Multiple sclerosis (MS) and Guillain-Barré syndrome (GBS) are diseases of the nervous system. They’re not the same, but they do have a lot of similarities.
Both MS and GBS are autoimmune diseases. This means they cause your body's immune system to attack its own tissues. They both start when the immune system attacks and damages something called myelin. That’s a layer of insulation that surrounds nerves. It also helps nerves transmit their messages.