Guillain-Barré syndrome (GBS) is a rare neurological disorder in which the body's immune system attacks part of the peripheral nervous system. It is one of several disorders involving weakness due to peripheral nerve damage caused by the person's immune system. Initial symptoms include unexplained sensations such as tingling in the feet or hands, or pain, followed by weakness on both sides of the body. The weakness can increase in intensity over a period of hours to days to weeks until the muscles cannot be used at all and the person is almost totally paralyzed. If breathing muscles are affected, the person is often put on a ventilator. Most individuals, however, have good recovery from even the most severe cases of GBS, although some continue to have some degree of weakness.
The exact cause of Guillain-Barré syndrome is unknown. It can occur a few days or weeks after the person has had symptoms of a respiratory or gastrointestinal viral infection. Occasionally, surgery will trigger the syndrome. In rare instances, vaccinations may increase the risk of GBS. Recently, some countries worldwide have reported an increased incidence of GBS following infection with the Zika virus.
A nerve conduction velocity (NCV) test, which measures the nerve's ability to send a signal, can aid the diagnosis. The cerebrospinal fluid that bathes the spinal cord and brain contains more protein than usual in someone with GBS, so a physician may decide to perform a spinal tap to obtain a sample of fluid to analyze.
There is no known cure for Guillain-Barré syndrome, but therapies can lessen the severity of the illness and accelerate the recovery in most individuals. People with GBS are usually admitted and treated in a hospital's intensive care unit. Plasmapheresis (also known as plasma exchange) and high-dose immunoglobulin therapy (IVIg) are used. Plasmapheresis seems to reduce the severity and duration of the Guillain-Barré episode. In IVIg therapy, doctors give intravenous injections of the proteins the immune system naturally makes to attack invading organisms. Both treatments are equally effective if started within two weeks of onset of symptoms. Supportive care is needed to address the many complications of paralysis as the body recovers and damaged nerves begin to heal. This can sometimes require placing the person on a ventilator, a heart monitor, or other machines that assist body function. As individuals begin to improve, they are usually transferred from the acute care hospital to a rehabilitation setting, where they can regain strength, receive physical rehabilitation and other therapy to resume activities of daily living, and prepare to return to their pre-illness life.
Guillain-Barré syndrome can be a devastating disorder because of its sudden and rapid, unexpected onset. Fortunately, 70% of people with GBS eventually experience full recovery. With careful intensive care and successful treatment of infection, autonomic dysfunction, and other medical complications, even those individuals with respiratory failure usually survive. Most people reach the stage of greatest weakness within the first 2 weeks after symptoms appear, and by the third week of the illness 90 percent of all individuals are at their weakest. The recovery period may be as little as a few weeks or as long as a few years. About 30 percent of those with Guillain-Barré still have a residual weakness after 3 years. About 3 percent may suffer a relapse of muscle weakness and tingling sensations many years after the initial attack. About 15 percent of individuals experience long-term weakness, and muscle strengh may not return uniformly.
Scientists are concentrating on finding new treatments and refining existing ones. Scientists are also looking at the workings of the immune system to find which cells are responsible for beginning and carrying out the attack on the nervous system. The fact that so many cases of Guillain-Barré syndrome begin after a viral or bacterial infection suggests that certain characteristics of some viruses and bacteria may activate the immune system inappropriately, and investigators are searching for those characteristics. Some studies show that normal variations in certain genes could increase the risk of developing GBS; however, more research is needed to identify and confirm associated genes. Using an animal model, scientists hope to identify which proteins in the peripheral nervous system (PNS) are at greatest risk of autoimmune attack and which components of the immune system contribute to the autoimmune response against the PNS. A greater understanding of how the immune system damages the PNS could lead to better treatments for autoimmune disorders such as GBS. Information from the National Library of Medicine’s MedlinePlus Guillain-Barre Syndrome