My first symptoms started when I was about 20. I noticed I would have a difficult time swallowing food - or get tired face muscles when chewing. I just assumed everybody else felt the same way? Then I started having what I called "spells" where I felt very tired and almost flu like - would lay down for about 24 hours and feel better. These spells hit every few months, than weeks, than every week, then during the week over the next 30 plus years.
I really started to have trouble when storm fronts came thru with sinus pressure - balance etc - winters were worst.
Extreme weakness came on in last 5 years or so - had tremors and asked Dr he said not to worry - what it turned out to be was shakiness from muscle weakness!
Neuro said since I had symptoms since early on that may be a good thing as it came and went and was not fast acting??? I dunno?