|Image by Guy Denning|
There is evidence that, between attacks, migraine-disordered brains function differently from normal ones. Studies show that migraine-affected brains have a decreased ability to habituate, or get used to a stimulus. If you expose a normal person to a constantly flashing light, then measure the signals evoked in the visual part of his or her brain, the signals will get smaller with time as the brain gets used to the light. But if you expose a person with migraine to a flashing light, the signal will grow larger with time.
"That's why migraineurs will notice small things that will irritate them, like a clock ticking in the background," says Goadsby. "A migraineur gets irritated by things because [he or she] can't get rid of them easily. A person that's not migrainous will just ignore things. The difference is quite stunning."
What does trigger migraine attacks in susceptible people is change. It seems that the migraine brain exists in a delicate physiological balance, with any fluctuation in sleep pattern, dietary pattern, stress level, hormone level, caffeine intake or even weather disrupting that balance and inciting an attack. Women are often plagued by migraine attacks just before their menstrual period, when their levels of estrogen and progesterone decrease. (And they frequently experience a worsening of symptoms with the onset of menopause.) Like a dropped pebble causes disturbance in a pond, a missed meal, late night or extra hour of sleep can trigger a migraine attack that reverberates hours later.
Because stress is often attributable to headaches, many migraineurs are surprised when they suffer attacks over the weekend or at the beginning of a vacation. But it's this "letdown" from normal stress levels that often initiates an attack, explains Charles. It's not recommended that migraine sufferers avoid vacations, of course, but rather that they try to manage stress during normal life.
Pattern disruption can set off a migraine. That makes a lot of sense. A massive trigger for me is lack of sleep which is a pretty big pattern disruption. Life is also full of stresses. Stress happens... apparently we can get hit with a migraine from the stress or from the stress let-down, so coming or going.
I find the research looking at our brains between attacks to find that they are not quite normal in functioning there to be quite fascinating... because that can explain the foundation we have to start with that leads to migraines being triggered.