Migraine is a primary headache disorder characterized by recurrent headaches that are moderate to severe. Typically, episodes affect one half of the head, are pulsating in nature, and last from a few hours to 3 days. Associated symptoms may include nausea, vomiting, and sensitivity to light, sound, or smell. The pain is generally made worse by physical activity, although regular exercise may have prophylactic effects. Up to one-third of people affected have aura: typically a short period of visual disturbance that signals that the headache will soon occur. Occasionally, aura can occur with little or no headache following it.
Migraine is believed to be due to a mixture of environmental and genetic factors. About two-thirds of cases run in families. Changing hormone levels may also play a role, as migraine affects slightly more boys than girls before puberty and two to three times more women than men. The risk of migraine usually decreases during pregnancy and after menopause. The underlying mechanisms are not fully known. They are, however, believed to involve the nerves and blood vessels of the brain.
Globally, approximately 15% of people are affected by migraine. In the Global Burden of Disease Study of 2010, it was ranked as the third most prevalent disorder in the world. It most often starts at puberty and is worst during middle age. As of 2016, it is one of the most common causes of disability. An early description consistent with migraines is contained in the Ebers papyrus, written around 1500 BC in ancient Egypt. The word migraine is from the Greek (hemikrania), 'pain in half of the head', from - (hemi-), 'half', and ? (kranion), 'skull'.
Signs and symptoms
Migraine typically presents with self-limited, recurrent severe headache associated with autonomic symptoms. About 15-30% of people living with migraine experience episodes with aura, and they also frequently experience episodes without aura. The severity of the pain, duration of the headache, and frequency of attacks are variable. A migraine lasting longer than 72 hours is termed status migrainosus. There are four possible phases to a migraine, although not all the phases are necessarily experienced:
The prodrome, which occurs hours or days before the headache
Prodromal or premonitory symptoms occur in about 60% of those with migraines, with an onset that can range from two hours to two days before the start of pain or the aura. These symptoms may include a wide variety of phenomena, including altered mood, irritability, depression or euphoria, fatigue, craving for certain food(s), stiff muscles (especially in the neck), constipation or diarrhea, and sensitivity to smells or noise. This may occur in those with either migraine with aura or migraine without aura. Neuroimaging indicates the limbic system and hypothalamus as the origin of prodromal symptoms in migraine.
Flickering animation a scintillating scotoma. The scintillations are of a zigzag pattern starting in the center of vision, surrounded by a somewhat larger area with distortion of shapes
Aura is a transient focal neurological phenomenon that occurs before or during the headache. Aura appears gradually over a number of minutes (usually occurring over 5-60 minutes) and generally last less than 60 minutes. Symptoms can be visual, sensory or motor in nature and many people experience more than one. Visual effects occur most frequently: they occur in up to 99% of cases and in more than 50% of cases are not accompanied by sensory or motor effects.
Vision disturbances often consist of a scintillating scotoma (an area of partial alteration in the field of vision which flickers and may interfere with a person's ability to read or drive). These typically start near the center of vision and then spread out to the sides with zigzagging lines which have been described as looking like fortifications or walls of a castle. Usually the lines are in black and white but some people also see colored lines. Some people lose part of their field of vision known as hemianopsia while others experience blurring.
Sensory aura are the second most common type; they occur in 30-40% of people with auras. Often a feeling of pins-and-needles begins on one side in the hand and arm and spreads to the nose-mouth area on the same side. Numbness usually occurs after the tingling has passed with a loss of position sense. Other symptoms of the aura phase can include speech or language disturbances, world spinning, and less commonly motor problems. Motor symptoms indicate that this is a hemiplegic migraine, and weakness often lasts longer than one hour unlike other auras.Auditory hallucinations or delusions have also been described.
