Serious autoimmune disorder with rapid-onset muscle weakness, pain, and sensation changes like numbness and/or tingling. Can be caused by the bacterium Campylobacter jejuni, and with the viruses Cytomegalovirus and Enterovirus.Encyclopedia Entry for Guillain-Barre Syndrome :Guillain-Barre Syndrome. Can be caused by the bacterium Campylobacter jejuni, and with the viruses Cytomegalovirus and Enterovirus.Information from Marcello Allegretti.