The brain is composed of soft, delicate structures that lie within the rigid skull. Surrounding the brain is a tough, leathery outer covering called the dura (door-a). Within the brain are (cranial) nerves that are responsible for many activities, such as eye opening, facial movements, speech and hearing. These nerves carry and receive messages that allow the person to think and function normally. There are also centers that control level of consciousness and vital activities, such as breathing. The brain is cushioned by blood and spinal fluid. There is very little extra room within the skull cavity.
An injury to the head causes the brain to bounce against the rigid bone of the skull. This force may cause a tearing or twisting of the structures and blood vessels of the brain, which results in a breakdown of the normal flow of messages within the brain. The damage to the brain generally is found deep within the brain tissue and can be thought of as small bruises in the brain. Just like a bruise in any other part of the body, there is local swelling in the area. Because the brain has no extra room within the closed skull cavity, there is nowhere for the brain to swell. The normal function of the brain signals are interrupted due to this swelling.
A contusion can happen to anyone, at any time. The most common causes of contusion include a blow to the head from a motor vehicle crash, fall or assault. People at higher risk are those who have difficulty walking and fall often, those who are active in high impact contact sports and people who are taking blood thinners, such as coumadin. Mild head injury, such as contusion, is a frequent cause for hospital admission.
Signs and symptoms
The signs and symptoms of a contusion include severe headache, dizziness, vomiting, increased size of one pupil or sudden weakness in an arm or leg. The person may seem restless, aggitated or irritable. Often, the person may have memory loss or seem forgetful. These symptoms may last for several hours to weeks, depending on the seriousness of the injury. Any period of loss of consciousness or amnesia of the head injury should be evaluated by a health-care professional. As the brain tissue swells, the person may feel increasingly drowsy or confused. If the person is difficult to awaken or passes out, medical attention should be sought immediately. This could be a sign of a more severe injury.
If your health-care provider suspects a contusion, the following tests may be ordered.
- CT scan
This is a special X-ray image of the brain. The test is performed by having the patient lie on a flat X-ray table that slides into a round, open scanner. The X-ray images are taken as the patient is lying still on the X-ray table. Often, this test involves the injection of a contrast dye to obtain better images of the brain structures (be sure to tell the technician if the person is allergic to contrast dye).
- MRI (magnetic resonance imaging)
This is a special non-X-ray image of the brain to examine the structures. No X-rays are used in this test. The test is performed by having the patient lie still while in the scanner, as the pictures are very sensitive to any movement. There is a machine-like sound while the pictures are being taken. The space inside the tube is quite snug; therefore be sure to notify the technician if the person has claustrophobia or is uncomfortable in tight places. Because this test is performed with a special high-power magnet, it may not be performed on anyone with a metal implant (i.e. artificial limbs, artificial joints, aneurysm clips, shrapnel or metal heart valves).
The treatment for a contusion is usually to watch the person closely for any change in level of consciousness. The person may need to stay in the hospital for close observation. Surgery is usually not necessary. Headache and dizziness are common, but if the headache persists or becomes severe, it is best to seek medical attention.
It is important to keep in mind that recovery from a traumatic brain injury can be very slow. Sometimes several days can go by without seeing any major visible change. This is not unusual, and it is best to ask the health-care providers if any changes have occurred. It is also important to try to get enough rest and nutrition while waiting for the patient to recover. It is normal to feel frustrated, overwhelmed, lonely and worried. Sometimes a friend, or support group can help. Before your stress gets out of control, tell someone who can help.
An excellent source for further information or support is
Brain Injury Association
1776 Massachusetts Ave.
NW Suite 100 Washington, DC, 20036