Sqiffy, I was in the same situation. Dx'd then un-dX'd with MS. The trouble was the new diagnosis was worse. I hope you have better luck. What was the trouble, why did they undo your Dx. Was it your spinal tap, That contributed to mine. Also my MRI. The damage was too symmetrical, and too diffuse. If those were the reasons they gave you, then we should talk. The other trouble, is that all the closer to naming it is to say it fit into a family of rare diseases. So I went trough testing and more testing. Still no names for it, but I am trying to get admitted to a couple of research centers who want to determine the genetic causes of undiagnosed leukodystrophies. It seems that us unknown leukos are the second largest group of myelin disorders.
I figure researchers have run into a lot of dead ends trying to puzzle information out of MS studies, and now figgure there might be as good or better returns, turning to genetic defects that cause myelin damages. Albee Messing got a large NIH grant for his work on Alexanders Disease, the rarest of the known leukos. The Alexander disease gene plays an important part in myelin repair, and the potential return of solving the Alexander disease puzzle is obvious for a lot of nerve damages folks. In my case, researchers figure that the genetic defect plays a role in interrupting my metabolic process, and this, in turn, causes a thinning of my myelin. This partially reinforced by my symptoms. I have virtually all of the MS symptoms. The strange part is that I got them all within a very short time. As did my brother. Which might show that the myelin thinned to a threshold level which, in turn, resulted in symptoms. My older sister's MRI actually shows more damage than mine, but she has no symptoms. We just accuse her of fatter myelin, and recommend diets to her (a little dark humor).
In the mean time, we are much like you, somewhat amused at it all. There are no treatments, no cures, and I have enough brain damages that I react strangely to a lot of medications. so nobody really wants to prescribe anything for me.
Our amusement, of course, was reinforced by my brother and I being seen by a bunch of children docs, at the Dornberger Childrens hospital in Portland, iin the Metabolic Lab at the chipmunk desk of the hospital. The guy testing us was Dr Grumpy (actually Grompe, a German name). At the same time my regular doctor was a former OB/Gyn whose last name is Lush.

So I was the only guy in the world being seen by a lush of a doctor for a chilren's disease handled by Dr Grumpy at the chipmunk desk.