Related Experiment Video

Updated: Aug 18, 2026

Permanent Cerebral Vessel Occlusion via Double Ligature and Transection
08:22

Permanent Cerebral Vessel Occlusion via Double Ligature and Transection

Published on: July 21, 2013

Watershed infarcts in the brain caused by microemboli

A Torvik, K Skullerud

    Clinical Neuropathology
    |January 1, 1982
    PubMed

    Insights

    Brain infarcts are often caused by microemboli lodging in leptomeningeal arteries, not blood flow slowdown. This study reinterprets vascular occlusions over watershed infarcts as primary embolic events.

    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.

    More Related Videos

    Embolic Middle Cerebral Artery Occlusion (MCAO) for Ischemic Stroke with Homologous Blood Clots in Rats09:11

    Embolic Middle Cerebral Artery Occlusion (MCAO) for Ischemic Stroke with Homologous Blood Clots in Rats

    Published on: September 17, 2014

    Microvascular Embolism Mouse Model for In Vivo Two-photon Microscopy Using Fluorescent Polystyrene Microspheres08:29

    Microvascular Embolism Mouse Model for In Vivo Two-photon Microscopy Using Fluorescent Polystyrene Microspheres

    Published on: November 21, 2025

    Related Concept Videos

    Stroke: Introduction and Types01:29

    Stroke: Introduction and Types

    A stroke is an acute neurological event caused by the sudden disruption of cerebral blood flow, leading to rapid loss of neuronal function. Neurons depend on continuous oxygen and glucose supply, so even brief interruptions can cause irreversible injury within minutes. Strokes are classified into ischemic and hemorrhagic types.Ischemic StrokeIschemic strokes are most common and occur due to arterial occlusion, depriving brain tissue of oxygen and nutrients. This leads to energy failure, ionic...
    Ischemic Stroke l: Introduction01:15

    Ischemic Stroke l: Introduction

    Ischemic stroke is an acute cerebrovascular condition in which blood flow to a brain region is suddenly interrupted, leading to tissue infarction. Neurons depend on continuous oxygen and glucose supply, so even brief reductions in perfusion cause energy failure, ionic imbalance, and irreversible injury. Ischemic strokes are classified into thrombotic and embolic types based on their underlying mechanisms.Thrombotic MechanismsThrombotic stroke develops when a clot forms within a cerebral artery.
    Ischemic Stroke ll: Pathophysiology01:15

    Ischemic Stroke ll: Pathophysiology

    An ischemic stroke occurs when a cerebral blood vessel becomes obstructed, most often by a thrombus or embolus, interrupting the delivery of oxygen and glucose to brain tissue. Because neurons rely on continuous aerobic metabolism, energy failure begins within minutes of reduced perfusion. The region receiving the least blood flow becomes the infarct core, an area of irreversible cellular death. Surrounding this core lies the penumbra, a zone of hypoperfused but still viable tissue that is...
    Hemorrhagic Stroke l: Introduction01:17

    Hemorrhagic Stroke l: Introduction

    A hemorrhagic stroke is an acute neurological event that occurs when a weakened cerebral blood vessel ruptures, allowing blood to accumulate within or around the brain. The sudden release of blood forms a focal hematoma that increases intracranial pressure, displaces neural tissue, and can obstruct cerebrospinal fluid pathways. These effects may be compounded by intraventricular extension of the hemorrhage, cerebral edema, or compression of adjacent structures, all of which contribute to...
    Hemorrhagic Stroke ll: Pathophysiology01:29

    Hemorrhagic Stroke ll: Pathophysiology

    A hemorrhagic stroke develops when a cerebral blood vessel ruptures, allowing blood to escape into the surrounding brain tissue, as in intracerebral hemorrhage (ICH), or into the subarachnoid space, as in subarachnoid hemorrhage (SAH). Because the skull is a rigid compartment, the sudden presence of extravascular blood rapidly increases intracranial pressure and compresses adjacent neural structures, leading to immediate tissue injury and impaired cerebral perfusion.Mass Effect and Primary...
    Transient Ischemic Attack l: Introduction01:26

    Transient Ischemic Attack l: Introduction

    A transient ischemic attack (TIA) is a brief episode of neurological dysfunction caused by a temporary, focal reduction in cerebral blood flow. Although symptoms resemble those of an ischemic stroke, the interruption in perfusion is short-lived and does not cause permanent infarction. TIAs are clinically important because they often serve as early warning events for future stroke.Mechanisms of Transient Cerebral IschemiaTransient cerebral ischemia may arise through several mechanisms. One...