The exact cause of Guillain-Barre syndrome isn’t known. The disorder usually appears days or weeks after a respiratory or digestive tract infection. Rarely, recent surgery or immunization can trigger Guillain-Barre syndrome. Recently, there have been a few cases reported following infection with the Zika virus.
In Guillain-Barre syndrome, your immune system — which usually attacks only invading organisms — begins attacking the nerves. In AIDP, the most common form of Guillain-Barre syndrome in the U.S., the nerves’ protective covering (myelin sheath) is damaged. The damage prevents nerves from transmitting signals to your brain, causing weakness, numbness or paralysis.
Once thought to be a single disorder, Guillain-Barre syndrome is now known to occur in several forms. The main types are:
1. Acute inflammatory demyelinating polyradiculoneuropathy (AIDP), the most common form in the U.S. The most common sign of AIDP is muscle weakness that starts in the lower part of your body and spreads upward.
2. Miller Fisher syndrome (MFS), in which paralysis starts in the eyes. MFS is also associated with an unsteady gait. MFS occurs in about 5 percent of people with Guillain-Barre syndrome in the U.S. but is more common in Asia.
3. Acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN) are less common in the U.S. But AMAN and AMSAN are more frequent in China, Japan, and Mexico.