The Back of the Head: Another Source of Migraine?
Is it possible for a pinched nerve under the scalp in the back of the head to cause pain in the forehead, or throughout the entire head? The simple answer is, Yes, probably so. The nerve in question in the back of the head (the greater occipital nerve ) isn’t a cranial nerve like the Trigeminal nerve, and it arises from the spinal cord. The Trigeminal nerve arises in the brain stem, which is closer to the brain, itself, and the two don’t meet through most of their individual courses. This is like the brakes/engine trouble analogy discussed previously. However, there has been recent appreciation of a long-known detail of the neuroanatomy of the brain stem and upper spinal cord: the Trigeminal nerve starts in the brainstem, but then sweeps down inside the spinal cord, does a u-turn and goes back up the cord and into the brainstem once again before exiting to give off its many branches. This loop of the Trigeminal, called (going down) the descending tract and the secondary ascending tract
