Do you have a regular Neurologist? Or a regular PCP?

ER doctor's only see you for a few minutes once.....and usually never again.....so they give the most logical diagnosis that fits whatever you've got going on at that specific moment. So, unfortunately, you never actually get what you really need.

I've had muscle cramping before and even in my hands but never to the point that I couldn't open my fist. What you're describing actually sounds like a seizure. Not sure about the steroids that were prescribed for it.

I'd keep track of how often these "spells" happen and show the next doctor you see so they can have an idea of how often they're occurring.

I hope things settle down for you.