What are these horrible sensations I'm having in my hands?

My arms have felt numb a lot lately, and for about a week the very tip of one of my fingers has felt numb. But now I am really concerned about both of my hands. I was just at my kids' school basketball game, and after some brief periods of clapping my hands, they began to feel very strange. It felt almost as if I had frostbite, but I hadn't gotten cold at all. They tingled, itched, burned and hurt all at the same time. When I lightly scratched the side of one finger because of the itching, the sensation was excruciating. You'd have thought I'd gouged and scd it down to the bone and ripped off flesh! It took quite a while of keeping them still for the sensations to stop. I saw a neurologist just this morning about some sleep problems, and she's ordering an MRI of me neck because of some other things she observed. But she doesn't know about this symptom with my hands that I just experienced after my appt. Should I let my doc know right away, or just wait til the MRI followup? What could be going on with my hands???