Why does scalp crawl at night ?

Question

I feel it's related to muscles because it's only when I sleep in one position, I can feel it one side scalp, down to neck and sometimes between shoulder. This is when I sleep with arm over pillow.

Logic side says muscles, anxiety worries it's brain tumor/aneurysm 

Answer 1

I would say possibly you're cutting off some of your circulation, by placing your arm over your pillow.

Answer 2

maybe you got Morgellons ?......