Classically the headache is unilateral, throbbing, and moderate to severe in intensity. It usually comes on gradually and is aggravated by physical activity. However, the effects of physical activity on migraine are complex and some researchers have concluded that, while exercise can trigger migraine attacks, regular exercise may have prophylactic effect and decrease frequency of attacks. The feeling of pulsating pain is not in phase with the pulse. In more than 40% of cases, however, the pain may be bilateral and neck pain is commonly associated with it. Bilateral pain is particularly common in those who have migraine without aura. Less commonly pain may occur primarily in the back or top of the head. The pain usually lasts 4 to 72 hours in adults, however in young children frequently lasts less than 1 hour. The frequency of attacks is variable, from a few in a lifetime to several a week, with the average being about one a month.
Rarely, aura occurs without a subsequent headache. This is known as an acephalgic migraine or silent migraine; however, it is difficult to assess the frequency of such cases because people who do not experience symptoms severe enough to seek treatment may not realize that anything unusual is happening to them and dismiss it without reporting any problems.
The migraine postdrome could be defined as that constellation of symptoms occurring once the acute headache has settled. Many report a sore feeling in the area where the migraine was, and some report impaired thinking for a few days after the headache has passed. The person may feel tired or "hung over" and have head pain, cognitive difficulties, gastrointestinal symptoms, mood changes, and weakness. According to one summary, "Some people feel unusually refreshed or euphoric after an attack, whereas others note depression and malaise." For some individuals this can vary each time.
The underlying causes of migraines are unknown. However, they are believed to be related to a mix of environmental and genetic factors. They run in families in about two-thirds of cases and rarely occur due to a single gene defect. While migraines were once believed to be more common in those of high intelligence, this does not appear to be true. A number of psychological conditions are associated, including depression, anxiety, and bipolar disorder, as are many biological events or triggers.
Studies of twins indicate a 34% to 51% genetic influence of likelihood to develop migraine. This genetic relationship is stronger for migraine with aura than for migraines without aura. A number of specific variants of genes increase the risk by a small to moderate amount.
Migraine may be induced by triggers, with some reporting it as an influence in a minority of cases and others the majority. Many things such as fatigue, certain foods, and weather have been labeled as triggers; however, the strength and significance of these relationships are uncertain. Most people with migraines report experiencing triggers. Symptoms may start up to 24 hours after a trigger.
Between 12 and 60% of people report foods as triggers. Evidence for such triggers, however, mostly relies on self-reports and is not rigorous enough to prove or disprove any particular trigger. A clear explanation for why food might trigger migraines is also lacking.
There does not appear to be evidence for an effect of tyramine - which is naturally present in chocolate, alcoholic beverages, most cheeses and processed meats - on migraine. Likewise, while monosodium glutamate (MSG) is frequently reported, evidence does not consistently support that it is a dietary trigger.
A review on potential triggers in the indoor and outdoor environment concluded that there is insufficient evidence to confirm environmental factors as causing migraine. They nevertheless suggested that people living with migraine take some preventive measures related to indoor air quality and lighting. This includes ventilation and various black out items to reduce light at the maximum rate.
Cortical spreading depression, or spreading depression according to Leão, is a burst of neuronal activity followed by a period of inactivity, which is seen in those with migraines with aura. There are a number of explanations for its occurrence, including activation of NMDA receptors leading to calcium entering the cell. After the burst of activity, the blood flow to the cerebral cortex in the area affected is decreased for two to six hours. It is believed that when depolarization travels down the underside of the brain, nerves that sense pain in the head and neck are triggered.
Adenosine, a neuromodulator, may be involved. Released after the progressive cleavage of adenosine triphosphate (ATP), adenosine acts on adenosine receptors to put the body and brain in a low activity state by dilating blood vessels and slowing the heart rate, such as before and during the early stages of sleep. Adenosine levels have been found to be high during migraine attacks. Caffeine's role as an inhibitor of adenosine may explain its effect in reducing migraine. Low levels of the neurotransmitter serotonin, also known as 5-hydroxytryptamine (5-HT), are also believed to be involved.
The diagnosis of a migraine is based on signs and symptoms.Neuroimaging tests are not necessary to diagnose migraine, but may be used to find other causes of headaches in those whose examination and history do not confirm a migraine diagnosis. It is believed that a substantial number of people with the condition remain undiagnosed.
