The blood vessel network in the brain of people with chronic migraines is deformed, scientists from the US said. Other studies have found that while migraines in old age may be less harmful, migraines before the age of 30 have a bad effect on the brain and cognitive behavior.
Migraine is currently one of the most common diseases in the US and European Union countries. In the USA alone, 28 million women suffer from permanent migraine attacks, while in the EU countries – about 35 million. Migraines affect women three times more often than men, but the forms of this disease usually appearing in men are stronger.
A team of scientists from the Perelman School of Medicine at the University of Pennsylvania, led by Prof. Brett Cucchiary studied the relationship between abnormalities in the structure of the brain and the occurrence of migraines. The so-called the arterial wheel of the brain, also known as the Willis wheel. It is discovered at the end of the XNUMXth century by an English physician, Thomas Willis, of the circular system of arteries supplying the brain that lie beneath it. Scientists have found that abnormalities in its structure may be associated with the occurrence of the worst forms of migraines – migraines with aura.
The causes of migraines
Previous hypotheses about the causes of migraines associated them with impaired blood flow in the blood vessels of the head – they were supposed to contract and expand, which was attributed to erroneous neural signals. Scientists at the University of Pennsylvania found that the cause was elsewhere. Abnormalities in the structure of the blood vessels supplying the brain cause an increased sensitivity to changes in blood flow, which results in erroneous neural signals triggering the mechanism of migraine.
People with migraines have marked differences in the structure of their blood vessels, which is the things a person is born with. These differences are related to changes in blood flow in the brain, and it is these changes that trigger migraines. This explains why drinking too little fluids and dehydration trigger headaches in some people, said Prof. Cucchiara.
His team studied 170 volunteers divided into three groups. The first group included those who had never experienced migraines, the second group had migraines with aura, and the third group included those who had migraine attacks without an aura.
The disturbed structure of vessels in the brain was common in the second group (73% of respondents) and in the third group (67% of respondents). In 50 percent. of the subjects in the first group, changes were also visible in the Willis Circle, but they were smaller and less pronounced than in the second and third groups.
Next, scientists used magnetic resonance angiography and a non-invasive real-time imaging method based on magnetic resonance to determine changes in the blood supply to the brain.
As one of the team members, prof. John Detre, the changes in blood flow associated with differences in the structure of the Willis wheel, are best seen in the back of the brain where the visual cortex is located. This may explain why the onset of aura migraine attacks are related to visual phenomena such as colored waves, dots and scotoma in front of the eyes, or even distortions causing tilting the image, noted Prof. Detre.
Deformation of the Willis wheel blood vessel network and migraine are closely related, but there are other causes of migraines due to blood flow disorders. Scientists say the trigger may be hypersensitivity to certain chemicals caused by these factors, and disturbances in blood flow may be caused by prolonged stress.
Migraines on a different basis
The findings of the American team are in line with the conclusions of previous studies by French scientists from Inserm and the Université Pierre et Marie Curie in Paris. The research team led by prof. Christophe Tzourio, found that migraines and paroxysmal headaches in the elderly are actually caused by relatively small changes in the brain detected with MRI scans. Scientists examined 780 people over the age of 65.
The changes that scientists have classified as partially unrelated to age come in two forms. The first is deep white matter lesions, the second is silent infarcts leading to loss of white matter tissue. Both types of changes result in the weakening of the small arteries in the brain, supplying the tissue of white matter, responsible, inter alia, for the exchange of information between different parts of the brain. The changes observed by scientists were the most severe in people with high blood pressure and in diabetics.
Damage to the network of vessels supplying white matter causes many adverse effects: migraines, paroxysmal headaches, and in the most severe cases, movement disorders and the risk of a stroke. Interestingly, another Inserm team noticed very similar changes in the white matter vessels in people with early forms of Alzheimer’s disease, especially as manifested by movement and cognitive impairment. According to the researchers, this could mean that intense and long-lasting, untreated migraines could damage blood vessels in the brain.
The team of prof. Tzourio decided to test this hypothesis. Researchers collected the results of a group of around 800 people from Nantes who had been researching the effects of aging for 10 years. They then conducted MRI of the brain in this group, with a thorough history of which the subjects complained of. The interview concerned especially migraines and paroxysmal headaches. The results clearly show that migraines in the elderly age do not impair cognitive functions and do not cause major damage to blood vessels in the brain. Worse if migraines start before the age of 30. Indeed, in this group, we see damage to blood vessels in the brain and a higher degree of cognitive impairment in people with persistent and long-term untreated migraines, Prof. Tzourio said.
As indicated by the results of the experiment, 21 percent. the surveyed people suffered from severe headaches during their lifetime. For over 70 percent in this group, they were associated with migraines, most of which were migraines with aura. MRI studies showed that these people had twice as often severe changes in blood vessels in white matter as people without headaches. However, despite this, the cognitive abilities of the changed and unchanged groups were almost identical. A reduction in these abilities has been observed in people who have complained of severe migraines since childhood.
According to another member of the research team, Dr. Tobias Kurth, these results are very important – they show that even with severe migraines and damage to the network of blood vessels supplying white matter, there is no fear of cognitive impairment. However, they can occur if such migraines begin relatively early – before the age of 30.
Botox – a miracle cure for migraines
The latest treatment for migraines, especially for severe forms of aura, is botulinum toxin type A, known as botox.
A team of scientists from the Medical College of Wisconsin, led by prof. Jeffrey L. Jackson, decided to test the effectiveness of the drug, because botox is the first therapy of this type offered in the form of cosmetic injections, for patients with chronic migraines and paroxysmal headaches. So far, random studies of the toxicity and efficacy of this preparation against migraines have not yielded conclusive results, but have led to approval for the therapy in the USA and in the European Union.
The team of prof. Jackson has made a careful analysis of the usefulness of Botox in treating these conditions. 5313 patients were divided into groups: with attacks of paroxysmal headaches or migraines (up to 15 per month) and chronic migraines or headaches (more than 15 attacks per month)
As it turned out, treatment with botulinum toxin A does not bring almost any reduction in the number of headache, tension or migraine attacks. There was also no effect in 676 patients with chronic migraines or headaches. Worse still, the use of botulinum toxin can exacerbate paroxysmal headaches in patients with chronic problems. Increased frequency of symptoms associated with migraine attacks, such as drooping of the upper eyelids, paraesthesia (tingling, numbness or marked changes in skin temperature), skin hypersensitivity, flabbiness and pain in the neck muscles, and muscle weakness has also been observed with the use of botulinum toxin.
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