Did you ever find out what this was? I have been experiencing this for a month now. Exactly that feeling like when you take your hair down from a pony tail. On top left side of my scalp. Please respond.
The pain is what can be described as an electric shock that only lasts seconds. And feels like my hair has been pulled back in elastic for far to long and far to tight.
I don't know if you laid in bed too long, or if you have build up on your scalp or what, but to get your scalp really clean, try shampoo with Neem oil in it. It is great.