hi again, about the LP, it is scary, and there are risks they warn you about, but mine was okay during the actual procedure.
there is a kit, they swab down part of your back, they explain what they're doing, they do a local anasthaetic, and for me when the doc started inserting the needle, it was more knowing that this object was penetrating my spinal cord millimetre by millimetre and being able to feel it moving at all that freaked me right out. i was making some hissing noises and the doc said does it hurt? and i said 'not pain, but i can feel it, and i don't want to know that it's there at all!'
so he withdrew the puncture he had started, froze me up a bit more, and redid it - second time was much better although still tense. they show you the samples they've taken out. pretty much just looks like water.
then the fun began. they'll tell you to lie down after because "some people get a headache afterwards"
when you poke a hole in your spinal cord, the fluid can escape, the pressure drops, and then unless you're lying down you get this excruciating headache. i tried to function for a few days, read up on it a little, pain killers were unreliable treatments so i was only able to get on the computer in fits and starts but i found some info on treatment and prevention. after that i self-prescribed three days of bed rest in order to let the punctures heal, and then i was okay. for prevention, they have to put the bevelled end of the needle into your spine at a particular angle so that the hole is self-sealing when there is internal pressure. if they put it in at the wrong angle the incision can flap both ways like saloon doors.
here's a link to info on avoiding the headache:
http://www.pulmonaryreviews.com/dec00/pr_dec00_puncturehead.html
and i also found this page interesting because it has an image that shows the different kind of holes that can be made that cause a problem:
http://www.geocities.com/HotSprings/Villa/5422/index.html
don't think i ever watched the technique video!
the results took a long time compared to the other bloodwork. my neuro referred to o-rings or something like that which i finally managed to figure out were the oligoclonal bands. the bands look like blurry bar code labels on a slide. mine indicated the damning chronic CNS inflammation that apparently is not seen in b12 deficiency and is seen in a large number of ms patients.
hope that helps