Between the PTT, ESR and several of the other tests done in the "Rule out" process, this mimic is usually picked up pretty quickly. Positive APS antibodies seem to be far more common (up to 5% of the healthy population - http://emedicine.medscape.com/article/333221-overview) than MS (high end is about 150 per 100,000 so about 0.15%).
Yes - Hughes Syndrome. Not always and easy dx, but a big mimic of MS.
Sticky blood it's called or, APS. It is (and if not) should be run by neuros during initial work ups where MS is a concern.
Like you say, it's treatable! I agree - def. overlooked. I had to make sure my ACl, and APl were run along w/the others. They were, but was not mentioned to me for some reason, and seemed to not be a concern.