What are the differential diagnoses for a patient presenting with a frontal headache?

Differential Diagnoses for Frontal Headache

Frontal headache most commonly represents tension-type headache or migraine, but you must systematically exclude life-threatening secondary causes before settling on a primary headache diagnosis. 1

Primary Headache Disorders

Tension-Type Headache

• Bilateral pressing or tightening quality with mild-to-moderate intensity, not aggravated by routine physical activity, and lacks prominent associated symptoms like nausea or photophobia 1, 2
• Most common primary headache disorder, affecting 38% of the population 3
• Does not awaken patients from sleep or worsen with Valsalva maneuvers 1

Migraine Without Aura

• Can present with frontal location, though typically unilateral 1
• Requires at least 2 of these characteristics: unilateral location, pulsating quality, moderate-to-severe intensity, or aggravation by routine physical activity 1
• Must have at least 1 of: nausea/vomiting OR both photophobia and phonophobia 1
• Lasts 4-72 hours and affects 18% of women and 6.5% of men 2, 3

Chronic Migraine or Medication-Overuse Headache

• ≥15 headache days per month for >3 months, with ≥8 days meeting migraine criteria 1
• Medication-overuse headache occurs with regular overuse of non-opioid analgesics ≥15 days/month or other acute medications ≥10 days/month for >3 months 1

Life-Threatening Secondary Causes (Red Flags)

Subarachnoid Hemorrhage

• Thunderclap headache ("worst headache of life") with abrupt onset 1, 4
• May have altered taste sensation 1
• Requires non-contrast CT head if presenting <6 hours from onset (sensitivity 95% on day 0, declining to 50% at 1 week) 1

Meningitis

• Frontal headache with neck stiffness and unexplained fever 1
• Requires urgent CSF examination 4
• Can be rapidly fatal if bacterial meningitis is missed 5, 6

Giant Cell Arteritis

• New-onset headache in patients >50 years with scalp tenderness and jaw claudication 1, 6
• Requires urgent ESR/CRP testing, though ESR can be normal in 10-36% of cases 1
• Urgent referral to rheumatology needed to prevent blindness 1

Brain Tumor or Space-Occupying Lesion

• Progressive headache that awakens from sleep and worsens with Valsalva maneuvers or coughing 1, 4
• Requires MRI brain with and without contrast (preferred modality with higher resolution and no ionizing radiation) 1

Increased Intracranial Pressure

• Headache worsening with coughing, sneezing, or exercise 1
• Consider pseudotumor cerebri syndrome, particularly in overweight females with papilledema 7
• Fundoscopy to check for papilledema is essential 7

Stroke or TIA

• Atypical aura with focal neurological symptoms 1
• Any unexplained abnormal neurological finding significantly increases probability of serious intracranial pathology 1

Other Secondary Causes to Consider

Sinusitis

• Frontal location is classic for frontal sinus involvement 1
• Consider dental panoramic radiographs if dental pathology or sinusitis suspected 1

Spontaneous Intracranial Hypotension

• Orthostatic headache: absent or mild on waking, onset within 2 hours of upright posture, >50% improvement within 2 hours of lying flat 1, 7
• Requires urgent referral to neurology within 48 hours 1
• Commonly missed because orthostatic component may not always be obvious 7

Cerebral Venous Thrombosis

• Consider with risk factors like cancer or hypercoagulable states 7
• Can present with increased intracranial pressure and headache 7

Cervicogenic Headache

• Provoked by cervical movement rather than posture 7
• May radiate to frontal region from cervical spine pathology 7

Diagnostic Algorithm

History Red Flags Requiring Urgent Evaluation

• Thunderclap headache (subarachnoid hemorrhage until proven otherwise) 1, 4
• New-onset headache after age 50 (giant cell arteritis, tumor) 1, 4
• Progressive worsening over weeks to months (tumor, subdural hematoma) 1
• Headache awakening patient from sleep (increased intracranial pressure) 1, 4
• Worsened by Valsalva, cough, or exertion (increased intracranial pressure) 1, 4
• Focal neurological symptoms or abnormal neurological examination (stroke, tumor, abscess) 1, 7
• Unexplained fever with neck stiffness (meningitis) 1
• Recent head or neck trauma (subdural hematoma, dissection) 4
• History of cancer or immunosuppression (metastases, opportunistic infection) 4, 3

Physical Examination Essentials

• Complete neurological examination including fundoscopy for papilledema 7
• Check for neck stiffness or limited neck flexion 1
• Assess for scalp tenderness (giant cell arteritis) 1
• Document any focal neurological deficits 1, 7

Diagnostic Testing Based on Clinical Suspicion

• Emergency non-contrast CT head: If presenting <6 hours from acute severe headache onset or acute trauma 1
• MRI brain with and without contrast: Preferred for subacute presentations, suspected tumor, or inflammatory process 1
• ESR/CRP: If temporal arteritis suspected in patients >50 years 1
• Lumbar puncture: If meningitis suspected or CT negative but subarachnoid hemorrhage still suspected 4
• Headache diary: Document frequency, duration, character, triggers, and medication use for suspected primary headache 1

Screening Tools for Primary Headache

• ID-Migraine questionnaire (3-item): Sensitivity 0.81, specificity 0.75, positive predictive value 0.93 1
• Migraine Screen Questionnaire (5-item): Sensitivity 0.93, specificity 0.81, positive predictive value 0.83 1

Common Pitfalls to Avoid

• Never assume chronic headache is always primary without considering secondary causes, especially with any change in pattern 7
• Do not miss spontaneous intracranial hypotension because the orthostatic component may be subtle 7
• Remember ESR can be normal in 10-36% of giant cell arteritis cases, so clinical suspicion should drive urgent referral 1
• Avoid ordering neuroimaging for typical primary headaches without red flags or abnormal examination, as this has low yield 1, 7
• Do not overlook medication-overuse headache in patients with frequent analgesic use, as this requires different management 1

Referral Guidelines

• Emergency admission: Any red flag present or patient unable to self-care without help 1
• Urgent neurology referral (within 48 hours): Suspected spontaneous intracranial hypotension 1
• Urgent rheumatology referral: Suspected giant cell arteritis 1
• Routine neurology referral (2-4 weeks): Suspected primary headache disorder, diagnosis uncertain, or first-line treatments fail 1