Over decades of intensive research into migraine pain and its causes, knowledge of this debilitating condition has improved greatly. There’s still lots to do to fully understand what happens in the brain to cause so many diverse symptoms, but thankfully it’s now widely accepted that migraine is not simply another term for ‘headache’.
Why Diagnosing Migraine is Problematical
It can help to consider headaches in general in order to get some understanding of where the difficulty comes from when trying to identify migraine pain.
Part of the problem is that there are primary and secondary headaches. Primary headaches are the cause of other symptoms, whereas secondary headaches are caused by outside factors. An example of a secondary headache would be that caused by overindulging on alcohol.
The challenge arises because both types of headaches cause pain, so getting to the underlying problem isn’t straightforward.
Chemical Migraine Triggers
Migraine is a brain disorder, affecting how the brain deals with sensory information such as light, sound, or smells. It’s now believed that a succession, or progression, of several chemical changes in the brain stem cause migraine pain.
When nociceptors (the brain cells that sense pain) detect changes, they release neuropeptides that affect nearby cells causing them to increase in sensitivity and release more neuropeptides.
Those chemicals go to work on the surrounding blood vessels and muscle tissue around the brain, which then relax and dilate, increasing blood flow. Some doctors believe this is cause of the classic migraine aura. When the neuropeptides reach a certain level, cranial vessels leak, causing swelling in the area. It’s thought to be the combination of these factors that eventually leads to migraine pain.
This progression, leading to the expansion (vasodilation) of blood vessels is part of what distinguishes a migraine from a standard headache, which is caused by the a narrowing (vasoconstriction) of the cranial blood vessels.
Headache Intensity and Duration
Because it’s so hard to diagnose migraine, criteria have been established that help to identify the patterns experienced by patients. These include:
- Headaches must occur at least five times a year
- They must last for between 4 and 72 hours
- Associated symptoms such as nausea, light or sound sensitivity should be present
- It should affect just one side of the head
- Have a pulsating quality and moderate to severe pain
Migraines are then categorized by type. For example:
- Chronic Migraines are those that occur 15 or more times per month
- Classic Migraines are headaches that are accompanied by a visual aura, causing bright lights in the eyes and possible blind spots before the onset of the pain
- Common Migraines don’t have an aura but come on suddenly and may be immediately preceded by cognitive problems
- Ocular Migraines are those that have an aura but no pain. There’s no cure for these, so sufferers just have to ride them out.
Migraines are different from cluster headaches, which are no less painful and also tend to come on very suddenly. Pain is likely focused behind one eye. They’re called cluster headaches because they occur in clusters over a period of time, then vanish completely before returning at a later date.
Testing for Migraine
Definitive tests for migraine don’t exist. Rather, doctors call on what’s known about chemical and bodily changes associated with migraine pain, then use advanced medical procedures to help them identify those changes.
These could include:
- MRI Scans: Magnetic Resonance Imaging uses a strong magnetic field to build up a 3D image of your brain tissue. It involves lying inside a large tube while the machine builds up the images. The test takes up to 45 minutes, and while it is painless in itself, people with claustrophobia may find it uncomfortable and distressing to be in an enclosed area.
- CT Scans: Computerized Tomography, which creates very detailed X-ray type images built up from several rays. The resulting 3D image can rule out blood clots or tumors and takes around 15 minutes.
Acute treatments involve non-steroidal anti-inflammatory drugs (NSAIDs) that work most effectively if the patient takes them before the pain arrives. Triptans are also often prescribed, and is a drug that mimics serotonin in the body, causing blood vessels to constrict and so preventing pain signals being sent to the brain.
People who suffer from chronic migraine may also find preventive treatments help. Sometimes anti-depressants may be prescribed, or anti-histamines to help regulate serotonin levels. Other types of preventive treatment include identifying personal triggers and avoiding them wherever possible.
When all else fails, a third treatment includes surgical procedures. There are several available that depend on the underlying cause of the migraine. Most procedures are minimally invasive, outpatient treatments, although some require general anesthetic.
Science improves our knowledge of migraine all the time, with more sophisticated treatments in constant development.