Tinnitus UTD

Introduction

Tinnitus is a perception of sound in proximity to the head in the absence of an external source.

• One or both ears

• Within or around the head

• sound is often buzzing, ringing, and hissing but can be other noises

• Intermittent or continuous

• Pulsatile or non-pulsatile

Fact Sheets

• Tinnitus - Better Health Victoria

Epidemiology

• Common

• It can occur in children

• Increases with age

• More common in men than women

Clinical Impact

• Varies widely

• Some people “experience” tinnitus", whilst others may “suffer from it”

• Concurrent mood disorders can increase the perception of disability

Pathogenesis

• Can be unilateral or bilateral

• Can be triggered anywhere along the auditory pathway

• Most patients have sensorineural tinnitus, due to hearing loss at the cochlea or cochlear nerve level

• Somatic sounds may be perceived as tinnitus and originate in structures near the cochlea. These sounds are usually vascular but can be produced by musculoskeletal structures. Somatic sounds are most often pulsatile and typically unilateral. Continuous single tone sounds are not usually somatic.

• Theories suggest that the central nervous system is the source or generator of all tinnitus that is not somatic.

• PET scans and functional MRI studies indicate loss of cochlear inputs to neurons in the central auditory pathways (due to cochlear hair cell damage, noise trauma, cochlear nerve lesions)

• Another construction likens tinnitus to phantom pain perception that is thought to arise from a loss of suppression of neural activity.

• Tinnitus has also been likened to a type of auditory seizure.

• Electric stimulation can suppress tinnitus in patients with profound hearing loss.

• Many patients with tinnitus have signs of anxiety or depression. Elevated serotonin levels have been found in some patients with tinnitus.

Etiology

Vascular Disorders

• Pulsatile tinnitus is most commonly vascular.

• Some vascular tinnitus is due to atherosclerotic plaque narrowing of blood vessels can be non-pulsatile.

• In one study, 50% of patients with pulsative tinnitus had a vascular cause, most commonly a dural arteriovenous fistula (AVF)

Arterial Bruits

• Arterial vessels near the temporal bone may transmit sound.

• The petrous carotid system is the most common source but other arteries may be involved.

• These patients usually do not have other symptoms like hearing loss, vertigo, or aural fullness.

Arterio-venous Shunts

• Congenital arterio-vascular malformations (AVMs) are rarely associated with hearing loss or tinnitus.

Paragangliomas

• Head and neck paragangliomas are highly vascular, typically benign neoplasms arising from cells of the paraganglia that are found around the carotid bifurcation.

Venous Hums

• These may be heard in patients with hypertension or raised intracranial pressure.

• Often described as a soft, low-pitched hum that may decrease or stop with pressure on the jugular vein, change in head position or with activity.

Neurologic Disorders

• Pulsatile tinnitus of muscular origin can result from spasm of one or both of the muscles within the middle ear (tensor tympani and the stapedius muscle).

• These can happen spontaneously or in the presence of diseases such as multiple sclerosis

• Clicking noises or irregular or rapid pulsations may also result from myoclonus of the palatal muscles that attach to the Eustachian tube orifice.

Eustachian Tube Dysfunction

• A patulous Eustachian tube can cause unilateral or bilateral tinnitus, with sounds similar to an ocean roar that may sync with breathing.

• It most commonly occurs are significant weight loss

• The symptoms may disappear when the patient lies down

• People may experience autophony (awareness of their own voice) and ear discomfort

• The cause of symptoms is too much and then too little aeration of the middle ear space with respiration

Other somatic disorders

• Somatic non-pulsative tinnitus is commonly caused by temporo-mandibular joint (TMJ) dysfunction

• Has been associated with whiplash injuries and cervical-spinal disorders

• Tinnitus may improve when patients respond favourably to treatment from symptoms of TMJ dysfunction

• The exact mechanism is not known

Tinnitus originating from the auditory system

• Most tinnitus is due to sensorineural hearing loss with resulting dysfunction of the auditory system.

Ototoxic Medication

• Tinnitus is commonly caused by ototoxic medications

• Typically this is bilateral

Otosclerosis

• Abnormal bone repair of the stapes footplate bone.

• Tinnitus can result when this damages cochlear structures

Vestibular Schwannoma

• Tumours compressing or stretching the cochlear nerve can cause tinnitus

Other causes

• Chiari Malformation, Presbycusis (age-related hearing loss), Infections, Nerve Compression, Congenital Hearing Loss and Endocrine or Metabolic damage.

