I had a touch of that last week. Lasted for four days.

Discovered it was sinus-flu related. My jaw hurt, neck muscles were stiff, my nasal passages were swollen at night, the migraine would pull me up short and double me over. Thought my brain was exploding... felt like someone was squeezing it like a balloon and it was stretching...stretching...about to burst...aggghh!... stretching...

Crap, what an awful time sleeping, too. A couple (and only a couple over 2 days) sinus tablets really helped the worst of it.