Vestibular evoked myogenic potential

摘要

Vestibular evoked myogenic potential(VEMP), is an electromyographic response of vestibular origin evoked by sound, vibration or electrical stimulation. VEMP is widely used as a clinical test of the otolith organs. Nowadays, two kinds of VEMP, cervical VEMP(cV EMP) and ocular VEMP(o VEMP) are clinically used. c VEMP is a test of sacculo-collic reflex while oV EMP is a test of utriculo-ocular reflex. Absence of responses, large interaural asymmetry of amplitudes, prolonged peak latencies, and abnormal thresholds of responses are regarded as abnormal responses. Clinical application to various diseases of the vestibular system was performed. Using VEMP, a new type of vestibular neuritis, inferior vestibular neuritis was established. A prominent feature of VEMP in Meniere's disease is a shift of a preferred frequency in cV EMP. The whole aspects of VEMP findings in patients with benign paroxysmal positional vertigo are not clarified yet. Sensitivity of cV EMP to vestibular schwannoma was 80.0%, while specificity was 52.7%. Concerning diagnosis of superior canal dehiscence syndrome(SCDS), o VEMP to air-conducted sound is the most helpful. Augmentation of o VEMP responses is a prominent feature in SCDS. I also presented "idiopathic otolithic vertigo", which I proposed as a new clinical entity based on VEMP findings. Some patients complained of lateral tilting sensation in the roll plane, or tilting or translational sensation in the pitch plane without rota-tory vertigo. Majority of patients with these symptoms had absent or decreased responses of o VEMP and/or c VEMP. I proposed that these patients could be diagnosed as having "idiopathic otolithic vertigo".