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Guillain-Barré Syndrome (GBS)

(Guillain-Barré's Syndrome; Acute Inflammatory Demyelinating Polyradiculoneuropathy; Acute Idiopathic Polyneuritis)


Michael Rubin

, MDCM, New York Presbyterian Hospital-Cornell Medical Center

Last full review/revision Dec 2020| Content last modified Dec 2020

Guillain-Barré syndrome is a form of polyneuropathy causing muscle weakness, which usually worsens over a few days to weeks, then slowly returns to normal on its own. With treatment, people may improve more quickly.

  • Guillain-Barré syndrome is thought to be caused by an autoimmune reaction.
  • Usually, weakness begins in both legs and moves up the body.
  • Electromyography and nerve conduction studies can help confirm the diagnosis.
  • People with Guillain-Barré syndrome are hospitalized immediately because symptoms can worsen rapidly.
  • Immune globulin given intravenously or plasma exchange speeds recovery.

(See also Overview of the Peripheral Nervous System.)

Guillain-Barré syndrome affects many peripheral nerves throughout the body (a polyneuropathy).

The presumed cause of Guillain-Barré syndrome is an autoimmune reaction. The body’s immune system attacks one or both of the following:

  • The myelin sheath, which surrounds the nerve and enables nerve impulses to travel quickly
  • The part of the nerve that sends messages (called an axon)

In about two thirds of people with Guillain-Barré syndrome, symptoms begin about 5 days to 3 weeks after a mild infection (such as a Campylobacter infection, mononucleosis, or another viral infection), surgery, or a vaccination.

In a few people, Guillain-Barré syndrome has developed after a Zika virus infection, or after COVID-19.

Insulating a Nerve Fiber

Most nerve fibers inside and outside the brain are wrapped with many layers of tissue composed of a fat (lipoprotein) called myelin. These layers form the myelin sheath. Much like the insulation around an electrical wire, the myelin sheath enables electrical impulses to be conducted along the nerve fiber rapidly.

When the myelin sheath is damaged, nerves do not conduct electrical impulses normally.

Insulating a Nerve Fiber

Weakness caused by Guillain-Barré syndrome usually worsens over 3 or 4 weeks, then remains the same or starts to return to normal. If it worsens for more than 8 weeks, it is considered chronic inflammatory demyelinating polyneuropathy (CIDP), not Guillain-Barré syndrome.

Symptoms of GBS

Symptoms of Guillain-Barré syndrome usually begin in both legs, then progress upward to the arms. Occasionally, symptoms begin in the arms or head and progress downward.

Symptoms include weakness and a pins-and-needles sensation or loss of sensation. Weakness is more prominent than abnormal sensation. Reflexes are decreased or absent. In 90% of people who have Guillain-Barré syndrome, weakness is most severe 3 to 4 weeks after symptoms start. In 5 to 10%, the muscles that control breathing become so weak that a mechanical ventilator is needed.

When the disorder is severe, the facial and swallowing muscles become weak in more than half of affected people. When these muscles are weak, people may choke when they are eating or become dehydrated and malnourished.

If the disorder is very severe, internal functions controlled by the autonomic nervous system may be impaired. For example, blood pressure may fluctuate widely, heart rhythm may become abnormal, people may retain urine, and severe constipation may develop.

In a variant called Miller-Fisher syndrome, only a few symptoms develop: Eye movements become paralyzed, walking becomes unsteady, and normal reflexes disappear.

Diagnosis of GBS

  • A doctor's evaluation
  • Electromyography and nerve conduction studies, magnetic resonance imaging, blood tests, and a spinal tap

Doctors can usually diagnose Guillain-Barré syndrome based on the pattern of symptoms. However, tests are done to confirm the diagnosis. If doctors suspect Guillain-Barré syndrome, people are admitted to the hospital to have the tests because the syndrome can worsen rapidly and impair the muscles involved in breathing. Breathing is evaluated frequently.

Tests may include the following:

  • Analysis of cerebrospinal fluid (which surrounds the brain and spinal cord) obtained by a spinal tap (lumbar puncture)
  • Electromyography and nerve conduction studies
  • Magnetic resonance imaging (MRI)
  • Blood tests

These tests can help doctors exclude other possible causes of severe weakness, which may resemble Guillain-Barré syndrome. For example, MRI can help exclude spinal cord damage due to compression (for example, by a tumor or an abscess) and transverse myelitis (inflammation of the spinal cord).

A combination of high protein levels and few or no white blood cells in the cerebrospinal fluid and characteristic results from electromyography strongly suggest Guillain-Barré syndrome.

Prognosis of GBS

Damage stops progressing within 8 weeks. Without treatment, most people with Guillain-Barré syndrome improve slowly over several months. However, with early treatment, people can improve very quickly—in days or weeks.

About 30% of adults and even more children with the disorder have residual weakness 3 years after the syndrome began. On average, fewer than 2% of people die.

After initial improvement, 3 to 10% of people with Guillain-Barré syndrome develop chronic inflammatory demyelinating polyneuropathy.

Treatment of GBS

  • Hospitalization and supportive care
  • If needed, use of a ventilator to help with breathing
  • Immune globulin or plasma exchange

Guillain-Barré syndrome can worsen rapidly and is a medical emergency. People who develop this syndrome should be hospitalized immediately. The sooner appropriate treatment is started, the better the chance of a good outcome. If symptoms strongly suggest Guillain-Barré syndrome, treatment is usually started without waiting for test results.

Supportive care

In the hospital, people are closely monitored so that breathing can be assisted with a ventilator if necessary.

People with weak facial and neck muscles may need to be fed through a catheter inserted in a vein (intravenous feeding) or through a tube placed directly into the stomach or small intestine through a small incision in the abdomen (called a PEG tube). Fluids may be given intravenously.

Being unable to move because muscles are weak can cause many problems, such as pressure sores and stiff, permanently shortened muscles (contractures). So nurses take precautions to prevent pressure sores and injuries by providing soft mattresses and by turning the people with severe weakness every 2 hours.

Physical therapy is started to help prevent contractures and preserve joint and muscle function and the ability to walk. Heat therapy may be used to make physical therapy more comfortable. Physical therapy may begin with the therapist moving the limbs for people (passive exercise). As the weakness subsides, people should move their own limbs (active exercise).

Immune globulin or plasma exchange

Immune globulin (a solution containing many different antibodies collected from a group of donors), given early and intravenously for 5 days, is the treatment of choice for Guillain-Barré syndrome.

If immune globulin is ineffective, plasma exchange (filtering of toxic substances, including antibodies to the myelin sheath, from the blood) can help.

These treatments shorten the hospital stay, speed recovery, and reduce the risk of death and permanent disability. Plasma exchange is usually done as soon as possible if people are worsening quickly. However, removing and replacing a lot of blood through a tube (catheter) inserted in a vein can cause low blood pressure and increase the risk of infection.

Because plasma exchange removes immune globulin from the blood, plasma exchange is not used at the same time as immune globulin. Plasma exchange is delayed for at least 2 to 3 days after immune globulin is given.

Other treatments

Corticosteroids do not help and may worsen Guillain-Barré syndrome.

Drugs Mentioned In This Article

Generic Name Select Brand Names
Immune globulin Gammagard S/D

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