Migraine
A primary headache disorder driven by transient neuronal and vascular dysfunction (cortical spreading depression generates the aura, trigeminovascular activation generates the pain), producing a stereotyped, self-limiting attack rather than a structural lesion.
In a nutshell
Migraine begins with a slow wave of cortical depolarisation, spreading depression, producing a gradually evolving aura, and activates trigeminal afferents around meningeal vessels to cause unilateral, throbbing pain with nausea and photophobia.
Classic presentation
A young adult with recurrent unilateral, throbbing headache lasting hours, accompanied by nausea, photophobia and phonophobia, occasionally preceded by an expanding visual aura.
Key points
- Aura evolves gradually over minutes because cortical spreading depression is a slow wave: this distinguishes it from the abrupt onset of TIA or stroke.
- Pain arises from trigeminovascular activation and neurogenic inflammation of meningeal vessels, explaining the throbbing quality and worsening with activity.
- Triptans abort an attack by acting on the trigeminovascular pathway and must be taken early; preventive drugs raise the attack threshold instead.
- Migraine is a clinical diagnosis; imaging is reserved for atypical features or red flags, not for typical presentations.
- Frequent use of acute medication can itself cause medication overuse headache, perpetuating the cycle.
First-line investigation
None routinely: diagnosis is clinical, based on the stereotyped attack pattern; imaging is reserved for red flags or atypical features.
First-line management
Early acute treatment with an NSAID or triptan plus antiemetic, and preventive therapy if attacks are frequent or disabling.
Exam traps
- Thunderclap headache maximal at onset is not migraine: it must trigger a subarachnoid haemorrhage work-up.
- Aura lasting more than an hour with abrupt, not gradual, onset should raise concern for stroke or TIA, not be assumed to be migrainous.
- Triptans are contraindicated in patients with cardiovascular or cerebrovascular disease because of their vasoconstrictive action, a common prescribing trap.
Educational content pending clinical review. Not medical advice.