The diagnosis of migraine without aura, according to the International Headache Society, can be made according to the following criteria, the "5, 4, 3, 2, 1 criteria":
Five or more attacks--for migraine with aura, two attacks are sufficient for diagnosis.
Four hours to three days in duration
Two or more of the following:
Unilateral (affecting half the head)
Moderate or severe pain intensity
Worsened by or causing avoidance of routine physical activity
If someone experiences two of the following: photophobia, nausea, or inability to work or study for a day, the diagnosis is more likely. In those with four out of five of the following: pulsating headache, duration of 4-72 hours, pain on one side of the head, nausea, or symptoms that interfere with the person's life, the probability that this is a migraine is 92%. In those with fewer than three of these symptoms the probability is 17%.
Migraine is divided into seven subclasses (some of which include further subdivisions):
Migraine without aura, or "common migraine", involves migraine headaches that are not accompanied by aura.
Migraine with aura, or "classic migraine", usually involves migraine headaches accompanied by aura. Less commonly, aura can occur without a headache, or with a nonmigraine headache. Two other varieties are familial hemiplegic migraine and sporadic hemiplegic migraine, in which a person has migraine with aura and with accompanying motor weakness. If a close relative has had the same condition, it is called "familial", otherwise it is called "sporadic". Another variety is basilar-type migraine, where a headache and aura are accompanied by difficulty speaking, world spinning, ringing in ears, or a number of other brainstem-related symptoms, but not motor weakness. This type was initially believed to be due to spasms of the basilar artery, the artery that supplies the brainstem. Now that this mechanism is not believed to be primary, the symptomatic term migraine with brainstem aura (MBA) is preferred.
Childhood periodic syndromes that are commonly precursors of migraine include cyclical vomiting (occasional intense periods of vomiting), abdominal migraine (abdominal pain, usually accompanied by nausea), and benign paroxysmal vertigo of childhood (occasional attacks of vertigo).
Retinal migraine involves migraine headaches accompanied by visual disturbances or even temporary blindness in one eye.
Complications of migraine describe migraine headaches and/or auras that are unusually long or unusually frequent, or associated with a seizure or brain lesion.
Probable migraine describes conditions that have some characteristics of migraines, but where there is not enough evidence to diagnose it as a migraine with certainty (in the presence of concurrent medication overuse).
Chronic migraine is a complication of migraines, and is a headache that fulfills diagnostic criteria for migraine headache and occurs for a greater time interval. Specifically, greater or equal to 15 days/month for longer than 3 months.
The diagnosis of abdominal migraine is controversial. Some evidence indicates that recurrent episodes of abdominal pain in the absence of a headache may be a type of migraine or are at least a precursor to migraines. These episodes of pain may or may not follow a migraine-like prodrome and typically last minutes to hours. They often occur in those with either a personal or family history of typical migraine. Other syndromes that are believed to be precursors include cyclical vomiting syndrome and benign paroxysmal vertigo of childhood.
Those with stable headaches that meet criteria for migraines should not receive neuroimaging to look for other intracranial disease. This requires that other concerning findings such as papilledema (swelling of the optic disc) are not present. People with migraines are not at an increased risk of having another cause for severe headaches.
Preventive treatments of migraine include medications, nutritional supplements, lifestyle alterations, and surgery. Prevention is recommended in those who have headaches more than two days a week, cannot tolerate the medications used to treat acute attacks, or those with severe attacks that are not easily controlled. Recommended lifestyle changes include stopping tobacco use and reducing behaviors that interfere with sleep.
The goal is to reduce the frequency, painfulness, and duration of migraine episodes, and to increase the effectiveness of abortive therapy. Another reason for prevention is to avoid medication overuse headache. This is a common problem and can result in chronic daily headache.
