What is the recommended workup for a previously healthy adult patient presenting with a persistent headache?

Workup for Persistent Headache in Previously Healthy Adults

Begin with a focused history and neurological examination to identify red flags, then obtain MRI brain imaging if any concerning features are present—particularly in patients over 50 years old, where new-onset headache mandates neuroimaging regardless of examination findings. 1, 2

Step 1: Obtain Critical Historical Features

Document the following specific elements to differentiate primary from secondary causes:

• Temporal pattern: Age at onset, duration of individual episodes, frequency of attacks, and pattern of progression (stable vs. worsening) 2
• Pain characteristics: Location (unilateral vs. bilateral), quality (throbbing, pressing, stabbing), and intensity 2
• Associated symptoms: Nausea/vomiting, photophobia, phonophobia, visual disturbances, or autonomic symptoms 2
• Medication use: Document all acute medication use and frequency per month to identify medication-overuse headache 2

Step 2: Screen for Red Flags Requiring Urgent Investigation

The presence of ANY of the following mandates immediate neuroimaging:

• Age ≥50 years with new-onset headache (this alone is sufficient indication) 1, 2
• Thunderclap onset (sudden, severe, "worst headache ever") 3, 2
• Progressive worsening over days to weeks 3, 2
• Headache awakening patient from sleep 1, 2
• Fever or systemic symptoms 3, 2
• Focal neurological deficits (weakness, sensory changes, visual field defects) 1, 2
• Impaired memory or altered mental status 1, 2
• Syncope 3, 2
• Recent head trauma 2
• Worsening with Valsalva maneuver 1

Step 3: Perform Complete Neurological Examination

Conduct a systematic assessment including:

• Mental status examination
• Cranial nerve testing (including fundoscopy)
• Motor and sensory function
• Deep tendon reflexes
• Coordination and gait testing 2

Any abnormal findings on neurological examination mandate immediate neuroimaging, regardless of headache characteristics. 1, 2

Step 4: Neuroimaging Decision and Modality Selection

When to Image:

Obtain neuroimaging if:

• Any red flag is present 2
• Abnormal neurological examination 1, 2
• Atypical headache features that don't fit primary headache patterns 2

Neuroimaging is NOT routinely indicated if:

• Patient has typical migraine features with normal neurological examination AND age <50 years 3
• Patient has tension-type headache with normal examination AND age <50 years 3

Imaging Modality:

MRI brain without and with contrast is the preferred imaging modality because it offers superior resolution for detecting structural lesions (tumors, stroke, subdural hematoma, venous thrombosis) without ionizing radiation. 1

CT head without contrast may be substituted only if:

• MRI is unavailable or contraindicated
• Acute hemorrhage is the primary concern (though MRI with gradient-echo sequences is equally sensitive) 1

Important caveat: CT is less sensitive than MRI for most structural pathology relevant to persistent headache. 1

Step 5: Consider Additional Testing When Indicated

Lumbar Puncture:

Perform if suspecting:

• Subarachnoid hemorrhage with negative CT (obtain CT first)
• Meningitis or encephalitis (with fever/altered mental status)
• Intracranial hypotension (orthostatic headache pattern) 3, 2

Laboratory Testing:

Consider basic metabolic panel (glucose, sodium) if systemic illness suspected, though imaging is typically more revealing than laboratory studies in the workup of persistent headache. 1, 2

Advanced Spine Imaging:

If orthostatic headache without recent spinal intervention suggests spontaneous intracranial hypotension, obtain MRI complete spine with fluid-sensitive sequences to identify CSF leak source. 3

Step 6: Interpret Imaging Results with Caution

Be aware that MRI may reveal clinically insignificant findings (white matter lesions, small arachnoid cysts, incidental meningiomas) that require careful interpretation to avoid unnecessary alarm, particularly in older patients. 1

Special consideration for cortical vein thrombosis: If MRI shows ipsilateral dural thickening and enhancement in a patient with severe persistent headache, consider cerebral venous thrombosis and obtain CT venography or MR venography for confirmation. 3

Common Pitfalls to Avoid

• Do not dismiss new-onset headache in patients ≥50 years as benign without imaging, even with normal examination—the diagnostic yield of significant pathology is substantially higher in this age group. 1
• Do not rely solely on patient recall of headache frequency; many patients underreport milder headache days. 3
• Do not assume normal CSF pressure excludes intracranial hypotension if clinical features are suggestive. 3
• Do not order CT when MRI is available—CT has significantly lower sensitivity for most causes of persistent headache. 1