Fluctuating hearing loss and recurrent vertigo in otosclerosis. An audiologic and temporal bone study

This report summarizes audiologic and temporal bone findings in a 47-year-old white female with recurrent attacks of vertigo, tinnitus, and bilateral hearing loss. A series of audiograms, obtained over a 15-year period, showed a fluctuating mixed (sensorineural and conductive) hearing loss with a relatively flat configuration in the left ear and a relatively stable, mild sensorineural loss with a sloping contour in the right ear. Temporal bone studies revealed the existence of otosclerotic foci bilaterally. In the left ear, the otosclerotic focus has grown close to the utricular and lateral ampullary nerves, displaced and ankylosed the stapedial footplate, invaded the endosteal zone (1,000-2,000 Hz area), and deformed the lateral cochlear wall. In the right ear, the otosclerotic invasion was limited to the inferior portion on the promontory (vestibular cecum) and round window niche.