Preventive migraine medications are considered effective if they reduce the frequency or severity of the migraine attacks by at least 50%. Guidelines are fairly consistent in rating topiramate, divalproex/sodium valproate, propranolol, and metoprolol as having the highest level of evidence for first-line use. Propranolol and topiramate have the best evidence in children; however, evidence only supports short term benefit as of 2020.
Acupuncture has a small effect in reducing migraine frequency, compared to sham acupuncture, a practice where needles are placed randomly or do not penetrate the skin. Physiotherapy, massage and relaxation, and chiropractic manipulation might be as effective as propranolol or topiramate in the prevention of migraine headaches; however, the research had some problems with methodology. Another review, however, found evidence to support spinal manipulation to be poor and insufficient to support its use.
Among alternative medicines, butterbur has the best evidence for its use. However, unprocessed butterbur contains chemicals called pyrrolizidine alkaloids (PAs) which can cause liver damage, however there are versions that are PA free. In addition, butterbur may cause allergic reactions in people who are sensitive to plants such as ragweed. There is tentative evidence that coenzyme Q10 reduces migraine frequency.
Feverfew has traditionally been used as a treatment for fever, headache and migraine, women's conditions such as difficulties in labour and regulation of menstruation, relief of stomach ache, toothache and insect bites. During the last decades, it has mainly been used for headache and as a preventive treatment for migraine. The plant parts used for medicinal use are the dried leaves or the dried aerial parts. Several historical data supports feverfew's traditional medicinal uses. In addition, several clinical studies have been performed assessing the efficacy and safety of feverfew monotherapy in the prevention of migraine. The majority of the clinical trials favoured feverfew over placebo. The data also suggest that feverfew is associated with only mild and transient adverse effects. The frequency of migraine was positively affected after treatment with feverfew. Reduction of migraine severity was also reported after intake of feverfew and incidence of nausea and vomiting decreased significantly. No effect of feverfew was reported in one study.
There is tentative evidence for melatonin as an add-on therapy for prevention and treatment of migraine. The data on melatonin are mixed and certain studies have had negative results. The reasons for the mixed findings are unclear but may stem from differences in study design and dosage. Melatonin's possible mechanisms of action in migraine are not completely clear, but may include improved sleep, direct action on melatonin receptors in the brain, and anti-inflammatory properties.
There are three main aspects of treatment: trigger avoidance, acute symptomatic control, and medication for prevention. Medications are more effective if used earlier in an attack. The frequent use of medications may result in medication overuse headache, in which the headaches become more severe and more frequent. This may occur with triptans, ergotamines, and analgesics, especially opioid analgesics. Due to these concerns simple analgesics are recommended to be used less than three days per week at most.
Paracetamol, either alone or in combination with metoclopramide, is another effective treatment with a low risk of adverse effects. Intravenous metoclopramide is also effective by itself. In pregnancy, paracetamol and metoclopramide are deemed safe as are NSAIDs until the third trimester.
Triptans such as sumatriptan are effective for both pain and nausea in up to 75% of people. When sumatriptan is taken with naproxen it works better. They are the initially recommended treatments for those with moderate to severe pain or those with milder symptoms who do not respond to simple analgesics. The different forms available include oral, injectable, nasal spray, and oral dissolving tablets. In general, all the triptans appear equally effective, with similar side effects. However, individuals may respond better to specific ones. Most side effects are mild, such as flushing; however, rare cases of myocardial ischemia have occurred. They are thus not recommended for people with cardiovascular disease, who have had a stroke, or have migraines that are accompanied by neurological problems. In addition, triptans should be prescribed with caution for those with risk factors for vascular disease. While historically not recommended in those with basilar migraines there is no specific evidence of harm from their use in this population to support this caution. They are not addictive, but may cause medication-overuse headaches if used more than 10 days per month.
Ergotamine and dihydroergotamine are older medications still prescribed for migraines, the latter in nasal spray and injectable forms. They appear equally effective to the triptans and experience adverse effects that typically are benign. In the most severe cases, such as those with status migrainosus, they appear to be the most effective treatment option. They can cause vasospasm including coronary vasospasm and are contraindicated in people with coronary artery disease.
