What is the initial test order for a patient presenting with frequent headaches?

Initial Test Order for Frequent Headaches

For a patient presenting with frequent headaches, the initial diagnostic approach should focus on identifying red flags that may indicate secondary headache causes, with neuroimaging (preferably MRI) being the primary diagnostic test when secondary headache is suspected. 1

Diagnostic Approach Algorithm

Step 1: Assess for Red Flags

Red flags requiring immediate evaluation include:

• Thunderclap headache (sudden onset, severe)
• Focal neurological symptoms
• Fever with neck stiffness
• Headache following head trauma
• Positional aggravation
• Valsalva-induced headache
• Associated symptoms such as weight loss or personality changes
• New onset of headache after age 50
• Abrupt change in headache pattern 1, 2

Step 2: Determine Headache Frequency and Pattern

• Ask directly: "Do you feel like you have a headache of some type on 15 or more days per month?" 1
• Request patient keep a headache diary to track frequency, as patients often underreport milder headaches 1
• Assess headache characteristics:
  • Location
  • Quality
  • Severity
  • Duration
  • Associated symptoms
  • Aggravating and alleviating factors 1

Step 3: Order Appropriate Tests Based on Findings

If Red Flags Present:

• Neuroimaging:
  • CT without contrast for suspected intracranial hemorrhage
  • MRI preferred for most other conditions 1
• Lumbar puncture: If subarachnoid hemorrhage is suspected and CT is negative 2, 3
• Blood tests: Including ESR/CRP if temporal arteritis is suspected (particularly in patients over 50) 3

If No Red Flags and Chronic Migraine Suspected:

• Diagnosis can often be made clinically if patient meets criteria for chronic migraine (≥15 headache days/month for >3 months with migraine features on ≥8 days/month) 1
• Evaluate for medication overuse, which affects up to 73% of chronic migraine patients 1

Special Considerations

Age-Related Concerns

• New-onset headaches in patients over 50 years warrant more aggressive investigation, as up to 15% may have serious underlying pathology such as stroke, temporal arteritis, neoplasm, or subdural hematoma 3

Post-Traumatic Headaches

• 30-90% of patients have headaches after mild head injury
• 1-3% may have life-threatening pathology including subdural and epidural hematomas that require neuroimaging 3

Diagnostic Yield

• The yield of neuroimaging in patients with headache and normal neurologic examination is quite low (brain tumors 0.8%, arteriovenous malformations 0.2%, aneurysm 0.1%) 3
• However, when red flags are present, the likelihood of finding significant pathology increases substantially 2

Common Pitfalls to Avoid

• Missing medication overuse headache: This can lead to daily or near-daily headaches that worsen with continued medication use 1
• Confusing migraine aura with TIA: These conditions can present similarly but require different management approaches 1
• Failing to diagnose chronic migraine: Only 20% of patients who fulfill criteria are correctly diagnosed 1
• Inadequate evaluation of "first or worst" headache: These always require thorough investigation to rule out subarachnoid hemorrhage 3

By following this systematic approach, clinicians can effectively differentiate between primary and secondary headache disorders, ensuring appropriate diagnostic testing while avoiding unnecessary procedures.