What is chronic migraine?
Chronic Migraine is defined as headache that occurs 15 or more days a month with headache lasting 4 hours a day or longer, of which at least 8 days are with migraine, for at least 3 consecutive months. By definition, people with Chronic Migraine are spending half their month living with debilitating headaches.
Based on findings from a publication summarising global Chronic Migraine prevalence rates, approximately 1% of the population, mostly women, suffer from Chronic Migraine. However, only 20% of people receive an accurate diagnosis for their condition.
People with Chronic Migraine experience a greater impact on their lives than people who have a lower frequency of migraine. Over a 3-month period, people with Chronic Migraine are more likely than those with episodic migraine to miss 5 or more days of: work or school, household work, and family activities.
What causes Chronic Migraine?
Causes for Chronic Migraine onset can vary, however there are number of well documented risk factors for Chronic Migraine. Some of these are outlined in the table below.
| Not easily modifiable |
Modifiable |
- Age
- Low education / socioeconomic status
- Head injury
|
- Obesity
- Medication overuse
- Stressful life events
- Caffeine overuse
- Snoring
- Other pain syndromes
|
Table 1: Chronic Migraine Risk factors (Source: Bigal ME, Lipton RB. Curr Opin Neurol 22:269–276)
What are the signs and symptoms of Chronic Migraine?
The following outlines the criteria that healthcare professionals use to determine whether someone has Chronic Migraine.
- Headache on 15 days per month for >3 months
- 5 prior migraine attacks, with or without aura
- On 8 days per month, headache fulfills criteria of:
- >2 of the following
- unilateral, pulsating, moderate or severe pain, aggravated by physical activity
- and ≥1 of the following:
- nausea and/or vomiting;
- photophobia and phonophobia
- ≥1 of the following reversible symptoms: visual, sensory, speech/language, motor, brainstem, retinal; AND ≥2 of the characteristics of aura
- Relieved with triptans or ergotamine