This page is designed to help those affected by brain injury, as well as their families and friends, by providing quick and clear definitions of medical terms.
You may find the services offered by Headway Bristol helpful: our services support both those with an acquired brain injury and their families and carers.
Acute subdural haematoma (ASDH)
An acute subdural haematoma is a clot of blood that develops between the surface of the brain and the dura mater (the brain’s tough outer covering) usually due to stretching and tearing of veins on the brain’s surface. These veins rupture when a head injury suddenly jolts or shakes the brain. These are the most lethal of all head injuries.
▶ Learn more about brain aneurysm on the Headway UK website.
Anoxic brain injury
Refers to a completely interrupted oxygen supply to the brain, which renders it unable to metabolise glucose. Damage to brain tissue begins after about 4 minutes.
▶ Read more about anoxic brain injury on the Headway UK website.
Brain
An organ of soft nervous tissue contained in the skull. It coordinates sensation, intellectual and nervous activity.
Brain (cerebral) aneurysm
A balloon-like swelling in the wall of an artery that may rupture, leading to life-threatening internal bleeding.
Brain injury
Any injury that impairs brain function.
▶ You can read more about the effects of brain injury on the Headway UK website.
Chronic subdural haematoma (CSDH)
A collection of blood on the brain’s surface, under the outer covering of the brain (dura mater). It usually begins forming several days or weeks after bleeding initially starts. Bleeding is usually due to a head injury.
Cognitive skills
Cognitive skills are the core skills your brain uses to think, read, learn, remember, reason and pay attention. Working together, they take incoming information and move it into the bank of knowledge you use every day at school, at work and in life.
Coma
A coma is a deep state of prolonged unconsciousness. During comas, patients cannot be awakened; fail to respond normally to stimuli (such as pain, light or sound); lack a normal wake-sleep cycle; and do not initiate voluntary actions.
Concussion
A temporary injury to the brain caused by a bump, blow or jolt to the head. It usually lasts up to a few days or weeks, although some people can have longer-lasting problems. Sometimes concussions require emergency treatment. See also post-concussion syndrome.
▶ You can learn more about concussion on the Headway UK website.
Confabulation
Unintentionally generating memories that are untrue or distorted to fill memory gaps; the individual in question believes these memories to be true.
Contrecoup
Contrecoup occurs when a force or blow causes the brain to strike the side of the skull opposite from a point of impact. They are often overlooked or misdiagnosed because of their location.
Diffuse axonal injury (DAI)
Diffuse axonal injury is a brain injury in which scattered lesions (tearing of nerve fibres) occur over a widespread area of brain tissues.
Dura mater
The tough, outermost layer of the three protective membranes (meninges) that surround the brain and spinal cord.
Embolism
Sudden blockage of an artery by a clot that has travelled from elsewhere in the circulatory system.
Encephalitis
This refers to brain swelling, often caused by infections. The brain can be damaged by the infection, the body’s immune response, and the effects of the swelling on the brain.
▶ Read more about encephalitis on the Headway UK website.
Executive function
The brain’s ability to plan, organise, solve problems, sequence, prioritise, self-monitor, self-correct, control and alter behaviour and judgement.
Extradural haematoma (EDH), also known as epidural haematoma
An extradural haematoma is a collection of blood that forms between the inner surface of the skull and outer layer of the dura mater. They are usually associated with a history of head trauma and frequently associated with skull fracture.
Focal lesion
Focal lesions are specific areas of injury to brain tissue following brain injury. Focal lesions may be created when an object penetrates the skull and directly injures one area of the brain.
Frontal lobe
The part of each cerebral hemisphere that controls important cognitive skills in humans (such as emotional expression, problem solving, memory, language, judgment, and sexual behaviours). These lobes are, in essence, the ‘control panel’ of our personality and ability to communicate.
Glasgow Coma Scale (GCS)
The Glasgow Coma Scale is the most common scoring system used to describe the level of consciousness in a person following a traumatic brain injury. A score of 8 or less indicates that the person is in a coma. The minimum possible score is 3. A maximum score of 15 indicates that the person can speak coherently, obey commands to move and can spontaneously open their eyes.
