Approach to Assessment of Headache

Definition and Classification

• Headache is pain or discomfort in the head or face region, classified as primary (migraine, tension-type, cluster) or secondary (underlying pathology causing the headache) 1, 2

Differential Diagnosis

• Migraine without aura: Recurrent moderate-to-severe unilateral, pulsating headache lasting 4-72 hours with nausea/vomiting, photophobia, and phonophobia; worsens with routine activity 1, 2
• Migraine with aura: Above features plus recurrent short-lasting visual/hemisensory disturbances preceding or accompanying headache 3
• Chronic migraine: ≥15 headache days/month for >3 months, with ≥8 days meeting migraine criteria 3
• Tension-type headache: Bilateral, mild-to-moderate pressing/tightening quality; lacks migraine features; not aggravated by routine activity 2
• Cluster headache: Strictly unilateral severe headache lasting 15-180 minutes with ipsilateral autonomic symptoms (lacrimation, conjunctival injection, nasal congestion, ptosis, miosis) 2
• Subarachnoid hemorrhage: Thunderclap headache ("worst headache of life"), may have altered taste sensation 4
• Meningitis: Headache with neck stiffness, unexplained fever 2, 4
• Brain tumor/space-occupying lesion: Progressive headache, awakens from sleep, worsens with Valsalva/cough 4
• Giant cell arteritis: New-onset headache in patients >50 years with scalp tenderness, jaw claudication 4
• Stroke/TIA: Atypical aura with focal neurological symptoms 2, 4
• Increased intracranial pressure: Headache worsening with coughing, sneezing, exercise 4
• Medication-overuse headache: ≥15 headache days/month with regular overuse of acute medications (non-opioid analgesics ≥15 days/month or other acute medications ≥10 days/month) for >3 months 3
• Spontaneous intracranial hypotension: Orthostatic headache (absent/mild on waking, onset within 2 hours of upright posture, >50% improvement within 2 hours of lying flat) 5

History and Physical Examination

• Age at onset: Migraine typically begins at/around puberty 3
• Duration of episodes: Migraine 4-72 hours; cluster 15-180 minutes; tension-type variable 2, 3
• Frequency: Episodic vs chronic (≥15 days/month) 3
• Pain location: Unilateral (migraine, cluster) vs bilateral (tension-type) 2
• Pain quality: Pulsating (migraine) vs pressing/tightening (tension-type) vs severe unilateral (cluster) 2
• Pain severity: Moderate-to-severe (migraine, cluster) vs mild-to-moderate (tension-type) 2
• Aggravating factors: Routine activity worsens migraine but not tension-type; Valsalva/cough suggests secondary causes 2
• Relieving factors: Lying flat improves orthostatic headache 5
• Accompanying symptoms: Nausea/vomiting, photophobia, phonophobia (migraine); autonomic symptoms (cluster) 1, 2
• Aura symptoms: Visual/hemisensory disturbances lasting <60 minutes 3
• Medication use: Acute and preventive medication history for medication-overuse headache 3
• Red flags: Thunderclap headache, new-onset headache after age 50, progressive worsening headache, atypical aura, recent head/neck trauma, headache awakening patient from sleep, headache brought on by Valsalva, cough, or exertion, focal neurological symptoms/signs, unexplained fever, neck stiffness or limited neck flexion, altered consciousness, memory, or personality, witnessed loss of consciousness 2, 4, 6

Investigations

• ID-Migraine questionnaire (3-item): Sensitivity 0.81, specificity 0.75, positive predictive value 0.93 1, 7
• Migraine Screen Questionnaire (5-item): Sensitivity 0.93, specificity 0.81, positive predictive value 0.83 1, 7
• Headache diary: Document frequency, duration, character, triggers, accompanying symptoms, medication use 1, 3, 7
• MRI brain with and without contrast: Preferred modality; higher resolution, no ionizing radiation; for subacute presentations or suspected tumor/inflammatory process 1, 2, 4
• Non-contrast CT head: If presenting <6 hours from acute severe headache onset (subarachnoid hemorrhage); sensitivity 95% on day 0, 74% on day 3, 50% at 1 week 4
• CT head: Acute trauma or abrupt-onset headache 6
• Dental panoramic radiographs: If dental pathology or sinusitis suspected 4
• ESR/CRP: If temporal arteritis suspected (patients >50 years with new-onset headache); note ESR can be normal in 10-36% of giant cell arteritis cases 4
• Morning TSH and free T4: If cold intolerance, lightheadedness present (hypothyroidism) 8
• Thyroid peroxidase (TPO) antibodies: If biochemical hypothyroidism confirmed 8

