I have used a private consultant and MRI, also nerve conduction tests. They were all negative for why I was having pins and needles, numbness, weakness. If there had been treatment necessary I could have gone back to the NHS for treatment. But…
Eventually, after a blood test, it seems it was a lot to do with vitamin D deficiency. You can get a blood test from Amazon (finger prick test that goes to an NHS hospital for analysis) that will tell you if that is a cause. Wish I had done that a LOT earlier!!!