INTRODUCTION:
Otosclerosis is a localized hereditary disorder of bone metabolism of otic capsule enchondral bone that leads to progressive hearing loss. It is characterized byabnormal bony remodeling, resulting in bone resorption and deposition. Cochlear otosclerosisrefers tolesions involving the cochlear endosteum causing sensorineural hearing loss with or without stapes fixation.
Vestibular symptoms associated with otosclerosis occur in 10-45% of patients and they may be the most distressing and primary symptom in cases with otosclerosis. So the assessment of each component of the vestibular system will facilitate a more complete evaluation. The vestibular evoked myogenic potentials test (VEMP) is used to assesse the saccular and the utricular functions using cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP), respectively. The video head impulse test (vHIT) measuresthe vestibulo-ocular reflex (VOR) to rapid impulsive head acceleration in the plane of each semicircular canal (SCC) and has allowed quantitative monitoring of individual canal function.

AIM OF THE WORK:
The aim of the work was to assess the function of the saccule, the utricle and the three semicircular canals using cVEMP, oVEMP and video HIT in patients with cochlear otosclerosis.