What conditions should be ruled out in a patient over 50 with new onset headaches?

New Onset Headaches After Age 50: Critical Conditions to Rule Out

In patients over 50 presenting with new onset headaches, you must aggressively investigate for secondary causes—particularly temporal arteritis, intracranial hemorrhage, mass lesions, and stroke—because late-onset primary headache disorders are uncommon and the incidence of life-threatening secondary headaches increases substantially with age. 1, 2, 3

Why Age 50 Matters

• Migraine typically remits with older age, making new apparent "migraine" after 50 inherently suspicious for an underlying secondary cause 1, 2
• Up to 15% of patients ≥65 years presenting with new-onset headaches have serious pathology including stroke, temporal arteritis, neoplasm, and subdural hematoma 4
• The Ottawa SAH Rule specifically flags age ≥40 years as a criterion requiring additional investigation for subarachnoid hemorrhage 1

Life-Threatening Conditions Requiring Immediate Workup

Subarachnoid Hemorrhage (SAH)

• Obtain non-contrast head CT within 6 hours of symptom onset (98.7% sensitivity when interpreted by fellowship-trained neuroradiologists) 1
• If CT is negative but clinical suspicion remains high, perform lumbar puncture >6 hours after symptom onset with spectrophotometric analysis for xanthochromia (100% sensitivity) 1
• Red flags include: thunderclap headache (instantly peaking pain), neck pain/stiffness, witnessed loss of consciousness, onset during exertion, or limited neck flexion 1

Temporal Arteritis (Giant Cell Arteritis)

• This is the most critical diagnosis not to miss in patients over 50 4, 5
• Headaches occur in 60-90% of temporal arteritis cases 4
• Immediately check ESR and C-reactive protein, but recognize that ESR can be normal in 10-36% of biopsy-proven cases 4
• Consider temporal artery biopsy for definitive diagnosis (though false-negatives occur in 5-44%) 4
• Untreated temporal arteritis leads to irreversible blindness and stroke 5

Intracranial Mass Lesions

• Brain tumors are found in 0.8% of patients with headache and normal neurologic exam on combined studies 4
• MRI brain is the preferred imaging modality for detecting mass lesions, posterior fossa pathology, and subtle structural abnormalities 3, 6
• CT scanning is appropriate for acute trauma or when hemorrhage is the primary concern 3, 6

Stroke and Vascular Events

• Chronic ischemic processes and acute strokes account for 1.2% of neuroimaging findings in headache patients 4
• Subdural hematomas (0.2% prevalence) present with nonspecific headaches and are particularly common after minor head trauma in elderly patients 4

Red Flag Features Mandating Investigation

Obtain neuroimaging if ANY of the following are present: 3, 6, 7

• New, worse, worsening, or abrupt onset headache (the "first or worst" headache)
• Recent head or neck injury
• Headache brought on by Valsalva maneuver, cough, or exertion
• Neurologic findings or symptoms (focal deficits, altered consciousness, seizures)
• Systemic signs or symptoms (fever, weight loss, malaise)
• Secondary risk factors (cancer history, HIV infection, immunosuppression)
• Papilledema on fundoscopic examination

Diagnostic Algorithm

Step 1: Immediate Assessment

• Perform thorough neurologic examination looking for focal deficits, papilledema, meningismus, or altered mental status 3, 6, 7
• Check vital signs including blood pressure
• Assess for temporal artery tenderness, jaw claudication, and visual symptoms 4, 5

Step 2: Laboratory Testing

• ESR and C-reactive protein (mandatory in all patients >50 with new headache to screen for temporal arteritis) 4, 5
• Complete blood count, metabolic panel
• Consider additional labs based on clinical context (coagulation studies if anticoagulated, HIV testing if risk factors present) 3, 7

Step 3: Neuroimaging

• MRI brain with and without contrast is the preferred modality for comprehensive evaluation 3, 6
• Non-contrast CT head if acute hemorrhage suspected or MRI unavailable 3, 6
• CT angiography or MR angiography if vascular pathology suspected 1

Step 4: Lumbar Puncture (When Indicated)

• Perform if SAH suspected with negative CT (>6 hours after onset) 1
• Consider if meningitis, encephalitis, or CSF pressure disorders suspected 3, 6
• Analyze for xanthochromia using spectrophotometry, cell count, protein, glucose, and cultures 1

Common Pitfalls to Avoid

• Do not assume migraine without thorough investigation in this age group—late-onset migraine (after age 40-50) deviates from typical patterns and requires exclusion of secondary causes 1, 2
• Do not rely solely on normal ESR to exclude temporal arteritis—up to 36% of biopsy-proven cases have normal ESR 4
• Do not delay CT beyond 6 hours if SAH suspected—sensitivity drops from 95% on day 0 to 74% by day 3 4
• Do not skip lumbar puncture after negative CT if thunderclap headache present—CT misses approximately 1.5 in 1000 SAHs even within 6 hours 1

Less Urgent but Important Considerations

• Medication overuse headache (particularly in patients taking analgesics ≥15 days/month or triptans ≥10 days/month) 8
• Cervicogenic headache from degenerative cervical spine disease 3, 7
• Hypertensive urgency/emergency 3
• Sleep apnea-related morning headaches 7