الفهرس 
Anatomy of the inner earOnly 14 pages are availabe for public view
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Abstract
Sudden sensorineural hearing loss is defined as hearing loss of at least 30 dB in three sequential frequencies in the standard pure- tone audiogram over3 days or less .the incidence of sudden sensorineural hearing loss at between five and 30 cases per 100,000 population per year.The causes of Sudden sensori-neural hearing loss include vascular , immune mediated and viral causes specially the mumps virus which accounts for 7% of the adult case. The varicella zoster virus can also be a cause specially in cases of Ramsy Hunt syndrome.
Hyperbaric oxygen therapy (HBOT) involves the intermittent inhalation of 100 per cent oxygen in chambers pressurized above one atmosphere absolute. The treatment duration and number of sessions required depend on the reason for HBOT. Each treatment duration can vary from 45 to 300 minutes, although most treatments are in excess of 90 minutes, for a variable number of sessions.The methods af administration of hyperbaric oxygen include In systemic hyperbaric oxygen therapy, the patient is entirely enclosed in a pressurized chamber and breathes oxygen at a pressure greater than one atmosphere (the pressure of oxygen at sea level). Thus this technique relies on the systemic circulation to deliver highly oxygenated blood to the target site
The other method is Topical hyperbaric oxygen therapy which is a technique of delivering 100% oxygen directly to an open-moist wound at a pressure slightly higher than atmospheric pressure. HBO has complex effects on immunity, oxygen transport and hemodynamic. The positive therapeutic effects come from a reduction in hypoxia and edema, enabling normal host responses to infection and ischemia .
the treatment of HBO could lead to greater improvement from the disease by increasing the oxygen concentration in the peripheral blood circulation and pO2 in the inner ear fluid.For the treatment of ISSNHL, HBOT has been applied over decades either alone or in addition to other medical treatments . In combination with HBOT, the overall success rate of ITS was superior when compared to i.v. steroid application.However, HBOT in addition to application of a vitamin cocktail and dexamethasone, did not improve chronic ISSNHL in another study.
Other lines of treatment includes oral steroids which act through potential decrease in any associated pathogenic inflammation and oedema. The use of oral corticosteroids is probably the most widely used therapeutic intervention in ISSNHL .
The intratympanic (IT) route of administration of corticosteroids for ISSNHL was introduced, with the goal of minimizing systemic side effects while allowing achievement of a higher drug concentration in the inner ear.
treatment of ISSNHL with combined therapy of systemic steroids and intratympanic injection results in higher rates and quality of hearing recovery as compared to treatment with systemic steroids alone.Antivial treatment also can be used but there is no evidence to support the routine use of antiviral therapy in ISSNHL.Other lines of treatment include vasodilator therap ,vitamins cocktails and explorative tymbanotomy with sealing of the round window membrane.