I can feel it in my magpie eye, people used to say when frost was on the way – the corn on the sole of their feet played up. And people with migraines or rheumatism also experience this: their pain symptoms sometimes increase with an approaching storm, heat, rain or cold. Can our bodies really feel weather changes coming?
“It seems like that,” says Sabine Parent from Middelburg. “Last March I suddenly had a gigantic migraine attack. I’ve had migraines since puberty and always related my attacks to my hormones, but this one had nothing to do with it. I was in bed for two days with a terrible headache, I was nauseous, couldn’t tolerate light, and nothing helped.” The 47-year-old yoga teacher was puzzled until an acquaintance told her that migraine attacks can also be triggered by weather changes. “It had become ten degrees colder within a day, one day you could go outside without a coat, the next you couldn’t go outside.”
Like Sabine, there are many people with migraines. Approaching thunderstorms, bright sunlight, heat, cold, strong winds – all kinds of weather conditions can trigger painful attacks, or so they experience. And also people with rheumatic diseases often report that some weather conditions make their pain worse.
Neurologists and rheumatologists hear it a lot in their consulting rooms. But science is having a hard time getting it right. Is the body indeed affected by the weather or is it a coincidence? What weather element does it provoke? And how could that work, biologically?
Migraine attacks can be triggered by various factors
Michel Ferrari migraine-expert
The answers are hard to come by: the weather is fickle, and the conditions are equally fickle and multifaceted.
Take migraine, the brain disorder in which patients have frequent bouts of severe headaches, often accompanied by nausea, and sometimes preceded by spots or glare in the field of view or tingling in a hand or lip – so-called aura symptoms. The attacks can last for hours to days. In the Netherlands, 1 in 10 people suffer from migraine. Migraine attacks can be triggered by various factors. For example, drinking wine. But only in people who are genetically sensitive to it. And with them only in a certain combination of circumstances. Not every glass of wine leads to an attack. Fatigue and hormonal fluctuations can influence this sensitivity, among other things,” says migraine expert Michel Ferrari, emeritus professor of neurology at the Leiden University Medical Center.
“Looks like it’s the same with the weather. But little good scientific research has been done on it. Because not all migraine patients are sensitive to it, and they are not always triggered by weather changes, the findings vary quite a bit.”
Acute drop in air pressure
A big question is which weather element can trigger a pain attack. Is that the temperature, the air pressure, the humidity, the wind speed? “It varies from patient to patient, but it probably has to do with a rapid change in air pressure,” Ferrari says. “People who are sensitive to it sometimes have an attack with an acute drop in air pressure, such as that often occurs before a storm like the Chinook in Canada, or the Mistral in France.”
Just before Parent’s attack at the end of March, the KNMI in De Bilt indeed registered a rare high air pressure of 1,045 hectoPascal (hPa) around March 19, a record for the month of March. In the following days, the temperature in Zeeland swung from 20 degrees Celsius to less than 7 degrees Celsius. The air pressure dropped from 1,030 to 1,001 hPa during the last days of March, a difference of almost 30 hPa.
It could very well be that that huge drop in Parent has provoked an attack. That can already happen at much smaller differences, according to a study of 34 migraineurs in Japan, which is often affected by typhoons. Three quarters of the patients experienced a migraine attack when air pressure drops between 6 and 10 hPa, often just before such a tropical storm erupted. Another Japanese study saw more attacks in weather-sensitive migraineurs with such pressure reductions, and not in non-weather-sensitive patients.
The body of some migraine patients could therefore be regarded as a thunderstorm forecaster. But how can a rapid drop in air pressure trigger a migraine attack? “We can only speculate about that,” Ferrari said. Even the biological mechanisms underlying a migraine attack are still largely unknown.
Small channels
A simple explanation that is often mentioned: When the air pressure drops rapidly, the tissues around the sinuses and sinuses expand, as does the brain. This puts pressure on the blood vessels and narrows them. But that is too easy to think, says Ferrari. “It’s a common misconception that the migraine aura is caused by vasoconstriction and the headache by vasodilation,” he says. “We have known since the 1980s that this is absolutely not the case. There’s vasodilation, but that’s it consequence of all kinds of migraine processes, not the cause. That has been seen in several studies where people have been studied while having a migraine attack in a brain scanner.”
Ferrari suspects that pressure-sensitive ion channels in nerve cells could play a role. These tiny channels in the walls of nerve cells open with a change in air pressure, allowing particles with an electrical charge, such as sodium, potassium or calcium ions, to pass through. The particles flowing in or out regulate the electrical activity of nerve cells. There are many different types of ion channels, each responding to different stimuli: to certain molecules, to calcium, to heat or cold, but also to pressure.
