural hearing loss - most common identified cause overall 1, 4, 5
- Noise exposure - occupational or recreational 1
- Age-related hearing loss (presbycusis) 1, 6
- Ototoxic medications - aminoglycosides, loop diuretics, chemotherapy agents 1, 6
- Meniere's disease - associated with vertigo and fluctuating hearing loss 5, 6
- Temporomandibular joint dysfunction 1
- Eustachian tube dysfunction 1
- Cerumen impaction - easily treatable cause 6
- Middle ear effusion 6
- Acoustic neuroma (vestibular schwannoma) - especially with unilateral presentation 5, 6
Pulsatile Tinnitus (Requires Urgent Evaluation)
Arterial Causes:
- Atherosclerotic carotid artery disease - most frequent cause at 17.5% of pulsatile cases 2, 3
- Arterial dissection - life-threatening, requires urgent identification 2, 3
- Arteriovenous malformations - high-flow vascular lesions 2
Arteriovenous Causes:
- Dural arteriovenous fistulas - 8% of cases, can lead to hemorrhagic or ischemic stroke if untreated 2, 3
Venous Causes:
- Idiopathic intracranial hypertension (pseudotumor cerebri) - second most common cause, particularly in young overweight women with headaches 2, 3
- Sigmoid sinus diverticulum or dehiscence - commonly associated with intracranial hypertension 2
- Jugular bulb abnormalities - high-riding jugular bulb or dehiscence of sigmoid plate 2
- Aberrant venous anatomy - persistent petrosquamosal sinus, abnormal emissary veins 2
Structural/Neoplastic Causes:
- Paragangliomas (glomus tympanicum/jugulare) - 16% of pulsatile cases, appear as vascular retrotympanic masses on otoscopy 2
- Adenomatous middle ear tumors - less common vascular masses 2
- Superior semicircular canal dehiscence - bony defect allowing transmission of vascular sounds 2
Diagnostic Testing Algorithm
Step 1: Initial Clinical Assessment (All Patients)
- Targeted history: Determine onset, quality of sound, noise exposure, medications, exacerbating factors, psychological impact, medical conditions 1
- Otoscopic examination: Critical to identify vascular retrotympanic masses (paragangliomas) and avoid delayed diagnosis 2
- Neurologic examination: Identify focal deficits suggesting intracranial pathology 2
- Auscultation: Listen over ears, neck, and skull for objective tinnitus 2, 7
- Jugular/carotid compression test: Relief suggests venous etiology or arterial dissection 2
Step 2: Audiometric Testing
Order comprehensive audiologic examination (pure tone audiometry, speech audiometry, acoustic reflex testing) for: 1, 3, 4
- Unilateral tinnitus
- Persistent tinnitus (≥6 months)
- Tinnitus associated with hearing difficulties
- Timing: Within 4 weeks for unilateral or asymmetric presentation 2
Step 3: Imaging Decision Tree
DO NOT IMAGE if: 1, 2
- Bilateral, symmetric, non-pulsatile tinnitus
- No localizing features
- No hearing loss
- No neurological abnormalities
URGENT IMAGING REQUIRED for: 1, 2, 3
Pulsatile Tinnitus Imaging Strategy:
First-line: High-resolution CT temporal bone (non-contrast) when suspecting: 2
- Paragangliomas or glomus tumors
- Jugular bulb abnormalities
- Superior semicircular canal dehiscence
- Aberrant vascular anatomy
First-line: CT angiography (CTA) head and neck with contrast when suspecting: 2
- Dural arteriovenous fistulas
- Arterial dissection
- Atherosclerotic carotid disease
- Sigmoid sinus diverticulum or dehiscence
- Arteriovenous malformations
- Use mixed arterial-venous phase (20-25 seconds post-contrast) to capture both arterial and venous pathology 2
Second-line: MRI with contrast and MR angiography (MRA) reserved for: 2
- Cerebellopontine angle lesions (acoustic neuroma)
- Vascular malformations not identified on CT/CTA
- Contraindications to iodinated contrast
- Negative CT/CTA but high clinical suspicion remains
Non-Pulsatile Tinnitus Imaging:
- MRI internal auditory canals with contrast for: 2
- Unilateral or asymmetric tinnitus
- Asymmetric hearing loss
- To evaluate for retrocochlear pathology (vestibular schwannoma)
Treatment Approach
Non-Pulsatile Tinnitus Management
Primary Treatment (Evidence-Based):
- Cognitive behavioral therapy (CBT) - only treatment proven to improve quality of life 3, 4
- Education and counseling - mandatory for all patients with persistent bothersome tinnitus about mechanisms, natural history, and management strategies 1, 3
Hearing-Related Interventions:
- Hearing aids - recommended for patients with any degree of hearing loss (even mild or unilateral), provide significant relief with strong evidence 2, 4
- Sound therapy and tinnitus retraining therapy - treatment options but evidence is inconclusive 4
Adjunctive Treatments:
- Melatonin - may help with sleep disturbance 4
- Antidepressants - for associated mood disorders 4
- Cognitive training - for cognitive impairments 4
Preventive Measures:
- Noise exposure avoidance - may prevent development or progression 4
Pulsatile Tinnitus Treatment
Treatment is cause-specific based on imaging findings: 2
- Paragangliomas/glomus tumors: Surgical resection, radiation therapy, or observation depending on size and symptoms 2
- Superior semicircular canal dehiscence: Surgical repair if symptoms debilitating 2
- Sigmoid sinus diverticulum: Surgical repair or stenting in severe cases 2
- Idiopathic intracranial hypertension: Responds dramatically to treatment in nearly 100% of cases when truly pulsatile 2
- Dural AVF or AVM: Requires catheter angiography for definitive diagnosis and endovascular or surgical treatment 2
Red Flags Requiring Urgent Evaluation
Immediate escalation needed for: 1, 3
- Sudden onset unilateral tinnitus with hearing loss
- Pulsatile tinnitus (especially objective tinnitus audible to examiner)
- Focal neurological deficits
- Severe anxiety or depression associated with tinnitus
Critical Pitfalls to Avoid
- Missing dural AVF - life-threatening cause requiring high index of suspicion; can present with isolated pulsatile tinnitus before catastrophic hemorrhage 2
- Dismissing pulsatile tinnitus as benign - nearly always requires imaging due to identifiable causes in >70% of cases 2
- Inadequate otoscopic examination - leads to delayed diagnosis of vascular retrotympanic masses (paragangliomas) 2
- Overlooking intracranial hypertension - particularly in young overweight women with headaches; can lead to vision loss if missed 2
- Ordering imaging for bilateral symmetric non-pulsatile tinnitus - represents inappropriate resource utilization with no benefit 2
- Delaying audiometry - obtain within 4 weeks for unilateral presentation even when patients don't report hearing difficulties 2