A brain injury is any type of trauma to brain cells that cause these cells to become temporarily inactive or to die altogether. They can be caused by many things including car accidents (70 percent), other types of accidents in the home or at work (10 percent), sports injuries (5 percent) and a lack of oxygen to the brain as is seen in cerebral palsy (1 percent). Unfortunately, the number of people being affected by brain injury is on the rise.

Traumatic brain injury is easily the most common cause of death in children under the age of 15 and even in those under 45, the risk of death due to traumatic brain injury is higher than it should be. The event that causes the injury is usually sudden and completely life-changing.

Brain Injury

The brain is probably the most complex organ of the human body. There are billions of nerve cells that are continually receiving and sending signals so that the human can communicate with the outside world. Information is both processed and stored in the brain in the learning process. Directions are given to the body by the brain in order for two way communication to occur.

The neurons interact and communicate with one another - not just individually but as a group of nerve cells that interact with other groups of nerve cells in a sort of "conference call". Exactly who participates in any given connection can change in seconds. Together the brain cells control our movements, the functionality of our organs, our thoughts, our feelings, our behaviour and our speech. It happens automatically without having to consciously think of what it is we need our brain to do. The brain has no limits when it comes to learning and experiential events. The cells of the brain are all connected in some way to other cells of the brain and the storage of experiences is not terribly orderly. New links between cells are happening all the time, creating ever new linkages between some areas of the brain and others.

While we know that the brain has different areas that handle different things, we don't yet know the function of every part of the brain, nor do we know how memories and learned things are interconnected. The brain is, however, our most active organ and it uses a great deal of sugar (as energy) and oxygen (to keep cells alive and metabolizing.

The brain takes up a full twenty percent of the oxygen pumped out from the heart. It takes very little time of no oxygen or insufficient oxygen to begin to lead to brain damage. After a few minutes, brain damage can be fatal. In addition, the vulnerability of the brain has led to the development of a very thick skull to completely encase the brain so that it is protected from traumatic injury. When the skull is breached due to trauma, the brain is apt to suffer some kind of brain damage. Whole sections of the brain or just individual cells can be traumatized or can die altogether. Bleeding into the brain causes other areas of the brain to suffer from a lack of oxygen that can be fatal to cells. Cells can go into "hibernation" as a result of trauma, only to be able to come back as normal cells once the status quo has become normal again.

When a Brain Injury Happens

If you were suffering from a brain injury, a number of things would happen. You would make attempts to move but nothing happens. You would find that your muscles no longer obey your internal commands. You may be unable to speak normally or at all. Visual problems can plague you and you may lose your sense of hearing, taste or smell. You may find you cannot think clearly and that your memory is impaired. Exactly what goes wrong depends on where in the brain you find you have injury. For example, in cerebral palsy, it is primarily the motor (movement) cortex that has suffered a brain injury. Important connections between the brain and movement cells have been destroyed. Even your personality can change as a result of brain trauma.

What can be Done?

In the immediate period of brain injury, providing as much oxygenation to the brain is the best way to assure that as few cells die as possible. Doctors need to diagnose the type of brain injury that is going on to see if anything immediate can be done to restore circulation to the brain. If some areas of the brain are irrevocably lost, then perhaps undamaged areas can take over the job of the damaged ones. This is called brain plasticity and can be an automatic process or one that happens with physical and occupational therapy. If even half of the brain dies, it is possible for the other half to take over processes that were lost in the brain injury.

Immediate Treatment

Even if the brain injury is considered mild, time is important in the healing process. As soon as the damage has been recognized, early treatment and therapy can be undertaken to improve the chances of recovery from the injury. The longer the injury lasts, the more brain cells die and the more cells are needed to make up for the lost ones. This is especially true of people who have brain haemorrhages and swelling on the brain that doesn't show up as an obvious symptom for several days.

Non-Immediate Brain Injury

Brain injury isn't always that easy to diagnose, especially when there is swelling on the brain. Because the brain is encased in a tight skull, swelling almost always results in brain injured cells. This can occur because of a number of events, including child abuse and blunt trauma to the brain/head. Bleeding in the brain can be sudden and obvious or can be slow and insidious, leading to headache and little else. Even so, haemorrhaging in the brain can cause brain injury that is long lasting. In such cases, there is little that can be done to reverse the brain damage that has already happened. The focus is on reversing the process causing the brain injury and on rehabilitation to restore brain function to levels as normal as possible.