Treatment and Referral

• NSAIDs or acetaminophen: First-line for mild-to-moderate migraine attacks 6
• Triptans or ergot derivatives: For moderate-to-severe migraine attacks or when NSAIDs fail 3, 6
• Antiemetics: For nausea/vomiting 6
• High-flow oxygen (100% at 12-15 L/min): First-line acute treatment for cluster headache 2
• Subcutaneous or intranasal triptans: Alternative acute treatment for cluster headache 2
• Urgent referral to neurology (within 48 hours): Suspected spontaneous intracranial hypotension, patient unable to self-care but has help 5
• Emergency admission: Patient unable to self-care without help, any red flag present 2, 4, 5
• Routine referral to neurology (2-4 weeks): Suspected primary headache disorder, diagnosis uncertain, first-line treatments fail 5
• Urgent referral to specialist/tertiary center (within 1 month): Diagnosis in doubt, first-line treatments fail, rapid clinical deterioration, serious complications 5
• Referral to rheumatology: Suspected giant cell arteritis 4

Ruling Out Migraine Based on ICHD-3 Diagnostic Criteria

Diagnostic Criteria for Migraine

• Migraine without aura is excluded if the patient does NOT have: at least 5 lifetime attacks lasting 4-72 hours, at least 2 of the following pain characteristics: unilateral location, pulsating quality, moderate-to-severe intensity, or aggravation by routine physical activity, and at least 1 of the following: nausea/vomiting, photophobia AND phonophobia, as per the International Headache Society 9
• Migraine with aura is excluded if the patient does NOT have: recurrent, short-lasting visual, sensory, speech/language, motor, brainstem, or retinal symptoms, and at least 3 of these characteristics: gradual spread over ≥5 minutes, two or more symptoms in succession, at least one unilateral symptom, at least one positive symptom, aura accompanied by or followed by headache within 60 minutes, as per the International Headache Society 9

Use of Headache Diaries and Screening Tools

• Headache diaries reduce recall bias and increase diagnostic accuracy, and if diary entries consistently fail to meet ICHD-3 criteria over multiple attacks, migraine is ruled out, according to the International Headache Society 9, 10
• The presence of a family history of migraine strengthens the suspicion of migraine, as migraine has a strong genetic component with higher prevalence among first-degree relatives, as noted by the International Headache Society 9, 10

Medication-Overuse Headache and Chronic Migraine

• Headache on ≥15 days/month with regular overuse of non-opioid analgesics on ≥15 days/month for ≥3 months, or any other acute medication on ≥10 days/month for ≥3 months, rules out simple episodic migraine and requires different management, as per the International Headache Society 9
• ≥15 headache days/month for >3 months, with ≥8 days meeting migraine criteria, represents chronic migraine, a distinct entity with substantially greater burden and different treatment requirements, according to the International Headache Society 9

Neuroimaging After Failed Physical Therapy for Migraines

Key Decision Point: Neurological Examination

• The American Academy of Neurology recommends that neuroimaging is not routinely indicated for patients with migraine who have completed physical therapy and continue to have headaches, provided the neurological examination remains normal 11, 12
• A normal neurological examination yields a low probability of finding serious intracranial pathology in migraine patients, with a rate of 0.2% (2/1086 patients), which is no higher than the 0.4% rate in completely asymptomatic volunteers 11, 12
• The presence of any unexplained abnormal neurological finding significantly increases the probability of detecting clinically significant intracranial pathology, and neuroimaging should be considered in such cases 11, 12, 13

Red Flag Assessment

• Progressive worsening of headache pattern over weeks to months is a concerning feature that would warrant MRI 11, 12
• Headache worsened by Valsalva maneuver, coughing, or exertion is a red flag that may indicate the need for neuroimaging 11, 12
• New-onset headache in patients >50 years old is a concerning feature that may require neuroimaging 11, 13
• Atypical aura features, such as focal neurological symptoms or prolonged duration >60 minutes, may warrant neuroimaging 13

When Imaging Is Appropriate Despite Normal Exam

• The American Academy of Family Physicians suggests that atypical features present in headaches that do not fulfill standard migraine criteria may warrant a lower threshold for imaging 13

Epidemiology and Critical Red‑Flag Indicators in Headache Disorders

Primary Headache Epidemiology

• Tension‑type headache is the most common primary headache disorder, affecting approximately 38 % of the general population【14】.
• Cluster headache has a prevalence of roughly 0.1 % of the population, presenting with strictly unilateral severe pain and ipsilateral autonomic features【14】.

Secondary Headache Red‑Flag Indicators

• Meningitis is a life‑threatening condition that requires immediate evaluation when patients present with headache accompanied by neck stiffness and fever【14】.

Medication‑Overuse Headache

• Medication‑overuse headache develops in individuals who experience ≥15 headache days per month and regularly overuse acute medications (non‑opioid analgesics ≥15 days/month or other acute agents ≥10 days/month) for more than 3 months, often arising from excessive treatment of migraine attacks【14】.

