A 54-year-old female with bilateral rapidly progressive hearing impairment, tinnitus and dizziness was sent to our ENT clinic. She also complained of headache and low grade fever. Pure tone audiometry showed bilateral severe sensori-neural hearing loss, and direction-changing positional nystagmus towards the upper ear side was observed. Neurological examinations revealed truncal ataxia and a positive Babinski's sign.
Electronystagmography (ENG) and eye tracking test (ETT) showed saccadic pursuit and hypometric saccade; optokinetic nystagmus (OKN) and optokinetic after nystagmus (OKAN) were impaired bilaterally.
Her serum TPHA titer was very high, so erythromycin was given orally in a daily dose of 1600 mg for 30 days. Her dizziness improved gradually, but hearing impairment progressed rapidly to bilateral total deafness. MRI revealed no significant lesion except a pituitary adenoma.
We suspected that otosyphilis and positional nystagmus was induced by stenosis of the basilar artery.