Brain Injury Overview

Having a brain injury when the brain is still developing can be devastating because the brain injury happens before the brain cells have the ability to differentiate and develop. This can mean greater injury to the brain than would be seen in adults.

On the other hand, the young person's brain has a great deal of plasticity. Plasticity means that other areas of the brain can be recruited to perform functions that were lost when the brain was damaged. Plasticity of the brain is more common, with greater recovery, in the baby or child with a brain injury.

Brain injury can happen in utero. There can be bleeding into the brain, medical problems in the mother or birth defects and cord injury that can cause bleeding or a lack of oxygenation of the brain cells while the baby is still in the womb. Brain cells die very quickly, within a few minutes, if lacking in oxygen or damaged by bleeding and they cannot regenerate or repair themselves.

Brain injury can happen at the time of birth. The baby can be born breech and may sustain a long period of time without adequate oxygen due to collapse of the umbilical cord. The umbilical cord may be insufficient for other reasons, including having the umbilical cord exit the uterus before the baby's head or having a knot in the umbilical cord. Even the placenta can be insufficient so less oxygen gets to the baby. These problems can lead to cognitive delays in the child or perhaps to cerebral palsy.

Brain injury can happen when the baby is born prematurely or is born weighing less than two pounds, regardless of the gestational age of the infant. Small babies have a greater chance of bleeding into the brain and episodes of hypoxia (low oxygen), which lead to brain injury.

Children can suffer from brain injury long after the neonatal period. They can be involved in serious falls or motor vehicle accidents. They can be subject to child abuse involving trauma to the head or abnormal shaking of the baby's head and body. If this occurs anytime up to age 2-3, the brain is still developing rapidly and brain injury can result in obvious defects in speech, motor development or coordination.

The two most common causes of brain injury in children are lack of oxygen and bleeding in the brain. The lack of oxygen is an obvious cause of brain injury. It can occur in the womb, at the time of birth or even after birth - in cases where the child stops breathing for a period of time or if the child suffers a near drowning incident. Bleeding can happen with a traumatic fall, a car accident or bleeding in the brain from child abuse or shaken baby syndrome. In such cases, the blood itself impairs the ability of the cells of the brain to get enough oxygen and the cells die. Bleeding can be from crucial blood vessels that, when damaged, fail to oxygenate the cells they are supposed to. These cells die as a result.

Because the cells of the brain are highly specialized, the type of injury you can see to the entire body depends on the areas of the brain involved. If primarily the motor system is involved, you can see paralysis, contractures of the extremities and abnormal movements. If the thinking or cortical functions are damaged, you will see learning disabilities that sometimes rise to the level of mental retardation or developmental delay. If the hearing parts of the brain are affected or the seeing parts of the brain are affected, those areas will be a part of the disability. Brain injury can look like just about anything, depending on the cells killed in the injury.

Children can have significant brain injuries by having strokes within the brain. Most childhood strokes are from a major bleed in the brain but certain abnormalities of the arteries can lead to strokes as well. A stroke can involve a major part of the brain, including half the brain. This leaves paralysis of one side of the body, the possibility of speech impairment and the possibility of other sensory impairments. Kids can have strokes even in infancy and these can be severely disabling and possibly life threatening.

The one thing that kids have that is an advantage over adults when it comes to brain injury is what's known as plasticity. What this means is that there are many cells in the brain that don't do anything in and of themselves except to wait for damaged cells to happen in the brain. The exact mechanism of how this happens is unclear. What's known is that scans show that other areas of the brain become active in doing things that the damaged areas of the brain used to do. The younger the child, the greater is the plasticity of the brain and the greater is the chance of recovery of some function that was lost at the time of the brain injury.

What plasticity looks like is a gradual recovery of lost function after an episode of brain injury. It is something that is more likely to happen if the child has immediate physical and occupational or speech therapies following the injury. In a sense, brain cells are recruited that had nothing else to do and become functional areas of brain doing tasks that they would not normally be intended to do.

This phenomenon can be demonstrated in PET scans or positron emission tomography scans. It involves giving radioactive glucose to the individual to see what area of the brain "lights up" or utilizes the radioactive glucose when a certain functions are performed by the body. The results can be striking, with cortical areas of the brain lighting up that would normally not be associated with movement when the child moves the extremity.

The child with a brain injury has a dramatic chance of some return of function. It depends on the area of the brain affected and on the age of the child.