I don't really have an answer to you, although I believe Galen and Pliny both know about comas and I would direct you to these two threads, which are likely to help. I'm showing my reviled Classicist face here to protest this statement:

GRRM is a historian too

I have never heard Martin describe himself as a historian, nor would any historian describe him as such. Martin has a BS in Journalism, and while that alone does not disqualify him at least from the mantle of the pop historian, he has no historical publications of any kind, neither in peer-reviewed publications nor in popular form. He has, to my knowledge, never engaged in any kind of scholarly historical study, nor has he been trained as a historian. The only stuff he's written on history have been a couple of fictional histories as supplements for some of his books, which only have the most threadbare resemblance to anything historical. I'm not one to rigidly adhere to pedantic definitions of this sort of thing (after all, am I a historian? A Classicist? A historiographer? You decide) but I don't know of any criterion under which Martin could legitimately be considered a historian