What is Guillain-Barré syndrome?
Guillain-Barré syndrome (GBS) is a rare neurological disorder in which your immune system mistakenly attacks part of the peripheral nervous system—the network of nerves located outside of the brain and spinal cord. GBS can range from a very mild case with brief weakness to nearly devastating paralysis, leaving you unable to breathe independently. Fortunately, most people eventually recover from even the most severe cases of GBS. After recovery, some people will continue to have some degree of weakness.
GBS can increase in intensity over a period of hours, days, or weeks until certain muscles cannot be used at all and, when severe, the person is almost totally paralyzed. In these cases, the disorder is life-threatening—potentially interfering with breathing and, at times, with blood pressure or heart rate.
Weakness—The weakness seen in GBS usually comes on quickly and worsens over hours or days. Symptoms are usually equal on both sides of the body (called symmetric). You may first notice weakness as difficulty climbing stairs or with walking. Symptoms often affect the arms, breathing muscles, and even the face, reflecting more widespread nerve damage. Occasionally symptoms start in the upper body and move down to the legs and feet. Muscles controlling breathing can weaken to the point that you might need a machine to help you breathe.
Most people reach the greatest stage of weakness within the first two weeks after symptoms appear; by the third week 90 percent of affected individuals are at their weakest.
Sensation changes—Since nerves are damaged in GBS, your brain may receive abnormal sensory signals from the rest of your body. This results in unexplained, spontaneous sensations, called paresthesias, that you may feel as tingling, a sense of insects crawling under the skin (called formications), and pain. Deep muscular pain may be experienced in the back and/or legs.
Unexplained sensations often occur first, such as tingling in the feet or hands, or even pain (especially in children), often starting in the legs or back. Children will also show symptoms with difficulty walking and may refuse to walk. These sensations tend to disappear before the major, longer-term symptoms appear.
Other symptoms may include:
- Difficulty with eye muscles and vision
- Difficulty swallowing, speaking, or chewing
- Pricking or pins and needles sensations in the hands and feet
- Pain that can be severe, particularly at night
- Coordination problems and unsteadiness
- Abnormal heartbeat/rate or blood pressure
- Problems with digestion and/or bladder control
Who is more likely to get Guillain-Barré syndrome?
GBS can affect anyone. It can strike at any age (although it is more frequent in adults and older people) and both sexes are equally prone to the disorder. GBS is estimated to affect about one person in 100,000 each year. It is not contagious or inherited.
The exact cause of GBS isn't known. Researchers don't know why it strikes some people and not others.
What they do know is that the affected person's immune system begins to attack the body itself. It may be this immune attack starts as a fight against an infection and that some chemicals on infecting bacteria and viruses resemble those on nerve cells, which, in turn, also become targets of attack. Since the body's own immune system does the damage, GBS is called an autoimmune disease (“auto” meaning “self”). Normally the immune system uses antibodies (molecules produced in an immune response) and special white blood cells to protect us by attacking infecting microorganisms (bacteria and viruses). In Guillain-Barré syndrome, however, the immune system mistakenly attacks the healthy nerves.
Many of the body's nerves are like household wires. There is a central conducting core in the nerves called the axon that carries an electric signal. The axon (an extension of a nerve cell) is surrounded by a covering, like insulation, called myelin. The myelin sheath surrounding the axon speeds up the transmission of nerve signals and allows the transmission of signals over long distances.
In most cases of GBS, the immune system damages the myelin sheath that surrounds the axons of many peripheral nerves; however, it also may also damage the axons themselves. As a result, the nerves cannot transmit signals efficiently and the muscles begin to lose their ability to respond to the brain's commands. This causes weakness.
Most GBS cases usually start a few days or weeks following a respiratory or gastrointestinal viral infection. Occasionally surgery will trigger the syndrome. In rare cases vaccinations may increase the risk of GBS (there have been reports of a few people who received a vaccine for the SARS-CoV-2 virus developing GBS, but the chance of this occurring is very low). Some countries worldwide reported an increased incidence of GBS following infection with the Zika virus.
How is Guillain-Barré syndrome diagnosed and treated?
The initial signs and symptoms of GBS are varied and there are several disorders with similar symptoms. Therefore, doctors may find it difficult to diagnose GBS in its earliest stages and may perform the following tests.
- Physical exam—Your physician will look at your physical symptoms, ask about your medical history, and conduct exams to assess how your muscles and nerves are functioning. Your physician or a specialist will note whether your symptoms appear on both sides of the body (the typical finding in Guillain-Barré syndrome) and the speed with which the symptoms appear (in other disorders, muscle weakness may progress over months rather than days or weeks). Your reflexes also will be checked: in GBS, deep tendon reflexes in the legs, such as knee jerks, are usually lost. Reflexes may also be absent in the arms.
- Nerve conduction velocity test (NCV)—This test measures the nerve's ability to send a signal. In GBS, the signals traveling along the damaged nerves are slow and this can provide clues to aid the diagnosis.
- Cerebrospinal fluid analysis—Your doctor also may remove and have analyzed a small sample of the cerebrospinal fluid that bathes the spinal cord, since the fluid in people with GBS contains more protein than usual but very few immune cells (measured by white blood cells).
Key diagnostic findings include:
- Recent onset, within days to at most four weeks of symmetric weakness, usually starting in the legs
- Abnormal sensations such as pain, numbness, and tingling in the feet that accompany or even occur before weakness
- Absent or diminished deep tendon reflexes in weak limbs
- Elevated cerebrospinal fluid protein without elevated cell count. This may take up to 10 days from onset of symptoms to develop.
- Abnormal nerve conduction velocity findings, such as slow signal conduction
- Sometimes, a recent viral infection or diarrhea.
