Migraine

Primary headache disorder characterized by recurrent episodic headaches, typically unilateral, pulsating, moderate-severe intensity, associated with nausea/vomiting and photophobia/phonophobia, often with identifiable triggers. Believed to involve trigeminovascular activation, cortical spreading depression (underlying aura), and neurogenic inflammation.

Classified by:

• Migraine without aura (most common, ~70-80%)

• Migraine with aura: transient focal neurological symptoms preceding/accompanying headache (visual most common, also sensory, speech/language, motor; hemiplegic migraine)

• Chronic migraine: headache ≥15 days/month for >3 months, with migrainous features on ≥8 days/month

• Menstrual migraine: associated with perimenstrual estrogen withdrawal

• Migraine with brainstem aura (formerly basilar-type): dysarthria, vertigo, tinnitus, diplopia, ataxia

• Status migrainosus: debilitating migraine lasting >72 hours

Four phases (not all present every attack): premonitory (hours-days before — mood change, food cravings, neck stiffness, yawning, fatigue), aura (if present, 5-60 min, fully reversible), headache (4-72 hours untreated), postdrome (fatigue, mood change, cognitive fogginess)

• Headache characteristics: unilateral (can be bilateral, especially in children), pulsating/throbbing, moderate-severe intensity, aggravated by routine physical activity

• Associated features: nausea ± vomiting, photophobia, phonophobia (patient seeks dark, quiet environment)

• Aura (if present): visual most common; scintillating scotoma, zigzag fortification spectra, expanding/migrating over 5-20 minutes, followed by or overlapping with headache onset

Triggers: stress (and post-stress relaxation), hormonal changes (menstruation, oral contraceptives), sleep disruption, fasting/skipped meals, specific foods (variable, individual; chocolate, cheese, alcohol/red wine, caffeine withdrawal), dehydration, weather changes, sensory stimuli (bright/flickering lights, strong odors)

Diagnostic criteria (ICHD-3, migraine without aura): ≥5 attacks fulfilling: duration 4-72 hours (untreated), ≥2 of (unilateral, pulsating, moderate-severe intensity, aggravation by activity), and ≥1 of (nausea/vomiting, photophobia+phonophobia)

Red flags ("SNOOP" mnemonic: warrant urgent investigation to exclude secondary headache): Systemic symptoms/illness (fever, weight loss, malignancy history), Neurological signs/symptoms (focal deficit, altered consciousness, papilledema), Onset sudden/thunderclap (subarachnoid hemorrhage until proven otherwise), Older age (>50, new headache — giant cell arteritis, malignancy), Pattern change (progressive, positional, precipitated by cough/exertion/Valsalva, or first/worst headache)

Clinical diagnosis based on ICHD-3 criteria and headache history/diary; neuroimaging NOT routinely required in typical migraine with stable pattern and normal neurological exam.

Neuroimaging (MRI preferred) indicated if:

• Red flag features present (see above)

• Atypical aura (prolonged, motor symptoms, first presentation of aura, or aura without headache in older patient)

• Abnormal neurological examination

• Change in headache pattern/frequency/severity

• First presentation after age 50

Differentials: tension-type headache (bilateral, pressing/tightening, mild-moderate, no significant nausea/photophobia), cluster headache (severe unilateral periorbital pain, autonomic features; lacrimation, ptosis, nasal congestion, shorter duration, circadian/seasonal clustering), medication overuse headache (regular analgesic/triptan use >10-15 days/month), secondary headaches (SAH, meningitis, venous sinus thrombosis, giant cell arteritis, idiopathic intracranial hypertension, tumor, cervicogenic headache).

Acute/abortive treatment (as early as possible in attack):

• Mild-moderate attacks: simple analgesics — NSAIDs (ibuprofen 400-600mg, naproxen 500-750mg, aspirin 900mg-1g) ± antiemetic (metoclopramide 10mg or domperidone 10mg; also has prokinetic benefit for gastric stasis during migraine, improving analgesic absorption)

• Moderate-severe attacks / NSAID non-response: triptans (5-HT1B/1D agonists) — sumatriptan 50-100mg PO (or 6mg SC for rapid onset/vomiting, or nasal spray), rizatriptan 10mg, zolmitriptan 2.5-5mg; can combine with NSAID for enhanced efficacy

• Contraindications: cardiovascular disease, uncontrolled hypertension, history of stroke/TIA, hemiplegic/brainstem aura migraine (vasoconstrictive risk)

• Avoid overuse (>10 days/month risk of medication overuse headache)

• Refractory/status migrainosus: IV fluids, IV antiemetics (metoclopramide, prochlorperazine), IV/IM ketorolac, consider IV dihydroergotamine (specialist setting), corticosteroids (dexamethasone) may reduce early recurrence

• Newer targeted acute agents (for triptan non-responders/contraindications): gepants (rimegepant, ubrogepant; CGRP receptor antagonists), lasmiditan (5-HT1F agonist, no vasoconstrictive risk but causes sedation, driving restriction)

Preventive therapy; indicated if: ≥4 headache days/month, significant disability despite acute treatment, frequent/prolonged/refractory attacks, medication overuse risk, or specific subtypes (hemiplegic migraine):

• First-line oral preventives: beta-blockers (propranolol 80-240mg/day), candesartan (8-32mg od), tricyclic antidepressants (amitriptyline 10-75mg nocte; also useful if comorbid tension-type headache/insomnia), anticonvulsants (topiramate 50-100mg/day; teratogenic, contraception counseling essential; sodium valproate; avoid in women of childbearing potential)

• CGRP-targeted therapies (for inadequate response to ≥2 oral preventives): monoclonal antibodies — erenumab, fremanezumab, galcanezumab (subcutaneous, monthly/quarterly); oral gepants (atogepant, rimegepant) also used preventively

• Botulinum toxin type A: licensed specifically for chronic migraine (≥15 headache days/month), administered as fixed-site injections every 12 weeks

• Trial preventive for minimum 8-12 weeks at adequate dose before judging efficacy; reassess need for continuation every 6-12 months

Non-pharmacological: trigger identification/avoidance (headache diary), regular sleep/meal schedule, hydration, stress management, regular exercise, consider CBT/biofeedback for chronic/refractory cases.

Menstrual migraine: mini-prophylaxis with NSAID or triptan started 2 days before expected onset through menstruation; hormonal manipulation (continuous combined contraception) in selected patients.

Referral: neurology for diagnostic uncertainty, red flag features, refractory/chronic migraine despite first-line preventives, atypical aura, or consideration of CGRP therapy/Botox.