Abstract
After taking a patient's medical history and conducting a clinical examination of the vestibular system, ocular motility, and cerebellum, vestibular function tests play a crucial role in diagnosing the causes of dizziness and other vestibular-related symptoms. When assessing a patient with vestibular dysfunction, the eyes are the most accessible organ for evaluation. The pathways from the labyrinth to the key vestibular processing centers in the brainstem and cerebellum, with control from higher centers in the cortex, are often challenging to observe directly. Therefore, accurate analysis of eye movements provides insights into the integrity of central transmission pathways. Consequently, the eyes are considered the window into the vestibular system and are utilized in vestibular function tests. These tests are vital for quantifying and documenting vestibular deficits, disease progression, and treatment efficacy.
Among various vestibular function tests, two are most commonly used in clinical practice: Ocular Movement Measurement (VideoNystagmoGraphy - VNG) and the Video Head Impulse Test (vHIT). Additionally, the results of these two tests are emphasized in the diagnostic criteria of the Bárány Society, such as the diagnostic criteria for bilateral vestibulopathy (2017) and the criteria for acute unilateral peripheral vestibulopathy/vestibular neuritis (2022). Moreover, VNG and vHIT can help differentiate between central and peripheral lesions.