Extrapyramidal System/Symptoms/Signs Should Be Retired

Abstract

The term "extrapyramidal system/symptoms/signs" and the acronym "EPS" have been abundantly used in neurology and psychiatry literature for more than a century. However, EPS has been increasingly criticized, especially by movement disorder neurologists, for its lack of clinical, anatomical, and physiologic definition. Contrary to traditional assumptions, pyramidal and extrapyramidal systems are not mutually exclusive. The acronym EPS, commonly used to denote drug-induced movement disorders, lacks specificity in conveying the nature and severity of these and other movement disorders. Consequently, we propose that the term is retired from scientific literature and that clinicians use specific phenomenologic descriptors for the various hypokinetc and hyperkinetic movement disorders.