Scientists say they may have FINALLY discovered what causes migraines - and how to put an end to them once and for all

Scientists have discovered a new way migraines happen - a breakthrough that might help them create new drugs for the debilitating condition. 

More than a million Americans suffer from migraines which leave them nauseous, in paralyzing pain and unable to get out of bed for hours at a time.

For one in four, they are also blighted with extreme light sensitivity, blurry vision and black spots, which make it difficult to function. 

Despite how common these migraines are, scientists understand little about what causes these attacks, and many people don't have medication that works. 

But researchers have found distinct proteins are created during a migraine with aura, which escape the brain through microscopic openings and trigger the intense pain.

Roughly 12 percent of Americans have migraines, according to Dr Gottschalk. Of those, about a quarter have migraine with aura, which includes odd visual distortions

Before some people feel a migraine, their vision gets interrupted. This happens as a wave of signals shoot across the brain, like in the pictured diagram. With these signals, a fluid that carries proteins that cause migraine get shunted out of the brain and head to pain receptors

In order for someone to feel pain, the migraine has to trigger pain receptors that sit outside it, which researchers have known for a long time. 

How migraines moved from the brain to the rest of the body had 'largely remained a mystery', Dr Jeffrey Iliff, from the University of Washington School of Medicine and Dr Andrew Russo from University of Iowa, who were not involved in the study said. 

Dr Iliff and Dr Russo called the authors 'pioneers' and said this could help us find new drugs for migraine sufferers, in a published response to the new study.

For people with moderate headaches, over the counter pain medications like Advil and Tylenol can often help. But for migraine sufferers, these usually aren't enough.

There are FDA approved medications for migraines, but for many people, these don't work, the study authors from the University of Copenhagen and the University of Rochester Medical Center said.

That's because migraines aren't just bad headaches, they're more serious than that, Dr Christopher Gottschalk, the director of Yale's Medicine's Headache and Facial pain Center, who wasn't involved in the research, said. 

So doctors will prescribe medications like triptans, which can treat a migraine after it begins, or antidepressants, anti-seizure drugs or beta-blockers, all of which should be able to prevent migraines. 

But there is a high amount of variability in these medications. Even if they do work, they come with some unpleasant side effects like nausea, insomnia, memory problems, weight gain and hair loss, Dr Gottschalk said. 

These side effects make these drugs 'not a good arrangement' for many migraine sufferers, he said, 'A lot of the time, the price is too much to bear for people.'

But in order to create drugs that more effectively treat migraines, doctors have to understand what causes them. Despite 'thousands of years' of study, it's still debated, the study authors said.

Researchers have known for a long time that migraines don't work directly on the brain, since the brain itself doesn't have the capability to feel pain.

The brain is surrounded by multiple membranes that shut it off from the rest of the body, and only let things that are absolutely essential through. It's difficult for molecules to get through these layers, whether they're coming or going. 

Researchers had no idea how these tricky migraines were bypassing these barriers.

But they did know that in certain kinds of migraines, about an hour to five minutes before the pain begins, people begin having odd, visual signs - like blurry vision, blinding lights and black spots. 

It turns out when aura begins, there's a flood of fluid and brain signals that move around the brain, pushing little molecules that trigger migraine. 

The study discovered that, in mice, the molecules that trigger migraine escape the brain by riding on this fluid - getting pushed out at a little gap where the nerve that controls the face protrudes from the brain. 

This was the first time someone identified this gap, Dr Iliff and Dr Russo wrote. 

They think that these tiny particles, which are little proteins, could be targeted by new drugs and stop migraine.  

'Although this work provides some of the strongest data to date for a role of the glymphatic system in migraine, there is much to discover,' Dr Illif and Russo wrote. 

Some of the molecules that were identified in this new study were already being investigated by drug companies, they said.

In 2018, the FDA released the first of these drugs, called calcitonin gene-related peptide inhibitors, after the particular protein that they are designed to fight against. 

At the time, the American Migraine Foundation called this kind of medication: 'the biggest news in migraine treatment and prevention in decades.' This still doesn't solve migraine for everyone though. 

So the other molecules the researchers found could be key, study author Dr Martin Kaag Rasmussen said, in enabling 'the discovery of new pharmacological targets, which could benefit the large portion of patients not responding to available therapies.'