A chronic relapsing form of experimental allergic encephalomyelitis and neuritis was induced by single sensitization of immature and adult Hartley guinea pigs. Clinically, the disease was characterized by relapses. Among them, a few animals showed a severe hearing loss. Histological studies of their cochleae showed a severe loss of ganglion cells and hair cells. The organ of Corti was atrophied but stria vascularis was no changes. There was granular precipitate in scala media and scala tympani.
