Menu

trigeminal nerve

TRPV4 and “Switching Off” Headache Pain

, 0

Imagine an old-fashioned but complex machine, based on switches.  When you turn on switch A, for example, it supplies power to switches AA, AB, and AC.  If you want power to go through these switches, you must turn them on.  And so there is a complicated interaction of hundreds of switches.

Don’t worry, that’s about as complicated as this article is going to get.  If you grasp the idea of the interaction of switches, that’s enough to understand the analogy.

Switch off MIGRAINE!

So what would happen if a switch got stuck?  Well, if it were stuck in the “on” position, you wouldn’t be able to stop the power flow through that switch.  If it were stuck in the “off” position, neither that switch nor any down the line would ever get power.

This is an over-simplified way to understand the way that some messages are sent through the body.  Each cell, for example, relies on something called “ion channels”, proteins which allow a flow of information through the wall of the cell.  Imagine it as a switch.

But what would happen if the protein wasn’t properly “programmed”?  It might let too much information through, or not enough.  It could get “stuck”.

Migraine research is focusing more and more on specific types of ion channels.  Consider this statement from a 2011 article in BMC Medicine:

We could now be at a watershed moment in this respect, as the genetic loci associated with typical forms of migraine are being revealed.  The genetic discoveries are the latest step in the evolution of our understanding of migraine, which was initially considered a cerebrovascular condition, then a neuroinflammatory process and now primarily a neurogenic disorder.  Indeed, the genetic findings, which have revealed ion channels and transporter mutations as causative of migraine, are a powerful argument for the neurogenic basis of migraine.

Many common migraine medications affect ion channels, such as verapamil and topiramate (Topamax).

But researchers are continually looking to new frontiers.  And one of these is the investigation into TRPV4, (a nice name for Transient receptor potential cation channel subfamily V member 4).  We know that TRPV4 is related to the sending of pain messages in the body.  Might it be involved in headache pain?

One of the interesting discoveries that researchers made was the link between TRPV4 and sunburn.  When TRPV4 is blocked, so is the sunburn pain (see Could discovery lead to end of sunburn pain?).

Trigeminal pain, often manifesting in face pain or headache, also seems to be closely related to TRPV4 (see TRPV4 is necessary for trigeminal irritant pain and functions as a cellular formalin receptor.).

A study published last year in Cephalalgia specifically looked at headache, and found that TRPV4 working in the tissue around the central nervous system (meninges) could actually contribute to migraine pain.

Is it possible that the hot pain of many headache conditions could be stopped with the flick of the TRPV4 switch?

Of course, it’s not that easy in real life to find the right switch and turn off pain without causing other problems.  And TRPV4 is one of only 30 channels in only on category.

We do know that various factors, such as environment (for example being exposed to chemicals in the air) can turn switches like TRPV4 on and off.  In other words, we’re not talking about flipping a switch that was never meant to be switched.  It could, for example, be that certain factors, in people with migraine, are flipping switches too often.  Perhaps a certain medication could put it back to normal.

This is a huge area of research, but we’re already using medications that involve ion channel “switching”.  Better understanding the switches helps us better understand headache and pain disorders, and directs us to the most likely methods of treatment.

If you want to dive even deeper into this topic, check out:

What is behind the dreaded Cluster Headache?

7

Just what causes one person to be a cluster headache sufferer?  As with many headache disorders, the cause of cluster headache is not completely understood.  But we are getting closer.

So here’s the question – what parts of the body are involved in the cluster attack?  And how are they involved?

The hypothalamus in Cluster Headache

1. The hypothalamus:  The hypothalamus is now thought to be the launching pad of the cluster attack.  It first becomes a suspect because it controls your 24 hour clock.  Cluster is a very regular disorder, in that it comes in cycles (hence the name – cluster).

About the size of a almond, the hypothalamus is found right above the brain stem.  Thanks to modern imaging techniques, we can see differences in the brain of a cluster headache sufferer.

2. The trigeminal nerve:  Parts of the trigeminal nerve are activated during a cluster attack.  This is a very important nerve in your face and jaw.  It’s involved in the eye pain, tearing and redness of cluster.  It can also help bring on the congestion.

3. The sphenopalatine ganglion:  A “ganglion” is a group of nerve cells.  This particular ganglion is located behind the nose.  Some cluster patients have found relief after surgery on the sphenopalatine ganglion.

4. Blood vessels:  Changes in blood flow may be involved in cluster, but we know now it’s not as central as we once thought.  There can be changes in blood flow, but the question is whether or not this is a result of an attack or a part of the cause.

5. Histamine:  Histamine has been a suspect because you can sometimes trigger an attack with histamine.  However, so far research has not been convincing.

We’re learning more and more about just how the hypothalamus is activating during a cluster attack.  Thanks to modern imaging and analyzing techniques (such as voxel based morphometry), we can see more of what goes on during an attack.  This has led to better treatments, but we still have a long way to go.

Just what is the “Common Headache”?

