VEMP の臨床応用 update

抄録

　The author presented recent topics concerning the clinical application of vestibular-evoked myogenic potential (VEMP). First, methods for detecting endolymphatic hydrops using cVEMP (cervical VEMP) were shown. Two methods, the glycerol cVEMP test and the cVEMP tuning property test, were introduced. Although the former is an orthodox method, it is time-consuming and can cause uncomfortable feelings, such as nausea or headaches. Although the latter method is easier, it does not provide information when subjects do not show responses to either 500-Hz or 1000-Hz tone bursts. Second, the application of oVEMP (ocular VEMP) to the physiological diagnosis of superior canal dehiscence syndrome (SCDS) was presented. Compared with oVEMP responses in healthy subjects, SCDS patients have lower thresholds and larger amplitudes in oVEMP, especially in response to air-conducted sound. Air-conducted sound oVEMP is very useful for the physiological diagnosis or screening of SCDS. The third topic was the combined use of VEMP and vHIT (video head impulse test) for the accurate diagnosis of vestibular disorders. While VEMP tests the otolith organ, vHIT tests the semicircular canal including the vertical canals. Therefore, the combined use of VEMP and vHIT can enable a more accurate diagnosis. As examples, the author presented two cases of episodic otolithic vertigo and vestibular neuritis.