Anatomy of self-injurious, stereotypic, and aggressive movements: evidence for involuntary explanation

J Clin Psychol. 1992 Nov;48(6):766-78. doi: 10.1002/1097-4679(199211)48:6<766::aid-jclp2270480611>;2-o.


Self-injurious movements, common in persons diagnosed with Tourette syndrome, or mental retardation, are typically difficult to eliminate. The author considers the possibility that certain self-injurious movements are involuntary phenomena. An anatomical analysis of high-frequency movements in a patient with severe head slapping is presented by tracing the muscles and nerves involved. The median nerve innervates muscles that bring the hand/arm to the head and also muscles that control this patient's other frequent movements, viz., pill-rolling, thumb-gouging, wrist-flapping, and pinching the neck or cheek. Other patients underwent similar investigation: one who headbangs, one who hits out repetitively, and one with non-injurious stereotypic movements. An anatomical explanation suggests that certain self-injurious, aggressive, and stereotypic movements are involuntary muscle contractions that reflect abnormal innervation along specific nerves.

MeSH terms

  • Adult
  • Aggression / physiology*
  • Brain / physiopathology
  • Brain Damage, Chronic / physiopathology*
  • Brain Damage, Chronic / psychology
  • Brain Mapping
  • Female
  • Humans
  • Intellectual Disability / physiopathology*
  • Intellectual Disability / psychology
  • Male
  • Motivation
  • Muscles / innervation
  • Peripheral Nerves / physiopathology
  • Seizures / physiopathology
  • Seizures / psychology
  • Self-Injurious Behavior / physiopathology*
  • Self-Injurious Behavior / psychology
  • Spinal Nerves / physiopathology
  • Stereotyped Behavior / physiology*
  • Tourette Syndrome / physiopathology*
  • Tourette Syndrome / psychology