Inner Ear Anomalies and Vestibular-Evoked Myogenic Potentials (VEMP)

Abstract

Inner ear malformations represent a major inner ear disorder in approximately 20 % of children with congenital sensorineural hearing loss. They are usually characterized by profound hearing loss, and their development delays gross motor functions such as head control or independent walking, because such functions are related to abnormal inner ear structures. However, it is not easy to unequivocally determine whether vestibular sensory cells of semicircular canals and otolith organs or primary vestibular afferent neurons are present in patients with inner ear malformations, particularly common cavity deformity. In an embryological study, it has been found that, in the human fetal developmental stage, the vestibular system develops earlier than the cochlear system. Thus, it is speculated that sensory cells of vestibular end organs and vestibular afferent neurons may be present in patient with inner ear malformations, which is similar to early-stage inner ear development.

In our study, we reported that VEMPs could be elicited with cochlear implant switched on and suggested that the electrical stimulation of a cochlear implant may directly stimulate the inferior vestibular nerve. If VEMPs are evoked with the cochlear implant switched on, it suggests that some of the inferior vestibular neurons are present. In contrast, if VEMPs are absent with the cochlear implant switched on, it suggests that the inferior vestibular neurons may be absent.