Tinnitus

Aka: Tinnitus, Ear Ringing

1. Definition
   1. Ringing in the ears, unrelated to external sounds
2. Epidemiology
   1. Moderate tinnitus Prevalence: 8% of age over 48 years old (U.S.)
   2. Older adults typically have persistent Tinnitus (rather than transient)
3. Pathophysiology
   1. CNS maladaptive response to insufficient, distorted or abnormal signals from the ear
4. Causes
   1. Subjective Tinnitus (audible only to patient)
      1. Primary ear conditions
         1. Sensorineural Hearing Loss (Presbycusis, occupational noise exposure)
            1. Most common Tinnitus cause
         2. Cerumen Impaction (or after cerumen removal)
         3. Meniere's Disease
         4. Acoustic Neuroma (Vestibular Schwannoma)
      2. Ototoxic
         1. See Ototoxic Medications
      3. Musculoskeletal Injury
         1. Head Injury
         2. Neck Injury
         3. Temporomandibular Joint Dysfunction
      4. Neurologic
         1. Multiple Sclerosis
         2. Vestibular Migraine
         3. Type I Chiari Malformation
         4. Idiopathic Intracranial Hypotension (Postdural Puncture Headache)
         5. Pseudotumor Cerebri
      5. Infectious
         1. Various infections have been associated including Syphilis
      6. Metabolic
         1. Hypothyroidism
         2. Vitamin B12 Deficiency
         3. Diabetes Mellitus
   2. Objective Tinnitus (actual internal sound heard, accounts for only 1% of cases)
      1. Arterial Bruit (e.g. Carotid Stenosis)
      2. Venous Hum
      3. Arteriovenous malformation
      4. Arterial dissection (e.g. carotid dissection, vertebrobasilar dissection)
      5. Palatal Myoclonus
      6. Spasm of stapedius muscle or tensor tympani muscle
      7. Patulous eustachian tube
5. History
   1. Associated events or exposures
      1. Chronic noise exposure or acoustic Trauma
      2. Recurrent otitis meda
      3. Head Injury or neck injury
      4. Preceding dental work
      5. Ototoxic Medications
   2. Associated symptoms
      1. Hyperacusis
      2. Temporomandibular Joint Dysfunction
      3. Headaches
         1. Idiopathic Intracranial Hypotension (Postdural Puncture Headache)
         2. Pseudotumor Cerebri
      4. Hearing Loss
         1. Most common cause of Tinnitus
      5. Vertigo
         1. Meniere Disease
         2. Vestibular Schwannoma
   3. Tinnitus characteristics (see history below)
      1. Bilateral (most common) or unilateral
      2. High pitched (most common) or low pitched
      3. Pulsatile, fluttering, clicking or crunching
6. History: Tinnitus Distribution
   1. Bilateral Tinnitus in two thirds of cases
   2. Unilateral causes
      1. Somatosensory (e.g. TMJ, head or neck injury)
      2. Acoustic Neuroma
      3. Meniere Disease
7. History: Tinnitus Frquency
   1. Middle or high frequency ringing or buzzing (e.g. cicada-like)
      1. Most common form of Tinnitus
      2. Inner ear etiology
      3. Often results from Ototoxic Drug (e.g. Aspirin)
   2. Low pitched or frequency Tinnitus
      1. Conductive Hearing Loss (roaring sounds)
      2. Meniere Disease
8. History: Pulsatile Tinnitus
   1. Pulsating sounds (especially unilateral in synchrony with heart beat)
      1. Vascular loop adjacent to Cranial Nerve VIII (see work-up under imaging)
      2. Cardiac murmur
      3. Carotid Bruit
      4. Cerebral Aneurysm
      5. Fistula or AV malformation
   2. Pulsating alone
      1. Increased fluid pressure at middle ear
   3. Pulsating, high pitched, irregular sounds
      1. Otosclerosis
9. History: Other Tinnitus characteristics
   1. Fluttering Tinnitus
      1. Intermittent spasm of tensor tympani muscle
      2. Associated with eye irritation or acute anxiety
   2. Clicking Tinnitus
      1. Palatal Myoclonus
         1. Rapid rhythmic twitching of ipsilateral Palate
      2. May respond to mild Sedation
   3. Crunching Tinnitus
      1. Temporomandibular JointArthritis
      2. Foreign body (e.g. hair) rubbing against TM
10. History: Tinnitus and Hearing Loss
    1. Tinnitus and unilateral Sensorineural Hearing Loss
       1. Acoustic Neuroma
    2. Roaring or low pitched Tinnitus, Hearing Loss and Vertigo
       1. Meniere's Disease
    3. Bilateral subjective Tinnitus without Hearing Loss
       1. Endocrine causes (e.g. Hypothyroidism)
       2. Ototoxic Medications
       3. Mood Disorder
11. Exam
    1. Otoscopy
       1. Cerumen Impaction
       2. Otitis Media
       3. Cholesteatoma
    2. Neurologic Exam
       1. Fundoscopic exam (for Papilledema)
