I just read a message that you sent on this ALS forum back in 2011. I am experiencing the exact same symptoms and was wondering if you were ever diagnosed and how you are today.
I know there is little chance you will ever see this but the same thing just happened to me that you described (right down to the sinus infection) and I was wondering if you ever found the answer as to the cause. If you see this please send me a visitor message or reply to this, I would appreciate it.