Traumatic Brain Injury (TBI) occurs when a person sustains an injury to the brain due to high impact or other trauma.

TBI can include a number of different injuries and illnesses.  It can be the result of an open head injury, a closed head injury, chemical or toxin ingestion, deprivation of oxygen, tumors, infections or stroke. The most common causes of TBI are car accidents, guns, and falls. Those who are at the highest risk of TBI are the young and elderly.

There are mild, moderate, or severe forms of TBI. A brain injury is classified as mild if loss of consciousness and/or confusion and disorientation is shorter than 30 minutes. While MRI and CAT scans are often normal, the individual has cognitive problems such as headache, difficulty thinking, memory problems, attention deficits, mood swings and frustration. These injuries are commonly overlooked.  Even though this type of TBI is considered "mild", the effect on the family and the injured person can be devastating.

Moderate to severe brain injury may include a headache that gets worse or does not go away, repeated vomiting or nausea, convulsions or seizures, an inability to awaken from sleep, dilation of one or both pupils of the eyes, slurred speech, weakness or numbness in the extremities, loss of coordination, and increased confusion, restlessness, or agitation.

References:

Traumatic Brain Injury.com (2004). What is Traumatic Brain Injury?  Retrieved November 2009: http://www.traumaticbraininjury.com/

National Institute of Neurological Disorders and Stroke (2009). What is Traumatic Brain Injury? Retrieved November 2009: http://www.ninds.nih.gov/disorders/tbi/tbi.htm