Magnesium is recognized as an inexpensive, over-the-counter supplement which some studies have shown to be effective in both preventing and treating migraine.
Intravenous metoclopramide, intravenous prochlorperazine, or intranasal lidocaine are other potential options. Metoclopramide or prochlorperazine are the recommended treatment for those who present to the emergency department.Haloperidol may also be useful in this group. A single dose of intravenous dexamethasone, when added to standard treatment of a migraine attack, is associated with a 26% decrease in headache recurrence in the following 72 hours. Spinal manipulation for treating an ongoing migraine headache is not supported by evidence. It is recommended that opioids and barbiturates not be used due to questionable efficacy, addictive potential, and the risk of rebound headache. There is tentative evidence that propofol may be useful if other measures are not effective.
Feverfew is registered as a traditional herbal medicine in the Nordic countries under the brand name Glitinum, only powdered feverfew is approved in the Herbal community monograph issued by European Medicines Agency (EMA).
Ibuprofen helps decrease pain in children with migraines and is the initially recommended treatment. Paracetamol does not appear to be effective in providing pain relief. Triptans are effective, though there is a risk of causing minor side effects like taste disturbance, nasal symptoms, dizziness, fatigue, low energy, nausea, or vomiting. Ibuprofen should be used less than half the days in a month and triptans less than a third of the days in a month to decrease the risk of medication overuse headache.
Long-term prognosis in people living with migraine is variable. Most people with migraine have periods of lost productivity due to their disease; however typically the condition is fairly benign and is not associated with an increased risk of death. There are four main patterns to the disease: symptoms can resolve completely, symptoms can continue but become gradually less with time, symptoms may continue at the same frequency and severity, or attacks may become worse and more frequent.
Migraine with aura appears to be a risk factor for ischemic stroke doubling the risk. Being a young adult, being female, using hormonal birth control, and smoking further increases this risk. There also appears to be an association with cervical artery dissection. Migraine without aura does not appear to be a factor. The relationship with heart problems is inconclusive with a single study supporting an association. Migraine does not appear to increase the risk of death from stroke or heart disease. Preventative therapy of migraines in those with migraine with aura may prevent associated strokes. People with migraine, particularly women, may develop higher than average numbers of white matter brain lesions of unclear significance.
Worldwide, migraine affects nearly 15% or approximately one billion people. It is more common in women at 19% than men at 11%. In the United States, about 6% of men and 18% of women experience a migraine attack in a given year, with a lifetime risk of about 18% and 43% respectively. In Europe, migraines affect 12-28% of people at some point in their lives with about 6-15% of adult men and 14-35% of adult women getting at least one yearly. Rates of migraine are slightly lower in Asia and Africa than in Western countries. Chronic migraine occurs in approximately 1.4 to 2.2% of the population.
These figures vary substantially with age: onset of migraine is most commonly between 15 and 24 years of age, and occur most frequently in those 35 to 45 years of age. In children, about 1.7% of 7 year olds and 3.9% of those between 7 and 15 experience migraine, with the condition being slightly more common in boys before puberty. Children as young as two years may be affected. During adolescence, migraine becomes more common among women and this persists for the rest of the lifespan, being twice as common among elderly females than males. In women migraine without aura are more common than migraine with aura; however in men the two types occur with similar frequency.
During perimenopause symptoms often get worse before decreasing in severity. While symptoms resolve in about two thirds of the elderly, in 3 to 10% they persist.
The Head Ache, George Cruikshank (1819)
An early description consistent with migraine is contained in the Ebers papyrus, written around 1500 BCE in ancient Egypt. In 200 BCE, writings from the Hippocratic school of medicine described the visual aura that can precede the headache and a partial relief occurring through vomiting.
A second-century description by Aretaeus of Cappadocia divided headaches into three types: cephalalgia, cephalea, and heterocrania.Galen of Pergamon used the term hemicrania (half-head), from which the word migraine was eventually derived. He also proposed that the pain arose from the meninges and blood vessels of the head. Migraine was first divided into the two now used types - migraine with aura (migraine ophthalmique) and migraine without aura (migraine vulgaire) in 1887 by Louis Hyacinthe Thomas, a French Librarian. The mystical visions of Hildegard von Bingen, which she described as "reflections of the living light", are consistent with the visual aura experienced during migraines.
