Hello Linroth,
I also haqd the samething. I think it took awhile after treatment but your right every time you look down it like this electric sensation shoots down your spine into your legs. I forget the proper terminology for this but it is some form of neuropothy. Mine lasted for I think about a yr and then it has subsided I still get a sensation every now and then and I'm over 6 yrs post tx.
Was told it is nothing serious. Hope all is well.
Mark.