What is the differential diagnosis and workup for a patient presenting with a constant pressure-like headache on the top of the head?

Differential Diagnosis and Workup for Pressure-like Constant Headache on Top of Head

A constant pressure-like headache on the top of the head requires a systematic diagnostic approach to rule out secondary causes before considering primary headache disorders. 1

Key Differential Diagnoses to Consider

Primary Headache Disorders

• Tension-type headache - typically bilateral with pressing/tightening character, mild to moderate severity, and not aggravated by routine physical activity 2
• Migraine - often unilateral, throbbing, moderate to severe, worsened by activity, with associated symptoms like nausea/vomiting and photophobia/phonophobia 3
• New daily persistent headache - a headache that becomes constant and unremitting within 24 hours of onset 4

Secondary Headache Disorders

• Spontaneous intracranial hypotension (SIH) - consider if headache improves when lying flat and worsens when upright 3
• Cerebral venous thrombosis - can present with increased intracranial pressure and headache, especially with risk factors like cancer or hypercoagulable states 3
• Intracranial mass lesions (tumors, arteriovenous malformations) - especially if associated with abnormal neurological examination 3
• Pseudotumor cerebri syndrome - particularly in overweight females with papilledema 3
• Cervicogenic headache - if provoked by cervical movement rather than posture 3

Red Flag Features Requiring Urgent Evaluation

• Thunderclap headache (sudden onset, worst headache of life) 5, 6
• New onset headache in patients over 50 years of age 3, 5
• Headache worsened by Valsalva maneuver or cough 3, 5
• Headache that awakens patient from sleep 3
• Progressively worsening headache pattern 6
• Abnormal neurological examination findings 3
• Fever or signs of systemic illness 6
• Headache in patients with cancer or immunosuppression 5, 4

Diagnostic Workup Algorithm

Step 1: Detailed History

• Characterize the headache: location, quality, severity, timing, aggravating/alleviating factors 4
• Ask about positional component (worse when upright, better when lying flat) to evaluate for SIH 3
• Inquire about associated symptoms: nausea, vomiting, photophobia, phonophobia 3
• Identify potential triggers: stress, missed meals, sleep disturbances 2
• Document medication use to evaluate for medication overuse headache 3

Step 2: Physical Examination

• Complete neurological examination including fundoscopy to check for papilledema 3, 1
• Vital signs to evaluate for fever or hypertension 6
• Examine head and neck for tenderness, range of motion, and trigger points 3
• Evaluate for meningeal signs if infection is suspected 6

Step 3: Initial Testing Based on Clinical Suspicion

• For typical presentation without red flags:

  • No neuroimaging is typically required for suspected tension-type headache with normal neurological examination 3, 2

• For atypical features or red flags:

  • Brain MRI with and without contrast (preferred over CT for non-acute evaluation) 3, 1
  • Basic laboratory tests: CBC, comprehensive metabolic panel, thyroid function tests 1
  • Consider lumbar puncture if increased intracranial pressure or subarachnoid hemorrhage is suspected 1, 5

Step 4: Additional Testing Based on Initial Results

• For suspected SIH: MRI with gadolinium to look for dural enhancement 3
• For suspected cerebral venous thrombosis: MR venography 3
• For suspected pseudotumor cerebri: lumbar puncture with opening pressure measurement 3

Management Considerations

• Primary headache disorders can be treated with appropriate medications after secondary causes are ruled out 3, 4
• Document headache patterns using a headache diary to aid in diagnosis and treatment monitoring 1
• Consider specialist referral for atypical presentations, treatment-resistant cases, or when secondary causes are suspected 3

Common Pitfalls to Avoid

• Assuming a chronic headache is always a primary headache disorder without considering secondary causes 6
• Ordering neuroimaging for typical primary headache presentations without red flags or abnormal examination findings 3, 7
• Missing the diagnosis of SIH because the orthostatic component may not always be obvious 3
• Failing to recognize that a change in pattern of a pre-existing headache may indicate a new secondary cause 6