Last edited 11/2020 and last reviewed 03/2023

There is no accepted aetiology of common migraine and migraine with aura.

Several theories are proposed:

Vascular theory:
    • some studies e.g. PET scans of migraineurs, suggest that the aura is due to an spreading area of vascoconstriction over the brain
    • there is some evidence that the headache in migraine is due to subsequent vasodilatation of blood vessels
    • the association of stroke with migraine supports a vascular aetiology
Neuronal theory:
    • aura are associated with spreading neuronal inhibition which does not respect vascular territories
    • neuronal dysfunction could be the cause of the spreading vasoconstriction

A hypothalamic trigger may cause periodic overactivity of the trigeminal pain pathways

Familial hemiplegic migraine (2)

  • new genetic data have allowed a more precise definition of Familial hemiplegic migraine than was previously possible. Specific genetic subforms have been identified: in FHM1 there are mutations in the
  • CACNA1A gene (coding for a calcium channel) on chromosome 19; in FHM2 there are mutations in the ATP1A2 gene (coding for a K/Na-ATPase) on chromosome 1; and in FHM3 there are mutations in the SCN1A gene (coding for a sodium channel) on chromosome 2. There may be other loci not yet identified

A family history of migraine is common, with the heritability estimated to be approximately 42% (3)