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Vasoreactivity and peri-infarct hyperintensities in stroke.
P Zhao1, D C Alsop, A Abduljalil
1Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
Impaired cerebral vasoreactivity after ischemic stroke affects blood flow augmentation and reduction. This reduced CO2 vasoreactivity (CO2 VR) is linked to worse outcomes and peri-infarct T2 hyperintensities.
Area of Science:
- Neurology
- Neuroimaging
- Vascular Neurology
Background:
- Cerebral vasoreactivity (CO2 VR) impairment post-ischemic stroke is not well understood.
- The impact of impaired CO2 VR on surrounding brain regions and clinical outcomes remains unclear.
Purpose of the Study:
- To investigate regional differences in CO2 VR after large artery ischemic stroke.
- To examine the relationship between CO2 VR, peri-infarct T2 hyperintensities (PIHs), infarct volume, and clinical outcomes.
Main Methods:
- 39 chronic stroke patients and 48 controls underwent 3-Tesla MRI.
- Anatomic and 3D-continuous arterial spin labeling MRI measured regional cerebral blood flow (CBF) and CO2 VR under varying CO2 levels.
Main Results:
- Stroke patients exhibited blunted blood flow augmentation with increased CO2 and exaggerated reduction with decreased CO2 compared to controls.
- Altered CO2 VR was observed both ipsilateral and contralateral to the stroke.
- Lower ipsilesional CO2 VR correlated with PIHs, larger infarct volume, and poorer outcomes. PIH cases showed globally lower CBF.
Conclusions:
- Patients with large artery ischemic infarcts show inadequate perfusion augmentation but preserved vasoconstriction.
- Peri-infarct T2 hyperintensities are associated with reduced cerebral blood flow.
- Future strategies should focus on preserving vasoreactivity to improve long-term stroke outcomes.
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