Anca, during 5 years (2002 to 2006). We included all patients with GBS who required mechanical ventilation (MV). An electromyogram was realized in all patients and found axonal demyelinization. We defined two groups: group 1 (group treated by IVIg: 0.4 g/kg/day during 5 days) and group 2 (group treated by PE: 4 PEs during 10 to 14 days). We collected demographic characteristics, clinical and thera