Haematoma
The pooling of blood following bleeding (a haemorrhage).
Haemorrhage
Blood loss, bleeding – an escape of blood from a ruptured blood vessel. This can then pool (a haematoma).
Emotional lability, also known as emotional incontinence
A disorder where the patient has excessive displays of emotion or expresses emotions that don’t match the situation.
Hydrocephalus
Refers to a build-up of fluid inside the skull. The resulting increase in pressure can cause damage to the brain.
▶ Read more about hydrocephalus on the Headway UK website.
Hypoxic brain injury
Refers to an inadequate oxygen supply to the brain, which renders it unable to metabolise glucose. Damage to brain tissue begins after about 4 minutes.
▶ Read more about hypoxic brain injury on the Headway UK website.
Meningitis
An infection that can causes the meninges (protective membranes surrounding the brain) to become inflamed. It can also infect the cerebrospinal fluid. Injury to the brain occurs due to increased pressure and inflammation.
▶ Read more about meningitis on the Headway UK website.
Open skull fracture, also known as a penetrating brain injury
A break in the skull that also involves an open wound, allowing the outside environment to come into contact with the brain. These are more dangerous than closed fractures because of the increased risk of infection. This could lead to brain injury.
Post-coma unresponsiveness (PCU)
A condition in which a medical patient is completely unresponsive to psychological and physical stimuli and displays no sign of higher brain function, no meaningful awareness of self or surroundings, no ability to speak or understand. They are kept alive only by medical intervention.
Post-concussion syndrome (PCS)
A complex disorder with various symptoms, such as headaches and dizziness that can last for weeks or sometimes months after the injury that caused the concussion.
Post-traumatic amnesia (PTA)
Post-traumatic amnesia is a state of confusion that occurs immediately following a traumatic brain injury. The injured person is disoriented and unable to remember events that have occurred after the injury. They may be unable to state where they are or what time it is.
Rehabilitation
Rehabilitation is a term that describes different kinds of specialist support and services that help natural recovery after a brain injury. The nature and timescale for rehabilitation can change depending on the type, severity and location of the person’s brain injury, as well as other factors such as age at the time of injury, and social support available following the injury. It can include physio, speech and language, cognitive, occupational therapy, neuropsychology and potential support work.
▶ Read more about rehabilitation on the Headway UK website.
Retrograde amnesia (RA)
Retrograde amnesia is a loss of access to memories of events that occurred, or information that was learnt, in the past. It can be caused by a brain injury or the onset of a disease impacting the brain.
Shunt
A device to draw off excess fluid in the brain. A surgically placed tube runs from the ventricles and deposits fluid into either the abdominal cavity, heart or large veins in the neck.
Stroke
A stroke is a sudden interruption in the blood supply of the brain. Most strokes are caused by an abrupt blockage of arteries leading to the brain (ischemic stroke). Other strokes are caused by bleeding into brain tissue when a blood vessel bursts (haemorrhagic stroke).
▶ Read more about strokes on the Headway UK website.
Subarachnoid haemorrhage (SAH)
Subarachnoid haemorrhage is a type of haemorrhage caused by bleeding into the space surrounding the brain. They can be caused by a ruptured aneurysm, arteriovenous malformation or head injury. Treatment focuses on stopping the bleeding and restoring normal blood flow.
Subdural haematoma (SDH)
Subdural haematoma is a type of intracranial haemorrhage that occurs beneath the dura mater (essentially, a collection of blood over the surface of the brain) and may be associated with other brain injuries. It often requires surgical intervention.
Traumatic brain injury (TBI)
A traumatic brain injury is sudden damage to the brain caused by a blow or jolt to the head. Common causes include car or motorcycle crashes, falls, sports injuries and assaults. Injuries can range from mild concussions to severe, permanent brain damage.
Traumatic subarachnoid haemorrhage (TSAH)
This is the most common type of subdural haematoma.