Guillain-Barré syndrome - Causes of Guillain-Barré syndrome

Guillain-Barré syndrome is an autoimmune condition (where the immune system attacks healthy cells and tissue). It's not known what causes the immune system to do this.

Most people develop Guillain-Barré syndrome after having another illness. This is usually a viral infection, such as the common cold, influenza, a throat infection, or sometimes a bacterial infection (see below).

It's thought the infection may trigger the immune system to attack nerve roots and peripheral nerves. The peripheral nervous system controls the body's senses and movements.

It's not possible for Guillain-Barré syndrome to be transmitted from one person to another and it's not inherited.

Immune response 

The immune system uses white blood cells to produce antibodies. Antibodies are infection-fighting proteins that attack the bacteria or virus causing the infection. However, in Guillain-Barré syndrome the antibodies react to the cells of the protective covering (myelin sheath) of the peripheral nerves.

This damages the nerves and slows down the nerve signals sent to your muscles. This causes the symptoms of Guillain-Barré syndrome, such as tingling, numbness, weakness and, in some cases, temporary muscle paralysis.

Possible triggers

Although the exact cause is unknown, most cases of Guillain-Barré syndrome occur after:

• a virus – such as the cytomegalovirus (a member of the herpes group), the Epstein-Barr virus or HIV
• a bacterial infection – such as infection from Campylobacter bacteria, a common cause of food poisoning

Vaccination

In the past, vaccinations (particularly the swine flu vaccination used during 1976-77) were thought to be a possible cause of Guillain-Barré syndrome. However, subsequent studies have shown there's virtually no risk of developing Guillain-Barré syndrome after being vaccinated.

During the 2009-10 swine flu pandemic, about 6 million doses of the vaccine Pandemrix were given in the UK. The Medicines and Healthcare products Regulatory Agency (MHRA), which monitors the safety of vaccines, received 15 suspected reports of Guillain-Barré syndrome during the pandemic. However, the diagnosis was not confirmed in any of these cases.