no, you can't quit cold turkey. the reason being, the cortisone that is normally secreted by your adrenal gland will stop being secreted because your body senses that you have enough, this feedback inhibition is one of the body's more amazing methods, i think. as you taper off an exogenous corticosteroid, your body detects less so gears up to secrete more. if you stopped all at once, your adrendal gland would take a little time to get the signal to start secreting it again so you would have a short period of time where you wouldn't have enough of it in your system. that's pharmacology 101, just for the information.

and the word you may be looking for is spinal stenosis?

for me, even doing a 1-2 week round of predisone, i can eat like a horse! i have to make a real concerted effort to eat like normal. i've never had mood or sleep disorders from 1-2 week doses (and with my asthma i've actually done those rounds way more times than i care to recall). though it is certainly possible.