Primary headache disorders are now accepted as physiological diseases, and advanced imaging-techniques have demonstrated a migraine generator in the brain stem and increased stimulus sensitivity in these patients. The underlying neuronal dysfunctions remain to to clarified and the existing neurophysiological methods have not yet been useful. More sensitive and reliable methods are therefore highly needed. The aims of the study are therefore to develop a sensitive and reliable method to demonstrate a cortical reorganisation and expansion of pain sensitive cortical areas in patients with migraine or tension-type headache.