Thanks for the info.
You are right about misdiagnosis.
Even though I passed the spinal tap, clinical exam and MRI tests, my neuro still wrote "probable MS" on his letter to me. They don't like to say it's definite as they change their minds. When I was in hospital I met a woman who was diagnosed with MS only to have the diagnosis reversed 10 years later. OK, so they didn't know what was wrong with her - she was not well - but a diagnosis can do a lot to wear someone down. If it turns out to be false, that's a terrible mistake to make.