What happens when our central guiding force, our brain, is suddenly struck by injury? In her report, "Love Lost & Found," NBC's Ann Curry chronicled the story of a young woman who suffers severe head trauma and damage to her brain in a car accident. After 10 horrifying days in a coma, she awoke to find herself in a state of bewilderment at the loss of many of her precious memories. In fact, she couldn't even remember her husband whom she had married shortly before the accident. How is it that this type of memory loss occurs? What happens to the brain when even our own hardheadedness can't protect us?
Despite its being encased in the thick bone of the skull, the human brain is still quite vulnerable, and even minor trauma can injure delicate brain tissue. In fact, according to the authors of Traumatic Head Injury: Causes, Consequences, and Challenge, "half a million Americans experience severe head injury each year." Fortunately, according to their research, most do survive. However, the fact that the brain is responsible for virtually everything we do, feel, learn, and experience makes any amount of injury a disturbance that can produce life-style consequences and often a long journey of rehabilitation for those who fall victim to the injury.
Traumatic brain injury occurs when the compression, twisting and distortion of the brain inside the skull associated with impact causes localized as well as widespread damage throughout the brain. The lobes most likely to be bruised in a traumatic brain injury are the frontal and temporal lobes. This is because of the bony ridges on the inside of the skull near the lobes. Traumatic brain injury occurs most often as a result of vehicle accidents, falls, blows, and gunshot wounds. In fact, according to the Dana Alliance for Brain Initiatives, among Americans of ages 15 to 25, traumatic brain injury (TBI) is the leading cause of death and neurological disorders.
Dr. Pamela Klonoff, clinical director for the Barrow Neurological Institute explains: "Most significant traumatic brain injuries produce a period of memory loss directly preceding the injury (retrograde amnesia) and a period of confusion associated with the inability to lay down new memory following an injury (post-traumatic amnesia). Each can span several minutes to several weeks or months. The longer the period of retrograde and post-traumatic amnesia, the more severe the traumatic brain injury."
When cells in the brain die, they are not replaced by new cells. Cells that were damaged but not destroyed may recover, and some cells might be trained to take over the function of the cells that were lost. Soon after the injury, the brain begins to swell (a process called edema). The swelling makes it hard for even the uninjured parts of the brain to work. That's why in the hospital the patient usually experiences temporary impairments, which begin to disappear as the swelling goes down. The rate of recovery is fastest during the first six months after the brain injury. The majority of recovery occurs during the first 12 months. Further recovery can take place, but it is usually much slower and more subtle.