Atypical Aura as a Red Flag

• An atypical aura that includes focal neurological symptoms or lasts longer than 60 minutes may indicate stroke or other serious intracranial pathology and warrants urgent investigation【14】.

Migraine Diagnostic Criteria and Differentiation from Tension‑Type Headache

Diagnostic Criteria for Migraine Without Aura

• Migraine without aura is diagnosed when a patient has experienced at least five lifetime attacks lasting 4–72 hours each, with ≥ 2 pain characteristics (unilateral location, pulsating quality, moderate‑to‑severe intensity, or aggravation by routine activity) and ≥ 1 associated symptom (nausea/vomiting or both photophobia and phonophobia)【15】.

Key Clinical Features that Favor Migraine over Tension‑Type Headache

• The presence of photophobia together with nausea strongly supports a migraine diagnosis and helps differentiate it from tension‑type headache【15】【16】.
• Tension‑type headache typically presents as a bilateral, pressing/tightening pain of mild‑to‑moderate intensity, not aggravated by routine activity, and lacks both nausea/vomiting and the combination of photophobia plus phonophobia【15】.

Persistent or Prolonged Headache Episodes

• A headache that does not resolve and lasts more than 72 hours should be considered status migrainosus (a prolonged single migraine attack) or may indicate the onset of a chronic daily headache【16】.
• Any headache episode exceeding 72 hours therefore warrants evaluation for status migrainosus and for possible secondary causes【16】.

Chronic Migraine Definition and Management Implications

• Chronic migraine is defined as ≥ 15 headache days per month for > 3 months, with ≥ 8 of those days meeting migraine criteria; this condition requires initiation of preventive therapy and referral to neurology【16】.

Key Clinical Characteristics and Management of Tension‑Type Headaches

Duration and Typical Course

• Tension‑type headache episodes can be highly variable, ranging from as short as 30 minutes to up to 7 days, and are often much briefer than migraine attacks, which last 4–72 hours when untreated. This variability is a distinguishing feature of tension‑type headache. 17

Differential Diagnosis

• Migraine attacks characteristically persist for 4–72 hours if left untreated, providing a clear temporal contrast with the generally shorter or more variable duration of tension‑type headaches. 18
• Medication‑overuse headache may arise when acute analgesics are taken on ≥15 days per month for ≥3 months, potentially mimicking a chronic tension‑type pattern and complicating diagnosis. 18

Preventive Therapy for Chronic Forms

• Chronic tension‑type headache, which is associated with disability levels comparable to migraine, is recommended to be treated preventively with amitriptyline as a first‑line agent. This recommendation is based on evidence from recent internal‑medicine studies. [19][20]

Pediatric Migraine Duration and Aura Diagnostic Criteria

Migraine Without Aura in Children

• In patients younger than 18 years, migraine attacks without aura may last 2 – 72 hours, extending the typical adult duration of 4 – 72 hours. This reflects the diagnostic time‑frame used in pediatric migraine assessment. 21, 22

Migraine With Aura Diagnostic Features

• Aura requirement: Diagnosis of migraine with aura mandates at least two attacks each featuring one or more fully reversible aura symptoms (visual, sensory, speech/language, motor, brainstem, or retinal). 21, 22
• Timing characteristics: At least three of six specific aura features must be present:
• Duration limits: Each aura symptom should not exceed 60 minutes; therefore, a maximum total aura duration of 180 minutes is permissible when three symptoms occur sequentially. Motor aura may persist up to 72 hours. These limits are important for identifying atypical aura that may suggest alternative pathology. 21, 22

Evidence strength for these criteria is not explicitly graded in the source material.

Evidence‑Based Headache Evaluation (American Family Physician 2002)

Red‑Flag Assessment

Identify urgent features that warrant immediate investigation or referral.

Clinical Characteristics of Primary Headaches

Migraine

Tension‑Type Headache

Cluster Headache

Medication History

Neuroimaging Indications

Imaging should be reserved for atypical presentations or red‑flag features.

Management Pitfalls (Evidence‑Based Recommendations)

All facts above are drawn from the American Family Physician guideline (2002) and are supported by the cited evidence.