There is no known cure for Guillain-Barré syndrome. However, some therapies can lessen the severity of the illness and shorten your recovery time. There are also several ways to treat the complications of the disease.
If you have GBS, you are usually admitted to and treated in hospital's intensive care unit due to possible complications of muscle weakness, problems that can affect any paralyzed person (such as pneumonia or bed sores), and the need for sophisticated medical equipment.
There are currently two treatments commonly used to interrupt immune-related nerve damage. Both are equally effective if started within two weeks of GBS symptoms.
- Plasma exchange (PE), also called plasmapheresis, involves removing some of your blood through a catheter. The blood cells from the liquid part of the blood (plasma) are extracted and treated and returned to your body. Plasma contains antibodies and PE removes some plasma; PE may work by removing the bad antibodies that have been damaging the nerves.
- Intravenous immunoglobulin therapy (IVIg) involved intravenous injections of immunoglobulins—proteins that your immune system naturally makes to attack infecting organisms. The immunoglobulins are developed from a pool of thousands of healthy donors. IVIg can lessen the immune attack on the nervous system and shorten recovery time. Investigators believe this treatment also lowers the levels or effectiveness of antibodies that attack the nerves by both “diluting” them with non-specific antibodies and providing antibodies that bind to the harmful antibodies and take them out of commission.
Anti-inflammatory steroid hormones called corticosteroids have also been tried to reduce the severity of GBS, but controlled clinical trials showed this treatment is not effective.
Supportive care is very important to address the many complications of paralysis as your body recovers, and damaged nerves begin to heal. Since respiratory failure can occur in GBS, your breathing should be closely monitored. Sometimes a mechanical ventilator is used to help support or control breathing. The autonomic nervous system (that regulates the functions of internal organs and some of the muscles in your body) can also be disturbed, causing changes in heart rate, blood pressure, toileting, or sweating, so you should be put on a heart monitor or equipment that measures and tracks body function. You also may need help with any difficulty from secretions in the mouth and throat. In addition to choking and/or drooling, secretions can fall into your airway and cause pneumonia.
As you begin to improve, you may be transferred from the acute care hospital to a rehabilitation setting. Here, you can regain strength, receive physical rehabilitation and other therapy to resume activities of daily living, and prepare to return to pre-illness life.
Because GBS can affect several parts of your body, you may need different methods and approaches to prevent or treat complications. For example, you may need a physical therapist to manually move and position your limbs to help keep the muscles flexible and prevent muscle shortening. Injections of blood thinners can help prevent dangerous blood clots from forming in leg veins. Inflatable cuffs may also be placed around your legs to provide intermittent compression. All or any of these methods helps prevent blood stagnation and sludging (the buildup of red blood cells in veins), which could lead to reduced blood flow in the leg veins. Muscle strength may not return uniformly; some muscles that get stronger faster may tend to take over a function that weaker muscles normally perform—called substitution. A physical therapist can select specific exercises to improve the strength of weaker muscles so their original function can be regained.
Occupational and vocational therapy helps you learn new ways to handle everyday functions that may be affected by the disease, as well as work demands and the need for assistive devices and other adaptive equipment and technology.
Long-term outlook for those with Guillain-Barré syndrome
Guillain-Barré syndrome can be a devastating disorder because of its sudden and rapid, unexpected onset of weakness—and usually actual paralysis. Fortunately, most people with GBS have a 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.
Your recovery can be slow or incomplete–anywhere from as little as a few weeks up to a few years. Some individuals still report ongoing improvement after two years. About 30 percent of those with Guillain-Barré have residual weakness after three years. About three 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; some may require ongoing use of a walker, wheelchair, or ankle support. Muscle strength may not return uniformly.
Ongoing fatigue, pain, and other annoying sensations can sometimes be troublesome. You may face physical difficulties and emotionally painful periods. You might find it extremely difficult to adjust to sudden paralysis and dependence on others for help with routine daily activities. Some people with GBS need psychological counseling to help them adapt. Support groups can often ease emotional strain and provide valuable information.
What are the latest updates on Guillain-Barré syndrome?
NINDS conducts research on disorders including GBS and funds research at major institutions and universities. Neuroscientists, immunologists, virologists, and pharmacologists are working collaboratively to learn how to prevent GBS and to make better therapies available when it strikes.
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 many cases of GBS begin after a viral or bacterial infection suggests that certain characteristics of some viruses and bacteria may activate the immune system inappropriately. Investigators are searching for those characteristics. Certain proteins or peptides in viruses and bacteria may be the same as those found in myelin, and the production of antibodies to neutralize the invading viruses or bacteria could trigger the attack on the myelin sheath.
Some studies show that normal variations in certain genes could increase risk of developing GBS; however, more research is necessary to identify and confirm associated genes. Since many of the genes that may increase the risk of GBS are involved in the immune system, their roles in fighting infection might contribute to the development of the condition.
NINDS-funded researchers have developed a mouse model with an altered autoimmune regulator gene that generates autoimmunity against the peripheral nervous system (PNS). Using this model, scientists hope to identify which PNS proteins 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.
Other NINDS-funded researchers are investigating the mechanisms by which IVIg treatment lessens the symptoms of GBS. By understanding these mechanisms, it may be possible to develop more effective treatments.
For research articles and summaries on GBS, search PubMed, which contains citations from medical journals and other sites.
How can I or my loved one help improve care for people with Guillain-Barré syndrome?
Consider participating in a clinical trial so clinicians and scientists can learn more about Guillain-Barré syndrome. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.
All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.
For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with GBS at Clinicaltrials.gov, a searchable database of current and past clinical studies and research results.
Where can I find more information about Guillain-Barré syndrome?
Information is available from the following resources:
GBS/CIDP Foundation International
Phone: 610-667-0131 or 866-224-3301