What Causes Episode Of Vertigo Along With Upper Body Shaking?

my dad is 78 and had what we think was an episode of vertigo but also had a 15 or seconds of upper body shaking-he also felt like his brain was shaking. He went to the emoergency room and they did a C.A.T. scan and an ekg and decided it wasn't a stroke. I am wondering about the shaking part.