# Tinnitus: Evaluation and Management

## Introduction

**Tinnitus** is the perception of sound in the absence of an external acoustic stimulus. It affects approximately **10-15% of the adult population** and causes significant distress in 1-2%. Tinnitus is a symptom, not a diagnosis, and may reflect a wide range of underlying otologic, neurologic, vascular, or systemic conditions. A systematic evaluation is essential to identify treatable causes and guide management.

## Classification

### Subjective Tinnitus
Perceived only by the patient; accounts for **>95%** of cases. Most commonly associated with sensorineural hearing loss, Described as ringing, buzzing, hissing, or humming.

### Objective Tinnitus
Audible to the examiner (with or without a stethoscope). Causes: **pulsatile** (vascular malformations, paragangliomas, carotid stenosis, dural AV fistulas, IIH) or **non-pulsatile** (palatal myoclonus, middle ear myoclonus, patulous Eustachian tube). Pulsatile tinnitus synchronous with heartbeat mandates vascular imaging.

### By Duration
**Acute**: <6 months. **Chronic**: >6 months (more likely to become bothersome).

## Pathophysiology

### Central Gain Theory
Hearing loss reduces peripheral input from the cochlea. The central auditory system compensates by **increasing neural gain** (hyperexcitability). Spontaneous neural activity in the auditory cortex is perceived as tinnitus. Explains why most tinnitus accompanies hearing loss.

### Additional Mechanisms
**Cochlear damage**: outer hair cell loss disrupts normal tonotopic signaling. **Dorsal cochlear nucleus hyperactivity**: abnormal firing patterns. **Limbic system involvement**: emotional response amplifies tinnitus perception (fear, anxiety, depression). **Somatosensory modulation**: TMJ disorders, cervical spine issues can modulate tinnitus in some patients.

## Etiology

### Otologic Causes
**Noise-induced hearing loss**: most common identifiable cause. **Presbycusis**: age-related hearing loss. **Meniere disease**: low-frequency tinnitus with fluctuating hearing loss, vertigo, aural fullness. **Otosclerosis**: conductive hearing loss with tinnitus. **Vestibular schwannoma**: unilateral tinnitus with asymmetric SNHL. **Cerumen impaction or middle ear effusion**.

### Non-Otologic Causes
**Ototoxic medications**: aminoglycosides, cisplatin, salicylates, loop diuretics. **TMJ dysfunction**: tinnitus may be modulated by jaw movement. **Cardiovascular**: hypertension, atherosclerosis (pulsatile). **Neurologic**: multiple sclerosis, intracranial hypertension. **Metabolic**: thyroid disease, anemia, diabetes. **Psychiatric comorbidity**: anxiety, depression (both a cause and consequence).

![Flowchart for the differential diagnosis of tinnitus distinguishing subjective from objective and pulsatile from non-pulsatile](/images/tinnitus-differential-flowchart.jpg)

## Evaluation

### History
**Character**: ringing, buzzing, pulsatile, clicking. **Laterality**: unilateral vs. bilateral; unilateral requires vestibular schwannoma workup. **Duration and onset**: sudden vs. gradual. **Associated symptoms**: hearing loss, vertigo, aural fullness, headache. **Modulating factors**: position changes, jaw clenching, loud noise. **Medication history**: ototoxic drugs. **Impact assessment**: sleep disturbance, concentration, emotional distress; validated questionnaires (THI — Tinnitus Handicap Inventory).

### Physical Examination
**Otoscopy**: cerumen, TM abnormalities, middle ear mass (glomus tumor). **Auscultation**: periauricular and cervical bruit (pulsatile tinnitus). **TMJ examination**: crepitus, tenderness, malocclusion. **Cranial nerve assessment**: facial nerve, vestibulocochlear nerve. **Valsalva maneuver and positional changes**: effect on pulsatile tinnitus.

### Audiologic Assessment
**Comprehensive audiometry**: air and bone conduction, speech discrimination. **Tympanometry**: middle ear pathology. **Tinnitus pitch and loudness matching**. **Minimum masking level**: determines the level of external sound needed to mask the tinnitus.

### Imaging
**MRI with gadolinium** (IAC protocol): indicated for unilateral tinnitus, asymmetric hearing loss, or clinical concern for retrocochlear pathology (vestibular schwannoma). **CT temporal bone**: if pulsatile tinnitus with suspected glomus tumor, aberrant carotid, or dehiscent jugular bulb. **CT/MR angiography**: for pulsatile tinnitus to evaluate vascular causes (dural AV fistula, carotid stenosis, venous anomalies).

