An update on tardive dyskinesia: from phenomenology to treatment.

Tardive dyskinesia (TD), characterized by oro-buccal-lingual stereotypy, can manifest in the form of akathisia, dystonia, tics, tremor, chorea, or as a combination of different types of abnormal movements. In addition to movement disorders (including involuntary vocalizations), patients with TD may have a variety of sensory symptoms, such as urge to move (as in akathisia), paresthesias, and pain. TD is a form of tardive syndrome-a group of iatrogenic hyperkinetic and hypokinetic movement disorders caused by dopamine receptor-blocking agents. The pathophysiology of TD remains poorly understood, and treatment of this condition is often challenging. In this update, we provide the most current information on the history, nomenclature, etiology, pathophysiology, epidemiology, phenomenology, differential diagnosis, and treatment of TD.