, 0

We’ve known for centuries that headaches come from different sources, and they come with different symptoms.  A hundred years ago we were calling some forms of migraine "sick headache".  Somewhere along the line we started talking about"tension headache" – just a little pain from muscle tension and stress.

Or so we thought.

Which 'Common Headache'?

We started to associate the so-called common headache with tension headache.  As we learned more about the anatomy of the head, we theorized that the muscle around your skull was getting tense and causing changed in blood flow.

But as we started to study migraine and other types of headache more closely, the mystery deepened.

Studies of tension headache weren’t always turning out the way we thought.  Why were people getting tension headaches when they weren’t even under stress?  And – wait – why do so many people with tension headache not have any more muscle tension than anyone else?

So we changed the name from tension headache to tension-type headache (meaning that we had no idea what caused it, but it certainly doesn’t seem to be muscle tension!).

Now comes another debate – how can we diagnose tension headache or migraine headache?  If we go by the symptoms, it would seem that tension-type headache is the most common headache.  What if we go by how many people actually go to the doctor?  Well, migraine is starting to gain on other types of headache.

But research is pointing in a new direction.  We now think that the mechanism of tension-type headache and the mechanism of migraine may not be so different.  In fact, many of the treatments for migraine seem to work well for those diagnosed with tension headache!

In his book The Keeler Migraine Method, Dr. Robert Cowan suggests that migraine is in fact the most common cause of headache.  In fact, he writes:

Studies suggest that 40 percent of migraineurs may be misdiagnosed as suffering from tension-type headaches because, unfortunately, both headache types may include features that we commonly associate with the other.  This happens because both headache types involve the trigeminal nerve system.  The trigeminal nerve system dips down well into the cervical spinal cord, and in tension-type headaches it can irritate the nerves that travel to the neck muscles and the muscles that tense the forehead and temples.  Almost anyone with a headache of any type is likely to tense the shoulder and neck muscles, so muscle tension is not a reliable indicator for headache type.

So if the common headache is actually a result of migraine, how can you be sure to get the right treatment?

Because primary headache is generally diagnosed by symptom, pay close attention to your symptoms.  Tell your doctor about anything you notice, such as sensitivity to light, the location of the pain, nausea, and what the pain feels like.  That will give you a better chance of getting the right treatment, whether for the tension-type headache, or the headache from migraine – which is probably a lot more common than we used to think.

Migraine and REM Sleep

0

It’s no secret that sleep issues are connected to migraine.  For example, check out Sleep apnea and migraine? and Solve child’s sleep problems = solve migraine?.

Building on previous studies, researchers from Missouri State University recently reported on a study that connected a lack of REM sleep with chronic pain.  The research was done on rats, which were deprived of REM sleep for three nights.

What happened?  There was an increase of expression in certain proteins which help regulate sensory response in facial nerves.  The same thing happened with another protein linked to starting chronic pain.

This type of response could cause problems with the trigeminal nerve, which is key in the migraine chain reaction.

Lead researcher Dr. Paul L. Durham says,"People with headaches often have a hard time sleeping.  It is easy to see how several nights of interrupted sleep can make people more susceptible to developing a chronic pain state."

Yet more information showing us how migraine and various types of chronic pain may be links to interruptions in sleep.

For tips from our visitors on getting to sleep with migraine, check here.

Chocolate for Migraine?

2

Chocolate has a notoriously bad reputation when it comes to migraine.  But much of that reputation isn’t deserved.  Although chocolate may trigger migraine in some, it may actually be ingredients accompanying the chocolate that cause the problem.

Chocolate for Migraine??

As a matter of fact, as you’ve probably heard before, cocoa has some health benefits.  And a recent study from Missouri State University, USA, shows it may have some benefits for headache sufferers in particular.

Now before you get too excited, this was an animal study – on mice.  The mice were fed a cocoa enriched diet for two weeks.  The mice were shown to have less inflammation than those who were deprived of cocoa (poor things!).

The authors of the study felt that a cocoa supplement may help with diseases of the head and face that involved the trigeminal ganglion (part of the trigeminal nerve), not just migraine.

The researchers feel cocoa could be an important part of an anti-inflammatory diet:  Cocoa enriched diets are able to repress the stimulated expression of proteins associated with the promotion and maintenance of inflammatory … responses said the researchers.

This is a very preliminary study, but it may lead to some helpful research in the future – possibly some new supplements that may be very effective.  Of course we shouldn’t all go out and start eating chocolate bars.  However, if chocolate isn’t a trigger for you, adding dark chocolate, low in sugar, and cocoa to your diet may decrease inflammation, as well as being an antioxidant, and a source of magnesium and folic acid.

More ideas and tips regarding chocolate and headache here.  And this video shows a healthy way to add cocoa to your diet, and why.

More on the study here:  Chocolate may ease migraines: Study

Back To Top
The articles on Headache and Migraine News are © 2004-2024 J. Cottrill.
Every effort is made to ensure the accuracy of each article, and to point you to further sources of information. However, this site is for informational purposes only and should never replace a visit to your doctor.