Well... honestly... I don't really know. But I'll go out on a limb here & say that, to me, a nerve tingling would be more rapid & sort-of under the skin, if that makes any sense. I'm an old goat & so I get those sorts of things periodically. I think it just comes with age.

A muscle twitch or spasm, on the other hand, is more "overt", so to speak. At least the way I've experienced it, it involved a quick jerking motion of one of my arms. I had this when I was on Cymbalta for a period of time. When I would be using the mouse to my laptop, all of a sudden & without warning my arm would just jerk forward an inch or two. (Depending on what I was doing on my computer at the time, it could produce some distressing results.) When I went off of my SNRI, this jerkiness went away. I no longer have it.)

Anyway those are my non-professional musings with regard to your post. Hope they help.