Dear Dr. Gott: My three-year-old grandson has been diagnosed with Guillain-Barre Syndrome. Could you please enlighten me on this mysterious disorder?

He has undergone MRIs, spinal taps and more. We were told it could come from a previous respiratory infection. We've also been told he is not to have any more flu shots, as this could sometimes trigger the condition.

He's unable to walk or use the fine movements of his hands, and it seems to have affected his speech. His face looks tired. He has physical and occupational therapy three times a week. Will he recover fully? I hurt just seeing him hurt.

Dear reader: Guillain-Barre Syndrome is a rare disorder in which the body's immune system attacks a portion of its central nervous system. It can affect anyone at any age.

About one person in every 100,000 suffers from the syndrome. It is unknown what sets the disease in motion. It has been known to occur a few days or weeks after symptoms of a respiratory or gastrointestinal viral infection appear.

Because vaccination can trigger the condition, your grandson's physicians are correct in denying flu shots. Initial symptoms include a tingling sensation in the legs that can spread to the arms and upper body.

The intensity can increase until certain muscles cannot be used at all. Symptoms can progress over the course of a few hours to a few weeks. The greatest degree of weakness is generally observed within the first two weeks following initial symptoms, and most patients are at their weakest point by the third week.

During the progression, patients may require the use of a heart monitor, respirator or other equipment that can help the body function. Because of the sophistication of the equipment, patients are most often treated in a hospital. Recovery can occur in as little as a few weeks with adjunct equipment.

There is no cure for Guillain-Barre, but there are several therapies that can lessen the severity of the illness and speed recovery in most patients. Plasma exchange is one form of therapy. It removes whole blood from the body. The blood is then processed so the red and white cells are separated from the plasma.

The blood cells, without the plasma, are then returned to the body, and the body then quickly and naturally replaces the plasma. With immunoglobulin therapy, a physician gives small quantities of proteins intravenously that the immune system uses to attack invading organisms.

Both procedures are equally effective, but immunoglobulin therapy is easier to administer. Steroid therapy has also been used to reduce the severity of symptoms.

However, clinical trials have determined the treatment is ineffective. Scientists continue to concentrate on researching new treatment while expanding and refining the ones that are currently in existence.

The physical and occupational therapy your grandson is undergoing is appropriate. It appears he is tapped into a good system, and I recommend he stick with it.

For additional information I recommend you write to NIH Neurological Institute, PO Box 580l, Bethesda, Maryland 20824, or call them at 800-352-9424.

Doctor Gott is a retired physician and the author of "Dr. Gott's No Flour, No Sugar Diet" and "Dr. Gott's No Flour, No Sugar Cookbook". Contact him c/o United Media, 200 Madison Avenue, fourth floor, New York, New York 10016.