How Does a Migraine Attack Begin?

Patient Expert & Health Professional
Medically Reviewed

Migraine is poorly understood by the general public. It’s a common misconception that Migraine is a bad headache brought on by improper eating, poor stress management, and overwork. Essentially, people with Migraine are blamed for their suffering. As long as we keep thinking of Migraine as a headache, the myths and stigma will continue.

What really happens

The truth about Migraine is much more complex. Sure, many people with Migraine may experience severe headaches, but it doesn’t stop there. You see, Migraine is a neurological disease. That puts it in the same category as other neurological diseases such as epilepsy, Parkinson’s, multiple sclerosis, and Alzheimer’s. People with Migraine don’t “get headaches.” Instead, they never stop having Migraine.

Migraine is characterized by periodic attacks, much in the way that epilepsy involves periodic seizures. Based on the current understanding of Migraine, when we encounter a trigger, the first thing to happen is a wavelike surge of electrical activity followed by reduced activity spreads across the cortex of the brain. This is called cortical spreading depression (CSD).

Contrary to the vascular theory of Migraine, advances in PET scanning have shown that CSD occurs prior to any dilation of blood vessels (vasodilation). In fact, Migraine can occur without any vasodilation. When there are vascular changes, they occur as a result of CSD.

Imagine an electrical tsunami pouring across the surface of the brain, leaving chaos in its wake. I first heard CSD described in this way during a session at the American Headache Society’s 59th Annual Scientific Meeting in June, 2017. As I began to explore the topic of CSD, I discovered that many sources use the analogy of a tsunami to describe it.

Cortical spreading depression isn’t a phase or symptom of Migraine. It’s the beginning of a migraine attack, the process occurring in the brain that causes the phases of an attack and the symptoms we recognize. Take a closer look at the process of a migraine attack. All of our symptoms can be explained as the brain’s attempt to restore normal functioning in response to CSD.

Day one

The result of CSD is disruption of brain function. Neurotransmitter activity is disrupted as the brain attempts to restore normal function. There can be a delay of eight to 12 hours from the time cortical spreading depression occurs and the onset of the characteristic symptoms of Migraine. During this time, mood can shift wildly, energy levels may rapidly rise or fall, and food cravings can occur. Excessive yawing, urination, changes in bowel function, and neck pain and stiffness can also occur. Many people with Migraine are completely unaware that these symptoms are the initial signs of a Migraine attack.

Day two and beyond

Finally, the characteristic signs of Migraine begin to appear. Senses may be disrupted. Blind spots, twinkling lights, and zig-zag lines may appear in the visual field. Lights, sounds, and odors can be magnified to painful levels. Within less than an hour, a one-sided, throbbing headache may begin. It is at this point that most people recognize the symptoms of Migraine and begin treatment.

Without treatment, this phase of a Migraine attack can last from four to 72 hours. The pain can be accompanied by nausea, vomiting, and vertigo. All the earlier symptoms can continue as well. If acute treatment does not work quickly, the combination of debilitating symptoms may force the person to retreat to a dark, quiet bedroom to sleep off the attack.

The postdrome (hangover)

The pain and associated symptoms finally subside, but the attack is still not over. A dull, residual headache, cognitive slowing, and sensitivity to light, sound, and odors may continue for another full day. Many people call this phase a “hangover” because the symptoms often resemble the hangover from a night of heavy drinking. “All the pain and none of the fun,” is a good way to describe this phase.

CSD really is like a tsunami. The wave of CSD disrupts our ability to function and it can take days for our brains to fully recover. The brain hasn’t fully recovered from CSD until all phases of a Migraine attack have ended. It is only after we recover from the postdrome that our neurological function has been restored to normal.

Once we understand the destructive effects of CSD, it becomes clearer why we must work to prevent as many Migraine attacks as possible. Migraine doctors recommend that we seek help early to reduce the risk of worsening symptoms. Just two or three attacks per month may warrant preventive treatment, especially if the attacks significantly interfere with work or daily activities. Preventing as many attacks as possible is essential for good Migraine management. Don’t wait until your attacks are out of control. Get help early. Don’t let this Migraine tsunami sweep you away.

See More Helpful Articles:

Anatomy of a Migraine

INFOGRAPHIC – Understanding the Anatomy of a Migraine

19 Less Often Discussed Migraine Aura Symptoms

14 Migraine Prodrome Symptoms

The Phases of a Migraine Attack and Their Symptoms