Migraine: Causes

Pathogenesis (disease development)

Exactly what causes migraine is not yet known. However, there are both established clues and assumptions as to what causes a migraine.Two main factors are thought to be responsible for migraine attacks: genetic causes and the influence of environmental factors. A special form of migraine, which runs in families, is inherited via a gene that has already been decoded. As far as genetic influences on the disease are concerned, scientists are relatively certain. The genetic cause also explains why the disease cannot be cured. Only the symptoms can be treated. However, it is not possible to eliminate the cause. During a seizure, both the blood and oxygen supply to the brain are reduced. It is thought that a specific area of the brain – brainstem and midbrain – activates branches of the trigeminal nerve during an attack. This nerve leads to the release of vasoactive neurotransmitters (messenger substances that influence vascular tone) in the blood vessels of the meninges and on the nerve tissue, with consecutive neurogenic inflammation of the dura (= painful inflammation of the outermost meninges). In most cases, sufferers know which factors trigger an attack in them. About 90% of all migraine patients have trigger factors. The pathogenesis of chronic migraine can be traced to permanent inflammatory processes in the periosteum (periosteum; i.e., nerve endings and blood vessels of the periosteum). This is the first indication of a locally circumscribed extracranial cause of migraine.

Trigger factors

Trigger factors that may precipitate an attack in migraine patients include:

  • Hormonal fluctuations in women during the menstrual cycle – such as premenstrual drop in serum 17-beta estradiol levels.
  • Rarely certain foods (e.g., chocolate, ice cream, cheese).
  • High consumption of table salt in combination with consumption of processed meats may trigger migraine. However, the mechanism of action is not yet known.
  • Fluctuations in caffeine levels in patients who regularly drink coffee.
  • Daily chewing gum consumption (1-6 /die).
  • Pleasure gum consumption:
    • Alcohol (especially red wine)
    • Nicotine/tobacco (smoking)
  • An altered sleep-wake rhythm
  • Stress, emotional stress

In extremely rare cases, ischemic apoplexy can trigger a migraine attack.

Etiology (causes)

The following risk factors are important in migraine.

Biographic causes

  • Genetic exposure
    • Genetic risk depending on gene polymorphisms:
      • Genes/SNPs (single nucleotide polymorphism; English : single nucleotide polymorphism):
        • Genes: LRP1, PRDM16, TRPM8.
        • SNP: rs13208321 in an intergenic region.
          • Allele constellation: AG (1.18-fold).
          • Allele constellation: AA (1.4-fold)
        • SNP: rs2561899 in the gene PRDM16
          • Allele constellation: AG (1.1-fold).
          • Allele constellation: GG (1.2-fold)
        • SNP: rs11172113 in the gene LRP1
          • Allele constellation: CT (0.9-fold).
          • Allele constellation: CC (0.8-fold)
        • SNP: rs10166942 in the TRPM8 gene.
          • Allele constellation: CT (0.85-fold).
          • Allele constellation: CC (0.7-fold)
  • Hormonal factors – hormonal fluctuations in women; often at the onset of menstrual bleeding (premenstrual drop in serum 17-beta estradiol level).

Behavioral causes

  • Nutrition
    • Fat – A low fat intake has a positive effect on the number as well as the severity of migraine attacks compared to a diet with moderate fat content.
    • Cheese, especially its component tyramine.
    • Chocolate, especially its component phenylethylamine
    • Hunger
    • Food abstinence
    • Micronutrient deficiency (vital substances) – see Prevention with micronutrients.
  • Consumption of stimulants
    • Alcohol, especially red wine (especially the components tyramine and sulfites).
    • Coffee – seizure risk increases from the third cup of coffee.
    • Tobacco (smoking)
  • Psycho-social situation
    • Anxiety
    • Stress
    • Relief after stressful situations
    • Sudden relaxation (Sunday migraine)
  • Change of sleep habits (or change of sleep-wake rhythm) and sleep deprivation.
  • Overweight (BMI ≥ 25; obesity) – risk factor for the development of chronic migraine: there is an almost linear relationship between body weight and the severity of chronic migraine: overweight people are not affected by migraine more often than slim people, but with increasing BMI (body mass index) the attacks become more severe and occur more frequently. In normal-weight individuals (BMI 18.5 to 24.9), 4% reported 10 to 15 headache days per month; in obese individuals (BMI 30 to 35), the rate was 14%, and in those with a BMI over 35, the rate was 20%.

Disease-related causes

  • Hypoglycemia (low blood sugar)
  • Persistent foramen ovale (PFO) – patent foramen ovale; this allows a cardiac right-to-left shunt at the atrial level (door-like connection between the atria); clustered occurrence of migraine in people with PFO; in addition, large PFOs are particularly common in migraine patients.

Medications

  • Taking hormonal drugs in women for contraception or menopause (menopause).
  • Fenfluramine (appetite suppressant).
  • Reserpine – antisympathicotonic; drug that inhibits the synthesis or release of norepinephrine; they are used in the treatment of hypertension (high blood pressure); however, they have relatively many side effects, which is why they are not drugs of first choice
  • Other medications: for more information, see “Drug side effects” under “Headache due to medication.”

Environmental pollution – intoxications (poisoning).

  • Flickering light
  • Noise
  • Stay at high altitude
  • Weather influences, especially cold; also foehn
  • Smoke