Stroke pattern in giant-cell arteritis mostly involves watershed areas

Area of Science:

• Neurology
• Vascular Neurology
• Cerebrovascular Disease

Background:

• Stroke is a rare but severe complication of Giant Cell Arteritis (GCA).
• Ischemic mechanisms in GCA stroke may involve arterial lumen narrowing and reduced distal blood flow.
• Watershed areas (WA) were hypothesized as predominant sites for GCA-related strokes.

Purpose of the Study:

• To investigate the distribution and characteristics of ischemic lesions in GCA-related stroke.
• To determine the role of watershed areas in GCA stroke pathology.
• To identify potential ischemic mechanisms in GCA stroke.

Main Methods:

• A comprehensive literature review was conducted.
• Cases of GCA-related stroke with available brain imaging were included.
• Analysis focused on lesion location and arterial territories.

Main Results:

• Of 75 GCA stroke cases, 48% involved anterior and 62.6% posterior territories.
• Up to 88.9% of anterior strokes likely affected WA.
• Middle cerebellar peduncle (MCP) lesions, characteristic of WA, were observed in 25.5% of posterior circulation strokes.

Conclusions:

• Ischemic lesions in GCA stroke primarily occur in watershed areas (WA), despite challenges in posterior circulation territory allocation.
• Middle cerebellar peduncle (MCP) lesions are highly characteristic of GCA and typically represent WA involvement.
• Low distal blood flow caused by focal arterial stenosis is the primary, but not exclusive, ischemic mechanism in GCA stroke.