It took over 3 years for my diagnosis. My initial symptom was double vision but it would come and go for months at a time so by the time I got in to see the doctor the double vision was gone. I also had leg weakness but to complicate the issue I had hip replacements (the old method) and knee replacement so my weakness was blamed on muscle weakness due to surgery. I was scheduled for another knee replacement and I woke up the day before the surgery with double vision. My doctor cancelled my surgery and was able to call in a favor and I saw a neurologist the following day. So to make a long story short my diagnosis took approximately 3 years.