What is Guillain-Barré syndrome?
Guillain-Barré syndrome is a disorder in which the body’s immune response, typically to an infection, causes nerve damage. The syndrome is rare, affecting about one to two people in 100,000 each year. It can present as a very mild case of brief weakness to devastating paralysis, affecting the muscles that allow a person to breathe on their own. Fortunately, most people eventually recover from even the most severe cases of Guillain-Barré, although some are left with some level of weakness.
There are several variants of Guillain-Barré syndrome. The most common variant is called acute inflammatory demyelinating polyneuropathy, or AIDP. This form affects the insulation around the nerves but usually not the nerves themselves. Two other variants, acute motor axonal neuropathy (AMAN) and acute motor and sensory axonal neuropathy (AMSAN), are much less common than AIDP, and they affect the nerves themselves. These three forms of Guillain-Barré syndrome typically cause arm and leg weakness. Breathing muscles may be involved in all the forms of Guillain-Barré syndrome, and some patients need a ventilator to breathe.
Guillain-Barré syndrome can occur in children, but the number of people who develop the syndrome increases as people get older. Men and women are equally prone to the disorder.
Miller Fisher syndrome is a rare, acquired nerve disease that is considered to be a variant of Guillain-Barré syndrome. It is characterized by abnormal muscle coordination, paralysis of the eye muscles, and absence of the tendon reflexes. Like Guillain-Barré syndrome, symptoms of Miller Fisher syndrome may be preceded by a viral illness.
What causes Guillain-Barré syndrome?
The exact cause of Guillain-Barré syndrome is unknown. Researchers do not know why it strikes some people and not others. It is not contagious or inherited, despite the fact that it can be triggered by an infection.
Guillain-Barré syndrome often occurs a few days or weeks after a respiratory or gastrointestinal infection. The most common preceding infection involves the bacterium Campylobacter jejuni, a common foodborne pathogen that can lead to infectious diarrhea. Less common triggers include cytomegalovirus, Epstein-Barr virus, HIV, and Zika virus. The newest infection to add to the list is SARS-CoV-2, the virus that causes COVID-19. Rarely, Guillain-Barré syndrome develops after surgery, trauma, bone marrow transplantation, or vaccination.
Do outbreaks of Guillain-Barré occur?
As described above, Guillain-Barré syndrome is not contagious. However, according to the CDC, outbreaks of associated pathogenic viruses and bacteria, including Campylobacter, can lead to clusters of people with Guillain-Barré syndrome. About one in every 1,000 reported Campylobacter illnesses leads to Guillain-Barré syndrome. As many as 40% of cases in the United States are thought to be triggered by Campylobacter infection.