Head in a vice

Scientific American has an article on migraines that takes a comprehensive look at the science of this painful and hallucinatory disorder.

The piece updates the science on migraines from the traditional but oversimplified ‘constricted blood vessels’ explanation to explore the interplay between nerves, neurotransmitters and lifestyle.

A crucial process seems to be cortical spreading depression that may be responsible, at least in part, for both the intense pain and the aura:

Aura appears to stem from cortical spreading depression—a kind of “brainstorm” anticipated as the cause of migraine in the writings of 19th-century physician Edward Lieving. Although biologist Aristides Leão first reported the phenomenon in animals in 1944, it was experimentally linked to migraine only recently. In more technical terms, cortical spreading depression is a wave of intense nerve cell activity that spreads through an unusually large swath of the cortex (the furrowed, outer layer of the brain), especially the areas that control vision. This hyperexcitable phase is followed by a wave of widespread, and relatively prolonged, neuronal inhibition. During this inhibitory phase, the neurons are in a state of “suspended animation,” during which they cannot be excited.

Neuronal activity is controlled by a carefully synchronized flow of sodium, potassium and calcium ions across the nerve cell membrane through channels and pumps. The pumps keep resting cells high in potassium and low in sodium and calcium. A neuron “fires,” releasing neurotransmitters, when the inward flow of sodium and calcium through opened channels depolarizes the membrane—that is, when the inside of the cell becomes positively charged relative to the outside. Normally, cells then briefly hyperpolarize: they become strongly negative on the inside relative to the outside by allowing potassium ions to rush out. Hyperpolarization closes the sodium and calcium channels and returns the neurons to their resting state soon after firing. But neurons can remain excessively hyperpolarized, or inhibited, for a long time following intense stimulations.

The article is remarkably comprehensive, probably as it’s written by neurologists David Dodick and John Gargus.

Link to SciAm article ‘Why Migraines Strike’ (via 3Q).

3 Comments

  1. Posted July 23, 2008 at 7:38 pm | Permalink

    It’s great to see some information about migraines, as they seem to be so poorly understood. Thanks for posting this!

  2. Tonon
    Posted August 13, 2008 at 4:02 pm | Permalink

    Many years ago my son had nocturnal Epilepsy and the doctors placed him on Tegretol.
    I did not like the idea but in fear went along with it. My boy suffered migraines also but did not complain.
    I found a maxomillian surgeon dentist who claimed he could heal people of their Migraines by placing an expanding palate plate in their mouths .
    We took our boy to the dentist and followed his procedure and slowly the headaches disappeared, and after that we got the courage to wean him of the Tegretol and my son has never had a fit since then. he is now 26.
    Unfortunately the good Dentist was de-registered as someone complained about his unique approach and was thrown out of the profession by the decision of one Judge who claimed he was nuisance to society.
    I met a few people from all over Australia who would visit the dentist for their check ups who all had migraines.They were all extremely pleased with the results.
    I also had a student at College which I referred to him as he had Chronic Fatique syndrome, for he would fall asleep in my class. ( Gosh I thought I must really be boring him)
    Anyhow he slowly got better after treatment and became a Librarian. His prior occupation had been a truck driver.
    I know this approach is more mechanical than drug related but I thought I would add it as I am eternally grateful to this ex Dentist called Dr. Newberry for helping my son and also operating on my wife for a different gum problem.
    cheers bruno

  3. Posted August 9, 2010 at 5:44 am | Permalink

    Migraines are very painful. I am a Dentist, and I have many patients that go through this.


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