As Erin said, take your written symptoms list with you. Just makes life much easier as you go down the road.

I would ask how many MG patients he is currently treating, and maybe what he lists as his subspecialty.

If you're comfortable he has the knowledge/experience level you're looking for, I'd go for things like:
1 - If I have a question can I call and get answers from you through your staff or return phone call without having to save them for my next appointment?
2 - What if you're out of town and I have an urgent matter or emergency?
3 - What is our plan for now, re: tests, meds, etc.
4 - What is your preferred treatment plan.
5 - Specific recommendations for my activity level - walking distance, hours at work, exercise, weight and repetitive activity restrictions.....

Ask about preparation for any tests he may be ordering for you ( & let us know prior, too - Annie found some great info on this). Ask if they will call you with results, and about when you should expect that call.

I also like to find out how far out they schedule. It can be very frustrating to have to wait three months to get in to find out what is the next step! A good neuro will be busy, but there is a limit to my willingness to wait!

And don't forget, no question is a stupid question. At this time you need lots and lots of information. Ask anything you want - sometimes the responses can be very telling on how they will deal with you.

I hope this first one is a good fit for you! Best of luck on the appointment!