Are migraines a self-defense mechanism?

An emerging theory suggests that migraine attacks might be the brain's self-protective response to oxidative stress, which is a cellular process tied to aging and increased susceptibility to disease.

Migraines are severe headache attacks that can last anywhere between a few hours and a few days, significantly impairing productivity and quality of life.

In the United States, the 1-year prevalence of migraine is between 11.7 percent and 13.2 percent, and recent surveys suggest that people who experience these attacks feel at risk of overusing medication to help them cope.

There is currently no cure for migraine, and no consensus regarding its causes. The most widely used treatments for migraine target its symptoms and include over-the-counter painkillers and triptans.

Now, Dr. Jonathan M. Borkum — a researcher from the University of Maine in Orono — is putting forth a new theory. Migraine attacks, he suggests, could be part of the brain's self-defense mechanism against oxidative stress.

Oxidative stress takes place when the system is no longer able to effectively counterbalance the impact of reactive molecules containing oxygen, which are known as "reactive oxygen species," leading to symptoms of biological aging and an increased susceptibility to functional decline.

Dr. Borkum details his novel approach to migraine in an article recently published in the journal Headache.

Protective effect of migraine components

Existing studies had already shown that migraineurs exhibit higher levels of oxidative stress, and the common triggers for migraine — such as noise, sleep deprivation, and air pollution — seem to worsen this imbalance.

"Oxidative stress is a useful signal of impending harm because a number of unfavorable conditions in the brain can give rise to it," explains. Dr. Borkum, which is why he suggests that treatments focusing on oxidative stress might be more effective in preventing migraine attacks.

Dr. Borkum considers different migraine components — the release of serotonin, for example, and cortical spreading depression, which is characterized by lack of measurable electric activity in the cortex — arguing that each of these elements actually constitutes a protective response.

The researcher cites both in vitro and in vivo studies of brain ischemia, which is an insufficient blood supply to the brain, suggesting that the typical components of a migraine attack have a neuroprotective function.

According to him, these responses stimulate antioxidant enzymes, decrease the production of oxidants, help to prevent the death of neural cells, and stimulate the growth of nervous tissue by releasing growth factors in the brain.

"There are feedback loops between these components of a migraine attack that tie them together into an integrated system," says Dr. Borkum. "Thus, it seems likely that migraine attacks are not simply triggered by oxidative stress, they actively protect and repair the brain from it."

He adds that despite the fact that we are used to thinking of migraine as a disease, its symptoms — including pain, hypersensitivity to auditory and visual stimuli, and nausea — are simply markers of the body's activation of its defense mechanism against a threat: in this case, oxidative stress.

"So," says Dr. Borkum, "the theory here tells us that to truly solve migraines we must look beneath the attack to understand the brain's underlying vulnerability, that is, what gives rise to the oxidative stress."

He also expresses a hope that should his theory be proven, more effective treatments for migraine might be found that target oxidative stress rather than just the symptoms of the headache attacks.

Moreover, learning more about this protective mechanism might point to preventive strategies against a spectrum of other neurodegenerative conditions.

"The existence of an integrated system for protecting and repairing the brain could turn out to be quite useful — for example, we might one day be able to learn from this mechanism how to prevent neurodegenerative diseases."

Dr. Jonathan M. Borkum