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Migraine and Other Primary Headache Disorders

Chapter 441 | Part 13: Neurologic Disorders · Part 13 – Neurologic Disorders · Chapter 441


Key Clinical Points

  1. Migraine is the second most common cause of headache and the leading neurologic cause of disability globally.
  2. Migraine attacks typically progress through four phases: premonitory (prodrome), aura, headache, and postdrome.
  3. Pathophysiology involves trigeminovascular system activation, CGRP/PACAP release, and brainstem/hypothalamus dysfunction.
  4. Triptans are 5-HT1B/1D agonists; Ditans are 5-HT1F agonists (acting only on neural targets).
  5. CGRP receptor antagonists (gepants) and monoclonal antibodies provide both acute and preventive options.
  6. Medication-overuse headache (MOH) is a risk with frequent use of analgesics, especially opioids or barbiturates.
  7. Preventive treatment is indicated for ≥ 4 migraine days per month; effect lag is 2–12 weeks.
  8. Neuromodulation (sTMS, nVNS, REN, Cefaly, Relivion) is FDA-cleared for both acute and preventive use.
  9. Migraine is generally not associated with life-threatening illness except in women on specific hormonal medications.
  10. Opioids are suboptimal for recurring headaches and may reduce the efficacy of triptans.

DEFINITION & CLASSIFICATION

Definition (Harrison's 24e): Disorders in which headache and associated features occur in the absence of any exogenous cause.

Migraine: Second most common cause of headache; most common neurologic cause of disability.

Tension-Type Headache (TTH): Characterized as a featureless headache. Most patients with disabling headaches have migraine.

Trigeminal Autonomic Cephalalgias (TACs): Includes conditions like cluster headache; full list in Table 441-1.

Primary Headache Disorders (Table 441-1)

Migraine Categories: Includes migraine without aura, migraine with aura (typical, brainstem, hemiplegic, retinal), chronic migraine, and complications like status migrainosus or migrainous infarction.TTH Categories: Infrequent episodic, frequent episodic, and chronic TTH.TACs Categories: Cluster headache (episodic/chronic), paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks (SUNCT/SUNA).Other Primary Disorders: Includes cough, exercise, sexual activity, thunderclap, cold-stimulus, external-pressure, stabbing, nummular, hypnic, and new daily persistent headache (NDPH).


EPIDEMIOLOGY

Prevalence: Affects ~15% of women and 6% of men over a 1-year period.Impact: Second most common cause of headache; leading neurologic cause of disability worldwide.


ETIOLOGY & PATHOPHYSIOLOGY

Sensory Sensitivity: Due to dysfunction of monoaminergic and other sensory control systems in the brainstem and hypothalamus.Trigeminovascular System: Activation of trigeminal neurons → release of vasoactive neuropeptides (CGRP, PACAP) at vascular terminals and within the trigeminal nucleus.Central Processing: Second-order trigeminal neurons cross midline → project to ventrobasal/posterior thalamic nuclei; also project to periaqueductal gray and hypothalamus.Descending Modulation: rudium pathways from locus coeruleus, parabrachial nucleus, and rostroventromedial medulla provide antinociceptive effects._

Neurotransmitter Involvement

5-HT (Serotonin): Involved in migraine pathophysiology; triptans target 5-HT1B and 5-HT1D receptors to arrest nerve signaling and promote vasoconstriction.Ditans: Target 5-HT1F receptor; act only at neural targets (no vasoconstriction).Dopamine: Premonitory symptoms can be induced by dopaminergic stimulation; migraineurs show dopamine receptor hypersensitivity (e.g., yawning, nausea, vomiting).Hypothalamus: Activation in the premonitory phase may explain the role of dopamine.

Genetic Factors

Ion Channel Involvement: Mutations suggest altered membrane excitability predisposes to migraine.FHM 1: CACNA1A gene (Ca2+ channel) mutation; accounts for ~50% of FHM cases.FHM 2: ATP1A2 gene (Na+-K+ ATPase) mutation; accounts for ~20% of FHM cases.FHM 3: SCN1A gene (Na+ channel) mutation.


CLINICAL FEATURES

Triggers: Altered sleep, hunger, stress let-down, physical exertion, weather/barometric changes, hormonal fluctuations (menses), alcohol, and chemical stimulants (nitrates).Patient Education: Migraine is an inherited tendency; it can be managed but not eradicated; generally not life-threatening except in specific cases involving estrogen/contraceptives.

