I have had a similar feeling, but it goes on in the back of my skull. It may be related to L'hirmettes (sp) for me ... although it does not travel down my body, but seems to occur within my brain. It only happens when I am sleeping too, and I have wondered if it is some kind of seizure.

It only happens once in a blue moon, maybe 2 - 3 times over a week, then I don't get it for months or years. I have never been tested because I figure if it was a seizure, it would keep happening.

I would mention this to the doc if I was you.

Cherie