Opisthotonus - wikipedia Opisthotonus Opisthotonus Opisthotonus in a patient suffering from tetanus. Painting by Sir Charles Bell, 1809. Opisthotonus or opisthotonos, from Greek roots, ὄπισθεν, opisthen meaning `` behind '' and τόνος tonos meaning `` 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. This abnormal posturing is an extrapyramidal effect and is caused by spasm of the axial muscles along the spinal column. Causes It is seen in some cases of severe cerebral palsy and traumatic brain injury or as a result of the severe muscular spasms associated with tetanus. It can be a feature of severe acute hydrocephalus. Opisthotonus can be produced experimentally in animals by transection of the midbrain ( between the superior colliculus and the inferior colliculus ), which results in severing all the corticoreticular fibers. Hyperextension occurs due to facilitation of the anterior reticulospinal tract caused by the inactivation of inhibitory corticoreticular fibers, which normally act upon the pons reticular formation. It has been shown to occur naturally only in birds and placental mammals. Opisthotonus is more pronounced in infants. Opisthotonus in the neonate may be a symptom of meningitis, tetanus, severe kernicterus, or the rare Maple syrup urine disease. This marked extensor tone can cause infants to `` rear backwards '' and stiffen out as the mother or nurse attempts to hold or feed them. Opisthotonus can be induced by any attempt at movement such as smiling, feeding, vocalization, or by seizure activity. A similar tonic posturing may be seen in Sandifer syndrome. Individuals with opisthotonus are quite challenging to position, especially in wheelchairs and car seats. Opisthotonus can sometimes be seen in lithium intoxication. It is a rare extrapyramidal side effect of phenothiazines, haloperidol, and metoclopramide. Opisthotonus with the presence of the risus sardonicus is also a symptom of strychnine poisoning. Opisthotonus is also described as a potential CNS symptom of heat stroke along with bizarre behavior, hallucinations, decerebrate rigidity, oculogyric crisis and cerebellar dysfunction. Opisthotonus is seen with drowning victims -- called the `` Opisthotonic Death Pose ''. This pose is also common in complete dinosaur skeletal fossils and it has been suggested that this is due to the animal drowning or being immersed in water soon after death. Opisthotonus is a symptom of Lavender Foal Syndrome, a lethal genetic disorder in horses. References Jump up ^ `` opisthotonos ''. Merriam - Webster. Retrieved 7 April 2015. Jump up ^ `` The Berkeley Science Review '' ( PDF ). Retrieved 2009 - 08 - 08. Jump up ^ Faux, Cynthia Marshall ; Padian, Kevin ( 2007 ). `` The opisthotonic posture of vertebrate skeletons : Postmortem contraction or death throes ? ''. Paleobiology. 33 ( 2 ) : 201 -- 26. doi : 10.1666 / 06015.1. JSTOR 4500148. Lay summary -- New Scientist ( November 23, 2011 ). Jump up ^ `` Lavender Foal Syndrome Fact Sheet ''. James A Baker Institute for Animal Health, Cornell University. Archived from the original on 2008 - 05 - 09. External links Classification ICD - 9 - CM : 781.0 DiseasesDB : 31293 External resources MedlinePlus : 003195 Symptoms and signs : nervous and musculoskeletal systems ( R25 -- R29, 781.0, 781.2 -- 9 ) Primarily nervous system Primarily CNS Movement disorders Dyskinesia : Athetosis Tremor Gait abnormality Scissor gait Cerebellar ataxia Festinating gait Marche a petit pas Propulsive gait Stomping gait Spastic gait Magnetic gait Lack of coordination Dyskinesia : Ataxia Cerebellar ataxia / Dysmetria Sensory ataxia Dyssynergia Dysdiadochokinesia Asterixis Other Abnormal posturing : Opisthotonus Sensory processing disorder : Hemispatial neglect Facial weakness Hyperreflexia Pronator drift Primarily PNS Gait abnormality Steppage gait Antalgic gait Primarily muscular Movement disorders Spasm Trismus Fasciculation Fibrillation Myokymia Cramp Gait abnormality Myopathic gait Trendelenburg gait Pigeon gait Other Tetany Meningism Primarily skeletal Rachitic rosary Clubbing Primarily joint Joint locking Retrieved from `` https://en.wikipedia.org/w/index.php?title=Opisthotonus&oldid=830461771 '' Categories : Neurotrauma Symptoms and signs : Nervous system Tetanus Hidden categories : Infobox medical condition ( new ) Talk About Wikipedia Български Deutsch Español فارسی Français Bahasa Indonesia Italiano Nederlands Polski Português Русский Українська 中文 5 more Edit links This page was last edited on 14 March 2018, at 23 : 51. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: the medical term opisthotonos (backward bending tone) means
Answer: 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