Closed Head Injury

Sorry, these's no room left

by Buck Tilton

After falling and cracking your head on a rock, after a sudden violent stop, your brain can be severely damaged . . . even if there is no apparent harm done to the outside of your head! Knowing how to recognize that you, or a friend, have a head injury, and knowing what to do about it, may prevent permanent disability ... or death.
Back when hunting was a way of life for everyone, tiny human brains enjoyed a simple life with few responsibilities ...breathing, digestion, translating primitive messages from the senses, keeping the body semi-erect. Thick skulls barely lifted above prehistoric eyebrows. There was nothing up there to fill a larger space. Then, suddenly, about 30,000 years ago, a mere drop in the bucket of earth time, an unexplained period of rapid brain growth began, a period that continues today. Brain evolution focused on the cerebrum, the gray matter, the part most people think of when they think brain. The other two main divisions of the brain, the cerebellum (for coordination) and the brain stem (for vegetative functions), haven't changed much. What you've got now is a big brain inside of a big head, somewhere between 16 and 22 pounds of head, the average weight range for an adult's bowling ball, and it's supported by a relatively skinny neck. What you've got now is an invitation to an accident.
Unfortunately, your brain is a fragile and easily damaged organ, susceptible to all sorts of injuries and deprivations. Fortunately, it lives inside protective plates of bones, fused strongly together, forming a natural helmet called the skull, or cranium.
Your brain takes up about eight/tenths of the space inside your skull. Most of the rest of the space is filled with blood vessels and cerebrospinal fluid (CSF), a dense, clear, colorless substance. CSF flows around the outside of the brain, through a latticework of fibers. Working together, fluid and fibers form the brain's primary shock absorption system, protecting the brain from the bumps and jiggles of everyday life. But, if your head smacks into something with sufficient force, your brain can slosh around enough to tear some of the blood vessels, and even bruise the brain itself, if it hits the inside of the skull. That's how you can have brain damage without headbone damage.
What happens inside the head is this. Blood flows out of the broken blood vessels in the head and, sometimes, blood serum starts to leak out of the vessels in the damaged area of the brain. Swelling results, but, unlike the rest of the body, there's no place for the swelling to go. As the space inside the head decreases, there is less and less room for the flow of life-sustaining blood. Initially, the brain stops making CSF, and starts to reabsorb what is already there . . . the brain tries to create more space. The brain can even limit the amount of blood flowing to itself. But, if the damage is sufficient, the brain's compensatory mechanisms cannot keep up with the swelling. Intracranial pressure (ICP) starts to rise, and, as a result, the brain is squashed.
You, or your friend, may have been bonked on the head, but 1) you never lost consciousness, or 2) the period of unconsciousness was brief, less than five minutes, which is called a concussion. Victims with this type of non-serious head injury may have difficulty remembering what happened, but the memory should return in about 30 to 45 minutes. However, there are certain signs of trouble which may appear, usually within 24 hours, rarely as long as away as 48 hours. The appearance of any one of these signs is reason to seek a physician's care as soon as possible.

1) CSF and/or Bleeding from Nose or Ears. Any drainage of clear fluid, or clear fluid mixed with blood, from nose or ears indicates a crack in the skull, which justifies quickly finding a physician.
2) Excessive Drowsiness. The injured person may be exhausted, but, if they go to sleep, it should be easy to arouse him with methods you would ordinarily use to awaken someone. If you can't arouse him, pressure is developing inside his head, and he needs a doctor.
3) Persistent Vomiting. It is common to vomit after a blow to the head. Should the victim vomit several times, or start vomiting hours later, he may have increasing intracranial pressure. Find a doctor.
4) Unusual Bruising. The appearance of bruises around the eyes (Raccoon eyes) or behind and below the ears (Battle's sign) indicate bleeding inside the head. This victim needs a physician.
5) Pupil Irregularity. If one pupil grows larger and less responsive than the other, pressure is developing on the side of the brain that controls the altered pupil. Seek a physician.
6) Loss of Coordination. If walking becomes unsteady, or if the victim loses the ability to use his arms and legs normally, he may have pressure increasing on his cerebellum, the center of coordination. He needs a doctor's care.
7) Speech Difficulty. If the victim loses the ability to speak, or if his speech becomes slurred, it might be from pressure on the cerebrum where the speech control center resides. Take him to a hospital.
8) Severe Headache. A headache that keeps getting worse is one sign of increasing pressure inside the victim's head. A doctor should be consulted.
9) Double Vision. If the victim starts to complain of any doubling of vision, or any failure of his eyes to move normally or focus normally, he may have damage to the back of his brain where messages from the eyes are interpreted, or pressure developing on an optic nerve. He needs to see a physician.
10) Seizures. Should a seizure (convulsion) occur, not an uncommon result of increasing intracranial pressure, protect the victim from injuring himself further during the event, place him on his side after the seizure to keep his airway open, and, as soon as possible, find a doctor.