The Study Of Dynamic Cerebral Autoregulation In Different Subtypes Of Acute Ischemic Stroke

Objective：According to TOAST classification, Stroke of large-artery atherosclerosis andsmall-artery occlusion are two primary subtypes of stroke. The underlying mechanisms ofhow these two subtypes affect dynamic cerebral autoregulation (dCA) might be different,resulting in varied clinical manifestation and outcomes. For this reason, We studied thepattern of dCA in these two subtypes.Methods: Sixty-one patients with acute unilateral middle cerebral artery (MCA) territorystroke (25with ipsilateral large-artery atherosclerosis and36with small-artery occlusion) and30healthy volunteers were enrolled. Non-invasive continuous cerebral blood flow velocityand arterial blood pressure were recorded simultaneously from each subject in supine positionusing transcranial Doppler on MCA bilaterally and servo-controlled plethysmograph on themiddle finger, respectively. Transfer function analysis was applied to derive autoregulatoryparameters, gain, phase difference (PD), and slope of step response.Results: In the large-artery atherosclerosis group, PD in affected hemisphere was43.8±17.3degree, which is significantly lower than the unaffected hemisphere (73.5±28.5degree,P<0.01), and the healthy group (P<0.01). However, PD is similar in the unaffectedhemisphere and healthy group (P>0.1). In the small-artery occlusion group, PD in the affectedhemisphere was similar to that in the contralateral hemisphere (34.6±16.8vs.33.8±20.7degree, P>0.1), both sides were significantly lower than the healthy group (all P<0.001).Theresults of the slope of step response agree with the findings in PD.Conclusions: In different subtypes of acute ischemic stroke，the pattern of DCA isdifferent, It is probably because of the multiple pathologic changes of cerebral blood vessels.