Attack Phases (Table 441-2)

Premonitory (Prodrome): Neck discomfort, higher center, cognitive impairment (brain fog), mood change, fatigue, yawning/sleepiness, polyuria/polydipsia, food cravings.Aura: Neurologic disturbance; e.g., scintillating scotoma (20–25% of patients).Headache Phase: Pain, nausea/vomiting, sensory sensitivity (photophobia, phonophobia, osmophobia), allodynia, vertigo.Postdrome: Tiredness, weariness, concentration impairment.


DIFFERENTIAL DIAGNOSIS

TTH vs. Migraine: TTH is featureless; migraine includes associated features (nausea, photophobia).TACs: Includes cluster headache and paroxysmal hemicrania.


DIAGNOSTIC APPROACH

  1. Initial Assessment: Identify repeated attacks of headache lasting 4–72 h with a normal physical exam and no other reasonable cause.
  2. Migraine Criteria (Table 441-3): Must have ≥ 2 features: Unilateral pain, Throbbing pain, Aggravation by movement, or Moderate/severe intensity.
  3. Associated Features: Must have ≥ 1 feature: Nausea/vomiting OR Photophobia and phonophobia.
  4. Chronic Migraine Identification: Diagnosis if patient has migraine on ≥ 8 days per month AND ≥ 15 total headache days per month.
  5. Disability Assessment: Utilize MIDAS (Figure 6) to quantify impact on daily life.

MANAGEMENT & TREATMENT

General Principles: Select treatment based on severity; use adequate dose as soon as possible. If symptoms persist/return within 60 min, increase initial dose or switch class.Nonpharmacologic Management: Trigger avoidance, regular sleep/diet, exercise, and stress reduction (yoga, meditation, biofeedback).

  1. Acute Attack Therapies (Table 441-4): Simple Analgesics: Acetaminophen, aspirin, caffeine (Excedrin Migraine: 2 tabs q6h, max 8/day). NSAIDs: Naproxen (220–550 mg PO bid), Ibuprofen (400 mg PO q3–4h), Tolfenamic acid (200 mg PO; repeat x1 after 1–2 h), Diclofenac K (50 mg PO). Triptans: Ergotamine/Caffeine (1mg/100mg, max 6/day, 10/week), Naratriptan (2.5 mg), Rizatriptan (5–10 mg), Sumatriptan (50–100 mg oral; 3–6 mg SC; 5–20 mg nasal), Frovatriptan (2.5 mg), Almotriptan (12.5 mg), Eletriptan (40 or 80 mg). Nasal Agents: Dihydroergotamine (Migranal/Trudhesa), Sumatriptan (Imitrex Nasal), Zolmitriptan (Zomig).* _Gepants: Rimegepant (75 mg ODT), Ubrogepant (50 or 100 mg), Zavegepant (10 mg nasal). Ditans: Lasmiditan (50, 100, or 200 mg). Dopamine Antagonists: Metoclopramide (5–10 mg/d), Prochlorperazine (1–25 mg/d), Chlorpromazine (0.1 mg/kg IV). Neuromodulation: sTMS, nVNS, REN, Cefaly, Relivion.

  2. Clinical Stratification of Acute Treatment (Table 441-5): Failed NSAIDs → Triptans (Sumatriptan, Almotriptan, Rizatriptan, Eletriptan, Zolmitriptan) or Gepants/Ditans. Slower effect/better tolerability → Naratriptan (2.5 mg), Frovatriptan (2.5 mg). Headache recurrence → Ergotamine 2 mg (most effective PR) or Naratriptan, Almotriptan, Eletriptan, Rimegepant, Ubrogepant. Early vomiting → Zolmitriptan 5 mg nasal, Zavegepant 10 mg nasal, Sumatriptan 25 mg PR or 6 mg SC. Very rapidly developing symptoms → Zolmitriptan 5 mg nasal, Zavegepant 10 mg nasal, Sumatriptan 6 mg SC, Dihydroergotamine 1 mg IM.

  3. Preventive Treatments (Table 441-6): Beta blockers: Propranolol (40–120 mg bid), Metoprolol (25–100 mg bid). Anticonvulsants: Topiramate (25–200 mg/d), Valproate (400–600 mg bid or 0.5–2 mg qd). CGRP Blockers: Eptinezumab (100-300 mg every 12 weeks), Erenumab (70-140 mg monthly), Fremanezumab (225mg/675mg), Galcanezumab (240mg load, 120mg monthly). Gepants: Rimegepant (75 mg every other day), Atogepant (10-60 mg daily). Neuromodulation: sTMS (4–24 pulses/day), nVNS (120s 2–3x daily), REN (45 min every other day), Cefaly (20 min daily).

