Increased Cerebrovascular Reactivity In Selected Brain Regions After Extracranial-Intracranial Bypass Improves The Speed of Visual Cancellation In Patients With Severe Steno-Occlusive Disease: A Preliminary Study

Abstract

\n The effect of the change in cerebrovascular reactivity (CVR) in each brain area on cognitive function after extracranial-intracranial bypass was examined as a preliminary study in 20 patients with severe steno-occlusive disease. CVR studies and the visual cancellation task (VC) were performed before and after surgery. The Speed and Accuracy scores of the VC, which increased with improvement after the operation, were evaluated. CVR increased postoperatively both ipsilaterally and contralaterally to the surgery. Before surgery VC completion time was delayed, but accuracy was relatively maintained. In stepwise and least absolute shrinkage and selection operator (LASSO) regression models, two regions (right inferior frontal gyrus and right uncus) for the Speed score and one region (right superior occipital gyrus) for the Accuracy score were common brain regions associated with CVR change after surgery. The Speed and Accuracy scores of brain regions of the right cerebral hemisphere, which may be anatomically distant from the blood vessel anastomosis, were related to CVR change. Moreover, in the ischemic stage, with reduced CVR but no cerebral infarction, processing speed might decrease to maintain accuracy, and revascularization might increase the processing speed. In revascularization, the relationship between CVR change and the speed-accuracy trade-off in each brain region should be considered.