What is the appropriate diagnostic workup for a 60‑year‑old woman with a 1.5‑week history of headache and inter‑scapular shoulder pain, tongue and lip paresthesias, and a 2‑week history of fatigue?

Diagnostic Workup for 60-Year-Old Woman with Subacute Headache, Interscapular Pain, Perioral Paresthesias, and Fatigue

This patient requires urgent evaluation for giant cell arteritis (GCA) given her age, headache pattern, and associated symptoms, combined with comprehensive metabolic and neurologic assessment to exclude other life-threatening causes including subarachnoid hemorrhage, stroke, and central nervous system inflammation. 1

Immediate Laboratory Assessment

The following blood tests must be obtained urgently:

• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to screen for GCA, which commonly presents with headache, fatigue, and can cause tongue/lip paresthesias due to lingual artery involvement 2, 3
• Complete blood count to evaluate for anemia, infection, or hematologic disorders contributing to fatigue and neurologic symptoms 1
• Comprehensive metabolic panel including glucose, electrolytes (especially calcium and magnesium), and renal function—hypocalcemia is a common cause of perioral tingling 1
• Thyroid-stimulating hormone to exclude hypothyroidism as a contributor to fatigue and headache 1
• Vitamin B12 and folate levels to detect deficiency-related neuropathy and fatigue 1, 4
• Morning cortisol and ACTH to rule out adrenal insufficiency, which presents with fatigue, headache, and can be life-threatening if untreated 1, 4

Neuroimaging—First Priority

MRI of the brain with and without gadolinium contrast is the mandatory first-line imaging study for this presentation. 1, 5, 6

The MRI protocol must include:

• Standard sequences (T1, T2, FLAIR, diffusion-weighted imaging) to evaluate for stroke, demyelination, mass lesions, or intracranial hemorrhage 1
• Gadolinium contrast administration to detect enhancing lesions such as meningitis, encephalitis, neoplasms, or inflammatory processes 1, 4
• Dedicated pituitary protocol to assess for pituitary or hypothalamic pathology that could explain combined endocrine and neurologic manifestations 1, 4

Non-contrast head CT should only be used if MRI is contraindicated or unavailable, or in the setting of thunderclap headache requiring immediate exclusion of subarachnoid hemorrhage. 5, 7 CT has inferior sensitivity for most secondary causes of subacute headache with neurologic features.

When to Perform Lumbar Puncture

Lumbar puncture is indicated if: 1, 4

• MRI reveals leptomeningeal enhancement or other inflammatory changes
• Clinical suspicion persists for aseptic meningitis, encephalitis, or CNS inflammation despite normal imaging
• Subarachnoid hemorrhage remains a concern after negative CT (within 6 hours of headache onset, a third-generation CT read by neuroradiologist may obviate LP) 5

CSF studies should include: opening pressure, cell count with differential, protein, glucose, Gram stain, bacterial culture, viral PCR panel (HSV, VZV), cytology, and oligoclonal bands. 1, 4

Additional Autoimmune and Infectious Screening

Based on clinical context, obtain:

• Serum protein electrophoresis if paraproteinemia or plasma cell disorder is suspected 1
• Autoimmune panel (ANA, anti-Ro/La antibodies) when connective tissue disease such as Sjögren's syndrome is considered 1, 4
• HIV testing when risk factors are present 1, 4

Neurology Consultation—Mandatory

Immediate neurology referral is required given the combination of headache, interscapular pain, and perioral paresthesias in a 60-year-old woman. 1, 8

The neurologist may order:

• Electromyography and nerve conduction studies to evaluate peripheral neuropathy if paresthesias remain unexplained after metabolic workup 1, 4
• MRI of the complete spine (cervical, thoracic, lumbar) with and without contrast if myelopathy, radiculopathy, or spinal pathology is suspected 1, 8
• Specialized autoimmune panels including aquaporin-4 IgG and paraneoplastic antibodies when inflammatory CNS disease is suspected 1, 4

Critical Red Flags Requiring Emergent Escalation

Immediate escalation to emergency department is warranted if: 5, 7

• Thunderclap (sudden-onset) headache develops
• Fever, neck stiffness, or meningeal signs appear
• Visual changes, diplopia, or jaw claudication emerge (highly suggestive of GCA with risk of permanent vision loss) 3
• Altered consciousness or focal neurologic deficits develop

Giant Cell Arteritis—Specific Considerations

Given this patient's age (60 years) and symptom constellation, GCA must be actively excluded: 2, 3, 9

• Temporal artery palpation should be performed—tenderness is highly suggestive 2
• ESR is typically markedly elevated (often >50 mm/hr), though slightly elevated ESR does not exclude GCA 2
• Temporal artery ultrasound can visualize vasculitic changes and may identify lingual artery involvement in patients with tongue pain 3
• Temporal artery biopsy remains the gold standard if clinical suspicion is high, even with normal or equivocal inflammatory markers 2
• High-dose corticosteroids (typically prednisone 40-60 mg daily) should be initiated immediately if GCA is strongly suspected, even before biopsy confirmation, to prevent irreversible vision loss 2, 3

Common Pitfalls to Avoid

• Do not delay endocrine testing (cortisol, ACTH) in patients with prominent fatigue—untreated adrenal insufficiency can precipitate life-threatening crisis 1, 4
• Do not rely solely on CT for subacute headache with neurologic features—MRI provides vastly superior sensitivity 1, 6
• Do not dismiss slightly elevated ESR in the context of headache and systemic symptoms in a patient over 50—GCA can present with modest inflammatory marker elevation 2
• Do not attribute perioral paresthesias to anxiety without first excluding hypocalcemia, B12 deficiency, and structural CNS lesions 1

Interscapular Pain—Differential Considerations

While interscapular pain can be musculoskeletal, in this context consider: 5, 8

• Aortic dissection (though typically presents with tearing chest pain radiating to back)
• Subarachnoid hemorrhage (can present with interscapular pain and headache) 5
• Spinal pathology including epidural abscess or hematoma if fever or neurologic deficits develop
• Referred pain from intracranial hypotension (though typically presents with orthostatic headache) 8

The combination of headache, interscapular pain, and neurologic symptoms mandates brain imaging first, followed by spine imaging if initial workup is unrevealing and symptoms persist. 1