Re: What can MRI NOT show?
MRI's, like many other tests, are simply not accurate 100% of the time. I agree with Jenny.
For example, I had tore my rotator cuff, which was picked up by the MRI, what was not picked up was the 1 inch spur that caused it.
My right leg kept giving out, the MRI revealed some previous damage and surgeries to the knee and my ACL was in tact. What it didn't show was that my ACL was completely gone, the elasticity was completely gone.
After my ACL was replaced, my knee got worse. Another MRI revealed nothing, Surgery revealed a hole the size of a quarter just above the kneecap where the kneecap had been tracking wrong.
As mentioned it may take a few different types of tests to fully reveal damage, if any.
I'd wait on the spinal tap to see what that tells you in regards to MS. Have you researched or talked to anyone else about other conditions that cause similar problems? It does sound a lot like MS but do you have any of the other symptoms such as memory loss, heat intolerance etc? I have been told that certain medications can induce MS like symptoms. Are you on any specific medications that may have those types of symptoms? Regalan for instance can cause major problems with rigidity as well as Seroquel etc.
Your doctor is wise in that he/she did a spinal tap, I hope you find answers soon.
No matter how great your illness or pain, there's always someone else who may be worse off.