## Management

| Treatment | Mechanism | Evidence Level | Best For |
|-----------|-----------|---------------|----------|
| Hearing aids | Reduce central gain, amplify external sound | Strong | Tinnitus with hearing loss (first-line) |
| CBT | Reduce emotional response and catastrophizing | Strong (best evidence) | Tinnitus-related distress |
| TRT | Directive counseling + sound therapy for habituation | Moderate | Chronic bothersome tinnitus |
| Sound therapy | External enrichment, masking | Moderate | Nighttime symptoms, quiet environments |
| Antidepressants (SSRIs) | Treat comorbid anxiety/depression | Moderate | Tinnitus with psychiatric comorbidity |
| Neuromodulation (TMS, VNS) | Modulate auditory cortex excitability | Emerging | Refractory cases (investigational) |

### Treatable Causes
**Cerumen removal, otitis media treatment, ossicular chain repair**. **Vestibular schwannoma**: appropriate management (observation, radiation, surgery). **Glomus tumor**: surgery or observation. **Dural AV fistula**: endovascular embolization. **Medication adjustment**: discontinue or reduce ototoxic drugs. **TMJ therapy**: dental splint, physical therapy.

### Hearing Aids
**Most effective intervention** for patients with tinnitus and hearing loss. Amplification reduces the central gain imbalance that drives tinnitus perception. Even mild hearing loss should be treated when tinnitus is bothersome.

### Sound Therapy
**External sound enrichment**: background noise, nature sounds, fans. **Tinnitus maskers**: wearable devices producing broadband noise. **Combination devices**: hearing aid + sound generator. **Notched sound therapy**: filtered music with energy removed at the tinnitus frequency.

### Cognitive Behavioral Therapy (CBT)
**Strongest evidence base** for reducing tinnitus-related distress. Does not eliminate the tinnitus percept but reduces the emotional reaction. Addresses catastrophizing, sleep disruption, and avoidance behaviors. Can be delivered individually, in groups, or via internet-based programs.

### Tinnitus Retraining Therapy (TRT)
Based on the **neurophysiological model** (Jastreboff). Combines **directive counseling** with **sound therapy** to promote habituation. Goal: reclassify tinnitus as a neutral signal, reducing limbic system activation. Requires 12-24 months of therapy.

### Pharmacotherapy
**No FDA-approved medication** specifically for tinnitus. Antidepressants (SSRIs, tricyclics): may help when comorbid depression/anxiety is present. Benzodiazepines: short-term relief but not recommended long-term (habituation, dependence). Melatonin: may help with tinnitus-related sleep disturbance. Supplements (ginkgo biloba, zinc, B vitamins): insufficient evidence for routine use.

![Summary of evidence-based management strategies for tinnitus including hearing aids, CBT, and sound therapy](/images/tinnitus-management-summary.jpg)

## Emerging Therapies

**Neuromodulation**: transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), vagus nerve stimulation paired with tones. **Cochlear implants**: for patients with severe/profound hearing loss and debilitating tinnitus. **Pharmacologic targets**: NMDA antagonists, potassium channel modulators (investigational).

![Audiogram and tinnitus matching results in a patient with noise-induced hearing loss and tonal tinnitus at 4 kHz](/images/tinnitus-audiogram-matching.jpg)

## Key Clinical Pearls

**Unilateral tinnitus** with asymmetric hearing loss requires MRI to rule out vestibular schwannoma. **Pulsatile tinnitus** synchronous with heartbeat demands vascular imaging (CTA/MRA). **Hearing aids** are the most effective first-line treatment for tinnitus patients with hearing loss. **CBT** has the strongest evidence for reducing tinnitus-related distress and should be offered to all patients with bothersome tinnitus. There is **no FDA-approved drug** for tinnitus — counsel patients against unproven supplements and treatments. Address **comorbid depression, anxiety, and sleep disturbance** as part of comprehensive tinnitus management.

## References

1. Tunkel DE, Bauer CA, Sun GH, et al. Clinical practice guideline: tinnitus. *Otolaryngol Head Neck Surg*. 2014;151(2 Suppl):S1-S40.
2. Langguth B, Kreuzer PM, Kleinjung T, De Ridder D. Tinnitus: causes and clinical management. *Lancet Neurol*. 2013;12(9):920-930.
3. Cima RFF, Maes IH, Joore MA, et al. Specialised treatment based on cognitive behaviour therapy versus usual care for tinnitus: a randomised controlled trial. *Lancet*. 2012;379(9830):1951-1959.
4. Henry JA, Dennis KC, Schechter MA. General review of tinnitus: prevalence, mechanisms, effects, and management. *J Speech Lang Hear Res*. 2005;48(5):1204-1235.