It is well known that multiple sclerosis is a demyelinating disease of multiple neurologicsigns and symptoms, but sudden sensorineural hearing loss is an uncommon manifestation. Wereport a rare case of multiple sclerosis in a 17- year-old female with sudden hearing loss. She showed obvious waves of delayed evoked otoacoustic emissions, despite a profound sensorineural hearing loss in pure tone audiograms and abnormal auditory brainstem responses in her left ear. These results indicate her normal cochlear function and retrocochlear dysfunction. Magnetic resonance imaging revealed several multiple sclerosis plaques. One month after the initial examination, her hearing recovered completely. This case report demonstrates the value of delayed evoked otoacoustic emissions in differential diagnosis.
