Guillain-Barré syndrome (GBS) is the term used to describe a spectrum of rare post-infectious neuropathies that usually occur in otherwise healthy patients. GBS is clinically heterogeneous and encompasses acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN), Miller-Fisher syndrome (MFS; see these terms) and some other regional variants.