Posted on 10/15/2015 3:35:58 PM PDT by moose07
It can start with flashing lights, a tingling sensation and a feeling of unease, followed by excruciating pain. Migraines can be triggered by lack of food or too much stress but their underlying cause has remained a mystery. Now researchers have found that a migraine may be triggered by a protein deep in the brain that stimulates the neurons controlling facial sensations.
The discovery creates a potential new target for safer migraine medicines and adds weight to the theory that neurons, not blood vessels, are responsible for migraine attacks.
“Where a migraine starts is a key question,” says Debbie Hay at the University of Auckland in New Zealand. “There has been a great deal of debate around the mechanisms of migraine. If we can pin this down, we may have better chances of preventing it.”
To investigate, Simon Akerman at New York University and Peter Goadsby at Kings College London, UK, studied two neuropeptides released by neurons thought to play a role in the pain associated with migraine.
These protein-like molecules, called VIP and PACAP, first raised suspicion after they were found to be elevated in blood drained from the brains of people having a migraine attack. When researchers administered these peptides to volunteers, they found that they could cause a headache or migraine about two hours later.
Both peptides widen blood vessels, which was thought to be significant in migraine. In fact, the only drugs specifically developed for migraine that are in use today – triptans – were designed to shrink blood vessels in the brain. As a result, they cannot be used by people with cardiovascular disorders.
The root of the problem
Akerman and Goadsby studied the effects of VIP and PACAP on a set of neurons that innervate the head and face, which are known to trigger a headache. The pair measured the electrical activity of these neurons in anaesthetised rats and studied blood vessels in the rodents’ brain to identify when they dilated or constricted.
Some rats were then given PACAP, while others were treated with VIP. Only PACAP caused the neurons to increase their activity – about an hour and a half after it was administered. This suggests that the peptide is responsible for kick-starting a migraine, says Akerman.
To block the effect, Akerman and Goadsby used molecules that block the receptors that PACAP binds to. The drugs made no difference when they were given to the rats intravenously, but when they were injected directly into the brain, the neurons responsible for a headache no longer surged with activity. “These receptors could genuinely represent a new therapeutic target for migraine,” says Akerman.
“It appears that these receptors are indeed important, and this is definitely vital to helping us understand migraine and for developing new treatments,” says Hay, who wasn’t involved with the work. “The receptors are a new and exciting target for migraine.”
In need of relief
New therapies are desperately needed. Triptans don’t work for half the people who try them, says Akerman. At any rate, their development was based on a misunderstanding of how migraine works.
In their study, Akermand and Goadsby found that both VIP and PACAP caused blood vessels to dilate, but that this effect only lasted for about 10 minutes. And in the case of PACAP, the widening of blood vessels did not happen at the same time as the overactivity of neurons. In other words, the dilation of blood vessels doesn’t seem to have anything to do with migraine.
Although triptans are prescribed as vasoconstrictors – drugs that shrink blood vessels – other research suggests that they also block the release of peptides like PACAP from neurons. Why this is only effective in half the people who take the drug is still a mystery.
What’s clear, is that vasoconstriction does not help migraine, says Akerman. “Triptans are effective, but for the wrong reasons.”
Mine peaked in my high school and early college years. I’d get about three a year, often with pseudo stroke symptoms including numbness on one side, partial blindness, and difficulty speaking and reading (which was a really wild...looking at a page and seeing groups of letters but not being able to see them as words). They’d start with the visual aura, then the other symptoms would kick in, then the pain. Thankfully they usually only lasted a few hours. As I got older they gradually became more and more rare and less and less intense. It’s been years now since I’ve had one.
Very interesting. I am most interested, as a serious migraine sufferer, in something that will stop them without having to take medication.
I’ve tried just about everything. My favorite triptan, Frova, works very well. However I have to take it so often and I don’t like having to, with any risks that might cause me. And it is extremely expensive.
