This article has a nice synopsis of Guillain-Barre Syndrome. The symptoms range from a tingling sensation in the legs and arms to paralysis. One of the treatments which seems to work for Guillain-Barre is plasmapheresis or exchanging the patients plasma because their plasma contained something which damaged the myelin.
Read more: http://www.ifaonline.co.uk/cover/feature/2024850/disease-guillain-barre-syndrome#ixzz1EFrAbTS9
Also in case you were interested in the part where the flu shot was linked to trigger Guillain-Barre here is a link to a reuter's article which explains it from 2006. But just looking at the numbers, it seems unlikely this is actually a trigger.