Possibly not an anxiety attack, but a sudden spike in anxiety. Often with GAD the sufferer experiences anxiety symptoms like chest pain and fogginess, weakness, and in general a lot of disassociation and 'weirdness.' Some times anxiety just feels really 'weird.'

In this thread I made a post about how anxiety attacks do not fit cookie cutter molds:
http://forums.psychcentral.com/anxie...ic-attack.html