i've been told--- but never done any research for myself-- that e-stim may be contraindicated in GBS------- but i think that's mainly because they're just not sure if it screws things up or not... either way, i think you just need to focus on proximal-to-distal progressive strengthening--- core stability stuff should come first... i've found that PNF seems to wake up some muscles that have some strength and is really helpful to increase the strength of the muscles that do return...
other than that, it's sort of just a waiting game......
good luck...
patrick, PT