Generally speaking an ER won't run a 2-5k test on you to sooth your anxiety. A good physical by a neurologist is what is warranted. That is much cheaper. If you are truly concerned you have MS, ask for a referral to a neurologist. If the neurologist says you are ok without one, accept that. They don't make their living by missing MS. If he believes its warranted then you can work out some sort of arrangements with a hospital, specifically one that receives funds by the state. Some can give you help based on income.