Originally Posted by ColinsMum
I understand that you probably didn't mean it this way, because of a difference between usage in British and American English, but please, in case any readers ever visit the UK or talk to British people, be aware that the term "spaz" is EXTREMELY offensive in British English. Really, extremely. I'm kind of shaking even though I know about the dialect thing.

http://en.m.wikipedia.org/wiki/Spastic

I don't think it's a difference in usage as much as more awareness and activism in one country as opposed to another. Like how the R word used to be used this way in the US and now isn't any more because people have become aware.