AVERT is a multicenter phase 2 clinical trial comparing a novel diagnostic strategy (VRT) to standard ED diagnostic care at three performance sites. The Specific Aims are to assess diagnostic accuracy, diagnostic workup costs, and estimate the short-term impact of correct diagnosis in anticipation of a larger, definitive phase 3 trial. Adult ED patients with a chief symptom of vertigo, dizziness, or unsteadiness, new or clearly worse in the previous 30 days, will undergo on-site vestibular function tests by trained research personnel using a portable, quantitative VOG recording device. Research personnel will also record a focused symptom history and bedside hearing tests. Eligible patients with at least one pathologic vestibular eye movement finding or pathologic ataxia will be randomized to VRT or standard ED care. Patients eligible for pre-randomization testing but excluded from randomization will be slated for the Observational Arm of the study and will undergo limited 1-month and 6-month phone follow-up. The VRT arm relies on an automated algorithm to interpret VOG results, thereby determining a patient-specific clinical care pathway. For safety, all VRT-arm study participants will undergo stroke protocol MRI before release. All randomized participants will undergo confirmatory testing at one week, including vestibular specialist exam and 1.5 or 3-Tesla research MRI combining stroke and internal auditory canal protocols. All randomized participants will also undergo 1-month and 6-month phone follow-up and medical record review to confirm diagnoses. Clinical findings, ED diagnoses, diagnostic resource utilization, treatments applied, and clinical events during follow-up will be recorded. A multidisciplinary, masked expert panel will adjudicate final diagnoses.