What Causes Tingling And Burning Pain In Both The Legs?

I have a complicated 7 year history of low back pain with radicular symptoms after prolapsing 2 discs at L4/ L5 when moving house and then L5/ S1 18 months ago. The subsequent CT (can t have MRI due to SCS) apparently showed no nerve impingement or stenosis. 11 weeks ago I had surgery to implant a 2nd lead into my SCS which was implanted 2 years ago and went back to work a month ago. Since my return, my back pain has got really bad, as has the sciatica. It has prgressed over this period so that last weekend I had electric shock type pains in my legs and then I m now getting very bad pins & needles and tingling in both legs, my back, my lower abdomen and yesterday also my saddle area . Today I just have it in my legs, hips and low back as well as burning pain down the sides of my legs but as the day goes on it generally gets worse and at night I can t feel the stimulation from my SCS as it is so stroing. It feels like I have cool water running down from my lower back and down both legs. I have an appointment for reprogramming at the end of the week. Do I take this progression seriously as possibly cauda equina syndrome or similar or leave it and see how it progresses? Many thanks.