Describe sudden sensorineural hearing loss.

Nature and Assessment

• Sudden sensorineural hearing loss (SSNHL) is conventionally defined as a loss of 30 dB or more, over at least 3 consecutive frequencies, developing within 72 hours.
• It is an otological emergency, and the commonest reason for a poor outcome is delay.
• It is unilateral, and the patient characteristically notices it on waking or on using the telephone
• Associated symptoms — tinnitus in most; aural fullness; and vertigo in about a third.

Treatment and Prognosis

• Treatment must begin immediately — ideally within 72 hours and certainly within 2 weeks.
• Systemic corticosteroids are the mainstay — prednisolone 1 mg/kg (up to 60 mg) daily for 7 to 14 days, then tapered
• Intratympanic steroid is given as salvage therapy where systemic treatment fails, and as primary treatment where systemic steroid is contraindicated — in diabetes, peptic ulcer, tuberculosis, hypertension, glaucoma and pregnancy.
• Combined systemic and intratympanic therapy is increasingly used from the outset in severe loss
• Other measures — antivirals, vasodilators, anticoagulants, dextran, carbogen inhalation and hyperbaric oxygen have all been used, and none has convincing evidence. Hyperbaric oxygen has the best of a weak case, as an adjunct within the first weeks
• Treat any identified cause, and stop ototoxic drugs
• Prognosis — spontaneous recovery occurs in a substantial proportion, perhaps a third to two-thirds, which is precisely why the evidence for treatment has been so hard to establish and why claims of success must be read carefully
• Good prognostic features — early treatment; mild to moderate loss; low-frequency or mid-frequency loss; NO vertigo; younger age; and early evidence of improvement
• Poor prognostic features — profound loss; downsloping or flat audiogram; vertigo; delayed presentation; advanced age; and vascular risk factors
• Follow UP with serial audiograms; and where the loss does not recover, hearing aids, a CROS aid or a bone-anchored device for single-sided deafness, and cochlear implantation where appropriate
• Warn the patient with a single hearing ear to protect it, and to present immediately if the other ear is affected
• Exclude wax and effusion first with a torch and fork; both are commoner causes of sudden deafness and are trivially treated
• Weber lateralises to the good ear in a true sensorineural loss.
• Treat within seventy-two hours if possible; the benefit of steroids falls away sharply over the following two weeks
• Arrange an MRI in every case, since a small but important proportion prove to be vestibular schwannomas