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
- 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)
- Russell, MB and Olesen, J. Increased familial risk and evidence of genetic factor in migraine. BMJ 1995; 311:541-543.
- Headache Classification Committee of the International Headache Society (IHS). The international classification of headache disorders, 3rd edition. Cephalalgia 2018; 38: 1-211
- Ashina M. Migraine. N Engl J Med 2020;383:1866-76. DOI: 10.1056/NEJMra1915327
Last edited 11/2020 and last reviewed 07/2021