Tinnitus

What is it?

Tinnitus can be perceived in one or both ears or in the head. It is usually described as a ringing noise, but in some patients, it takes the form of a high-pitched whining, electric buzzing, hissing, humming, whistling sound, or as ticking, clicking, roaring, “crickets” or “tree frogs” or “locusts (“Cicada”)”, tunes, songs, beeping, or even a pure steady tone like that heard during a hearing test. It has also been described as a “whooshing” sound, as of wind or waves. Tinnitus can be intermittent, or it can be continuous, in which case it can be the cause of great distress. In some individuals, the intensity can be changed by shoulder, head, tongue, jaw, or eye movements.

Prevalence

Tinnitus impacts up to 50 million people in the United States and millions more worldwide. Most commonly caused by noise exposure, tinnitus drastically reduces quality of life for 250 million people worldwide.  Tinnitus is common; about one in five people between 55 and 65 years old report symptoms on a general health questionnaire.

Causes

Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period (but usually with some duration), ear infections, foreign objects in the ear, nasal allergies that prevent (or induce) fluid drain, or wax build-up. In-ear headphones, whose sound enters directly into the ear canal without any opportunity to be deflected or absorbed elsewhere, are a common cause of tinnitus when volume is set beyond modest or moderate levels.

Tinnitus can also be caused by natural hearing impairment, such as aging/presbycusis., as a side effect of some medications or caffeine, and as a side effect of genetic/congenital hearing loss. However, the most common cause is noise-induced hearing loss

Types

Objective tinnitus

In some instances, a clinician can detect an actual sound emanating from the patient’s ears. This is called objective tinnitus. Objective tinnitus can arise from muscle spasms that cause clicks or crackling around the middle ear. Some people experience a sound that beats in time with the pulse (pulsatile tinnitus, or vascular tinnitus). Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow or increased blood turbulence near the ear (such as from atherosclerosis) but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear. Rarely is pulsatile tinnitus a symptom of potentially life-threatening conditions such as carotid artery aneurysm or carotid artery dissection.

Subjective tinnitus

Subjective tinnitus can have many possible causes, but most commonly results from otologic disorders a?? the same conditions that cause hearing loss. The most common cause is noise-induced hearing loss, resulting from exposure to excessive or loud noises. Tinnitus, along with sudden onset hearing loss, may have no obvious external cause. Ototoxic drugs can cause subjective tinnitus either secondary to hearing loss or without hearing loss and may increase the damage done by exposure to loud noise, even at doses that are not in themselves ototoxic.

Subjective tinnitus is also a side effect of some medications, such as aspirin, and may also result from an abnormally low level of serotonin activity. It is also a classical side effect of quinidine. Over 260 medications have been reported to cause tinnitus as a side effect. In many cases, however, no underlying physical cause can be identified.

Causes of subjective tinnitus include:

  • Otologic problems and hearing loss:
    • conductive hearing loss
    • external ear infection
    • acoustic shock
    • loud noise or music
    • cerumen (earwax) impaction
    • middle ear effusion
    • sensorineural hearing loss
    • excessive or loud noise
    • presbycusis
    • Meniere’s disease
    • acoustic neuroma
    • mercury or lead poisoning
    • ototoxic medications
      • analgesics:
        • aspirin
        • nonsteroidal anti-inflammatory drugs
      • antibiotics:
        • Ciprofloxacin
        • aminoglycosides, e.g., gentamicin
        • chloramphenicol
        • erythromycin
        • tetracycline
        • tobramycin
        • vancomycin
        • doxycycline(Vibramycin)
      • chemotherapy and antiviral drugs:
        • bleomycin
        • interferon
        • pegylated interferon-alpha-2b
        • cisplatin
        • mechlorethamine
        • methotrexate
        • vincristine
      • loop diuretics:
        • bumetanide
        • ethacrynic acid
        • furosemide
      • others:
        • chloroquine
        • quinine
        • antidepressants
        • varenicline (Champix)
        • naproxen
  • neurologic disorders:
    • chiari malformation
    • multiple sclerosis
    • head injury
    • skull fracture
    • closed head injury
    • whiplash injury
    • temporomandibular joint disorder (TMJ)
      • metabolic disorders:
        • thyroid disease
        • hyperlipidemia
        • vitamin B 12 deficiency
        • iron deficiency anemia
  • psychiatric disorders:
    • depression
    • anxiety
  • other causes:
    • tension myositis syndrome
    • fibromyalgia
    • vasculitis
    • hypertonia (muscle tension)
    • thoracic outlet syndrome
    • Lyme disease
    • hypnagogia
    • sleep paralysis
    • glomus tympanicum tumor
    • anthrax vaccines which contain the anthrax protective antigen
    • benzodiazepine withdrawal
    • nasal congestion

