BTW: I tried to google this question and this is the answer I came up with from Yahoo answers. It gave me a good chuckle:
*No, i Am Not Dreamed When i Had Coma, After One Month After Coma, i Had Got Dreamed, i Had Got Coma For 7 Days (At !5/April/2005 i Had Got Accident For Grinded Drum, i Do Not Know it Because My Employee, Buy Second Drum Ex Chemical Drum, i Just Think, i Was Oil Drum, So i Do Not Open The Out Put Hole, Because, i Think it Just Ex Oil, Because The Drum Write Oil, So When i Grinded And it Exploded, My Grind Tools Fly Over Six Meter And Hit Of My Factory Roof, And Broke My Factory Roof, Many Of My Face Skull Are Broken, And My Eyes Blind One Now, Many People Said One Eye Jack, He…He…, Best Regards, EddyLim777@yahoo.com.sg
*
I do not specifically know the answer, but I suspect it would very much depend upon upon the cause and nature of the coma. All comas are not created equal. You should be able to tell reasonably reliably when someone in a coma is dreaming by looking to see if they are having REMs (rapid eye movements). For ordinary sleep, anyway, the correlation between REMs and dreaming is pretty good (though not perfect).
If the coma patient eventually wakes up, just asking them is not likely to be much use. Ordinary sleepers forget most of their dreams anyway, unless they are woken whilst actually in a period of REM sleep (which does not usually happen). On the other hand, if you are woken after only a few seconds of REM, it can seem as though you have been dreaming for a long, long time, so even if someone wakes from a coma and tells you that they have been dreaming the whole time, this can’t be trusted, because it might really all have been nothing but a short period of REM just before they awoke.
I was in a coma for twelve days. I had very intense, life-like dreams, but I’m not sure they happened when I was in the coma or after I’d started coming out of it.
I’ll piggyback a question I’ve been wondering: Is it true that 30 days in a coma seems to be a point of no return and that it’s almost impossible for a victim to come out of it after that? So I’ve heard.
I was in a coma after a doctor perferated my colon and sent me home. I was septic for 2 days before getting to the emergency room. I almost died, my brother died 6 months prior and the doctor told my family that he did everything he could and it was now up to God.
While I was in the coma, I did dream. I also saw things that I maybe shouldnt have and I remember quite a bit. My sister said I knew people were there to visit before she did when I was coming out of the coma. I also talked in 3rd person (I dont remember that) as I could not speak, she drew the alphabet on a white board and all I remember was having difficulty pointing. She said I spelled “Jena wants to live” My nickname is Jena.
Through it all, my faith has become so strong. If you seriously have questions, I will answer them from my experience. I did hear people and knew who was there, I was in a coma but created my own reality in my mind. I remember.
(The wife and I recently watched both seasons of Life on Mars.)