Brain mri couple of more nonspecific white matters compared to 6 mths ago, syms of ms, neurologist didn't explain what it means and want to do s.tap. he said my case it's complicated. blood works were neg. loosing balance all the time & gait issue.tx?

If the MRI demonstrates changes in white matter lesions, this is highly suspicious, but not fully confirmatory, of Multiple Sclerosis. It would be of great value to add MRI of cervical spine, and spinal fluid presence of oligoclonal bands would confirm diagnosis. Perhaps your case is challenging, and maybe, a second opinion would be appropriate.

Your doctor is ethically obligated at least to TRY to explain your case to you in terms you can understand. You have the right to expect that. Ask him WHY it's complicated and put him/her on the spot: ask if (s)he thinks you'd benefit from a second opinion.