What are primary headaches and how do the three types differ?
A primary headache is a headache disorder in its own right, not a symptom of another disease. The three exam-relevant types are migraine, cluster headache (a trigeminal autonomic cephalalgia) and tension-type headache (TTH). TTH is the most common primary headache; migraine is the second most common and a leading cause of disability. The International Classification of Headache Disorders, 3rd edition (ICHD-3) defines each.
| Feature | Migraine | Cluster headache | Tension-type headache |
|---|---|---|---|
| Side | Often unilateral | Strictly unilateral, orbital / supraorbital / temporal | Bilateral |
| Quality | Pulsating / throbbing | Excruciating, non-fluctuating, explosive | Dull, pressing, band-like tightness |
| Intensity | Moderate to severe | Very severe (10/10) | Mild to moderate |
| Duration | 4–72 hours | 15–180 minutes | 30 minutes to 7 days |
| Behaviour | Prefers to lie still in a dark room | Restless, paces or rocks | Can continue routine activity |
| Associated | Nausea, vomiting, photophobia, phonophobia; aura in some | Ipsilateral lacrimation, red eye, nasal congestion, ptosis / miosis | Nausea absent or very mild |
| Aggravated by routine activity | Yes | No (patient is restless) | No |
| Sex | More in women | Men about three times more than women | — |
What are the diagnostic criteria and types of migraine?
Migraine is a genetically influenced neurological disorder of recurrent, moderate-to-severe, usually unilateral headaches with nausea and sensitivity to light and sound. It affects roughly 12% of the population (up to 17% of women and 6% of men), peaks between ages 35 and 39 and ranks among the leading causes of disability. Migraine without aura is the commonest type, accounting for 75% of cases.
| Criterion | Requirement |
|---|---|
| A | At least 5 attacks |
| B | Headache lasts 4–72 hours (untreated or unsuccessfully treated) |
| C | At least 2 of: unilateral, pulsating, moderate-to-severe, aggravated by (or causing avoidance of) routine activity |
| D | During headache at least 1 of: nausea/vomiting, or photophobia and phonophobia |
| E | Not better explained by another ICHD-3 diagnosis |
- Migraine with aura: at least 2 attacks with fully reversible aura (visual, sensory, speech, motor, brainstem or retinal). The aura develops gradually over 5 minutes or more, each symptom lasts 5–60 minutes, and the headache follows within 60 minutes. About 25% of patients have aura; visual aura is commonest.
- Chronic migraine: headache on 15 or more days per month for more than 3 months, with migraine features on at least 8 days per month.
- Hemiplegic migraine: aura with motor weakness. Familial types are channelopathies: FHM1 — CACNA1A (calcium channel, chromosome 19), FHM2 — ATP1A2 (Na+/K+ ATPase, chromosome 1), FHM3 — SCN1A (sodium channel).
- Migraine with brainstem aura (formerly basilar migraine) and retinal migraine (monocular visual loss) are the other aura variants.
- Complications: status migrainosus (attack over 72 hours), persistent aura without infarction (over 1 week) and migrainous infarction.
What is the pathophysiology of migraine?
The older vascular theory (vasodilation causes headache, vasoconstriction causes aura) is no longer considered viable. Current understanding is neuronal: cortical spreading depression of Leão, a propagating wave of neuronal and glial depolarisation, is thought to cause the aura and to activate trigeminal afferents, producing inflammation in the pain-sensitive meninges and the headache.
- Trigeminovascular system: activation releases substance P, calcitonin gene-related peptide (CGRP) and neurokinin A, causing neurogenic inflammation and sensitisation.
- CGRP is a potent vasodilator of cerebral and dural vessels and mediates pain transmission from trigeminal vessels. This is why CGRP-targeted drugs now exist (see below).
- Serotonin is involved; PACAP levels rise during attacks.
- Triggers: stress, hormonal change (menstruation), skipped meals, weather change, sleep disturbance, bright light, alcohol (particularly wine). About 76% of patients report triggers.
