It's all in the eyes.
There have been studies done which claim that if the patient has their eyes open (or flickering) during a seizure, then it is neurogenic in nature. Conversely, if the eyes are closed it is more likely to be a psychological event (pseudoseizure). Apparently the studies are so predictable as to be almost diagnostic.
It is now one of the first signs I look for when I see a witnessed seizure, and I have, on one occasion, said out loud in front of patient and family - "We will be here for you when you have finished", to a young girl with her eyes screwed tightly closed and no loss of continence. Funnily enough, she made a "miraculous recovery" with no post-ictal phase a few seconds later.
Eyes, eyes, eyes. It's almost all you need to know.
http://www.webmd.com/epilepsy/news/2006061...ogical-seizures
http://thelastpsychiatrist.com/2006/06/pse...s_seizures.html
http://drkatie.wordpress.com/2008/07/26/pseudoseizure/