An Introduction to Tinnitus
Tinnitus is a very common condition, reported in almost two thirds of adults. Tinnitus – the word finds its origin in the latin word tinnire which means ‘to ring’.
Definition of tinnitus is hearing a sound in the absence of an external stimulus or a source of the sound.
Based on the examiner’s perspective, it is classified as:
- Subjective
- Objective
If the patient alone can hear it, it is called a subjective tinnitus, if it can be heard by an observer it is considered objective.
Based on the onset and duration it has been divided into:
- Acute < 6 months
- Chronic > 6 months
Based on quality it is described as:
- Pulsatile
- Continuous
If tinnitus is associated with a bilateral symmetrical sensorineural hearing loss, or no cause is identified it is considered a primary tinnitus, else it is called secondary.
Causes of tinnitus
A wide variety of conditions give rise to tinnitus. These can be easily remembered or ruled out based on their location.
External ear
Any condition that partially or completely obstructs the ear canal can cause tinnitus. This includes conditions like impacted wax, otitis externa, otomycosis, osteoma of the canal etc.
Middle ear
Function of the middle ear is to conduct the sound collected by the external ear to the inner ear. Any pathology that hampers this will cause tinnitus with a conductive hearing loss. Examples of middle ear pathology that may cause ringing of the ear include otitis media with effusion, cholesteatoma, otosclerosis, acute and chronic otitis media, tumours of the middle ear.
Inner ear
Inner ear consists of the membranous cochlea, utricle, saccule and three semicircular canals housed with a bony cavity, from these organs arise the cochlear and vestibular nerves . These are the sensory organs for hearing and balance. Any pathology originating here will cause tinnitus which is associated with hearing loss or imbalance and vertigo or any combination of the four. These conditions include Meniere’s disease, inflammation of the inner ear, toxicity of the inner ear, tumours of the inner ear or the vestibular nerve.
Cause other than ear
Other causes can be classified into:
Local causes
- Fasciculations or tremors of the muscles of middle ear – stapedius and tensor tympani muscle
- Aberrant carotid artery or its branches
Loco-regional causes
- Vascular causes – carotid bruits
- Temporomandibular joint clicks
- Bruxism
- Nasopharyngeal carcinoma
Other systemic causes
- Depression
- Renal failure
- Liver failure
- Arrhythmias
Idiopathic tinnitus
Where after extensive evaluation no cause was found for the symptom. Unfortunately approximately 30% of patients will fall in this category
Conclusion
It is a very common but mostly benign symptom. It is not a diagnosis by itself. Its presence is very distressing for the patients and causes significant anxiety, loss of concentration, sleep and productivity.
A thorough history and examination is necessary by an ENT doctor to make an initial diagnosis which should be further confirmed by a battery of tests.
Treatment depends on the causes that are identified and include – medicines, hearing aids, tinnitus masking, cognitive behavioural therapy