In an older adult (>50 years) with recent giant cell arteritis (GCA), what type of stroke is most commonly seen?

Stroke Type in Giant Cell Arteritis

In older adults with giant cell arteritis, posterior circulation (vertebrobasilar) ischemic stroke is the most common stroke type, occurring when GCA causes inflammatory stenosis or occlusion of the vertebral and basilar arteries. 1, 2, 3

Stroke Epidemiology and Mechanism in GCA

• Ischemic stroke occurs in 2.8–7% of patients diagnosed with GCA, making it a less common but serious complication compared to visual loss. 2, 4
• The majority of GCA-related strokes involve the posterior circulation due to vasculitic involvement of the vertebral arteries and, less frequently, the basilar artery. 2, 3
• Stroke results from inflammatory arterial wall thickening, intimal hyperplasia, and progressive luminal stenosis or occlusion of the extradural vertebral or carotid arteries. 5, 4

Clinical Recognition and Red Flags

Multiple stenoses or occlusions in the vertebrobasilar territory are highly suggestive of GCA-related stroke, affecting approximately 70% of stroke patients with concomitant GCA versus only 7.9% of non-GCA stroke patients. 3

Key clinical indicators that should raise suspicion for GCA in stroke patients include:

• Older age (median 85 years in GCA-stroke patients versus 69 years in non-GCA stroke patients). 3
• Markedly elevated inflammatory markers: ESR typically >75 mm/h (versus 11 mm/h in non-GCA stroke) and CRP >3.8 mg/dL (versus 0.25 mg/dL). 3
• Anemia (hemoglobin 10.4 g/dL versus 14.6 g/dL in non-GCA patients). 3
• Constitutional symptoms including headache, jaw claudication, temporal tenderness, weight loss, or fever. 1, 6

Diagnostic Approach

Cervical duplex ultrasound should be performed to evaluate for the characteristic "halo sign" in both temporal and vertebral arteries, which indicates arterial wall inflammation. 2

• Temporal artery biopsy (≥1 cm specimen) remains the gold standard for definitive diagnosis, though it may be negative in cases of isolated large-vessel GCA. 5
• Vascular imaging with MR/CT angiography or PET can confirm large-vessel involvement when temporal artery biopsy is negative or unavailable. 1, 5
• Diffusion-weighted MRI is superior to CT for detecting acute cortical ischemic lesions in GCA-related stroke, identifying silent brain infarction in 19–25% of patients with retinal artery occlusion. 1

Immediate Management Protocol

Initiate high-dose oral prednisone 40–60 mg daily immediately upon suspicion of GCA-related stroke, without delaying for diagnostic confirmation. 5

• For threatened vision loss or critical cranial ischemia, administer IV methylprednisolone 500–1000 mg daily for 3 days, then transition to high-dose oral glucocorticoids. 1, 5
• Add low-dose aspirin 75–150 mg daily to all GCA patients to reduce cardiovascular and cerebrovascular ischemic events. 1, 5
• Tocilizumab is the preferred adjunctive agent for reducing glucocorticoid requirements and preventing stroke recurrence in GCA patients with ischemic complications. 5

Critical Pitfalls to Avoid

Do not delay glucocorticoid treatment while awaiting temporal artery biopsy or specialist consultation, as stroke can be the initial presentation of GCA and prompt treatment is highly effective in preventing recurrence. 5, 6

• Do not dismiss GCA in stroke patients with negative temporal artery biopsy, as isolated large-vessel GCA may not show temporal artery involvement; proceed with large-vessel imaging. 1
• Do not rely solely on ESR or CRP for diagnosis, as no single test has perfect sensitivity; clinical suspicion should drive decision-making in older patients with vertebrobasilar stroke and elevated inflammatory markers. 6
• Recognize that stroke may be the atypical initial presentation of GCA without classic symptoms of headache or jaw claudication, particularly in posterior circulation territory. 6, 3