DEAR MAYO CLINIC: My grandson played rugby in college. He suffered a concussion and now has trouble with many mental functions, including maintaining thoughts. His peripheral vision has been affected and noise prevents him from working. What could help him return to normal? He's 23 years old and should be in the prime of his life. Instead, he just stays in the house all the time.

ANSWER: Symptoms caused by a concussion often go away within several weeks. But sometimes they may last much longer. In those cases, it can be useful to consult a physician with expertise in treating concussions. Ongoing care, including rehabilitation therapy, may help your grandson better manage his symptoms and return to a more active lifestyle.

A concussion is a mild traumatic brain injury, usually caused by a blow to the head. When the head is hit, the brain moves inside the skull. In some situations, when, for example, an elbow or shoulder hits against a person's head, the impact can make the head and brain rotate rapidly at different angles. This movement can cause abnormal function of individual brain cells, along with inflammation and swelling in the brain. It also may disrupt the delicate nerve fibers that connect brain cells to each other. These changes within the brain interfere with its ability to function normally.

A concussion can cause a wide variety of symptoms. They may include physical problems, such as headache, blurred vision, nausea and vomiting. Symptoms often include cognitive complaints, too, such as confusion, amnesia, slowed thinking or mental fogginess. Concussions can have emotional effects. A person with a concussion may be irritable or depressed and show changes in personality. A concussion may lead to sleep problems, as well.

Signs that a physician may see when someone suffers a concussion often include balance problems, slowed visual tracking and impaired memory. Computerized neurologic testing may be used to help assess brain function. Such a test works best when a similar test performed before the injury is available for comparison. Many sports teams -- both professional and recreational -- now use these tests.

About 80 percent to 90 percent of concussion symptoms resolve within 7 to 10 days. When symptoms persist well beyond the expected time frame, they fall into a category known as post-concussion syndrome.

Immediately after a concussion -- for the first 24 to 72 hours -- rest is the cornerstone of treatment. Once the initial symptoms go away and, if used, computerized test results are within an acceptable range, a physician determines whether it's safe to begin a step-by-step return to an exercise program. If a patient can go through those steps without symptoms, a return to full activity may be possible.

In the case of your grandson, it seems his initial symptoms never cleared and left him in what's known as a post-concussive state. He should consider consulting with a neurologist or a sports medicine physician who specializes in concussion management.

Several therapies may be useful. He may benefit from a type of therapy called vestibular rehabilitation, which would help him work on his vision, balance and hearing. A consultation with an expert in psychology, as well as cognitive rehabilitation, may help him manage the mental slowness and emotional impact of his injury. This is particularly significant because some research has shown a correlation between concussions and depression.

Research currently is ongoing regarding the way exercise may be used in treating post-concussion syndrome. But for people in this situation, exercise should always be done under the direction of a physician.

Each person responds differently to a traumatic brain injury such as a concussion. Therefore treatment must be individualized. It is important for your grandson to find a concussion expert who can help him create a treatment plan that fits his unique needs. -- Jennifer Maynard, M.D., Family Medicine, Mayo Clinic, Jacksonville, Fla.
