Hi Sue,
You just haven't found the right dr to dx this. Mine, seems to change his mind all the time. then when I have an appt, he brings it up. Now he has dx me with spinal stenosis along with everything else. I would say you have it, and yes nerve root clumping is A I thought too.
On one of my MRI's they said I had nerve clumping consistant with Arachnoiditis. To me that says that I do have it. I had a neuro tell me that no one will touch me with this disease, so I might as well get over trying new dr's. He is kinda fwd with his comments, that is why I like him. LOL
On my last appt he said that the pain pump would not be in my favor anymore since the trial, b/c I have no spinal fluid flowing into my lumbar area. He didn't say what was blocking it, but I will ask on my next appt.
Becky