Guillain-Barré syndrome is an acute illness which is caused by inflammation of peripheral nerves leading to loss of sensation, muscle weakness and, in more serious cases, complete paralysis and breathing difficulty. In almost eighty per cent of children these symptoms follow a recent illness (usually viral). This infection is thought to trigger a faulty response in the immune system.

The disease varies in speed of onset with children reaching their maximal disability over a matter of days or, much more gradually over a period of up to four weeks. Initial symptoms consist of tingling, numbness, unsteadiness and progressive weakness usually affecting the feet and then the hands and gradually progressing up the limbs. At the height of their illness about a quarter of children remain able to walk but the other three quarters loose their mobility and about sixteen per cent need to be artificially ventilated on an intensive care unit.

The diagnosis of Guillain-Barré syndrome is confirmed with a combination of lumbar puncture, where a high protein content is demonstrated in the cerebrospinal fluid and nerve conduction studies, which show slowing of nerve conduction in the nerve roots and/or peripheral nerves.

Recovery usually begins in two to three weeks and may be accompanied by pain and tingling in the limbs. Most children are able to walk unaided by six weeks and most are free from symptoms by about three months. Minorities of patients have some residual problems but these children are usually still able to walk unaided. The condition can occur at any age but there appear to be peak ages of onset in childhood at four years and twelve years. In general children make a much better recovery than adults.

In Guillain-Barré syndrome the body's immune system attacks part of the peripheral nervous system. Usually Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection. The body's immune system begins to attack the body itself, causing what is known as an autoimmune disease.

Currently, plasmapheresis and high-dose immunoglobulin therapy are used. Plasmapheresis seems to reduce the severity and duration of the Guillain-Barré episode. In high-dose immunoglobulin therapy, doctors give intravenous injections of the proteins that in small quantities, the immune system uses naturally to attack invading organism.