Synopsis
Differentiate cluster headache, paroxysmal hemicrania, SUNCT or SUNA and hemicrania continua by temporal pattern and indometacin response, while excluding structural mimics.
- Trigeminal autonomic cephalalgias combine strictly unilateral trigeminal-distribution pain with ipsilateral cranial autonomic activation or attack-related restlessness.
- Duration and frequency are the quickest discriminator: cluster lasts 15–180 minutes, paroxysmal hemicrania 2–30 minutes, and SUNCT or SUNA usually seconds to minutes.
- Paroxysmal hemicrania usually occurs more than five times daily and responds absolutely to adequate indometacin, making a supervised trial diagnostically important.
Key red flags
Abnormal ocular movements, field loss, endocrine symptoms, persistent Horner syndrome, bilateral or changing signs, late atypical onset or incomplete syndrome raises concern for structural disease.
Investigation priorities
Capture untreated duration in seconds or minutes, attack number, continuous background pain, triggers and exact autonomic signs.
Management branches
Severe side-locked orbital or temporal pain occurs with cranial autonomic symptoms.
- Record untreated duration precisely, daily frequency, background pain, bout-remission pattern, triggers, restlessness and which autonomic signs occur on the pain side.
- Map minutes-to-hours attacks towards cluster, 2–30-minute high-frequency attacks towards paroxysmal hemicrania, seconds-to-minutes attacks towards SUNCT or SUNA, and continuous pain towards hemicrania continua.
Key medicines
Indometacin diagnostic and preventive trialUse a headache-specialist titration to an adequate therapeutic exposure, then reduce to the lowest dose that maintains complete control if diagnosis is confirmed.
LamotrigineStart at the specialist low dose and titrate slowly over weeks using the current BNF schedule and interaction-specific adjustments.