Chronic migraine: basic facts
How does the physician diagnose Chronic Migraine?
If you have a history of occasional migraines and the attacks have become more frequent over months or years, so that you now have headache on more than 15 days a month, then a diagnosis of chronic migraine is possible. Another cause must be ruled out by appropriate investigation, but chronic migraine remains the most common cause of chronic headache.
Simply put you must have:
- A history of migraine with or without aura
- 15 days of headache per month
- 8 days are migraines (the other may look like tension type)
- This situation must be there since at least 3 months
- No other cause for the headaches
What if I have good months and bad months and my frequency is sometimes 8 and sometimes 17?
Remember that migraine frequency fluctuates, and we know now that many patients may have a very bad month in the «chronic» category, then go back down to episodic. We call this the roller coaster of migraine.
For this reason, some researchers now believe that putting people with migraine in boxes does not represent the true continuum of migraine. It may be important for research to create categories, but the real life is more complicated.
I heard that migraine is a chronic disease…even in the episodic form.
It is correct. «Chronic» may have two meanings. It can mean «for a long time» and even episodic migraine may last for decades, affecting the person from childhood to older age. But «chronic migraine» in the Headache Classification refers to the frequency of the attacks. This is somewhat confusing.
I seem to have a mix of migraine and tension headache…is it chronic migraine?
People with chronic migraine often report headaches of different intensities: low-intensity headache that can be there almost daily, some moderate attacks, and some severe attacks. According to the Classification, 8 days per month have to be clearly migrainous to diagnose CM.
If you’d like to read more about the 0-1-2-3 approach to track headaches, see here.
What are the risk factors of developing chronic migraine?
Every year, almost 5% of people with episodic migraine develop chronic migraine. The term «chronification» refers to this transformation. Some factors are associated with the risk of chronification. For some of these factors, vicious circles following the Ping Pong Theory can start and be difficult to break.
Risk factors for chronic migraine
1) Female gender
2) Diabetes, arthritis, other chronic pain
3) High frequency of attacks in recent months
4) History of trauma to the head or neck
5) Sleep problems
6) Obesity
7) Depression
8) Regular intake of caffeine
9) Overuse of acute medication
Another way to picture the vicious circles of chronic migraine is illustrated below:
The situation was episodic, attacks increased maybe in a particular context, bad vicious circles started, and now the chronic state endures. This is why working on lifestyle can be very beneficial. (See this post)
If I overuse acute medications, do I have only medication-overuse headache?
No. You have chronic migraine AND medication overuse. That may sound technical, but it’s important. We know now that medication overuse is not always the key factor for the deterioration of migraine. Some people withdraw and don’t improve. For this reason, overuse is added to chronic migraine, and must be managed of course! (See this post)
Is chronification irreversible?
Good news: chronic migraine can re-transform into episodic migraine. 25% of people with chronic migraine will return to an episodic state after 2 years. If chronification is caused by a factor that is treated or resolved, migraines can improve. Appropriate treatment can of course lead to improvement.
Is chronic migraine a cause of disability?
Migraine (even in its chronic form) is not listed as a cause of disability in the USA. Sadly, this forces people with migraine to make their claim based on associated conditions like depression or anxiety. In Canada, the situation must be investigated.
Is chronic migraine caused by depression?
People with chronic migraine experience depression more frequently than the general population, but the association is even stronger with anxiety. Anxiety can both contribute to and result from chronic migraine. This Ping Pong relationship is typical of migraine (See this post). If you suffer from depression or anxiety, it is important to seek treatment.
Is chronic migraine caused by neck problems?
The nervous system is very complex. Having chronic pain in one area of the body can cause the nervous system to be sensitized and more prone to developing pain in other areas. Chronic migraine is more frequent in people who have suffered head trauma or whiplash injury. The neck and the head share the same sensation system (See this post). It is therefore possible that neck pain influences headache. Conversely, migraine can produce neck pain even in people having no real neck problems because of shared sensation.
In conclusion, chronic migraine is a severe disabling form of migraine. It should be treated with a global approach.
REFERENCES
Buse DC,. Migraine Progression: A Systematic Review. Headache. 2019;59(3):306-38.
Becker WJ. The Diagnosis and Management of Chronic Migraine in Primary Care. Headache. 2017;57(9):1471-81.
Adams AM, et al. The impact of chronic migraine: The Chronic Migraine Epidemiology and Outcomes (CaMEO) Study methods and baseline results. Cephalalgia. 2014.
Diener HC et al. Chronic migraine–classification, characteristics and treatment. Nat Rev Neurol. 2011;8(3):162-71.
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