Introduction
Benign paroxysmal positional vertigo (BPPV) is the most common pathogenesis of peripheral vertigo, and semicircular canal (SCC) involvement and underlying pathophysiologic mechanisms determine the direction and characteristics of nystagmus [1]. Meniere’s disease is an internal ear disease that courses with spontaneous vertigo attacks, fluctuating sensorineural hearing loss, ear fullness, and tinnitus [2]. Vestibular neuritis (VN) is selective, acute, or subacute inflammation of the vestibular nerve. Mostly superior branch of vestibular nerve is affected and dysfunction of these fibers arises [3].
Video head impulse test (vHIT) is a new and important physiological test to detect the gain of the vestibulo-ocular reflex (VOR) for each semicircular and finds out overt and covert catch-up saccades with the head impulse and gaze deviation [4, 5]. Although the caloric test is the gold standard in the diagnosis of peripheral vestibular diseases, vHIT is a simple and fast test, it does not cause nausea and discomfort in the patient, and provides a separate evaluation for each SCC [5, 6]. While vHIT is recommended as an important diagnostic test for VN and MD in the literature, it has been reported as unnecessary and unfavorable in BPPV patients[5, 7]. However, there are a few clinical studies not including the detailed analysis of BPPV patient’s findings. The information for vHIT results for BPPV in the literature was generally derived from the results of a group of patients with acute or peripheral vertigo.