In head injury, a coup injury occurs under the site of impact with an object, and a contrecoup injury occurs on the side opposite the area that was hit. Coup and contrecoup injuries are associated with cerebral contusions, a type of

traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity ranging from mild traumatic brain injury (mTBI/concussion) to severe traumati ...

in which the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

bruise A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur c ...

d. Coup and contrecoup injuries can occur individually, or together as a coup–contrecoup injury. When a moving object impacts the stationary head, coup injuries are typical, while contrecoup injuries are produced when the moving head strikes a stationary object. Coup and contrecoup injuries are considered focal brain injuries – those that occur in a particular spot in the brain – as opposed to diffuse injuries, which occur over a more widespread area. Diffuse axonal injury is the most prevalent pathology of coup contrecoup. The exact mechanism for the injuries, especially contrecoup injuries, is a subject of much debate. In general, they involve an abrupt deceleration of the head, causing the

to collide with the inside of the skull. It is likely that

inertia Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes the velocity to change. It is one of the fundamental principles in classical physics, and described by Isaac Newto ...

is involved in the injuries, e.g. when the brain keeps moving after the skull is stopped by a fixed object or when the brain remains still after the skull is accelerated by an impact with a moving object. Additionally, increased intracranial pressure and movement of cerebrospinal fluid following a trauma may play a role in the injury.

Mechanisms

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. The injuries can also be caused solely by acceleration or deceleration in the absence of an impact. Contrecoup injury may be produced by tensile forces. These forces directly disrupt

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

axon An axon (from Greek ἄξων ''áxōn'', axis) or nerve fiber (or nerve fibre: see American and British English spelling differences#-re, -er, spelling differences) is a long, slender cellular extensions, projection of a nerve cell, or neuron, ...

s, 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 Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, ...

, 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. The

visual system The visual system is the physiological basis of visual perception (the ability to perception, detect and process light). The system detects, phototransduction, transduces and interprets information concerning light within the visible range to ...

may be affected. Contrecoup contusions are particularly common in the lower part of the

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neur ...

s and the front part of the

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pr ...

s. Injuries that occur in body parts other than the brain, such as the lens of the eye, the lung, 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

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

s 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 They Might Be Giants, often abbreviated as TMBG, is an American alternative rock and Children's music, children's band formed in 1982 by John Flansburgh and John Linnell. During TMBG's early years, Flansburgh and Linnell frequently performed as ...

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

External links

* {{wiktionary-inline, contrecoup Neurotrauma