User:Doctorgubernaculum/Idiopathic sudden sensorineural hearing loss

Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) is defined as sudden sensorineural hearing loss (SSHL) of 30 decibels over 3 contiguous frequencies in a maximum course of 3 days, without any identifiable cause(1).

Etiology ISSHL makes of 71% of SSHL cases (2). Although idiopathic, it's primary pathology appears to be cochlear in origin, and as such the specific etiology is difficult to test for but may include ischemia, autoimmune, trauma, ototoxic medications, as well as cochlear and/or labyrinthine membrane damage (3). Rationale for an ischemic cause revolves around the poor blood perfusion of the organ of corti, and low oxygen tension in the perilymph of those given the diagnosis of ISSHL (4).

Clinical Presentation Patients commonly present waking up with unilateral hearing loss (90% of the time), tinnitus (90%), aural fullness, and vertigo (50% of the time) (5).

Treatment Intratympanic or oral steroids, and hyperbaric oxygen are the mainstays of treatment recommended by the American Academy of Otolaryngology. The Undersea and Hyperbaric Medical Society recently approved this condition as an approved indication for hyperbaric oxygen therapy (6).

Less well established treatments include zinc and magnesium supplementation, apheresis of fibrinogen and low density lipoprotein (LDL) administration, tympanotomy and sealing of the round window, and instillation of hypaque and dextran.

Prognosis Patients with low frequency loss appear to have more favorable outcomes (7). It can spontaneously resolve in patients anywhere from 25% to 70% of the time.