Wow - lots of questions. How about some answers? (Or, since I'm not a medical professional, a layman's opinion.)
As I surf the Runner's World bulletin boards I've noticed a pattern where people seem to view the imaging tests (specifically CT Scan and MRI) as the "proof" one needs to determine what is going on. Heck, these technologies let the Dr. look inside the body in high degrees of detail. One would think seeing is the best way to determine the actual problem.
I had an experience that challenged this assumption. I started getting a variety of symptoms that pointed to sciatic nerve issues. (Remember that "Sciatica" is a set of symptoms, not a problem per se.) There are a couple of conditions that can cause pain via the sciatic nerve. The two most common (I believe) problems that cause sciatica symptoms are:
- Protruding L4/L5 disc which pushes on the sciatic nerve as it exits the spinal canal.
- Piriformis Syndrome - where the Piriformis muscle becomes tight and pinches the sciatic nerve deep in the hip.
Feeling better, I attempted a bike ride. After one 30 minute ride the pain returned - very localized in my hip. That really got me thinking: If a disc in my back was the problem, how could it push on that nerve to make it hurt in just that localized spot? It just didn't make sense to me. I really wondered if the disc diagnosis was correct, however I felt trapped because the MRI had "proven" the disc was the problem.
I decided to see an orthopedist to get another set of eyes on my situation. He reviewed the MRI in detail (technology is great: in the exam room he logged onto the hospital's servers across town and pulled up my MRI) and said something fascinating: "I could pull 100 people off the street with this same MRI and none of them would have back pain. That disc is not your problem."
It turns out it was Piriformis Syndrome that was causing my sciatic nerve symptoms. After some massage and stretching and PT work focused on the hip I was good to go.
Even when you think you have proof, convince yourself that the proof really is proof. It may not be.