Concussion

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. Because of this damage, the normal function of the brain signals are interrupted.

Concussion categories

Grade 1
The mild concussion occurs when the person does not lose consciousness (pass out) but may seem dazed.

Grade 2
The slightly more severe form occurs when the person does not lose consciousness but has a period of confusion and does not recall the event.

Grade 3
The classic concussion, which is the most severe form, occurs when the person loses consciousness for a brief period of time and has no memory of the event. Evaluation from a health-care provider should be performed as soon as possible after the injury.

A concussion can happen to anyone, at any time. The most common causes of concussion 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 those who are taking blood thinners, such as coumadin. Mild head injury, such as concussion is a frequent cause for hospital admission, with an estimate of more than 600,000 cases per year in the United States.

Signs and symptoms

The signs and symptoms of a concussion 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.

Diagnostic tests

If your health-care provider suspects a concussion, 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).

Treatment

The treatment for a concussion 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.

Post-concussion syndrome may occur in some people. The syndrome generally consists of a persistent headache, dizziness, irritability, memory changes and vision changes. The person may seem overly emotional or unable to control their emotions. Some people experience unexplained depression. Difficulty with concentration or problems with thinking and planning ahead also are reported. Symptoms may begin weeks or even months after the initial injury. Although the symptoms generally resolve over time, some people need a rehabilitation specialist to oversee a program for recovery.

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
(202) 296-6443
(800) 444-6443

 University of Missouri - Columbia University of Missouri System