The past and future of vestibular functional testing

―From the Heisei to the Reiwa period―

Abstract

　Vestibular function testing is very important for establishing the correct diagnosis of vertigo and dizziness, and is especially helpful for isolating the affected side and the responsible lesion. Until the end of the Showa period, caloric nystagmus was the gold standard for this examination, but it was inadequate to examine the otolith function. During the Heisei period, vestibular evoked myogenic potential (VEMP) and video head impulse test (vHIT) were introduced, which enable detailed examination of the functions of the inner ear and vestibular nerve. In these examinations, cervical VEMP (cVEMP) is used to evaluate the sacculus, and inferior vestibular nerve function, which examination is used to evaluate vestibular neuritis, acoustic neuroma, and superior semicircular canal dehiscence. Until now, endolymphatic hydrops was detected using glycerol-or furosemide-loaded cVEMP; however, these tests have side effects, such as headache, and take several hours to perform. To address these concerns, we introduced the tuning property test and confirmed its diagnostic usefulness. The tuning property test is very useful because it does not require any drugs and can be completed in a short time. During the Reiwa period, additional research on the properties and clinical usefulness of the tuning property test are needed.