I'll second bob-o. If you have pain originating in the back of your head, it's possible that it is from the occipital nerve. If so, you might find relief in occipital nerve blocks or occipital nerve stimulation.
DX: NDPH, Recovered CRPS
RX: Lamictal, Abilify, Verapamil, Provigil, Clonazepam, Rozerem, Emsam
PRN: DHE IM, Droperidol IM, Toradol IM, Haloperidol, Zyprexa, Lodine, Thorazine, Zofran