Watershed infarcts in the brain caused by microemboli

Area of Science:

• Neurology
• Pathology
• Vascular Biology

Background:

• Vascular occlusions in leptomeningeal arteries over brain watershed infarcts are common.
• These occlusions are typically attributed to thrombi formed secondary to reduced blood flow.

Observation:

• Analysis of patient groups revealed atheromatous and tumor emboli preferentially lodging in watershed areas.
• Cases of watershed infarcts following hypotension showed minimal arterial occlusion, questioning stagnation thrombosis.
• Platelet microemboli were also identified as a cause of embolization.

Findings:

• Microemboli, not stagnation thrombi, are the primary cause of vascular occlusions in leptomeningeal arteries over watershed infarcts.
• Emboli preferentially lodge in watershed areas, leading to brain infarcts.
• Multiple pathogenetic mechanisms contribute to embolization in these regions.

Implications:

• Revises the understanding of stroke pathogenesis in watershed territories.
• Highlights the critical role of microemboli in causing specific types of brain infarcts.
• Suggests potential targets for therapeutic interventions aimed at preventing embolic stroke.