Acquired brain injury (ABI) describes brain injuries of all types that occur after birth, and can be divided into 2 categories, Traumatic (TBI) and non-traumatic.
Acquired brain injuries are not present at birth. They can be causes include
Traumatic head injury from motor vehicle crashes or sporting or other accidents;
Stroke, cerebrovascular accident (CVA) or haemorrhage;
Brain tumour or treatment;
An incident that causes a lack of oxygen to the brain eg near drowning;
Infections such as meningitis or encephalitis;
Alcohol, drug abuse or poisoning.
Traumatic brain Injury, which is caused by a blow to the head or by the head being moved rapidly. There is usually some loss of consciousness. The brain tissue can become damaged and stop working properly. This damage may be short term and repair itself quickly. In other situations, eg coma, it may take longer to repair or there may be some permanent damage.
Non-traumatic brain injury covers situations where the cells are damaged or killed by toxic substances, lack of oxygen, pressure, direct infection or stroke.
Therefore whilst both ABI and TBI are not present from birth it refers to the way in which the injury was acquired.