I can imagine that these drugs work for people who have seizures with an approaching thunderstorm
Michel Ferrari migraine-expert
A number of genes linked to migraine in recent decades have been implicated in such transport of calcium and potassium ions. For example, Ferrari discovered a genetic abnormality in a calcium channel in a rare hereditary form of migraine. “One of the consequences of this is that very quickly” spreading depolarisation occurs in the brain. That is a phenomenon that plays a very early role in migraine.” It’s an electrical discharge of nerve cells that slowly spreads across the cerebral cortex, like the ripples in water when you throw a pebble into it. One cell discharges the cell next to it. “In migraine, it spreads over a part of the brain, and then it slowly extinguishes again. This creates an increased blood flow first and then a decreased one.”
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Also read: 2021 Nobel Prize in Medicine for the discoverers of receptors for pressure, heat and pain
Ferrari speculates: “We know that there are also certain ion channels that open acutely due to pressure reduction. Then there can be swelling of the brain tissues, edema, and perhaps also spreading depolarisation.” The expanding electrical discharge activates the so-called trigeminovascular system. The nerve fibers in that system connect the brainstem to the meninges and blood vessels within it. Upon activation, CGRP is released, calcitonin gene-related peptide, and that substance changes the perception of pain and widens blood vessels. It can be found in higher concentrations in the blood during a migraine attack.
Three new migraine drugs that have been on the market since last year, CGRP inhibitors, are taking advantage of this. They prevent attacks in half of the migraine patients – not in the other half. Ferrari: “It has not been researched, but I can imagine that these drugs work for people who have attacks when there is an approaching thunderstorm or storm. The disadvantage is: they are expensive and are reimbursed to a limited extent.”
Dutch weather
For people with rheumatism, typical Dutch weather, with rain showers and cold, often has a major influence on their complaints, hears rheumatologist Jaap van Laar of the University Medical Center Utrecht in his consulting room. “Especially in patients with rheumatoid arthritis – that is joint rheumatism, an autoimmune disease – and in patients with osteoarthritis, another form of rheumatism in which cartilage slowly disappears due to damage.” In patients who go on holiday to a dry, warm country, such as Spain or Greece, the complaints disappear like snow in the sun.
However, as with migraine, the relationship between the weather and joint pain is difficult to establish in scientific research. In a large review article, British researchers were unable to make a connection two years ago. But an equally recent British study called Cloudy with a chance of pain, it worked. “It is the best conducted study to date,” says Van Laar.
In it, researchers had nearly 2,700 people with chronic pain due to arthritis, osteoarthritis or other forms of rheumatism record how much pain they had every day for more than a year, in an app on their smartphone. They linked this, with the location data in the phone, to the measurements of the nearest weather station. This allowed them to compare days with little pain and days with a lot of pain for each participant. The research shows that on days with high humidity, high winds and low air pressure, these people are 20 percent more likely to have their pain flare up.
Small nerve fibers
Like Ferrari, Van Laar can only guess at how windy, wet weather could worsen pain in rheumatic patients. “It is very difficult to do scientific research on it. Pain is a subjective sensation felt in the pain center in the brain. This is influenced by all kinds of circumstances: sleep, mood swings, personal characteristics. And also the weather.”
There are hypotheses, based on studies in humans and rats. For example, that scar tissue or inflammatory tissue may react differently to cold or moisture. Or that small nerve fibers that register pain – already more sensitive in people with arthritis – react to low air pressure, or to small movements caused by changes in temperature and air pressure. Van Laar: „We have known for a few years now that nerve fibers play an important role in joints. The nervous system not only influences the inflammatory activity in rheumatism, but also the perception of pain. We don’t know to what extent weather conditions directly affect a joint, for example on the swelling of the tissues there, or whether they work indirectly via the brain.”
Patients should dress warmly, stay indoors if they find it too cold or wet
Jaap van Laar rheumatologist
Rain or shine, keep moving is the best thing that rheumatism patients can do, says Van Laar. “Patients should dress warmly, stay indoors if they find it too cold or wet, and keep moving. And if they can’t keep it anymore and have the money for it, move to Spain.”
All in all, sometimes the body does indeed look like a thermo-, hygro- or barometer, and that of some people with migraine can even predict a storm. But for the weather forecast it is better to just base ourselves on the real weather stations. In fact, there are now also ‘weather reports’ for people with migraine and rheumatism, which warn against weather that can worsen their complaints. In this way, those patients can at least see whether they can expect more or less pain.
And those corns? There is certainly no scientific evidence for their weather-predicting properties. Yet there is a kernel of truth in this folk wisdom. Corns are remarkably often on the vulnerable feet of people with rheumatism.