Question about Guillian-Barre Syndrome (sp?)

I am a little confussed on this... Is Guillian Barre caused by a virus? and what are the first symptoms? My text book says that it is caused by a GI/Resp infection but does not specify a viral infection and says the first symptoms are weakness in the lower extremitys ****Several sites on the internet say it is directly related to a viral infection and others say the first symptoms are tingling in the hands.

I know it sounds silly that I would be stressing over such small detail but.......... I'm desprate to know whether Guillain Barre follows a viral infection or if the first symptoms are tingling in the hands!

THANKS to anyone who has any insight on this!!

Amy