cant figure out why i get a pain in the back of my head every time i get a cold chill, from walking into a colder room. i just had a lower spine mri and was wondering if the pain was from the narrowing of spinal canal 1.0 cm .also disk bulging annular fissuring displacement of l5 nerve root and says alot more.i have had some pretty good head injuries .i fell on back of my head nov 2009 around then my left arm and hand was numb off and on each day for 4 or 5 weeks. just giving some history to see what you thik.thanks !