Coup and contrecoup injury

Coup injury may be caused when, during an impact, the brain undergoes linear acceleration and deceleration forces or rotational forces, causing it to collide with the opposite side of the skull. These forces directly disrupt neurons, axons, other neural and meningeal structures, and blood vessels in local or diffuse patterns, typically leading to various cellular, neurochemical and metabolic effects. ==Features==

Contrecoup, which may occur in shaken baby syndrome and vehicle accidents, can cause diffuse axonal injury. In some circumstances, concussive injury can cause microvascular disruption, hemorrhage, or subdural hematoma. Closed head injury (coup contrecoup) can damage more than the impact sites on the brain, as axon bundles may be torn or twisted, blood vessels may rupture, and elevated intracranial pressure can distort the walls of the ventricles. Diffuse axonal injury is a key pathology in concussive brain injury. Contrecoup contusions are particularly common in the lower part of the frontal lobes and the front part of the temporal lobes. and the skull may also result from concussion. ==History==

In the 17th century, Jean Louis Petit described contrecoup injuries. In 1766, the French surgeon Antoine Louis coordinated a meeting of the Académie Royale de Chirurgie on contrecoup injuries, at which papers were to be presented, one of which would be chosen to receive the respected prize, the ''Prix de l'Académie Royale de Chirurgie''. The presenter of the chosen paper was not awarded the prize because he failed to make recommended changes. In 1768, the group met again on the topic, and Louis Sebastian Saucerotte won the prize for his paper describing contrecoup injuries in humans and experiments on animals and recommending treatments such as bloodletting and application of herbs to patients' heads. ==In popular culture==

• In the Perry Mason TV series, contrecoup lacerations were used as evidence in at least two episodes, including "The Case of the Jaded Joker" (1959) and "The Case of the Bluffing Blast" (1963). • In "Hawkeye", an episode of M*A*S*H, Captain Hawkeye Pierce, M.D. diagnoses himself as having a contrecoup injury. • In "Meld", an episode of Star Trek: Voyager, the ship's doctor is able to use the distinction between coup injury and contrecoup injury to determine that a dead crewman was murdered. • "Contrecoup" is the title of a They Might Be Giants song off their 2007 album The Else. It was written as a challenge to create a song using the words "contrecoup", "craniosophic", and "limerent", and likens an infatuation to the effects of a traumatic brain injury. • In Stephen King's novel Duma Key, the main character has brain damage from a contrecoup injury (spelled "contracoup"). • The distinction between coup and contrecoup injuries is described and portrayed in "Betrayal, Part 2", a 2019 episode of the BBC television drama series Silent Witness. ==References==