Sudden Sensorineural Hearing Loss
Sudden sensorineural hearing Loss should be regarded as an otologic emergency.
Patient should be evaluated by otolaryngologist ENT specialist) .
A thorough history, physical examination, appropriate laboratory and radiologic investigations including gadolinium enhanced MRI, and Audiometry tests should be carried out to find out known cause.
A tapering course of steroid is prescribed.
Antiviral medication may be considered.
Sudden Sensorineural Hearing Loss is defined as a hearing reduction greater than 30 db, over at least 3 consecutive frequencies (on pure tone audiogram), occurring over or less than 3 days. May be mild to severe reduction of hearing, usually affects one ear and there may be tinnitus and dizziness.
Most People (30-65%) may have a spontaneous recovery; others may have permanent hearing difficulties.
There is no conclusive evidence as why it happens but some theoriesare suggested:
Generally 90% cases are idiopathic where cause is not known. Viral diseases appears to be most common cause (about 60% cases) as shown by association with herpes.
There may be partial or complete blockage of circulation or vascular spasm to inner ear and nerves of hearing.
There may be rupture of delicate inner ear membrane after strong physical activity or sudden change in barometric pressure (flying/scuba diving).
Immune theory may play a role, because of its association with Cogan syndrome, SLE, Lupus and AIDS.
In most cases reason remains unclear.
Diagnosis of SSNHL requires thorough investigation to determine any known causes of sudden hearing loss.
A thorough and detailed history of associated symptoms, noise exposure, any trauma, fever, medication and family history of hearing loss is necessary to determine the diagnosis.
Ear examination by ENT specialist with otoscopy and pneumotoscopy is critical step.
Hearing assessment by Tunning fork test, pure tone audiometry (PTA) and speech audiometry should be done. Tympanometry, Auditory Brainstem Response and Otoacoustic emission may be useful.
Radiologic study should be done especially for patients with unilateral sensorineural hearing loss, such as MRI with gadolinium/CT temporal bone to investigate IAC/CPA tumors.
FTA-antibodies for syphilis
ANA, RA Factor, ESR for autoimmune disease
CBC for infection
TH for thyroid function
RBS/PPBS for Diabetes
Cholesterol/triglycerides for hyperlipidemia
It is an otologic emergency and challenge to otolaryngologist.
Thorough history, physical examination, appropriate laboratory and radiologic investigations including gadolinium enhanced MRI, and Audiometry tests should be carried out to find out known cause such as:– Infection (bacterial-meningitis/viral-mumps, herpes), Tumor, Trauma, Acoustic trauma, Ototoxic drugs (amino glycoside antibiotics), and Systemic diseases (hypothyroidism, Diabetes mellitus).
If an etiologiy is apparent, appropriate treatment may be initiated such as antibiotics for infection, withdrawal of ototoxic drugs.
In most cases cause remains unknown thus existent treatment aims at improving blood flow.
Optimal treatment is still under research and controversies exist but treatment versus non-treatment and early treatment is proved to give better result.
Antivirals- Because of common association with viral infection antiviral medication is prescribed by some clinicians.
Steroids- Most widely accepted treatment option studies shows improved recovery rate with use of steroid. It can be given orally, or by injection, or Trans tympanic by means of middle ear instillation or round window micro catheter.
Vasodilator to improve blood flow or oxygenation to inner ear. Clinical studies shows mixed results. Carbogen inhalation, Papaverin, Histamine, Nicotin and Niacin have been used.
Immunosuppressant- Wang et al etanercept in experimental animal study improves hearing result.
General measures for sudden sensorineural hearing Loss
Low salt diet
Avoid caffeine, nicotine and alcohol,
Avoid noise exposure,
Avoid heavy physical activity,
Well balanced diet
Alpha-lipoic Acid, Antioxidants, Co-enzyme Q10.
Zinc, Magnesium, Calcium,
Vitamin D, B –Complex, Vitamin C
50-65% spontaneous recovery within first 4-6 weeks
Negative factors in prognosis:
Age more than 65 years or less than 15 years
Severe hearing loss specially affecting high frequency
Hearing loss in opposite ear
Treatment protocol should be carefully applied and potentially harmful treatment should be avoided. A thorough evaluation to be done on emergency basis and all efforts should be taken to find out known causes. Steroids are most widely accepted treatment options.
There is strong but not well explained association between kidney and inner ear. Drugs that are ototoxic are frequently nephrotoxic too (aminoglycoside antibiotics, loop diuretics, potacium bromates, non steroidal antiinflamatory agents)
Alports syndrome a hereditary disorder affects both kidney and inner ears….
Hereditary factors are commonly involved with sensorineural hearing loss, It may be a isolated snhl or associated with some syndrome. In presbiacusis and noise induced hearing loss genetic factors may be responsible.
Wardenburg syndrome; Autosomal dominant transmission, consists of:
Distopia canthorum (lateral displacement of medial canthi)
Broad nasal root
Confluence of medil portion of eyebrows
Partial or total heterochromia iridis
A white forelock
Sensorineural hearing loss
SNHL and ocular manifestations
With or without vestibular defects
Inner ear anomalies
Multiple sclerosis and SNHL: Multiple sclerosis of is characterized by multiple area of CNS demylination , inflammation and glial scarring. Age of onset is 20-30 years, rare before 10 and after 60 years of age.
Clinical course may be almost symptom free or rapidly progressing disabling disorder.
There may be remissions and relapses.
Cause may be related to genetic, autoimmune or viral, but largely unknown.
Four to 10% patients of multiple sclerosis develop sensorineural hearing loss
Tests done should be p/t audiometry, speech discrimination tests, acoustic reflex and ABR. MRI permanent damage to your ear. seems that hearing aids are available in newer styles and sizes.
Conventional hearing aid converts sound waves to electrical waves while digital transfers sound waves using exact mathematical calculations that are processed by a computer.
Programs are switched depending on the listening environment a person is in at the moment. As an example, one program will work in a conversation, while the other may work best while in a lecture hall, or movie theater setting.
Bluetooth Interface: Technology that lets hearing aids wearers to wirelessly connect to cell phone or other Bluetooth devices. MP3 players, computers, in car blue tooth compatible.
Data Logging: Stores data in the hearing aids or more precise and objective fine tuning.
Learning / Training: Teaches your hearing aids how you wear it, volume you listen with and then it will automatically make these changes based on the wears needs.
Directional Microphone Systems: This hearing aid provides very high customer satisfaction.
Digital Noise Reduction (DNR): Background noise is less disturbing with a higher degree of listening comfort.
Impulse Noise Reduction: Designed to improve listening comfort.
Wind Noise Reduction: Does what is says by decrease the whooshing noise of wind blowing across the hearing aid microphone. Great for the outdoor enthusiasts.
Feedback Management: Helps get rid of annoying whistling.
Telecoil / Autotelecoil: Picks up signal from a compatible telephone.