Hmm interesting! Although a scary episode for you with the cat hovering around! There is nothing in hamsterlopedia about narcolepsy, but it would be interesting to know; if I find anyting on the net I'll report back here; comparing it to human narcolepsy symptoms it sounds plausible, but I know there are quite a few differences between humans and hamsters!
As long as Nigel is healthy and happy, that's the main thing