History

• Description of tinnitus

  • Episodic or constant

  • Pulsatile or non-pulsatile

  • Rhythmicity

  • Pitch

  • Quality of the sound

  • Exacerbating and relieving factors

• Previous ear disease

• Noise exposure

• Hearing status and hearing difficulty

• Head injury

• Symptoms of TMJ dysfunction

• Medications and supplements

• Medical conditions (hypertension, atherosclerosis, neurological illness, prior surgery)

• Mental health including anxiety, depression and insomnia.

Vascular

• Tinnitus that is distinctly pulsing or rushing, flowing and humming is usually vascular

• Tinnitus usually increases in frequency and intensity with exercise

• Can be linked or sync up with their pulse

• Changes in intensity or pitch with head motion or body position indicates vascular.

Clicking

• Indicates physiological or somatic cause such as Myoclonus of the palatal muscles.

Tone

• High-pitched is most common and indicates sensori-neural hearing loss or cochlear injury

• Low-pitched tinnitus is often seen in patients with Meniere’s

Examination

• Complete head to neck exam

• Cranial Nerve examination

• Tympanic membranes

• Oral team for palatal myoclonus

• If suspected vascular then auscultation over the neck, periauricular, temple, orbit and mastoid.
  

Specialist Testing

Suspected vascular tinnitus — Patients with infrequent episodes of pulsatile tinnitus or those with short-duration, mild tinnitus can be initially observed.

Frequent or constant pulsatile tinnitus can herald a potentially life-threatening illness and these patients should be evaluated by a specialist. When physical examination does not reveal a specific vascular or musculoskeletal source then further investigations to rule out a central nervous system such as an AVM or AVF. CT or MRI angiography.

Suspected auditory system tinnitus — For patients with tinnitus associated with hearing loss or a change in hearing, audiometric tests may help determine if the tinnitus originates within the auditory system and are essential in the evaluation. Any patient with constant unilateral or bilateral tinnitus persistent for six months or more should also be referred for a formal audiology evaluation

Treatment

• Correctly identify comorbidities and directly address the effects of tinnitus on quality of life

• For many, tinnitus is chronic and the goal is to lessen it’s impact and associated disability, rather than cure.

• Many treatment modalities have been studied but evidence for most of these interventions has not been demonstrated in randomised trials.

Depression

• Patients with depression required appropriate treatment. Some studies have shown overall benefit whereas others have not. Further research is required.

Insomnia

• Patients should have insomnia treated with the goal of reducing the severity of tinnitus.

Vascular abnormalities

• Vascular causes of tinnitus may benefit from a variety of procedures.

Presbycusis + hearing loss

• Patients with conductive hearing loss to the outer or middle ear may benefit from surgery to correct the conductive defect.

Ototoxic medications

• Tinnitus due to ototoxic effects on the hair cells of the cochlear may be reversible after stopping the medication.

Other

• Cochlear rescue medications are under investigation

• Correct any metabolic and hormone imbalances

• Treat of patulous Eustachian tube can be treated

Behavioural Therapies

• Tinnitus retraining therapy (TRT) - This involves bypassing and overriding abnormal auditory cortex neural connections.

• Biofeedback and stress reduction programs - This is a relaxation technique that teaches people to control autonomic body functions. The goal is to manage tinnitus-related distress.

• Cognitive behavioural therapy - Alters psychological responses by identifying coping strategies, distraction skills and relaxation techniques. Patients must be motivated as they are required to keep diaries and perform homework.

Medications

• No overwhelmingly effective options.

• Lots of small studies show some benefit to medications like misoprostol, lidocaine, benzodiazepines, carbamazepine, dexamethasone.

• Other medications have been found to have no effect including anticonvulsants, gingko biloba, melatonin, niacin, zinc, copper and manganese.

Other therapies

Other therapies have been studies in patients with tinnitus, most of which have been found to be no more effective than placebo, however tinnitus support groups have members who have experienced a true non-placebo benefit from:

• Masking - Devices resembling hearing aids designed to produce low-level sounds that reduce the perception of tinnitus

• Electrical stimulation - Small electrodes placed on the bony cochlea

• Acupuncture - No evidence of benefit

• Repetitive transcranial magnetic stimulation (rTMS) - Limited data showing benefit but is safe and larger studies are needed

Reference

• Diagnosis of Tinnitus - Up To Date

• Treatment of Tinnitus - Up To Date

• Patient Education: Tinnitus - Up To Date

• Diagnostic Imaging Pathway - Radiology Across Borders