       2. Visual field cut
       3. Cranial Nerve deficit
       4. Finger-Nose-Finger Test
    3. Head and neck exam
       1. Provocative maneuver testing (e.g. Tinnitus on jaw clenching, neck range of motion)
       2. Carotid Bruit
    4. Tympanometry
    5. Hearing Testing
    6. Tuning Fork Tests
12. Labs
    1. Complete Blood Count
    2. Thyroid Stimulating Hormone
    3. Lipid profile
13. Diagnostics
    1. Pure tone Audiometry (Formal audiology testing)
       1. Asymmetric Hearing Loss may suggest Acoustic Neuroma
          1. Average difference >10 dB over 1 to 8 KHz range (high Test Sensitivity for Acoustic Neuroma)
          2. Average difference >15 dB over 0.5 to 3 KHz range (high Test Specificity for Acoustic Neuroma)
          3. Cheng (2012) Otolaryngol Head Neck Surg 146(3): 438-47 [PubMed]
    2. Electronystagmography
       1. Group of 4 tests of eye movement in response to external stimuli
       2. Consider if Meniere Disease is suspected
          1. Meniere Disease will demonstrate unilateral vestibular hypofunction
14. Imaging
    1. MRI brain with contrast and including Internal Auditory Canals
       1. Consider based on history and exam (especially if Acoustic Neuroma suspected)
       2. Best study for identifying Acoustic Neuroma
          1. Replaces Auditory Brainstem Testing (ABR) for Acoustic Neuroma diagnosis
    2. CNS Arterial imaging (CT angiogram head and neck, MR Angiogram brain and neck or carotid Ultrasound)
       1. Consider in arterial pulsatile Tinnitus
       2. Evaluate for Cerebrovascular Disease
    3. CNS Venous imaging (e.g. CT or MR Venography)
       1. Consider in venous pulsatile Tinnitus (along with a Lumbar Puncture)
       2. Evaluate for Pseudotumor Cerebri
15. Evaluation: Less than 3 weeks (acute)
    1. Assess for and correct acute Tinnitus causes
       1. See causes above
       2. Loud noise exposure
       3. Otitis Media
       4. Cerumen Impaction
       5. Ototoxic Medication
       6. Head or neck injury
       7. Focal neurologic deficit
    2. Indications for early diagnostic evaluation (e.g. Audiometry, MRI Brain)
       1. Focal neurologic deficit
       2. Focal exam finding (e.g. Cholesteatoma, retrotympanic lesion)
       3. Unilateral Tinnitus >3 weeks (exclude Acoustic Neuroma)
       4. Acute symptoms persist >3 weeks
16. Evaluation: More than 3 weeks (chronic)
    1. Abnormal exam findings (same approach as described above under the acute, <3 week evaluation)
       1. Manage acute causes (e.g. Cerumen Impaction, Otitis Media, TMJ Dysfunction)
       2. MRI brain and Audiometry indications as above
          1. Includes evaluation for unilateral Tinnitus (Acoustic Neuroma)
    2. Tinnitus with intermittent Hearing Loss or Vertigo
       1. Evaluate for Meniere Disease
       2. Diagnostics: Audiometry, Electronystagmography, MRI Brain
       3. ENT referral
    3. Pulsatile Tinnitus
       1. Most commonly caused by Pseudotumor Cerebri, Carotid Stenosis and Glomus tumors
       2. See Imaging above for arterial and venous cause evaluation
       3. Consider nonvascular causes in negative work-up (e.g. Otosclerosis, tensor tympani muscle, stapedius muscle)
    4. Abnormal Audiometry
       1. Asymmetric Sensorineural Hearing Loss should prompt MRI Brain for Acoustic Neuroma evaluation
       2. Consider ENT Consult
17. Management
    1. Correct underlying medical problem
    2. Eliminate possible Ototoxic Medications
    3. Exclude serious causes
       1. Acoustic Neuroma and other CNS Lesions
       2. Carotid Stenosis and other vascular conditions
       3. Cholesteatoma and other other treatable local ear lesions
       4. Meniere Disease (Vertigo and Hearing Loss)
       5. Sudden Sensorineural Hearing Loss
          1. Acute Hearing Loss with Tinnitus (consider acute onset Meniere's Disease)
          2. Dose Corticosteroids (See SSNHL)
    4. Reassurance
    5. Antidepressants (SSRI)
    6. Noise masking
       1. Soft, monotonous noise (e.g. fan or radio) at night
       2. Hearing Aid amplifies background noise
    7. Avoid ineffective measures
       1. Ginkgo Biloba is not effective
          1. Rejali (2004) Clin Otolaryngol 29:226-31 [PubMed]
18. Resources
    1. American Tinnitus Association
       1. http://www.ata.org
19. References
    1. Crummer (2004) Am Fam Physician 69(1):120-8 [PubMed]
    2. Lloyd (2008) Clin Otolaryngol 33(1): 25-8 [PubMed]
    3. Yew (2014) Am Fam Physician 89(2): 106-13 [PubMed]