I’d do anything if I could be migraine free with no horrible side effects.
Have you/anyone heard that triptans might cause/are a real risk of causing a cerebral stroke?
After getting the good CT scan news that I didn’t have a brain tumor—my helpmate was happy, having advised me to “have your head examined” for years, nyuk nyuk ) and then finally finding something that works—and I guess I’m lucky there, if they don’t work half the time—then I get the bad news:
“They could kill you.” ? Hey, whoa!
I get 8-12 a MONTH.
I am extremely careful with my diet. But it seems some can’t be prevented.
I do thank Gd for Frova.
Until they come out with something better, I wish doctors wouldn’t be so stingy with the triptans. There are actually studies where people have taken them daily. I wouldn’t want to live if I didn’t have something that both relieves / prevents the agony AND allows me to just keep living my busy life with no time off. I could do an ad for Frovatriptan because I depend on it so much.
Just found the local trade name.
Never tried them ,but looking at the data : https://en.m.wikipedia.org/wiki/Triptan. , it wouldn’t be advisable.
Thanks anyway. :)
At the worst time, I was taking the maximum 100 mg @ day for three-day bad stretches. Then I was fine for a few days, I went days without taking anything.
The docs would prescribe six (6) pills only a time, and two different doctors acted like I was main-lining heroin using them up too quickly.
If your drugs are expensive, search `Planet Drugs Direct’, a Canadian outfit I have used.
There are several but this one seems the best. If you pay $500 for, say, Zomig generic from an American pharmacy, you can knock one of the zeros off that price with PDD.
No kidding, it’s that much cheaper.
I get weekly newsletters from this website,if any further developments occur, and I spot it, I’ll post it.
(Three comas, yuk)
I don’t know what my Chiro does, but it works. After his massage therapist gets done with me I’m a new person.
Know all that very well.
Hey thanks! I don’t have any heart problems and my blood pressure is good.
I think Yaelle will corroborate that when you are in the middle of one of these severe attacks, you’ll take the risk of anything short of a 4 pound sledge to the head to alleviate the pain.
It doesn’t look too risky but I suppose if I suffer a debilitating stroke I can always go back to
practicing law.
One of the downsides to triptans is a kind of `hangover’, some slurring of speech and other minor things, but acceptable to avoid that RR spike through the head sensation.
Yaelle, before triptans my Dad tried everything and was eventually prescribed (I think) lithium carbonate with good results. It is also used for bipolar conditions so ... hmmm.
I’ll talk to my doctor next week.
Get in her face, shove stuff off her desk, etc. ;^)
Good luck to you.
Some people have healing hands.
This may be the case.
Or he relaxes the blood vessels in the neck and scalp.
You are certainly correct! Migraines are awful. I had them for years sometimes with the fuzzy aurora sometimes without. I had headaches triggered by allergies too. About 6 hours after eating certain things like corn and chocolate, I would be in severe pain sometimes with vomiting. All this was gone by the time I was 55 or 60 so maybe hormones played a role in it too.
I’m taking Imitrex (Sumatriptan) as well. They are my ‘ miracle pills ‘. My husband can’t relate to the pain and discomfort at all. He never had a headache in his life! The lucky guy.
I get both, the visual are painless but then I can’t read or drive. I have not had a lot of luck with Tiptans for the headache pain when I have those, every day but have had some real relief with botox, 32 shots every three months in the head. The shots are uncomfortable but not as bad as the headaches
The migraine hangover. I know it well.
“...looking at a page and seeing groups of letters but not being able to see them as words). They’d start with the visual aura, then the other symptoms would kick in, then the pain.”
Exactly, precisely what I experienced several times as an adolescent.
Yes your husband is a lucky man and it is a “miracle pill”!
I’ve had a lot of luck with a combo of Advil and Excedrin at the same time. Usually two pills of each with milk or light food. Works great.
My daughter suffered with migraines for decades. Cured with beta-blockers.
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