Spinal Tap Necessary?

My 35 year old daughter has been seeing a neurologist due to numbness and tingling, lightheadedness and various other symptoms.  She's had several physicals, blood work and an MRI and is going for an MRI with contrast next week. The doctor has ruled out Lyme and said her proteins are O.K. and thinks it could be MS.   My daughter is really scared about having a spinal tap if it gets to that.  Is it absolutely necessary to have a spinal tap if the MRI with contrast is inconclusive?  Is there anything that can be done instead?  She had a baby in February and had an epidural that didn't work.  Is it possible that the epidural is causing her symptoms?

[patsy10]

I'm not quite sure what proteins he is referring to.  The proteins they check for MS are found in spinal fluid and checked when they do the tap.  If the MRI with contrast is normal there is another noninvasive test to look for MS.  It's called evoked potentials.  You can have visual evoked potentials to look for optic neuritis and or somatosensory evoked potentials which measure the nerve conduction from your toes to your brain.  Supposedly, these tests are very sensitive in finding lesions missed on MRI.  They just put electrodes on different areas of the body.  It takes a long time though.  I had them done and it took like 4 or 5 hours.  If the MRI shows something then they can diagnose MS based on symptoms and MRI findings alone without a spinal tap.   If there was some kind of damage from the epidural, it would affect her from the level they placed it down.  It would not cause symptoms above that level.