Application of vestibular evoked myogenic potentials in otosclerosis patients with vertigo

Otosclerosis is a progressive disease with a remodeling process causing ossicular malformation and conductive hearing loss. Otosclerosis patients with vertigo can present with abnormalities of ocular and/or cervical vestibular evoked myogenic potentials (VEMPs) due to pathological damage of the utricle, saccule, semicircular canals and cochlea. These abnormalities are more common than those after caloric testing and bone-conducted hearing thresholds and their relative frequency reflects the degree of the aforementioned damage. Air- and bone-conducted pure-tone average VEMPs can be elicited in ears with otosclerosis. The evaluation of air-conducted VEMP thresholds can be added to the diagnostic work-up of otosclerosis in case of doubt thus improving the differential diagnosis in patients with air-bone gaps. As saccule has the closest anatomical proximity to the sclerotic foci, it is the most prone vestibular structure to otosclerotic damage. A study of saccular function suggests that a vestibular dysfunction is due to the direct biotoxic effect of the materials released from the otosclerosis foci on saccular receptors. Another investigation using bone-conducted VEMPs elucidates the origin of balance troubles in otosclerosis patients. Nine of ten patients complaining of dizziness and/or vertigo show abnormal results on this testing. Recent research convincingly demonstrates a considerable diagnostic effectiveness and reliability of VEMPs in otosclerosis. This study aimed at revising the scientific literature addressing the main techniques used to generate vestibular-evoked myogenic potentials and their clinical applications in otosclerosis patients with vertigo.