Well I just voted. I shake internally only, and I don't have complex PTSD. My diagnosis is severe chronic. The only time I shake externally is when I'm cold or ill.
Hmm well I need to modify my original response, last night I was having nightmares and when I woke up/half woke up I was shaking externally, more than once in the night actually. I don't recall that ever happening to me before, but it was quite pronounced last night.