What is tinnitus and how is it treated?

What is Tinnitus and How to Treat It

Definition and Classification

Tinnitus is the perception of sound in the absence of an external acoustic stimulus—it is not a disease but a symptom of an underlying condition that affects 10-15% of adults and requires clinical intervention in approximately 20% of cases. 1

Tinnitus is classified into two main types:

• Subjective tinnitus is perceived only by the patient, comprises 70-80% of cases, and is most commonly associated with sensorineural hearing loss 2
• Objective tinnitus is audible to the examining clinician and should prompt immediate evaluation for underlying vascular abnormalities 1

Further classification distinguishes:

• Pulsatile tinnitus: repetitive sound coinciding with heartbeat, often vascular in origin, requiring urgent imaging evaluation because over 70% have identifiable structural or vascular causes including life-threatening conditions like dural arteriovenous fistulas or arterial dissection 3
• Non-pulsatile tinnitus: continuous or constant non-synchronous sound, most commonly associated with sensorineural hearing loss 1

Patients describe the sound quality variably as ringing, buzzing, clicking, pulsations, hissing, humming, whistling, or roaring 1, 2

Primary Causes

Sensorineural hearing loss (SNHL) is the most common underlying cause of tinnitus, with various etiologies including: 1

• Presbycusis (age-related hearing loss) is the most frequent etiology in older adults 1
• Noise exposure (occupational or recreational including concerts and firearms) causes both tinnitus and hearing loss 1
• Sudden sensorineural hearing loss can trigger acute tinnitus 1
• Cochlear synaptopathy ("hidden hearing loss") triggers irreversible auditory nerve fiber degeneration without affecting outer hair cells, leading to difficulty understanding speech in noisy environments 1

Secondary and Dangerous Causes Requiring Urgent Evaluation

For pulsatile tinnitus, the American College of Radiology identifies these potentially life-threatening vascular causes: 3

• Atherosclerotic carotid artery disease (most frequent cause at 17.5% of pulsatile cases) 3
• Arterial dissection (potentially life-threatening, requires urgent identification) 3
• Dural arteriovenous fistulas (8% of cases, can lead to hemorrhagic or ischemic stroke if untreated) 3
• Paragangliomas and glomus tumors (highly vascularized skull base tumors, 16% of cases) 3
• Idiopathic intracranial hypertension (second most common cause of pulsatile tinnitus) 3

Other structural causes include:

• Otosclerosis causing conductive hearing loss 1
• Superior semicircular canal dehiscence (bony defect allowing transmission of vascular sounds) 3
• Jugular bulb abnormalities and sigmoid sinus diverticulum or dehiscence 3
• Ototoxic medications 1

Psychogenic factors:

• Anxiety and depression contribute to tinnitus and require prompt identification due to increased suicide risk 1

Clinical Evaluation Algorithm

Step 1: Determine Urgency Based on Tinnitus Characteristics

For pulsatile tinnitus (objective or subjective): Proceed immediately to imaging evaluation as this indicates underlying vascular or structural abnormality in over 70% of cases 3

For non-pulsatile tinnitus: Assess for the following red flags requiring imaging: 4

• Unilateral or asymmetric presentation
• Associated with focal neurologic abnormalities
• Associated with asymmetric hearing loss
• Present for 6 months or longer

Step 2: Physical Examination Specifics

• Otoscopic examination to identify vascular retrotympanic masses (paragangliomas appear as vascular masses behind tympanic membrane) 3
• Carotid and jugular compression test: tinnitus relieved by compression suggests venous etiology (sigmoid sinus abnormalities, jugular bulb variants) or arterial dissection 3
• Assess for objective tinnitus by listening with stethoscope over temporal area, periauricular region, and neck 3
• Screen for anxiety and depression given increased suicide risk in severe cases 1

Step 3: Audiologic Testing

Comprehensive audiologic evaluation is indicated for: 4

• Unilateral tinnitus
• Tinnitus present for 6 months or longer
• Any accompanying hearing problems

Step 4: Imaging Decision Algorithm

For pulsatile tinnitus, order as first-line imaging: 3

• High-resolution CT temporal bone (non-contrast) when suspecting: paragangliomas, glomus tumors, jugular bulb abnormalities, superior semicircular canal dehiscence, or aberrant vascular anatomy 3
• CT angiography (CTA) of head and neck with contrast when suspecting: dural arteriovenous fistulas, arterial dissection, atherosclerotic carotid disease, sigmoid sinus diverticulum/dehiscence, or arteriovenous malformations 3

For non-pulsatile tinnitus: 4

• Imaging is not typically indicated for subjective, non-pulsatile, bilateral tinnitus without localizing features 3
• Imaging is indicated if unilateral/asymmetric, associated with focal neurologic abnormalities, or associated with asymmetric hearing loss 4

Reserve MRI with contrast and MR angiography for: 3

• Suspected cerebellopontine angle lesions or acoustic neuroma
• Vascular malformations not identified on CT/CTA
• When CT/CTA are negative but clinical suspicion remains high

Treatment Approach

Evidence-Based Treatments

Cognitive behavioral therapy (CBT) is the only treatment that has been shown to improve quality of life in patients with tinnitus and should be the primary therapeutic intervention. 4

The American College of Radiology recommends a combination of sound therapy and CBT-based counseling as having the strongest evidence base, although clinical trials are constrained by patient heterogeneity 5

Adjunctive Therapies

• Hearing aids when hearing loss is identified (even mild or unilateral hearing loss) 5
• Wide-band sound therapy can provide symptomatic relief 5
• Tinnitus retraining therapy is a treatment option, though evidence is inconclusive 4
• Melatonin may help with sleep disturbance 4
• Antidepressants may help with mood disorders 4

Specific Treatments for Identified Causes

• Paragangliomas or glomus tumors: surgical resection, radiation therapy, or observation depending on size and symptoms 3
• Superior semicircular canal dehiscence: surgical repair if symptoms are debilitating 3
• Sigmoid sinus diverticulum: surgical repair or stenting in severe cases 3

Prevention

Avoidance of noise exposure may help prevent the development or progression of tinnitus. 4

Critical Pitfalls to Avoid

• Missing dural arteriovenous fistula: This life-threatening cause requires high index of suspicion and appropriate vascular imaging, as it can present with isolated pulsatile tinnitus before catastrophic hemorrhage 3
• Dismissing pulsatile tinnitus as benign: Pulsatile tinnitus almost always requires imaging evaluation due to identifiable causes in >70% of cases 3
• Inadequate otoscopic examination: Can lead to delayed diagnosis of vascular retrotympanic masses (paragangliomas) and inappropriate imaging selection 3
• Overlooking intracranial hypertension: Particularly in young, overweight women with headaches, can lead to vision loss if missed 3
• Failing to screen for severe anxiety or depression: These patients require prompt identification and intervention due to increased suicide risk 1
• Abrupt benzodiazepine discontinuation: Withdrawal from clonazepam can cause same-night relapse of tinnitus symptoms; gradual tapering is essential 2