Cause:Idiopathic
Pathophys:
Endolymphatic hydrops in scala media causes increased pressure in scala media. Probably due to diminished resorption causing organ of corti damage and semicirc canal involvement
Attack probably represents an endolymphatic rupture with mixing of endo- and perilymph; endolymph has an intracellular ionic content
Sx:
Si:Decreased auditory discrimination, in contrast to conductive losses; recruitment
Lab:Audiometry shows sensorineural loss without air-bone gap. Recruitment of sound so that loudness increases abruptly with slight increase in decibel level, ie, abnormally loud above their abnormally high threshold; this is the distinguishing feature between cochlear (Ménière's, presbycusis) and retrocochlear disease
Rx:
Salt, caffeine, and alcohol restriction
Medications:
Surgical: rarely need; labyrinthectomy through middle ear if hearing already gone there; endolymphatic saccule to subarachnoid space shunt; sacculotomy; 8th nerve section