Definition and Overview
Chronic migraine is a condition in which headaches occur more than 15 days a month for more than 3 months, of which 8 or more days show migraine features. The process of a patient experiencing intermittent migraines gradually increasing the frequency of headaches and turning them into chronic migraines is called 'chronization of migraines.'
Approximately 1.4-2.2% of the world's adult population suffers from chronic migraine. Approximately 2.5-3% of episodic migraine patients convert to chronic migraine each year. Compared to intermittent migraine, chronic migraine causes greater impairment in daily life, requires more hospital visits, and is more common with comorbidities such as depression and anxiety.
cause
The causes of migraine becoming chronic are divided into correctable factors related to lifestyle and factors that are difficult to correct.
Correctable factors include excessive use of painkillers (more than 10 to 15 days per month), obesity (body mass index over 30, 1.4 times the risk), excessive caffeine intake (more than 400 mg per day), sleep disorders (insomnia, sleep apnea), stress, and depression or anxiety.
Factors that make correction difficult include being female, low socioeconomic level, experiencing head trauma, and having a high frequency of existing headaches (more than 10 days per month).
If you take painkillers frequently, the brain's ability to suppress pain weakens. This increases the sensitivity to pain and increases the frequency of headaches. In a population-based study, painkillers containing sleeping pills (risk 2.06 times) and narcotic analgesics (risk 1.98 times) were identified as independent risk factors for chronicity.
Repeated migraine attacks cause the brain's pain-processing neurons to become increasingly sensitive. Sensitized nerve cells respond to stimuli that normally would not cause pain. The phenomenon of feeling pain even with light touch (allodynia) accounts for approximately 60-70% of chronic migraines, making it more common than intermittent migraines (approximately 30-40%).
Brain imaging studies in patients with chronic migraine have reported decreased volume and increased white matter lesions in brain regions involved in pain control. It is not yet known whether these changes are the cause or the result, but they suggest that there are structural changes in the brain's pain control function.
symptoms
The main symptoms of chronic migraine are:
- Headaches that last more than 15 days a month
- Eight or more of those days have migraine characteristics: throbbing pain on one side of the head, moderate to severe intensity, and worse with daily activities.
- Hypersensitivity to light or sound
- Accompanied by nausea or vomiting
- Allodynia that causes pain even with light touch (occurs in approximately 60-70% of cases)
- Fatigue, difficulty concentrating, mood changes
Approximately 30-50% of chronic migraine patients suffer from depression, and 30-50% suffer from anxiety disorders.
diagnosis
The international diagnostic criteria for chronic migraine are as follows.
A. Headaches occur more than 15 days per month for more than 3 months. B. There were five or more headaches that met the diagnostic criteria for migraine. c. Any of the following applies to more than 8 days per month for more than 3 months: (1) Headache meeting the diagnostic criteria for migraine; (2) headache equivalent to migraine with aura; (3) Headache diagnosed as migraine and treated with triptan, etc., which was effective D. Not better explained by another diagnosis.
If overuse of painkillers is accompanied, chronic migraine and medication overuse headache are diagnosed simultaneously. After discontinuing overuse of painkillers, the patient is observed for two months and if the headaches decrease to less than 15 days per month, the patient is reclassified as an intermittent migraine.
Approximately 50-80% of chronic migraine patients suffer from overuse of painkillers. If you use general painkillers for more than 15 days a month or triptans or combination painkillers for more than 10 days a month for more than 3 months, you are diagnosed with medication overuse headache.
treatment
Stop overuse of painkillers
The first step in treating chronic migraine accompanied by painkiller overuse is discontinuation of the overused medication. Withdrawal symptoms such as rebound headaches, nausea, anxiety, and sleep disturbances may occur for 2 to 10 days after discontinuation, but most get better within 2 to 8 weeks. Studies have shown that just stopping overuse of painkillers significantly reduced the frequency of headaches in about 50% of patients.
preventive medication
Among the preventive drugs for chronic migraine, the ones with the highest level of evidence are topiramate and Botox injection (botulinum toxin type A).
In clinical trials, topiramate was confirmed to be effective in reducing the number of migraine days per month by an additional 3.5 days compared to placebo. In a large-scale clinical trial, Botox injections further reduced the number of monthly headache days by an average of 1.4 to 2.3 days compared to placebo at 12 weeks, and during 24 weeks of treatment, the number of monthly headache days decreased by an average of 8 to 9 days compared to before treatment.
CGRP (calcitonin gene-related peptide) targeted therapy is a new class of preventive drugs that block substances involved in the occurrence of migraines. It is used as an additional treatment option in patients who lack response to existing preventive medications.
Neuromodulation treatment
Progress and Complications
If chronic migraine is left without proper treatment, headache frequency and intensity tend to remain or worsen. The likelihood of depression, anxiety disorders, and sleep disorders increases, and economic losses due to absenteeism from work and decreased work ability are approximately 4 to 5 times that of intermittent migraines.
By combining appropriate preventive treatment with lifestyle modifications, a significant number of patients can reduce the frequency of headaches to the level of intermittent migraines. Improvement was reported in approximately 50% of patients simply by discontinuing overuse of painkillers.
life guide
Lifestyle recommendations for managing chronic migraine are as follows:
- Limit painkillers to no more than 2 to 3 times a week, and record the number of days taken in a headache diary.
- Maintain regular sleep habits. It is good to go to bed and wake up at the same time every day.
- Do aerobic exercise for at least 30 minutes at least 3 times a week.
- Limit caffeine intake to less than 200 mg (about 2 cups of coffee) per day.
- Practice relaxation techniques or breathing techniques to manage stress.
- Keep a headache diary to identify factors that cause headaches (food, environment, stress, etc.).
- If depression or anxiety persists, seek psychiatric treatment.
- If you are overweight, aim to maintain an appropriate weight.