How is migraine treated — abortive and preventive drugs?
| Option | Details |
|---|---|
| NSAIDs (ibuprofen, naproxen, diclofenac, aspirin) or paracetamol | Mild-to-moderate attacks without vomiting |
| Triptans (sumatriptan, zolmitriptan, eletriptan, rizatriptan, almotriptan) | First-line for moderate-to-severe attacks, especially with allodynia. 5-HT1B/1D agonists. Sumatriptan 6 mg subcutaneous; limit to under 10 days per month |
| Antiemetics (metoclopramide, prochlorperazine, chlorpromazine) | Adjunct for nausea; diphenhydramine to prevent dystonia with metoclopramide |
| CGRP receptor antagonists (gepants) — rimegepant, ubrogepant | For triptan non-responders or those with coronary disease |
| Ergots (ergotamine, dihydroergotamine) | Parenteral rescue and bridge for status migrainosus; ischaemic complications |
- Preventive drugs: propranolol or metoprolol (beta-blockers), amitriptyline or venlafaxine, topiramate or valproate, flunarizine or verapamil, CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab).
- OnabotulinumtoxinA for chronic migraine (headache on 15 or more days per month lasting 4 or more hours a day).
- Indications for prevention: frequent or disabling attacks, failure or contraindication of acute drugs, risk of medication overuse, menstrual migraine, hemiplegic migraine, brainstem aura.
What is cluster headache and how is it treated?
Cluster headache is the commonest of the trigeminal autonomic cephalalgias (TACs), affecting about 0.1% of people; onset is typically around 30 years and men are about three times more often affected. Smoking is strongly associated. It is regarded as one of the most severe headaches, with 10/10 unilateral orbital or supraorbital pain.
- ICHD-3: at least 5 attacks of severe unilateral orbital, supraorbital or temporal pain lasting 15–180 minutes, with at least one ipsilateral autonomic sign (conjunctival injection or lacrimation, nasal congestion or rhinorrhoea, eyelid oedema, forehead sweating, miosis or ptosis) or restlessness, at a frequency from one every other day to eight per day.
- Autonomic signs: lacrimation/red eye in about 90%, nasal congestion in 84%.
- Circadian pattern: attacks often at the same time, typically at night; the hypothalamus is implicated (PET activation of inferior hypothalamic grey matter).
- Episodic (bouts of 7 days to 1 year separated by remission of 3 months or more) vs chronic (no remission, or remission under 3 months, for at least 1 year).
- Triggers: alcohol, nitroglycerin, heat, stress.
| Aim | Drug | Note |
|---|---|---|
| Acute | 100% oxygen by mask | Level A recommendation; unique to cluster headache; at least 66% respond within about 10 minutes |
| Acute | Subcutaneous sumatriptan, or zolmitriptan nasal spray | Oral triptans are too slow |
| Prevention (first-line) | Verapamil (starting 240 mg once daily) | Monitor ECG |
| Transitional bridge | Oral prednisone short course; suboccipital blockade | For short, infrequent cluster periods or while waiting for verapamil to act |
| Others | Lithium, valproate, melatonin; hypothalamic deep brain stimulation for refractory cases | — |
What is tension-type headache, and what is medication overuse headache?
Tension-type headache is the commonest primary headache. ICHD-3 requires at least 10 episodes; each lasts 30 minutes to 7 days, is bilateral, pressing or tightening (non-pulsating), of mild-to-moderate intensity and not aggravated by routine physical activity. Nausea, vomiting, photophobia and phonophobia are typically absent or very mild. It is classified as infrequent episodic, frequent episodic or chronic. Acute treatment is with ibuprofen 400 mg or paracetamol 1000 mg; for chronic TTH the best-studied preventive is amitriptyline.
Medication overuse headache (MOH), formerly rebound headache, is a secondary chronic headache occurring on 15 or more days per month for 3 or more months in a patient using acute treatment too often: simple analgesics or NSAIDs on 15 or more days per month, or triptans, ergots, opioids or combination analgesics on 10 or more days per month. Treatment is education and withdrawal of the overused drug; symptoms may worsen early and withdrawal effects last up to about 10 days.
How are headaches asked in NEET PG and INI-CET?
- Drug of choice: abortive migraine → triptan; cluster headache attack → 100% oxygen; cluster prophylaxis → verapamil; paroxysmal hemicrania → indomethacin.
- Duration clues: 4–72 hours migraine; 15–180 minutes cluster; 2–30 minutes paroxysmal hemicrania; seconds SUNCT.
- Behaviour clue: restless and pacing = cluster; lies still in a dark room = migraine.
- Genetics: familial hemiplegic migraine → CACNA1A, ATP1A2, SCN1A.
- Contraindication: triptans in coronary artery disease and hemiplegic migraine.