Hey Wendy that's one of the things I was going to suggest...
At least now with 2 people on the OBE thing it will seem like it's/we're less nuts

They could also be kundalini related symptoms.
Off the metaphysical side of things, it could very easily be a "simple " CRPS electric shock type of deal.
The way you describe it Geordie - specifically the fact that it is right before sleep - really resonates with Firedancers's pre-OBE "diagnosis."