I have some similar feelings, but not limited to head. Sometimes I meditate and go through the chakras and I feel the tingling each time I move to the next chakra. It spreads from the chakra to connected areas, like any larger muscles around it. Haven't bothered to find out about it since I don't take this meditation thing seriously. It's just a nice way to relax. Other times, like in the examples above, they don't give me the same sensation, but I feel more like my mind is loosing up the connection with my head , or I get goosebumps. But it's not the same. Sometimes when I am stressed and in the state that should give me the tingling sensation, instead I hear (and feel too) this kinda piercing buzz that goes through one ear to the other in a split second and then back and forth. Very unpleasant feeling.