A rare acute neurological disorder in which the immune system mistakenly attacks part of the peripheral nervous system. Guillain-Barré syndrome (GBS) primarily destroys the myelin that covers the peripheral nerves, causing the nerve signals to slow down. This damage can result in weakness and sometimes paralysis of the legs, arms, face, and breathing muscles. GBS is often preceded by a bacterial or viral infection and can occur early in the course of HIV infection.