What is the appropriate workup for a patient with a persistent and consistent headache?

Workup for Persistent and Consistent Headache

The appropriate workup for persistent and consistent headache requires careful assessment for "red flags" that suggest secondary causes, followed by thorough evaluation of headache characteristics to determine the specific primary headache disorder if no secondary causes are identified. 1

Initial Assessment: Identifying Red Flags

When evaluating persistent headache, first screen for these warning signs that necessitate urgent evaluation:

• Sudden onset ("thunderclap" headache)
• New headache after age 50
• Change in established headache pattern
• Headache that wakes patient from sleep
• Headache worsened by Valsalva maneuver or positional changes
• Neurological deficits (focal weakness, altered mental status)
• Fever or signs of infection
• History of cancer, HIV, or immunosuppression
• Headache following trauma
• Headache associated with seizures

Diagnostic Workup Algorithm

Step 1: History and Physical Examination

Focus on:

• Headache characteristics (location, quality, severity, duration)
• Associated symptoms (nausea, vomiting, photophobia, phonophobia)
• Frequency and pattern
• Aggravating/alleviating factors
• Medication use (prescription and OTC)
• Complete neurological examination

Step 2: Neuroimaging

Indications for neuroimaging based on the U.S. Headache Consortium guidelines 2:

• Patients with atypical headache patterns
• Presence of neurological signs
• Rapidly increasing frequency of headaches
• History of uncoordination
• Headache that awakens patient from sleep
• Abrupt onset of severe headache
• Marked change in headache pattern
• Persistent headache following head trauma

Step 3: Additional Testing (if indicated)

• Blood tests: CBC, ESR, CRP (if inflammatory cause suspected)
• Lumbar puncture: If subarachnoid hemorrhage or meningitis is suspected
• EEG: Only if seizure disorder is suspected 2

Differential Diagnosis Framework

Primary Headache Disorders

1. Migraine:

   • With or without aura
   • Episodes lasting 4-72 hours
   • Unilateral, pulsating quality, moderate/severe intensity
   • Aggravated by activity
   • Associated with nausea/vomiting, photophobia, phonophobia 1

2. Tension-type headache:

   • Bilateral, pressing/tightening quality
   • Mild to moderate intensity
   • Not aggravated by routine physical activity
   • No nausea/vomiting (or mild nausea only)

3. Cluster headache:

   • Severe unilateral orbital/temporal pain
   • Short duration (15-180 minutes)
   • Associated with autonomic symptoms (lacrimation, rhinorrhea)
   • Refer to neurologist 3

4. Medication overuse headache:

   • Headache ≥15 days/month
   • Regular overuse of acute headache medication
   • Non-opioid analgesics ≥15 days/month or other medications ≥10 days/month for >3 months 1

Secondary Headache Disorders

Evaluate for:

• Vascular disorders (stroke, aneurysm)
• Space-occupying lesions
• Infectious causes (meningitis, encephalitis)
• Intracranial pressure abnormalities
• Cervicogenic headache
• Temporomandibular joint dysfunction
• Sinus disease (often misdiagnosed as "sinus headache" when actually migraine) 1

Common Pitfalls to Avoid

• Misdiagnosing "sinus headache" when symptoms are actually migraine with autonomic features 1
• Failing to recognize medication overuse headache in patients using analgesics regularly 1
• Missing chronic migraine diagnosis (only 20% of patients who fulfill criteria are correctly diagnosed) 1
• Confusing migraine aura with transient ischemic attack (TIA has sudden and simultaneous onset) 1
• Not considering vestibular migraine in patients with dizziness and headache 1

Referral Criteria

Refer to neurologist when:

• Uncertain diagnosis
• Cluster headache
• Migraine with persistent aura
• Headache with associated motor weakness
• Poor response to preventive strategies 3

Refer to emergency department for:

• Worst headache of life
• Acute neurological deficits
• Altered mental status
• Signs of increased intracranial pressure
• Fever with meningeal signs

By following this structured approach, clinicians can effectively evaluate persistent headaches, identify concerning features requiring urgent attention, and develop appropriate management strategies for primary headache disorders.