After my abnormal brain MRIs, my understanding is that the diagnosis came down to either some kind of encephalitis or multiple sclerosis. But test results have to come back first. I was even set up with a follow-up with an MS specialist. Once my anti-NMDA receptor encephalitis test came back positive though, that follow-up got cancelled and replaced with a neuro-immunologist that specializes in these sorts of things.

And even if I did have an MS, there are various sub-types that require going through something quite complicated call the McDonald criteria: https://en.wikipedia.org/wiki/Diagnosis_of_multiple_sclerosi...