Thread: Electricity in my head...?

I was wondering if anyone knows what this is...
It only happened to me once, about a year ago, but a friend of mine used to get the same thing all the time.
I've had a bit of a look around and it sounds a little bit like some people's description of sleep paralysis, but I've always been curious about its cause:

I had woken from a dream and could feel myself in my bed, but I felt this electricity building in my head. The sound and feeling grew stronger and more unbearable but I couldn't move my body or open my eyes to make it stop. It lasted for at least a minute, and the pressure inside my head seemed to build and make it more difficult for me to move. It was excruciatingly uncomfortable and I was relieved when it finally stopped.

1. What may have caused this?

2. Does it have any use, if it happens again?