Tinnitus is a common and debilitating medical symptom encountered in the field of Otolaryngology. It is the conscious perception of auditory stimulus without the presence of external auditory stimulus and is often described by patients as a ringing, humming, pulsing or clicking sound. Tinnitus can range from a quiet background noise to loud audible sounds.
Type of Tinnitus
Type of tinnitus | Definition |
Subjective tinnitus | Only patient hears the tinnitus. |
Objective tinnitus | External observers can hear the tinnitus. |
Pulsatile tinnitus | Synchronous with heartbeat and usually vascular in origin. Can be subjective or objective. Pulsatile tinnitus can raise concern for underlying significant pathology. |
Primary tinnitus | Idiopathic tinnitus and can be associated with sensorineural hearing loss. |
Secondary tinnitus | Tinnitus with underlying cause e.g., otosclerosis, vestibular schwannoma, or Menière’s disease. |
Causes of tinnitus
- External ear
- Wax impaction and otitis externa.
- Middle ear
- Otosclerosis, otitis media and cholesteatoma.
- Stapedial myoclonus.
- Eustachian tube dysfunction may cause tinnitus. Common cause includes significant weight loss and radiation at the nasopharynx. A patient may complain about unusual awareness of voice and ear discomfort.
- Inner ear
- Vestibular schwannoma. Tumours may compress the vestibular and cochlear nerves.
- Meniere’s disease.
- Ototoxic medications such as salicylates, quinine, aminoglycoside, and cisplatin.
- Sensorineural hearing loss is predominantly secondary to cochlear hair cell dysfunction.
- Presbycusis i.e., age related hearing loss.
Vascular Causes
- Vascular disorders
- Examples include dural arteriovenous fistula, carotid-cavernous sinus fistula.
- Arterial bruits
- A common site for bruit is the petrous carotid system and evaluation for atherosclerotic disease is recommended.
- Arteriovenous shunt
- Congenital arteriovenous fistula rarely causes tinnitus. Dural arteriovenous fistulae are frequently associated with dural venous sinus thrombosis. A dural arteriovenous fistula may cause intracranial haemorrhage and prompt identification can be lifesaving.
- Paraganglioma
- Highly vascular and often originate from carotid bifurcation, at the jugular bulb or at the tympanic arteries in the middle ear. The lesion may be palpable in the head and neck region or visible as a reddish/blue mass through the tympanic membrane. Paraganglioma can also cause conductive hearing loss, sensorineural hearing loss and cranial nerve palsies.
- Venous hum
- Common in systemic hypertension, increased intracranial pressure and dominant jugular bulb. Hum may disappear with pressure at the jugular vein or with a change in head position.
Other Causes
- Neurological disorder
- Spasm of middle ear muscles (e.g., tensor tympani and stapedius muscle) can cause pulsatile tinnitus. Commonly seen in patients with ontological disease and multiple sclerosis.
- Myoclonus of palatal muscle may cause clicking tinnitus. Myoclonus of palatal muscle is associated with multiple sclerosis, microvascular disease of the brainstem and metabolic or toxic neuropathy.
- Chiari malformation with a low cerebellar tonsillar herniation may cause tension in the auditory nerve.
- Somatic disorders
- Examples include temporomandibular joint dysfunction following whiplash injury and cervical spine disorder.
- Other causes include intracranial lesions such as chondrosarcoma, endolymphatic sac tumours and aberrant carotid artery.
- Noise exposure
- Head injury
- Psychological e.g., Anxiety and depression
Assessment of Tinnitus
- History forms an important component. Important questions to ask include the following:
- Frequency and description of tinnitus (e.g., rhythmicity, episodic or constant, pulsatility, pitch and quality of sound). Pulsatile tinnitus can be associated with exercise, change in head position and patients may also notice a pattern with their pulse.
- Past medical history of previous ear disorder, noise exposure, head injury, hearing disorder, temporomandibular joint dysfunction, hypertension, atherosclerosis, and neurological disorders.
- Use of ototoxic medication should be reviewed.
- Impact of tinnitus on daily life such as depression, anxiety and insomnia should be explored.
- Physical examination includes the following:
- Complete head and neck examination
- Otoscope examination
- Cranial nerve examination
- Tuning fork e.g., Weber and Rinne’s test
- Pure tone audiometry
- Tympanometry
- Wide jaw opening may suppress palatal myoclonus
- Auscultation of neck, periauricular area, temple, orbit and mastoid if vascular tinnitus is suspected
- MRI of the Internal Auditory Meatus (MRI IAMs) for asymmetric tinnitus, hearing loss and neurological signs (e.g., facial numbness & weakness, vertigo, and suspected stroke)
- CT angiography and MR angiography for pulsatile tinnitus
Treatment
- Limited medical treatment
- Reassurance
- Hearing aids for hearing loss
- Wideband sound therapy
- Cognitive behavioural therapy and counselling
- Relaxation therapy
- Surgery for Otosclerosis and Meniere’s disease
Key Points
- Tinnitus is a common medical presentation in otolaryngology, general practice and the A&E department.
- Thorough history and examination is important when investigating for tinnitus.
- Pulsatile tinnitus is commonly vascular in origin and warrants urgent investigation. Common causes of pulsatile tinnitus include arteriovenous malformation, arteriovenous fistula, arterial bruit and paraganglioma.
- Clicking tinnitus is commonly associated with neurological disorders causing palatal myoclonus and inner ear muscle myoclonus.
- Pulsatile tinnitus is commonly investigated with CT and MR angiography.
- Tinnitus arising from the auditory system requires pure tone audiometric testing.
- Treatment for tinnitus is limited but may include a hearing aid, reassurance, relaxation therapy and middle ear surgery.
References
1) Recommendations | Tinnitus: assessment and management | Guidance | NICE [Internet]. Nice.org.uk. 2022 [cited 25 February 2022].
2) Baguley D, McFerran D, Hall D. Tinnitus. The Lancet. 2013;382(9904):1600-1607.
3) Esmaili A, Renton J. A review of tinnitus. Australian Journal of General Practice. 2018;47(4):205-208.
4) Baldwin A, Hjelde N, Goumalatsou C, Myers G, Collier J. Oxford handbook of clinical specialties. 10th ed. Oxford University Press; 2016.
5) Dinces E. UpToDate [Internet]. Uptodate.com. 2022 [cited 4 August 2022].
Written by Dr Pavithran Maniam (FY2) & reviewed by Mr Tom Paterson (ST6 ENT Registrar)
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2 thoughts on “Tinnitus”
Can we recover from drug induced tinnitus?
According to Pubmed one can recover from it.