Evidence‑Based Diagnostic Criteria, Red‑Flag Features, and Initial Work‑up for Headache in Adults ≥ 50 years (cited)

Primary Headache Disorders

• Tension‑type headache typically presents with bilateral, pressing or tightening pain of mild‑to‑moderate intensity that is not worsened by routine physical activity. 24
• Tension‑type headache lacks the nausea/vomiting and combined photophobia‑phonophobia that characterize migraine attacks. 24
• Cluster headache is strictly unilateral, severe, and lasts 15–180 minutes per attack, occurring 1–8 times daily. 24
• Cluster headache is accompanied by ipsilateral autonomic signs (lacrimation, conjunctival injection, nasal congestion, ptosis, miosis, eyelid edema) that are pathognomonic. 24
• The prevalence of cluster headache is ≈ 0.1 % of the general population, underscoring the need for vigilance despite its rarity. 24
• Medication‑overuse headache (MOH) is defined by ≥ 15 headache days per month together with regular overuse of non‑opioid analgesics on ≥ 15 days/month or other acute headache medications on ≥ 10 days/month for > 3 months. 24
• MOH often develops secondary to frequent treatment of migraine attacks, creating a self‑perpetuating cycle. 24

Life‑Threatening Secondary Headaches

• Subarachnoid hemorrhage (SAH) presents as a thunderclap (“worst‑of‑life”) headache with abrupt onset. 24
• Non‑contrast head CT performed within 6 hours of symptom onset has a sensitivity of ≈ 95 % for SAH; sensitivity falls to ≈ 74 % by day 3 and ≈ 50 % by one week. 24
• If the early CT is negative, lumbar puncture with spectrophotometric analysis for xanthochromia is 100 % sensitive from 12 hours to 2 weeks after bleed onset. 24
• Meningitis commonly presents with headache accompanied by neck stiffness and unexplained fever; immediate evaluation is required. 24

Red‑Flag Features Requiring Urgent Investigation

• Any unexplained fever in a patient with new‑onset headache after age 50 mandates immediate neuro‑imaging or emergency referral. 24
• The presence of any of the following red‑flag signs (collectively cited) obligates urgent imaging or specialist assessment:
  
  • Thunderclap headache (maximal intensity within seconds)
  • New‑onset headache after age 50 (≈ 12‑fold higher risk of serious pathology)
  • Progressive worsening over weeks to months
  • Headache that awakens the patient from sleep
  • Atypical aura with focal neurological symptoms lasting > 60 minutes
  • Recent head or neck trauma
  • Headache precipitated by Valsalva maneuver, coughing, or exertion
  • New focal neurological deficits on examination
  • Neck stiffness or limited neck flexion
  • Altered consciousness, memory change, or personality alteration
  • Witnessed loss of consciousness
  • Papilledema on fundoscopic exam

Initial Diagnostic Imaging

• For suspected SAH or other acute severe headache presenting within 6 hours, non‑contrast CT is the first‑line imaging modality because of its high early sensitivity. 24
• For subacute presentations, suspected tumor, inflammatory disease, or when CT is nondiagnostic, MRI with and without contrast is the preferred study. 24

Laboratory Evaluation

• When giant cell arteritis is a consideration, ESR and CRP should be obtained, recognizing that 10‑36 % of patients may have normal ESR values despite active disease. 24

Strength of evidence: The cited source (Nature Reviews Neurology, 2021) provides expert review and consensus statements; specific levels of evidence are not detailed in the article.

Use of Contrast‑Enhanced Brain MRI for Patients with Migraine‑Associated Visual Disturbances

Indications for Contrast‑Enhanced MRI

• The American College of Radiology (ACR) recommends that brain MRI performed both with and without gadolinium contrast is the preferred imaging modality when evaluating visual disturbances and suspected pathology of the brain, optic pathways, or cranial nerves【25, 26】.
• In patients with migraine who present with visual disturbances, contrast‑enhanced MRI is advised to comprehensively exclude structural lesions, inflammatory processes (e.g., optic neuritis, demyelinating disease), vascular malformations, and neoplastic pathology, all of which are better characterized with contrast【25, 26】.
• Contrast‑enhanced MRI provides superior detection of mass lesions, inflammatory disease of the optic pathways or brain parenchyma, and vascular abnormalities that may manifest as visual symptoms【25, 26】.
• For a young adult (e.g., 27‑year‑old) with migraine‑related visual disturbances awaiting neurology evaluation, the ACR advises that the brain MRI be performed with contrast【25, 26】.

Situations Where Non‑Contrast MRI May Be Acceptable

• The ACR acknowledges that if gadolinium cannot be administered because of severe renal impairment, a prior severe allergic reaction, or patient refusal, a non‑contrast brain MRI can still provide diagnostic value, though it is considered a compromise to the optimal approach【25, 26】.
• Non‑contrast MRI may be used only when:
  
  • Estimated glomerular filtration rate (eGFR) is < 30 mL/min/1.73 m², or【25】
  • The patient has a documented severe gadolinium allergy or【25】
  • The patient adamantly refuses contrast after informed discussion or【25】.

Practical Decision Algorithm

• Order MRI brain WITH and WITHOUT contrast when any of the following are present:
  
  • Visual disturbances (as in the described case)【25, 26】.
• Reserve non‑contrast MRI only under the contraindications listed above【25】.

Note: The ACR guideline does not assign a formal strength grade to these recommendations in the cited sources.