2, 3 AVS can be caused by peripheral or central lesions. AVS constitutes approximately 10% to 20% of emergency department (ED) dizziness, 2 so is responsible for approximately 400,000 to 800,000 US ED visits annually. Acute vestibular syndrome (AVS) is a well-defined clinical syndrome 1 of continuous vertigo or dizziness with nausea or vomiting, head-motion intolerance, gait unsteadiness, and nystagmus lasting days to weeks.
