hi. A month ago, while at work I suddenly got an extremely sharp, shooting pain from the back (left side) of head , which shot straight to the front. the pain was so fast that before i had time to proerly react it was over. the best way to describe it, is like a knife, shooting like a lightning bolt. over the next couple of weeks, i kept getting these same pains, in differant locations on the head, ad different itesnsity, but usually so sharp they stop me in my track. They stopped for a couple of days recently, but again last night, i had a huge one which was quite scary, this continued with further pains, and a slight headache . i have no idea what could cause this.