Opisthotonus

Opisthotonus
Opisthotonus in a patient suffering from tetanus. Painting by Sir Charles Bell, 1809.
SpecialtyNeurology
SymptomsAbnormal posturing

Opisthotonus or opisthotonos (from Ancient Greek: ὄπισθεν, romanized: opisthen, lit. 'behind' and τόνος, tonos, 'tension') is a state of severe hyperextension and spasticity in which an individual's head, neck and spinal column enter into a complete "bridging" or "arching" position.[1][2]

This extreme arched pose is an extrapyramidal effect and is caused by spasm of the axial muscles along the spinal column. It has been shown to occur naturally in birds, snakes suffering from advanced boid inclusion body disease, and placental mammals, among existing animals; it is observed in some articulated dinosaur fossils.[3][2]

  1. ^ "opisthotonos". Merriam-Webster. Retrieved 7 April 2015.
  2. ^ a b "The Berkeley Science Review" (PDF). Archived from the original (PDF) on 2012-05-17. Retrieved 2009-08-08.
  3. ^ Cite error: The named reference Faux & Padian 2007 was invoked but never defined (see the help page).