A trepanated skull, from the Neolithic. The perimeter of the hole in the skull is rounded off by ingrowth of new bony tissue, indicating that the person survived the operation.
Trepanation, the deliberate drilling of holes into a skull, was practiced as early as 7,000 BCE. While sometimes people survived, many would have died from the procedure due to infection. It was believed to work via "letting evil spirits escape".William Harvey recommended trepanation as a treatment for migraines in the 17th century.
While many treatments for migraine have been attempted, it was not until 1868 that use of a substance which eventually turned out to be effective began. This substance was the fungus ergot from which ergotamine was isolated in 1918.Methysergide was developed in 1959 and the first triptan, sumatriptan, was developed in 1988. During the 20th century with better study-design, effective preventive measures were found and confirmed.
Society and culture
Migraine is a significant source of both medical costs and lost productivity. It has been estimated that migraine is the most costly neurological disorder in the European Community, costing more than EUR27 billion per year. In the United States, direct costs have been estimated at $17 billion, while indirect costs -- such as missed or decreased ability to work -- is estimated at $15 billion. Nearly a tenth of the direct cost is due to the cost of triptans. In those who do attend work with a migraine, effectiveness is decreased by around a third. Negative impacts also frequently occur for a person's family.
^ abArmstrong C (April 2013). "AAN/AHS update recommendations for migraine prevention in adults". American Family Physician. 87 (8): 584-5. PMID23668450.
^ abLinde M, Mulleners WM, Chronicle EP, McCrory DC (June 2013). "Valproate (valproic acid or sodium valproate or a combination of the two) for the prophylaxis of episodic migraine in adults". The Cochrane Database of Systematic Reviews (6): CD010611. doi:10.1002/14651858.CD010611. PMID23797677.
^Wan D, Wang C, Zhang X, Tang W, Chen M, Dong Z, Yu S (1 January 2016). "Association between angiotensin-converting enzyme insertion/deletion polymorphism and migraine: a meta-analysis". The International Journal of Neuroscience. 126 (5): 393-9. doi:10.3109/00207454.2015.1025395. PMID26000817. S2CID34902092.
^Negro A, Rocchietti-March M, Fiorillo M, Martelletti P (December 2011). "Chronic migraine: current concepts and ongoing treatments". European Review for Medical and Pharmacological Sciences. 15 (12): 1401-20. PMID22288302.
^Kaniecki R, Lucas S (2004). "Treatment of primary headache: preventive treatment of migraine". Standards of care for headache diagnosis and treatment. Chicago: National Headache Foundation. pp. 40-52.
^Pringsheim T, Davenport W, Mackie G, Worthington I, Aubé M, Christie SN, et al. (March 2012). "Canadian Headache Society guideline for migraine prophylaxis". The Canadian Journal of Neurological Sciences. 39 (2 Suppl 2): S1-59. PMID22683887.
^Eken C (March 2015). "Critical reappraisal of intravenous metoclopramide in migraine attack: a systematic review and meta-analysis". The American Journal of Emergency Medicine. 33 (3): 331-7. doi:10.1016/j.ajem.2014.11.013. PMID25579820.
^ abSumamo Schellenberg, E.; Dryden, D. M.; Pasichnyk, D.; Ha, C.; Vandermeer, B.; Friedman, B. W.; Colman, I.; Rowe, B. H. (2012). "Acute migraine treatment in emergency settings". PMID23304741. Cite journal requires |journal= (help)
^Jackson JL, Kuriyama A, Hayashino Y (April 2012). "Botulinum toxin A for prophylactic treatment of migraine and tension headaches in adults: a meta-analysis". JAMA. 307 (16): 1736-45. doi:10.1001/jama.2012.505. PMID22535858.