Pain therapy in practice. What can PET tell us about idiopathic headache?

The concept of vascular headache as a pathophysiological unity implies that the source of pain is a vascular lesion. However, diagnostic PET scanning of patients suffering from primary headache has brought revolutionary new insights in this field, shedding light on the mechanisms inducing this pain. The new knowledge in general confirms the key aspects of the concept, namely that the pathogenesis of migranous headache can be attributed to an imbalance of the brain stem neurons which control the antinozizeption and the extra- and intracranial blood flow. The pathogenesis of cluster-type headache is assumed to be induced by a disorder of the central nervous system in the pace-maker cells or circadian regions of the hypothalamic grey matter. A possible dilatation of the large vessels near the base is not due to a specific type of headache but rather is an unspecific reaction to trigeminal activation. (orig./CB)