MRI evidence of reperfusion injury associated with neurological deficits after carotid revascularization procedures

Background and purpose: Some patients develop major neurological complications after carotid revascularization procedures, despite the lack of new infarcts or classical hyperperfusion syndrome. Methods: In four patients who developed major neurological deficits after carotid revascularization procedures, but without evidence of new ischemic infarcts or hyperperfusion, we performed post-procedural MRI [diffusion-weighted image (DWI), perfusion-weighted image (PWI), pre-and post-contrast fluid-attenuated inversion recovery (FLAIR) image] immediately after and 1 day after the procedure. Results: Post-gadolinium FLAIR images on 1 day after the procedures showed prominent leptomeningeal enhancements in the revascularized hemispheres. These radiological findings disappeared on follow-up FLAIR images accompanied by the clinical improvement over the following several days after the procedures. Conclusion: Reperfusion syndrome may be associated with transient severe neurological deficits after carotid revascularization in patients without new ischemic events or classical hyperperfusion syndrome.