the migraine brain

The migraine brain or hypersensitive brain


< bron: C. BERNSTEIN, E. MCARDLE, The Migraine brain, 2008, New York. p. 40-44

1. Het brein is een overgevoelig orgaan

Like a thoroughbred racehorse, the migraine brain is hypersensitive, demanding and overly excitable. It insists that everything in its environment remain stable. A migraine brain is always on alert, ready to overreact to any stimulus it finds displeasing. That could be red whine or weather changes or stress. It could be dust, strong perfume or lack of sleep. The irritants that trigger a migraine vary from one person to the next and can almost be anything.

2. Migraine begrijpen 

For many years, migraine was believed to be a problem with the vascular system.  Many doctors thought that migraine were caused by 'vasodilation': blood vessels in the brain expanding and pressing on pain sensitive structures. But this theory wasn't perfect: it couldn't explain many of the characteristics of migraine attacks such as nausea and aura.

In recent years, our understanding of migraine has progressed a great deal. We know now that it is a complex neurological disease that involves much more than the vascular system.

The vasodilation theory probably works backwards: migraines aren't caused by blood vessels expanding; rather, blood vessels are thought to expand as a result of a migraine attack.


 3. Cortical Spreading Depression

The latest research points to 'cortical spreading depression' as the physical reaction that begins a migraine. It isn't a depression at all: it's a superexcitability of the brain!
Cortical Spreading Depression (CSD) is a dramatic wave of electrical excitation that spreads across the surface of the brain when something upsets it.
Researchers have found that CSD seems to explain many if not all aspects of migraine.


4. How migraine works

A migraineur's central nervous system is overly sensitive to certain stimuli.

a) When it encounters something it doesn't like (weather change for example), it sends a red alert to the overly excitable migraine brain.

b) The migraine brain reacts by setting off CSD.

c) In CSD, a wave of electrical excitement moves rapidly across the brain. During CSD, nerve cells in the brain become depolarized initially, then hyperpolarized, causing depression.In short, cell membranes, the outer protective layer of each cell, becomes unstable, allowing changes in the usual chemical balance. This instability spreads to other nearby cells in chain reaction.

d) This wave of excitement does a number of things, including igniting the trigeminal nerve, a sensory nerve on either side of the face and head that supplies sensation and pain to the face and the head.

e) The trigeminal nerve then releases neuropeptides, small proteins that cause inflammation and dilate blood vessels in your head and around your head.

For more than half of migraineurs, only one of the two trigeminal nerves responds in the migraine-change-reaction, so they feel the pain on one side of their face and head.
In fact, the word migraine is from a French word that's a derivation of the ancient Greek word 'hemicrania', meaning one side of the head.
Which side of the face will feel the pain? It may change with each new headache.