Brain Imaging Exposes New Information on Cluster Headaches

Using positron emission tomography (PET) to examine the cause of cluster headaches, researchers found that the hypothalamic region in affected people consistently lit up, indicating activity in that part of the brain.

The investigators, who presented their findings at the 40th annual scientific meeting of the American Association for the Study of Headache in June, studied cluster headache attacks in 17 patients after administering nitroglycerin to trigger the pain.

By injecting the patients with water labeled with a radioactive tracer, the research team was able to monitor cells undergoing more activity. That activity was recorded by a PET camera, then processed and reconstructed by computer so that the areas of greatest activity "lit up" on a computer-generated image.

The scientists discovered that the hypothalamic region of the brain, the part of the central nervous system that contains the brain's biological clock, lit up more than other regions during an attack.

"This suggests we need to consider a radical reappraisal of the pathophysiology of cluster headache," said lead researcher, Peter J. Goadsby, M.D., Ph.D., professor of clinical neurology at the Institute of Neurology, Queen Square, London-CLG