http://en.wikipedia.org/wiki/Conus_medullaris

and here is a comparison of conus with cauda equina:
http://www.ncbi.nlm.nih.gov/books/bv...ab.table.10144
You don't seem to have the symptoms for conus.

You will find more info at the neurologist's, and probably have tests to
determine what is going on. Try not to worry too much. This will make the pain worse.

But just so you know, you can just turn funny and pinch something.
I did that many years ago, and both legs just went out on me, and I had
terrible pain. (I had been digging up peony bushes, earlier). And I just turned
to speak to my husband on the right, and bingo. It healed up within a week, the acute part. I stayed flat on my back for 2 days, and very conservative
activities for the rest of the week (no bending, turning). And once it healed up it never came back. I didn't even go to the doctor! (I was young and inexperienced then).

Since then I have had spinal Xrays, which found congenital spina bifida occulta, so I am very careful now how I turn/lift, or dig in the garden!
I also have spondylolisthesis grade 2, but I have no pain with that either. http://orthoinfo.aaos.org/fact/thr_r...pcategory=Spin

Many people can have congenital spinal problems. And these can be silent for many as well.

What helped me was immobilization, heat alternated with ice packs, aspirin (Ibuprofen wasn't invented yet), etc. And I never had a recurrance either. It was a one time deal, but my X-rays tell another story!