Opened in 2014, Mission Hospital's Neuroscience & Spine Institute stands as the premier neurosurgical facility in Orange County

Injuries to the Structures of the Brain

In adults and children over the age of two, the brain sits inside a closed box. In children under the age of two, the bones of the skull have not fused together so there is some ability to expand. The brain is comprised of only three things inside

  • 80% is the brain where thinking, moving, speaking, and other important life activities are directed
  • 10% is blood rich in oxygen and glucose and other substances our brain needs to survive
  • 10% clear fluid like water called Cerebrospinal fluid (CSF) which cushions the brain.

Since the brain box only has one opening where the brain meets the spinal cord, these three things must remain in its original equal amounts. If there are increases in blood, CSF, or brain size from swelling, this will cause more pressure inside the head. Any disturbances or changes in these three things will cause a person not to be as awake (may be completely unconscious) or communicate with others, not be able to move their arms/legs, or do the normal things people do when awake like eating, reading, talking, processing information, or interacting purposefully in the world. If this happens, the trauma team of doctors, nurses, therapists, and staff must act quickly to discover the problem and try to manage the injury.

There are many types of TBI. There are injuries to the coverings around the brain called the skull bones and meninges, blood vessels that bring blood to the brain, as well as the brain itself.

Injuries to the Bones/Coverings/Blood Vessels of the Brain

It is important to understand how bones and coverings around the brain actually protect it. Since the brain sits inside the skull, a blow to the outside of the head can break one of the skull bones without injuring the brain itself. These skull fractures can be the kind where the bone is depressed downward (depressed skull fracture) or just a crack in the bone (linear skull fracture). Often, the bones will heal on their own except where the bone is depressed which may requires surgery to reposition the bone back to its original shape.

The coverings of the brain have blood vessels that cross over them to get blood to and from the brain. If the blow to the head is strong enough (this can happen even in a fall), the blood vessels can break causing arterial or venous blood to collect around the coverings and between the skull bones and brain. If the amount of blood is too great, it can cause so much pressure inside the closed box so that the brain can actually die from the lack of blood flowing to it in the blood vessels. One of the top priorities of the emergency and neurotrauma team is to quickly check out the injured person and get special brain scans to check for any bleeding or brain swelling. If the blood vessels have broken and are bleeding, the neurosurgeon (doctor who specializes in the operating on the brain) will take the person to the Operating Room (OR) to stop the bleeding and remove the blood that has collected if it is near the outside surface of the brain.

Injuries to the Brain

The brain has the coverings and the clear water (CSF) to protect it from injury but sometimes the person will hit their head so hard the brain will move inside the bones of the skull and bounce back and forth. This can cause bruising (or contusions) to the brain. Often the first day the bruises may not even be seen but over several days, it will get bigger and bigger. The concern is that the bruise in the brain tissue also has water in it which causes the brain to swell. If swelling happens, it can take days to weeks to go down to normal. If the swelling gets too much, then the pressure will increase inside the skull making it very hard for the brain to get its constant supply of blood rich in oxygen and food. The brain doctor or neurosurgeon may have to place a special small measuring device down into the brain temporarily to monitor the pressure inside the skull. This information will allow the nurses, doctors, and therapists to decide what medications or other treatments are needed to reduce the swelling of the brain.

The brain has many different lobes or parts to it. For instance, the front of the brain (frontal lobe) works to help sort information on thinking, making decisions, knowing how to act in the most appropriate manner, speak words, go to the bathroom, and move the arms/legs and face. The top middle of the brain (parietal lobe) helps to translate information on touch, feel, images, art, music, reading, writing, math, and how the body exists in the world. The side part of the brain (temporal lobe) helps with memory, understanding what is being spoken, hearing and other functions. The back part of the upper brain (occipital lobes) help with seeing. The bottom part of the brain has the balance/equilibrium function (cerebellum) and the important brain stem where all of our functions for heart rate, breathing, blood pressure are contained. Also, the messages that come up to the brain and down to the spine travel through the brain stem. Depending on what part of the brain has been injured, a person may have different symptoms or signs of their injuries. Often the doctors and nurses cannot tell what will be affected for weeks or months after the original injury.