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A Thrombotic Stroke Model Based On Transient Cerebral Hypoxia-ischemia
Published on: August 18, 2015
Hypoperfusion without ischemia surrounding acute intracerebral hemorrhage
A R Zazulia1, M N Diringer, T O Videen
1Department of Neurology and Neurological Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA.
Summary
Acute intracerebral hemorrhage (ICH) patients show reduced cerebral blood flow and oxygen consumption around the clot, but not ischemia. This periclot hypoperfusion indicates altered brain metabolism, not tissue damage from lack of oxygen.
Area of Science:
- Neurology
- Neuroimaging
- Cerebrovascular Disease
Background:
- A hypoperfused zone around acute intracerebral hemorrhage (ICH) is often assumed to be ischemic.
- Understanding the metabolic state of this periclot region is crucial for patient management.
Purpose of the Study:
- To investigate whether ischemia is present in the periclot area of acute ICH patients.
- To quantify cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF) in the periclot region.
Main Methods:
- Positron emission tomography (PET) was used to measure CBF, CMRO2, and OEF in 19 acute ICH patients (5-22 hours post-onset).
- Measurements were taken in a 1-cm zone around the clot and compared to contralateral regions in patients without midline shift.
- PET data were corrected for partial volume effects from clot and ventricles.
Main Results:
- Periclot CBF and CMRO2 were significantly reduced compared to contralateral values (P < 0.0005).
- Periclot OEF was lower than both hemispheric and contralateral regional OEF (P = 0.05).
- CMRO2 reduction exceeded CBF reduction, leading to decreased OEF.
Conclusions:
- The periclot hypoperfusion in acute ICH is characterized by reduced CMRO2 and CBF, with a lower OEF.
- This metabolic profile suggests no evidence of ischemia in the periclot zone within 22 hours of hemorrhage onset.
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