(BQ) Part 2 book “Rapid interpretation of balance function tests” has contents: Videonystagmography/ electronystagmography, rotational studies, postural control studies, tests of otolith function. | 5 Videonystagmography/ Electronystagmography Overview of Videonystagmography/ Electronystagmography Videonystagmography (VNG)/electronystagmography (ENG) are utilized to evaluate the integrity of both the peripheral and central vestibular systems. Commonly, the ocular motor studies described in the previous chapter are performed as part of the VNG/ENG. The ocular motor portion of the VNG/ENG provides the majority of the information regarding central vestibular function. Most other portions of the test battery reveal information regarding the peripheral vestibular system. VNG/ ENG is the only means to assess vestibular function on one side independent of input from the opposite side. Therefore, it is an invaluable tool for identifying the side of a unilateral peripheral vestibular lesion (Figure 5–1).1 This study involves the use of either surface electrodes placed on the inner and outer canthi of the eyes to record the corneo-retinal potentials (ENG) or eye movement video monitoring using infrared cameras (VNG) to assess the vestibular ocular 53 54 Rapid Interpretation of Balance Function Tests Information Gained from VNG / ENG Cause for Symptoms Physiologic Compensation Status Peripheral vs Central Compensated vs Uncompensated Unilateral vs Bilateral Figure 5–1. VNG/ENG provides information regarding peripheral and central vestibular integrity. reflex (VOR) during several –5 The information obtained from these subtests can provide information regarding symptom causality and physiologic compensation status. Components of VNG/ENG Spontaneous Nystagmus Test Spontaneous nystagmus can result from central or peripheral vestibular pathology. Nystagmus from a peripheral etiology results from an asymmetry in the firing rates in the right and left vestibular afferent Spontaneous nystagmus of central etiology results from more complex neural processes. Test Administration The patient is in a seated position with the eyes opened, while .