Trigeminal Autonomic Cephalalgias Management (Table 441-7 & 8)

Cluster Headache: Acute: Sumatriptan injection/nasal, Zolmitriptan nasal, Oxygen, nVNS. Prevention: Verapamil (160–960 mg/d), Galcanezumab (300 mg SC), Melatonin (9–12 mg/d), Topiramate (100–400 mg/d), Lithium (400–800 mg/d).Paroxysmal Hemicrania: Acute: Indomethacin. Prevention: Indomethacind, nVNS.SUNCT/SUNA: Prevention: Lamotrigine, Gabapentin.


COMPLICATIONS & PROGNOSIS

Medication-Overuse Headache (MOH): Result of frequent use of acute analgesics; especially opioids or barbiturates.Status Migrainosus: Defined in Table 441-1 as a complication.Migrainous Infarction: Potential complication listed in Table 441-1.


SPECIAL POPULATIONS

Women and Reproductive Years: Sensitivity to triggers is amplified during the menstrual cycle. Migraine is not associated with life-threatening illness except in women on oral estrogens or contraceptives.


KEY PEARLS & HIGH-YIELD POINTS

Triptan vs Ditan: Triptans (5-HT1B/1D) cause vasoconstriction; Ditans (5-HT1F) do not.Opioid Use: Opioids are suboptimal for recurring headache and may decrease response to triptans.CGRP Blockers: Include both monoclonal antibodies (Eptinezumab, Erenumab, Fremanezumab, Galcanezumab) and small molecules (Rimegepant, Atogepant).Clinical Rule for Acute Treatment: If symptoms do not abate within 60 min, increase dose or switch class.


Reference Tables

TABLE 441-1 Primary Headache Disorders, Modified from International Classification of Headache Disorders-III (Headache…

Harrison's 22e, p.3463

1. Migraine 1.1 Migraine without aura
1.2 Migraine with aura
1.2.1 Migraine with typical aura
1.2.1.1 Typical aura with headache
1.2.1.2 Typical aura without headache
1.2.2 Migraine with brainstem aura
1.2.3 Hemiplegic migraine
1.2.3.1 Familial hemiplegic migraine (FHM)
1.2.3.1.1 Familial hemiplegic migraine type 1
1.2.3.1.2 Familial hemiplegic migraine type 2
1.2.3.1.3 Familial hemiplegic migraine type 3
1.2.3.1.4 Familial hemiplegic migraine, other loci
1.2.3.2 Sporadic hemiplegic migraine
1.2.4 Retinal migraine
1.3 Chronic migraine
1.4 Complications of migraine
1.4.1 Status migrainosus
1.4.2 Persistent aura without infarction
1.4.3 Migrainous infarction
1.4.4 Migraine aura-triggered seizure
1.5 Probable migraine
1.5.1 Probable migraine without aura
1.5.2 Probable migraine with aura
1.6 Episodic syndromes that may be associated with migraine
1.6.1 Recurrent gastrointestinal disturbance
1.6.1.1 Cyclical vomiting syndrome
1.6.1.2 Abdominal migraine
1.6.2 Benign paroxysmal vertigo
1.6.3 Benign paroxysmal torticollis
A 1.6.4 Infantile colic
A 1.6.6 Vestibular migraine
3. Trigeminal autonomic cephalalgias 3.1 Cluster headache
3.1.1 Episodic cluster headache
3.1.2 Chronic cluster headache
3.2 Paroxysmal hemicrania
3.2.1 Episodic paroxysmal hemicrania
3.2.2 Chronic paroxysmal hemicrania
3.3 Short-lasting unilateral neuralgiform headache attacks
3.3.1 Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)
3.3.1.1 Episodic SUNCT
3.3.1.2 Chronic SUNCT
3.3.2 Short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA)
3.3.2.1 Episodic SUNA
3.3.2.2 Chronic SUNA
3.4 Hemicrania continua
3.5 Probable trigeminal autonomic cephalalgia

TABLE 441-2 Migraine Symptoms by Attack Phase Premonitory (prodromal) - Neck discomfort - Higher center • Cognitive…

Harrison's 22e, p.3464

  • Premonitory (prodromal)
    - Neck discomfort
    - Higher center
    • Cognitive impairment (brain “fog”)
    • Mood change
    • Fatigue
    - Homeostatic
    • Yawning/sleepiness
    • Polyuria/polydipsia
    • Food cravings
    Aura
    - Neurologic disturbance, such as scintillating scotoma
    Headache phase
    - Pain
    - Nausea/vomiting
    - Sensory sensitivity
    • Photophobia
    • Phonophobia
    • Osmophobia
    • Allodynia
    • Vertigo
    Postdrome
    - Tiredness
    - Weariness
    - Concentration impairment