Treatment

There is no cure for tinnitus.

Many treatments for tinnitus have been claimed, with varying degrees of statistical reliability:

Objective tinnitus:

  • Gamma knife radiosurgery
  • Shielding of cochlea by teflon implant
  • Botulinum toxin
  • Cleaning the ear canal of wax/debris
  • Using a neurostimulator

Subjective tinnitus:

  • Drugs and nutrients
    • Lidocaine injection into the inner ear was found to suppress the tinnitus for 20 minutes, according to a Swedish study.
    • Tricyclics (amitriptyline, nortriptyline) in small doses
    • Avoidance of caffeine, nicotine, or salt can reduce symptoms, but tinnitus can also be induced by reducing caffeine and/or quitting smoking.
    • The consumption of alcohol has been found to both increase and decrease the severity of tinnitus. Therefore, alcohol’s effect on the severity of tinnitus is dependent on the causes of the individual’s affliction, and cannot be considered a treatment.
    • Zinc supplementation (where serum zinc deficiency is present)
    • Etidronate or sodium fluoride (otosclerosis)
    • Lignocaine or anticonvulsants (usually in patients responsive to white noise masking)
    • Melatonin (especially for those with sleep disturbance)
    • Sertraline
    • Vitamin combinations (lipoflavonoid)
  • Electrical stimulation
    • Transcranial magnetic stimulation or transcranial direct current stimulation
    • Transcutaneous electrical nerve stimulation
    • Direct stimulation of auditory cortex by implanted electrodes
    • Berthold Langguth, German neurologist, would apply an electric or magnetic current for stimulation over the head of the patient to reduce ringing sound. Dirk De Ridder, Belgian neurosurgeon, implanted electrodes to the brain of sufferers to normalise overactive neurons. Cambridge University scientists also found lidocaine, an anaesthetic, reduces the sound in 2/3 of patients for 5 minutes, but it needs another drug to suppress its dangerous effects.
    • Vagus nerve stimulation
  • External sound
    • Low-pitched sound treatment has shown some positive, encouraging results.(UC, Irvine press release)
    • Tinnitus masker (white noise, or better ‘shaped’ or filtered noise)
    • Tinnitus retraining therapy
    • Auditive stimulation therapy (music therapy)
    • Auditive destimulation therapy (also called “notched music” therapy) uses individually designed music with the patients’ favorite music altered to remove the musical tones that match the aural frequencies associated with their tinnitus. The removal of these tones alleviates the tinnitus by destimulating brain activity for these specific frequencies.
    • Compensation for lost frequencies by use of a hearing aid.
    • Ultrasonic bone-conduction external acoustic stimulation
    • Avoidance of outside noise (exogenous tinnitus)
  • Psychological cognitive behavioral therapy

Prognosis

The prognosis of tinnitus depends on the type and severity of the cause.

For tinnitus due to acute acoustic trauma, approximately 35% of cases report subsiding tinnitus at 3 months after the trauma, with approximately 10% of these cases being the degree of complete disappearance of the tinnitus, as studied among young men having acquired tinnitus from gunshots.