title: Dynamic cerebral autoregulation is heterogeneous in different subtypes of acute ischemic stroke.
abstract: OBJECTIVE
  Stroke of large-artery atherosclerosis and small-artery occlusion are two main subtypes of stroke according to TOAST classification. The underlying mechanisms of how these two subtypes affect dynamic cerebral autoregulation (dCA) might be heterogeneous, resulting in varied clinical conditions and outcomes. We therefore studied the pattern of dCA in these two subtypes.
  
  
  METHODS
  Forty-one patients with acute unilateral middle cerebral artery (MCA) territory stroke (15 with ipsilateral large-artery atherosclerosis and 26 with small-artery occlusion) and 20 healthy volunteers were enrolled. Non-invasive continuous cerebral blood flow velocity and arterial blood pressure were recorded simultaneously from each subject in supine position using transcranial Doppler on MCA bilaterally and servo-controlled plethysmograph on the middle finger, respectively. Transfer function analysis was applied to derive autoregulatory parameters, gain, phase difference (PD), and slope of step response.
  
  
  RESULTS
  In the large-artery atherosclerosis group, PD in affected hemisphere was 42.9±18.5 degree, which is significantly lower than the unaffected hemisphere (72.4±29.9 degree, P<0.01), and the healthy group (P<0.01). However, PD is similar in the unaffected hemisphere and healthy group (P>0.1). In the small-artery occlusion group, PD in the affected hemisphere was similar to that in the contralateral hemisphere (33.8±17.9 vs. 32.6±21.1 degree, P>0.1), both sides were significantly lower than the healthy group (all P<0.001).The results of the slope of step response agree with the findings in PD.
  
  
  CONCLUSIONS
  DCA in different subtypes of acute ischemic stroke is heterogeneous, which might be attributed to the varied pathologic changes of cerebral blood vessels.
authors.affiliation: Neuroscience Center, Department of Neurology, the First Norman Bethune Hospital of Jilin University, Chang Chun, China.
authors.forename: Zhen-Ni
authors.initials: ZN
authors.lastname: Guo
authors.affiliation: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Xueyuan Avenue, Shenzhen University Town, Shenzhen, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Center for Neurovascular ultrasound, the First Norman Bethune Hospital of Jilin University, Chang Chun, China.
authors.forename: Yingqi
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Neuroscience Center, Department of Neurology, the First Norman Bethune Hospital of Jilin University, Chang Chun, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Yan
authors.affiliation: Neuroscience Center, Department of Neurology, the First Norman Bethune Hospital of Jilin University, Chang Chun, China.
authors.forename: Cunling
authors.initials: C
authors.lastname: Lv
authors.affiliation: Neuroscience Center, Department of Neurology, the First Norman Bethune Hospital of Jilin University, Chang Chun, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Jin
authors.affiliation: Neuroscience Center, Department of Neurology, the First Norman Bethune Hospital of Jilin University, Chang Chun, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006439:Hemodynamics; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000503:physiopathology*; D002537:Intracranial Arteriosclerosis / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology