"electrical" shock

I’m asking this question to cecil, too, however, i’d like to see what i could be dealing with here. here’s the question:

Here’s something that’s been bothering me for a little while now. Sometimes, when I’m trying to sleep (or just laying down in general), I’ll get a sensation similar to a powerful electrical shock. I also get hypnagogic myoclonus, however this “shock” feeling is much different. Rather than my limbs jerking, it’s usually my back and neck; when it happens, my vision goes white and I hear a warble or tinitis-like tone. I’ve been told everything from “oh, it’s nothing” to “that’s a precursor to spontanious human combustion!” Any clue?

Well I think we can rule out spontaneous human combustion but, uh, that really sounds like you should go see a doctor. Nothing that interferes with your vision can possibly be good.