TABLE 441-3 Simplified Diagnostic Criteria for Migraine

Harrison's 22e, p.3466

REPEATED ATTACKS OF HEADACHE LASTING 4–72 H IN PATIENTS WITH A
NORMAL PHYSICAL EXAMINATION, NO OTHER REASONABLE CAUSE FOR THE
HEADACHE, AND:
AT LEAST 2 OF THE FOLLOWING
FEATURES:
PLUS AT LEAST 1 OF THE FOLLOWING
FEATURES:
Unilateral pain Nausea/vomiting
Throbbing pain Photophobia and phonophobia
Aggravation by movement
Moderate or severe intensity

TABLE 441-4 TREATMENT of Acute Migraine DRUG Simple Analgesics Acetaminophen, aspirin, caffeine NSAIDs Naproxen…

Harrison's 22e, p.3467

DRUG TRADE NAME DOSAGE
Simple Analgesics
Acetaminophen, aspirin, caffeine Excedrin Migraine Two tablets or caplets q6h (max 8 per day)
NSAIDs
5-HT Receptor Agonists—Triptans
1B/1D
Oral
Ergotamine 1 mg, caffeine 100 mg Cafergot One or two tablets at onset, then one tablet q½h (max 6 per day, 10 per week)
Naratriptan Amerge 2.5-mg tablet at onset
Rizatriptan Maxalt 5–10-mg tablet at onset
Maxalt-MLT
Sumatriptan Imitrex 50–100-mg tablet at onset
Frovatriptan Frova 2.5-mg tablet at onset
Almotriptan Axert 12.5-mg tablet at onset
Eletriptan Relpax 40 or 80 mg at onset
Zolmitriptan Zomig 2.5-mg tablet at onset
Zomig Rapimelt
Nasal
Dihydroergotamine Migranal Nasal Spray
Trudhesa Nasal Spray
Prior to nasal spray, the pump must be primed 4 times; 1 spray (0.5 mg) is
administered, followed in 15 min by a second spray
One spray into each nostril
Sumatriptan Imitrex Nasal Spray 5–20 mg intranasal spray as 4 sprays of 5 mg or a single 20 mg spray
Zolmitriptan Zomig 5 mg intranasal spray as one spray
Parenteral
Dihydroergotamine DHE-45 1 mg IV, IM, or SC at onset and q1h (max 3 mg/d, 6 mg per week)
Sumatriptan Imitrex Injection
Alsuma
Sumavel DosePro
3, 4, or 6 mg SC at onset (may repeat once after 1 h for max of 2 doses in 24 h)
CGRP Receptor Antagonists—Gepants
Oral
Rimegepant
Ubrogepant
Nasal
Zavegepant
Nurtec
Ubrelvy
Zavzpret
75 mg ODT PO
50 or 100 mg PO; a second dose may be taken 2 h after the first, if needed
10 mg intranasal, single spray to one nostril once in 24 h
5-HT Receptor Agonist—Ditans
1F
Oral
Lasmiditan
Reyvow 50, 100, or 200 mg PO
Dopamine Receptor Antagonists
Reglan,a generica
Compazine,a generica
Generica
Reglan,a generic
Compazine,a generica
Other
Parenteral
Opioids
Other
Neuromodulation
Single-pulse transcranial magnetic stimulation (sTMS)
Noninvasive vagus nerve stimulation (nVNS)
Remote electrical neuromodulation (REN)
Transcutaneous supraorbital nerve stimulation
External concurrent occipital and trigeminal
neurostimulation (eCOT-NS)
Generica
Savi Dual
gammaCore
Nerivio
Cefaly
Relivion
Multiple preparations and dosages; see Table 14-1
Two pulses at onset followed by two further pulses
Two doses each of 120 s
30- to 45-min stimulation to the upper arm
60-min stimulation
30- to 60-min stimulation

