Mine started innocenty enough too - woke up one morning with right foot and hand completely numb - had been fine the night before, then started literally falling over..... the docs poo pooed it at first - said would just go away, that it was post viral... I finally got to see a neuro - who started running tests asap as the NCS she did the very same day showed damage - and that was 10 years ago... it has never stopped progressing - but at least I know they have done all the tests and treatments out there the could help... have you looked at the stickies? check out the liza jane spreadsheets - if you can find the cause now the faster you move the better if there is a way to "treat" in any way.... (you've already had some pretty telling tests - were they all negative???????)(especially the ANA, LP, and nerve biospy - at least it sounds like you have a very motivated doc which is great)

Keep searching.....