A few thoughts, not necessarily in any order of importance:
As a patient, you are entitled to your medical records. It might be real helpful for you to get them, to see exactly what the neuro IS saying. Or ask your general practioner to get them, then sit down with you and help interpret what they're saying. You can request them (usually you have to do this in writing) and they can supply them, but some doctors will charge you for them. If you ask that they be sent to your primary doctor, that'll usually happen without any charge to you, as a matter of "professional courtesy".
We of course don't have access to them. 9 Lesions appeared on your MRI? location of them is important, and the results of the evoked potentials test would be another tool, but it sounds like indeed they're thinking you do have MS, and the spinal tap would be one more confirmation (or perhaps could lead them to a different path to explore.)
The fleeting paralysis is a puzzler. Of course, it might be a matter of interpretation. How I interpret paralysis and how you are using the word, might be what is confusing me. But sometimes fleeting symptoms like that are indicative of an underlying problem - -which apparently has been discovered with the MRI.
The eye thing: it might be useful too for you to see an opthamologist -- a person with a medical degree, and whose specialty is vision -- who can examine your eyes and see if perhaps the "occlusion" wasn't perhaps optic neuritis. Many neuros can simply see this when they look in your eyes, but a trip to the opthamologist might be good in that -- if it IS something like an occlusion, or something even more serious, the opthamologist would be able to give you a thorough exam and rule in or rule out those things more accurately than a trip to the ER.
Your original question: I don't think the diagnosis of MS is being made on either the "temporary eye problem" or the "temporary paralysis". I think the diagnosis is being made on the basis of the 9 lesions that appeared on the MRI, and perhaps other clinical signs (including the evoked potentials) that you had done at the neuros office.
...I am not a doctor, nor health professional, and don't pretend to be one, here.....