“Dizziness” and “unsteadiness” are daunting complaints in the ED. An acute change in gait or coordination can represent a wide range of disease processes that can be difficult to quickly tease apart. This lecture will help identify the temporal relationship of symptom progression, as well as relevant questions and physical exam findings in order to rapidly differentiate emergent and reversible causes of acute ataxia. Learn to separate the differential, focusing on the acute intervenable causes. The goal is to help the physician quickly identify life-threatening and disabling causes of acute ataxia.