The word ‘migraine’ derives from the Greek ἡμικρανία (hemikrania), ‘pain on one side of the head’, from ἡμι- (hemi-), ‘half’, and κρανίον (kranion), ‘skull’.
Infrasound, sometimes referred to as low-frequency sound, is sound that is lower in frequency than 20 Hz (hertz) or cycles per second, the “normal” limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high.
I would like to draw your attention to a recently published article about migraine and infrasound in the Swedish Medical Journal “Läkartidningen”
As you well know, migraine is a polygenic inherited disease with occasional episodes of headache. It is also well known that people with migraine are more sensitive to sound and light than the normal population, especially during an attack of migraine headache. Furthermore it is a well known fact that pulsating sound and flickering light are strong triggers to elicit an attack of migraine.
Migraine is a very common condition in the population with a 15% prevalence for migraine headache. It is quite obvious that the genetic predisposition is much higher – everyone with a genetic disposition will not suffer from migraine headaches. You may well live with the genetic predisposition and never suffer from migraine headache in all your life.
Recent studies have found that these genetic changes affect among others the Ca-channels. This channelopathy increases the cellular depolarization and as a result the nerve cells are more sensitive to stimulation – less stimulus is needed to trigger a nerve-potential.
The main triggers for migraine are – as we all know – all kinds of sensory stimulation, food containing biogenic amines such as tyramine, glutamine, histamine etc., and increased levels or fluctuating levels of estrogen.
Thus sound is a trigger. Loud noise of varying amplitude is a strong trigger that will increase the neural sensitivity in persons with migraine. For example a teacher with a genetic tendency to migraine in a noisy classroom. After a while all senses will become more sensitive (more sensitive to sound, more sensitive to light, more sensitive to vestibular stimuli for example). Hyperacusis makes the situation in the classroom worse and eventually an attack of migraine headache will appear.
Low frequency noise or infrasound noise is no exception. Even if the sound is not heard the sound pressure will exert the same force on the eardrum as audible sound. The sound waves will be transmitted to the inner ear and hair cells are then stimulated. Even if the stimulation is not recognized as sound it will affect brainstem centers and elicit other sensations.
Infrasound is normally not possible to hear, you more likely will feel it as a vibration. Low frequency sound is possible to hear if the volume (sound pressure in dB) is strong enough. But it is a known fact that there are persons who can hear low frequency sound and infrasound at sound pressure levels of 40 db or less. If you have migraine and have developed hyperacusis it is most likely that you are as sensitive to low frequency sound as to normal sound.
Infrasound from wind turbines has properties that differ from other types of infrasound such as infrasound emanating from natural sources (eg wind, rivers) and from artificial sources including road traffic. Infrasound from road traffic (as well as the other examples) has a continuous, constant character – a kind of constant background noise. Infrasound from wind turbines has a fluctuating character with varying amplitude. Infrasound from wind turbines also has three distinct frequencies with higher amplitude than the average infrasound pressure (blade pass frequencies).
A third issue is that the sound pressure for infrasound and low frequency sound is much stronger than the sound pressure for the sound you can hear (for audible sound). If the measured sound pressure at a given distance is 40 dB for audible sound, then the sound pressure for infrasound is 60–80 dB at the same measuring point. Additionally infrasound is amplified inside buildings by resonance effects.
Thus the conclusion is that low frequency sound and infrasound from wind power has the qualities to trigger increased sensitivity and eventually migraine headache or other migraine-symptoms – such as vertigo or tinnitus (without headache).
As migraine is so common in the population, this is a relationship that you cannot avoid considering.
Furthermore there is increasing knowledge that continuous stimulation of triggers eventually will create a central sensitisation in the brain with a chronic extremely increased sensitivity to sensory stimulation.
I hope that you will take these facts in consideration and advocate for further studies and work for a safe distance for wind power from homes and workplaces that will protect the public health. So If you are home and you get the attack Shut down your TV, turn of your washer and dryer, dishwasher and close the windows and limit the infrasound possibilities.
Second research ; Danish researchers have taken a crucial step toward a new explanation of where and why it hurts when we have a migraine.This throbbing pain in the head, which is usually accompanied by other symptoms such as nausea and sensitivity to light and sound, has been puzzling scientists for centuries.
The new discovery represents a break with the prevailing theory in recent decades:
“This turns on the head our existing ideas of the mechanisms behinds migraines. For many years it was thought that the pain was caused by expanded blood vessels outside the skull,” says Professor Jes Olesen, of The Danish Headache Center (DHC), Glostrup Hospital, Denmark, who co-authored the new study, published in The lancet Neurology journal.
“When MRI scans show that the blood vessels do not expand, there must be another reason why the patients get headaches.” Less arterial expansion than expected.
- Contrary to what has previously been believed, they found that the arteries on the outside of the skull did not expand during migraine attacks,
Arteries inside the skull were only slightly expanded on the side where the headache was felt, compared to the other side where no pain was felt.
They treated the attacks with sumatriptan, which is the most popular migraine drug on the market. And then they made another MRI scan of the brain.They observed that the arteries inside the brain remained expanded even after the migraine headache had passed.
Migraine sufferers usually experience a severe headache, which feels like a throbbing pain at the front or on one side of the head. This pain is usually accompanied by several autonomic nervous system symptoms.Migraine pain is further aggravated by movement, for instance if you bend your head forward or climb stairs.It is therefore not uncommon to hear complaints from migraine patients who worry that their head is about to explode. The new study shows that such worries are unfounded.
This suggests that the old theory that sumatriptan works by narrowing the arteries may not be right after all. The new findings prepare the ground for studies into why sumatriptan still works even though the beneficial effect does not appear to be linked to the narrowing of arteries.
The new discovery has paved the way for a new theory: migraine pain occurs because the nerve fibers around the blood vessels become extra sensitive.
This means that the blood’s normal pulsation in an artery feels like an intense, throbbing pain. If this is the case, it is as yet uncertain why it is so.
At the same time, the findings can also be used to reassure migraine sufferers who worry that their arteries are about to explode during an attack. They’re not.
The findings indicate that a change occurs in the nervous control of the blood vessels locally in the brain, and at the same time there is a change in the pain regulation . Future medical treatment should also seek to ensure that the drug will function inside the central nervous system/the brain and must be able to pass the blood-brain barrier.“Non-medical treatments may eventually manage to modulate these systems from other angles.
Believe it or not, soaking your feet in hot water will help your head feel better. By drawing blood to your feet, the hot-water foot bath will ease pressure on the blood vessels in your head. For a really bad headache, add a bit of hot mustard powder to the water.• For a tension headache, place a hot compress on your forehead or the back on your neck. The heat will help relax knotted-up muscles in this area.
Thank you for reading.
Steve Ramsey, PhD- Public Health.
Calgary, Alberta- Canada.