It's used in Australia and means someone is having a spastic attack or going off their head.
Stop having a spazzattack for nothing ffs!
by Lynne Phillips January 8, 2005
When a retarded or autistic person starts going crazy (or spastic) and starts attacking everyone in sight.
Xiu: "Did you see that spazzattack Harold had?"
Jerry: "Yeah that's cool but have you seen my giant dick?"
Xiu: "Please cement your mouth shut Jerry."
by TimeForACrusade October 30, 2018