Migraine Award funded by Australian Equity Trustees
Finding the key to the migraine riddle.
Dr Geoffrey Lambert
Prince of Wales Clinical School, University of New South Wales
Co-Investigator: Professor Alessandro Zagami
One-third of women will suffer from migraine at some stage of their life and, across the population about 1 in 6 people are migraineurs. But migraine is mysterious in a special way- differs from cancer and heart disease in a very baffling way- there is no pathology. You can’t perform a brain scan or a blood test to determine if someone is suffering from a migraine. The only way you can be sure is to ask them.
Migraine is definitely an organic disease. But, if we can’t find anything wrong inside the head of a migraine patient, what could be causing such an excruciating pain? We know that many trigger factors- bright light, wine, stress can precipitate a migraine headache, but we don’t know why or how. The pain of migraine APPEARS to arise from the dura mater which covers and protects the brain from injury. We all probably know that pain is a “warning signal” or alarm that tells us all is not well. Pain tells us to withdraw our hand from the hotplate or to visit the dentist. So… what is migraine pain warning us of?
After many years of research, we have concluded that the pain warning which we receive during a migraine headache is a false alarm caused by an overly sensitive warning system.
We believe- that the circuitry which controls the sensitivity of the migraine pain alarm system is buried deep in the brain, but the controls for that circuitry are higher up- in the cerebral cortex, the conscious part of the brain. When a migraineur encounters one of her trigger factors, some neurons in the cortex become over-activated. These over-active neurons affect the controls of the alarm circuitry, which then causes normal sensations from the head to be perceived as painful sensations- that is to say, as a headache.
So far, we have been able to show that the brain contains just such an alarm system and that migraine triggers can indeed activate it by cranking up its sensitivity. We are now moving ahead to investigate the precise mechanisms by which this tweaking of the alarm system occurs. If we can discover this mechanism, we may be able to prevent migraine by preventing excitation in the cerebral cortex or by stopping the excitation from reaching down into the brainstem to generate a false alarm. This would be the “magic bullet” that migraine researchers and migraineurs have been seeking for 150 years.