Traumatic brain injury

Traumatic brain injury
Other names	Intracranial injury, physically induced brain injury[1]
CT scan showing cerebral contusions, hemorrhage within the hemispheres, and subdural hematoma. There is also displaced skull fracture of left transverse parietal and temporal bones.[2]
Specialty	Neurosurgery, pediatrics
Symptoms	Physical, cognitive, sensory, social, emotional, and behavioral symptoms
Types	Mild to severe[3]
Causes	Trauma to the head[3]
Risk factors	Old age,[3] alcohol
Diagnostic method	Based on neurological exam, medical imaging[4]
Treatment	Behavioral therapy, speech therapy

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 traumatic brain injury.^[5] TBI can also be characterized based on mechanism (closed or penetrating head injury) or other features (e.g., occurring in a specific location or over a widespread area).^[6] Head injury is a broader category that may involve damage to other structures such as the scalp and skull. TBI can result in physical, cognitive, social, emotional and behavioral symptoms, and outcomes can range from complete recovery to permanent disability or death.

Causes include falls, vehicle collisions and violence. Brain trauma occurs as a consequence of a sudden acceleration or deceleration within the cranium or by a complex combination of both movement and sudden impact. In addition to the damage caused at the moment of injury, a variety of events following the injury may result in further injury. These processes may include alterations in cerebral blood flow and pressure within the skull. Some of the imaging techniques used for diagnosis of moderate to severe TBI include computed tomography (CT) and magnetic resonance imaging (MRIs).

Prevention measures include use of seat belts and helmets, not drinking and driving, fall prevention efforts in older adults and safety measures for children.^[7] Depending on the injury, treatment required may be minimal or may include interventions such as medications, emergency surgery or surgery years later. Physical therapy, speech therapy, recreation therapy, occupational therapy and vision therapy may be employed for rehabilitation. Counseling, supported employment and community support services may also be useful.

TBI is a major cause of death and disability worldwide, especially in children and young adults.^[8] Males sustain traumatic brain injuries around twice as often as females.^[9] The 20th century saw developments in diagnosis and treatment that decreased death rates and improved outcomes.