Incidence, prevalence, demographics
Brain injury strikes over 1.5 million people per year. That’s one injury every 20 seconds. Approximately 500,000 of those injuries require hospitalization, and close to 75,000 injuries result in death. Between 70,000 and 90,000 survivors sustain injuries that are long-term or permanent. There are currently over 5 million Americans living with disabilities resulting from brain injury. Although these figures can be discouraging, they may also help caregivers realize that they are not alone.
Anyone can get a brain injury, although it is more common among males between the ages of 15-24, and adults over age 75. Motor vehicle accidents are the leading cause of brain injury, accounting for 44 percent of all cases. Falls are the second leading cause, accounting for 26 percent of all brain injuries. Falls are, however, the leading cause of injury in the elderly. Assaults with and without firearms account for 17 percent of injuries. (Brain Injury Association of America, 2003).
How the Brain Works
For many brain-injury survivors and their loved ones, it may be helpful to learn about the areas of the brain that have been damaged, and what can happen as a result of the damage. Although a great deal is known about brain function, there is still much more to be learned.
In healthy adults, the brain is composed of neurons (nerve cells), which are essentially communication fibers. Neurons carry messages throughout the brain and body, and the brain uses these messages to perform various functions, including moving, breathing, thinking, speaking, sensing, emotion, and most of the things our bodies can do. The brain is protected by cerebrospinal fluid, three linings (meninges) and the skull.
The brain itself is divided into left and right hemispheres. Within each hemisphere are four sections, or lobes: frontal, occipital, parietal, and temporal. Toward the base of the brain are the cerebellum and brain stem. Each section of the brain has certain functions associated with it, as described below.