Several definitions of brain injuries exist in current literature. The acquired brain injury definition is broader in scope and is often termed the “umbrella” definition as it includes traumatic brain injury.

Acquired brain injuries are typically brain injuries occurring after birth but not related to degenerative diseases, congenital or hereditary factors. They may cause temporary or permanent impairment(s). Impairments can include physical functions, cognition and psychosocial behaviors. Causes of acquired brain injury can include, but are not limited to the following:

• Strokes
• Traumatic Brain Injury (TBI)
• Substance Abuse
• Hypoxia (oxygen deprivation to the brain)
• Toxic Exposures
• Infections
• Seizures
• Tumors

In basic terms, traumatic brain injuries are typically defined as a blow or jolt to the head or body or a penetrating head injury that disrupts brain function. It should be noted that not all blows and jolts to the head result in a TBI. It should also be noted that you don’t necessarily have to hit your head to sustain a brain injury. Impairments from this type of injury can be temporary or permanent.

The severity of a TBI may range from ‘mild’—a brief change of mental status or consciousness, to ‘severe’—an extended period of unconsciousness or memory loss after injury. Most TBI’s that occur each year are ‘mild’, commonly called concussions.

Causes of traumatic brain injury can include, but are not limited to the following:

• Falls
• Motor vehicle crashes
• Struck by/against events
• Assaults
• Gunshot wounds
• Sports injuries
• Blasts
• Other injuries caused by trauma

TBI can cause a wide range of functional short- or long-term changes affecting thinking, sensation, language, or emotions.

• Thinking (i.e., memory and reasoning)
• Sensation (i.e., touch, taste, and smell)
• Language (i.e., communication, expression, and understanding); and
• Emotion (i.e., depression, anxiety, personality changes, aggression, acting out, and social inappropriateness)

TBI can also cause epilepsy and increase the risk for conditions such as Alzheimer’s disease, Parkinson’s disease, and other brain disorders that become more prevalent with age.

About 75% of TBIs that occur each year are concussions.

A brain injury is as unique as each person who sustains one. “If you have met one person with a brain injury, you have met one person with a brain injury” is a quote that resonates for many individuals. Brain injury is not confined to any one age, ethnicity, gender or geographical location. Brain injuries can occur anytime, anywhere, and to anyone. The consequences of brain injury may be apparent (a person is paralyzed on one side) or invisible (a person has memory challenges but does not appear to have a physical disability.)

There are many variables that can influence the prognosis and rate of recovery from a brain injury, including, but not limited to, the following:

• Type of injury
• Severity of injury
• Location of injury
• Circumstances surrounding the injury
• Age of individual injured
• Premorbidity (state of functionality prior to the occurrence of brain injury)
• Access to supports and services
• Life outlook

BIAC is here to help you understand brain injury, various definitions (including concussions), and causes of brain injury. For more information about brain injury, read Brain Injury Basics in the Resource Directory