Scientists have used an unconventional experiment to identify some of the differences that might exist in the brains of people who suffer from migraine compared with those who don't: putting them on a virtual roller coaster.
It turns out that those who get migraine attacks tend to experience more motion sickness and more dizziness when they even imagine themselves to be on a roller coaster. Their brains also show differences in neural activity that seem to relate to this.
While migraine has long been linked to motion sickness and other vestibular symptoms – conflicts between what our senses are telling us and how we're feeling – the approach in this virtual roller coaster study means detailed fMRI brain scans can be run while these sensations are being experienced.
"People with migraine often complain of dizziness, balance problems and misperception of their body's place in space during migraine," says neurologist Arne May, from the University of Hamburg in Germany.
"By simulating a virtual roller coaster ride, our study found that some of these problems are not only magnified in people who experience migraine, but they are also associated with changes in various areas of the brain.
"By identifying and pinpointing these changes, our research could lead to a better understanding of migraine which could in turn lead to the development of better treatments."
May and his colleagues enlisted 20 people with a history of migraine (averaging four migraine attacks per month) who were patients at a headache clinic, and 20 people who hadn't experienced any problems with migraine.
While the brain scans were being run, participants were shown first-person perspective videos of a roller coaster ride, together with accompanying audio to make the experience more immersive. They were then quizzed about their feelings and sensations afterwards.
The experiences didn't bring on any migraine attacks, but 65 percent of the migraine patients reported motion sickness compared with 30 percent of the control group. These feelings of nausea also lasted longer and were more intense for the migraine patients.
With the fMRI scans, the researchers observed increased activity in five brain areas in people with a history of migraine – including two parts of the occipital gyrus, which is involved in visual processing.
"One other area of the brain where we found pronounced nerve cell activity in people with migraine was within the pontine nuclei, which helps regulate movement and other motor activity," says May.
"This increased activity could relate to abnormal transmission of visual, auditory and sensory information within the brain."
It's still early days for this research, but being able to compare brain activity of migraine patients and non-migraine patients, while they are experiencing symptoms closely linked with the development and onset of migraine attacks, should prove useful for scientists.
With about 15 percent of the world's population – over a billion people – thought to suffer from migraine, efforts to understand more about why these attacks happen and ultimately to find a cure could potentially improve a huge number of lives.
The researchers have already begun comparing changes in brain activity shown in this study to the changes in brain activity that accompany migraine – and any links could open up promising new options for treatment.
"Future research should now look at larger groups of people with migraine to see if our findings can be confirmed," says May.
The research has been published in Neurology.