New research from the Norwegian University of Science and Technology (NTNU) has discovered how the brain responds differently to migraine pain in people who haven’t had enough sleep.
Migraine, which can be characterised by pulsing headaches, nausea and an increased sensitivity to sound, are the leading cause of disability in people between 16 and 50.
“Migraine [is] a great burden for both the individual and society,” says postdoctoral fellow at the NTNU and author of the study, Petter Moe Omland.
“This is a very common disorder that we need to understand better so that better treatment can be provided.”
According to Headache Australia, 4.9 million Australians experience migraine, with 23% of households containing at least one person who lives with migraine.
Similarly, the American Migraine Foundation says that in the US, 37 million Americans are impacted by migraine, which is roughly one in every four households.
In a previous study, researchers showed that a lack of sleep can slow down the activation of nerve cells in the brains of people with migraine.
“It is well known that sleep can relieve migraine headaches, migraine attacks can start during or after sleep, and many people with migraine say that disturbed sleep triggers attacks,” says Omland.
But the relationship between sleep deprivation and migraine has been largely unexplained, until now.
“Now we know more about the link between pain and sleep,” Omland said.
The link between pain and sleep
Throughout two studies, the research team measured the brain activity of 140 participants who had insufficient sleep over a two-night period.
The research was conducted as a blind study meaning the researchers did not know whether a participant suffered from migraine or not.
Each participant was examined twice, once after two nights of normal sleep and then again after two nights of reduced sleep.
The team used an electroencephalogram (EEG) to record signals from the brain. To supplement this data, participants also used an electronic meter that logged sleep and a sleep diary.
“None of this was dangerous, but it was clearly uncomfortable. People with migraine are incredibly good at volunteering for trials because they want there to be more knowledge about the disease,” says Omland.
The results showed that when there was insufficient sleep, the cerebral cortex in people with migraine responded differently to pain than the control group.
The cerebral cortex is the outermost layer of the brain responsible for memory, consciousness and perception.
The research suggests that insufficient sleep in people with migraine may result in an increased inhibitory response in parts of the cerebral cortex making the migraine more intense.
“The pain is not dampened as much as in healthy people,” explains Omland.
“The mechanisms that are supposed to reduce pain do not work quite as in people who do not have migraine.”
Omland himself has a history of migraine, which is what inspired the research.
“The fact that I got these headaches myself became an extra motivation to understand more.”
“After a long period when I slept very little, I started waking up with severe migraine attacks in the middle of the night. It was very troublesome.”
The study is published in Cephalagia, a medical journal at the forefront of headache treatment.