TABLE 441-5 Clinical Stratification of Acute Specific Migraine Treatments

Harrison's 22e, p.3468

CLINICAL SITUATION TREATMENT OPTIONS
Failed NSAIDs/
analgesics
First tier
Sumatriptan 50 mg or 100 mg PO
Almotriptan 12.5 mg PO
Rizatriptan 10 mg PO
Eletriptan 40 mg PO
Zolmitriptan 2.5 mg PO
Rimegepant 75 mg
Ubrogepant 50 or 100 mg
Lasmiditan 50, 100, or 200 mg
Slower effect/better tolerability
Naratriptan 2.5 mg PO
Frovatriptan 2.5 mg PO
Infrequent headache
Ergotamine/caffeine 1–2/100 mg PO
Dihydroergotamine nasal spray 2 mg
Headache recurrence Ergotamine 2 mg (most effective PR/usually with
caffeine)
Naratriptan 2.5 mg PO
Almotriptan 12.5 mg PO
Eletriptan 40 mg
Rimegepant 75 mg
Ubrogepant 50 or 100 mg
Early vomiting Zolmitriptan 5 mg nasal spray
Zavegepant 10 mg nasal spray
Sumatriptan 25 mg PR
Sumatriptan 6 mg SC
Very rapidly developing
symptoms
Zolmitriptan 5 mg nasal spray
Zavegepant 10 mg nasal spray
Sumatriptan 6 mg SC
Dihydroergotamine 1 mg IM

TABLE 441-6 Preventive Treatments in Migraine a DRUG Beta blocker

Harrison's 22e, p.3470

DRUG DOSE SELECTED SIDE EFFECTS
Beta blocker
Propranolol
Metoprolol
40–120 mg bid
25–100 mg bid
Reduced energy
Tiredness
Postural symptoms
Contraindicated in asthma
10–75 mg at night
25–75 mg at night
25–75 mg at night
75–150 mg/d
Anticonvulsants
Topiramate 25–200 mg/d Paresthesias
Cognitive symptoms
Weight loss
Glaucoma
Caution with nephrolithiasis
Valproate 400–600 mg bid Drowsiness
Weight gain
Tremor
Hair loss
Fetal abnormalities
Hematologic or liver abnormalities
0.5–2 mg qd
CGRP pathway blockers
Eptinezumab
Erenumab
Fremanezumab
Galcanezumab
100 or 300 mg IV every 12 weeks
70 or 140 mg SC monthly
225 mg monthly or 675 mg q3 months, SC
240 mg loading then 120 mg monthly, SC
Nasopharyngitis
Nasopharyngitis, constipation
Injection site reactions
Nasopharyngitis
Rimegepant
Atogepant
75 mg every other day
10, 30, or 60 mg once daily
Nausea abdominal pain/dyspepsia
Constipation, nausea
5–15 mg qd
4–24 mg daily
5–20 mg daily
3–12 mg nightly
Neuromodulation
Single-pulse transcranial magnetic stimulation (sTMS)
Noninvasive vagus nerve stimulation (nVNS)
Remote electrical neuromodulation (REN)
Transcutaneous supraorbital nerve stimulation
4–24 pulses per day
120-s treatments 2–3 times daily
45 min every other day
20 min daily
Lightheadedness
Tingling
Tinnitus
Site discomfort, irritation or pain
Muscle twitching
Well-tolerated; some local sensory symptoms
Local paresthesia
155 U

TABLE 441-7 Clinical Features of the Trigeminal Autonomic Cephalalgias Gender Pain

Harrison's 22e, p.3471

CLUSTER HEADACHE PAROXYSMAL HEMICRANIA SUNCT/SUNA
Gender M > F F = M F ~ M
Stabbing, boring
Excruciating
Orbit, temple
Throbbing, boring, stabbing
Excruciating
Orbit, temple
Attack frequency 1/alternate day–8/d 1–20/d (>5/d for more than half the time) 3–200/d
15–180 min 2–30 min
Autonomic features Yes Yes Yes (prominent conjunctival injection
and lacrimation)a
Yes Yes
Alcohol trigger Yes No No
No No
Indomethacin effect Yesc
Sumatriptan injection or nasal spray
Zolmitriptan nasal spray
Oxygen
nVNSc
No effective treatment
Preventive treatment Verapamil
Galcanezumab
Indomethacind
nVNS
Lamotrigine
Topiramate
Melatonin
Topiramate
Lithium Gabapentin

TABLE 441-8 Preventive Management of Cluster Headache

Harrison's 22e, p.3472

SHORT-TERM PREVENTION LONG-TERM PREVENTION
EPISODIC CLUSTER HEADACHE EPISODIC CLUSTER HEADACHE AND
PROLONGED CHRONIC CLUSTER
HEADACHE
Prednisone 1 mg/kg up to 60 mg qd,
tapering over 21 days
Verapamil 160–960 mg/d
Galcanezumab 300 mg SC
Greater occipital nerve injection (local
anesthetic and corticosteroids)
Verapamil 160–960 mg/d
nVNS 6–24 stimulations/d
Melatonina 9–12 mg/d
Topiramatea 100–400 mg/d
Lithium 400–800 mg/d