Tinnitus: Causes and Treatment

Tinnitus is the perception of any kind of sound in the absence of actual external auditory stimuli. This ‘sound’ may be a ringing, humming or buzzing in the ears. Almost everyone has experienced tinnitus at least once as a humming noise which is especially prominent when faced with silence. Though often bothersome, tinnitus is usually harmless and there is no need for panic. However, there are several underlying causes for tinnitus which should be explored and evaluated in someone who is experiencing prolonged symptoms of uncontrollable tinnitus.

Classification of Tinnitus

Tinnitus is classified into two types

• Subjective Tinnitus: This refers to tinnitus that can only be heard by the individual. It is usually caused by problems in the ear, the nerves conducting sound to the brain or within the brain itself. This is the most common type of tinnitus.
• Objective Tinnitus: This is a type of tinnitus which can be heard by both the patient and the physician. This is generally due to abnormal blood vessels near the eye or due to abnormal muscle contractions.

Causes of Tinnitus

1. Related to the Ear
   1. Presbyacusis: This is age related hearing loss
   2. Noise related hearing loss
   3. Blockage of external ear canal with ear wax or foreign bodies
   4. Infections of the middle ear cavity: Acute or chronic otitis media
   5. Meniere’s disease: This is a disease of the inner ear with increased pressure of the fluid in the internal ear canals. This is associated with hearing loss.
   6. Tumors within the ear cavity
2. Vascular causes:
   1. Arteriovenous malformations: These are abnormal connections between arteries and veins which lead to abnormal blood flow around the ear with resulting sound
   2. Glomus tumors in the head and neck region: These are vascular masses which cause a pulsatile tinnitus.
   3. Hypertension
3. Neurological disorders:
   1. Myoclonus of palate or middle ear muscles: this is a abnormal motion of the muscles in this region causing a clicking sound to be heard
   2. Temporal lobe epilepsy: The temporal lobe in the brain is the area for processing sound. Seizure activity involving this region can cause the perception of sounds
   3. Multiple sclerosis: This is an autoimmune disease affecting the nervous system and can cause tinnitus if it damages areas involved with sound processing.
   4. Tumors along the nerve which conducts sound from the ear to the brain.
4. Other Head and Neck Conditions
   1. Trauma: Injury to the skull or neck can damage the structures around the ear
   2. Temporomandibular joint disorder: This is the joint where the jaw connects to the skull and is present in front of the ear. Abnormalities with the joint can cause a popping sound to be heard.
5. Drug induced: Several drugs which ae toxic to the ear can lead to hearing loss and tinnitus
   1. Diuretics or water pills
   2. Some antibiotics
   3. Several anti-cancer medications
   4. Non steroidal anti-inflammatory drugs (NSAIDs)

Symptoms of Tinnitus

The sound heard may be a humming, buzzing, whooshing, clicking or roaring noise. Along with the sound, other associated symptoms may be present depending on underlying cause

• Hearing loss
• Fullness in the ears or heaviness
• Feeling of imbalance
• Headache

Evaluation of Tinnitus

Tinnitus is a symptom which is generally idiopathic, which is to say that it has no underlying cause. However, since several conditions can present with tinnitus, a thorough evaluation is necessary and it is recommended to visit a specialist in Ear, Nose and Throat diseases. The following are useful in diagnosis:

• Clinical examination of the head and neck and ears: An E.N.T. specialist would look at the patient’s ears using an otoscope which will help to visualise the ear canal and ear drum.
• Pure tone Audiometry: This is a test to evaluate for hearing loss. Sounds at various intensities and frequencies are played to the individuals who is asked to indicate if they can hear them.
• Magnetic Resonance Imaging (MRI): An MRI is used to look for any masses in the head and neck area and can also visualise any tumors within the skull.
• Arteriography: This is an imaging test to visualise the blood vessels around the ear for malformations or narrowing.

Management of Tinnitus

If an underlying cause for tinnitus has been found, the following specific treatment options are available:

• Hearing Aids: these are very beneficial for those with age related or noise induced hearing loss.
• Clearing of wax: This is useful if there is an obstruction of the external ear with impacted wax.
• Surgery: In the case of tumors being the underlying cause a team approach involving various specialists is needed to plan for operating the mass.
• Botulinum Toxin injection: In patients with tinnitus secondary to myoclonus of palatal and middle ear muscles, injecting the muscle with botulinum toxin (Botox) can control the muscle spasm and decrease the clicking sounds.
• Masking devices: These are devices which produce sound which is hoped to drown out the tinnitus. They are occasionally beneficial in idiopathic tinnitus.
• Counselling, antidepressants and anti-anxiety medications: On occasion, if no cause is found and the individual continues to experience distressing tinnitus, meeting with a psychologist or psychiatrist for therapy may help. Use of meciations may also be beneficial.

References:

1. Causes of tinnitus. American Tinnitus Association. http://www.ata.org/understanding-facts/causes.[Internet]. 2015 [cited 2018 Aug 10].
2. Michael Gleeson, Tinnitus, French’s Index of Differential Diagnosis 15^th Edition