The CSF can show several things that are indicative of MS (and considered in conjunction with other testing).

I have MS but did NOT have oligoclonal bands even in the midst of my first flair. But I did have high IgG Index and IgG Synthesis in my spinal fluid.

My doc. also did a visual evoked potentials test because there was some question in the beginning as to whether I had MS due to a long running fever. The visual evoked potentials was on the border of abnormal in my left eye which showed a slight delay. Combined with the MRI that had enhanced and non-enhanced lesions, the high IgG Index and Synthesis, they concluded MS.

NurseNancy is right--keeping a symptom journal is a good idea!