There was a British charity, The Spastic Society. They became fairly high profile in the early 80s being involved in children’s magazine shows for fund raising. Often children with conditions would be featured. The intent was that featuring them would make the condition more relatable, but kids saw them more freaks to be mocked.

It resulted in “spastic” / “spaz” becoming school playground taunts to the extent that the charity changed it’s name to avoid the term.