--and yes, both Guillain Barre syndrome and MS are distinct possibilities here, depending on what the MRI's and some other tests show (they really should be doing MRI's of your brain and upper spinal cord on a high Tesla machine, to really check for demyelination).

Guillain Barre is analogous to demyelinating disease of the peripheral, as opposed to the central, nervous system, and there are a number of variants, though tests that definitively lead to the diagnosis can be equivocal at times. And there is considerable variation as to the severity of the presentation.

See:

http://neuromuscular.wustl.edu/antibody/gbs.htm

http://www.nlm.nih.gov/medlineplus/m...sclerosis.html