The unbearable lightness of the extrapyramidal system

J Hist Neurosci. 2012 Jul;21(3):280-92. doi: 10.1080/0964704X.2011.595652.

Abstract

The concept of the extrapyramidal system comprises an amalgam of disparate and often conflicting ideas with a tortuous history. To the theoretical neuroscientist or practicing clinician, it promptly evokes semantic associations that are hardly reminiscent of its original meaning. The purpose of this article is to revisit the sources of the extrapyramidal concept and to examine the transformations that it went through from its inception, in the late 1890s, up to the neuroimaging revolution of the 1980s. Our review shows that the use of "extrapyramidal" as a surrogate for the basal ganglia, disorders of movement, or certain manifestations of spastic hemiplegia does not apply to humans; rather, it represents the historical product of the unwarranted translation of results of animal experimentation into the interpretation of clinical findings on human patients, misguided clinico-anatomic deductions, and fanciful phylogenetic notions. We conclude that the extrapyramidal concept is a valid and robust anatomic concept as long as it strictly refers to the collection of descending fibers originating in a few discrete brainstem tegmental motor nuclei that project to the spinal cord.

Publication types

  • Historical Article

MeSH terms

  • Basal Ganglia / anatomy & histology
  • Basal Ganglia Diseases / history*
  • Basal Ganglia Diseases / physiopathology
  • Extrapyramidal Tracts / anatomy & histology
  • Extrapyramidal Tracts / physiology
  • Hemiplegia / history
  • Hemiplegia / physiopathology
  • History, 19th Century
  • History, 20th Century
  • Humans
  • Neurology / history*
  • Reflex, Babinski / history