title: Is Dynamic Cerebral Autoregulation Bilaterally Impaired after Unilateral Acute Ischemic Stroke?
abstract: OBJECTIVE
  Whether dynamic cerebral autoregulation (dCA) is impaired focally in the affected hemisphere or bilaterally in both the affected and nonaffected hemispheres after ischemic stroke remains controversial. We therefore investigated the pattern of dCA in acute ischemic stroke patients with different subtypes.
  
  
  METHODS
  Sixty acute ischemic stroke patients with unilateral anterior circulation infarct [30 with large artery atherosclerosis (LAA), 13 with small vessel disease (SVD), and 17 with coexisting LAA and SVD] and 16 healthy controls were enrolled. Spontaneous arterial blood pressure and cerebral blood flow velocity fluctuations in both bilateral middle cerebral arteries using transcranial Doppler were recorded over 10 minutes. Transfer function analysis was applied to obtain autoregulatory parameters, autoregulation index (ARI), phase difference (PD), and gain.
  
  
  RESULTS
  PD was significantly lower on both the ipsilateral and contralateral sides in the LAA group (ipsilateral, 30.74 degrees; contralateral, 29.17 degrees) and the coexisting LAA and SVD group (20.23 degrees; 13.10 degrees) than that in healthy controls (left side, 51.66 degrees; right side, 58.48 degrees) (all P < .05), but there were no significant differences between the 2 sides when compared with each other in all groups. However, in the coexisting LAA and SVD group, phase on both sides was significantly lower when compared with that in the LAA and SVD groups, respectively. The results of ARI were consistent with the findings in PD.
  
  
  CONCLUSIONS
  The results indicate that dCA is bilaterally impaired in acute ischemic patients with LAA, and the coexisting SVD may aggravate the bilateral impairment of dCA.
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Li
authors.initials: L
authors.lastname: Xiong
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Tian
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Neuroscience Center, Department of Neurology, The First Norman Bethune Hospital of Jilin University, Changchun, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Thomas
authors.initials: T
authors.lastname: Leung
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Vincent
authors.initials: V
authors.lastname: Mok
authors.affiliation: Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China. Electronic address: jia.liu@siat.ac.cn.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China. Electronic address: fiona.xy2000@gmail.com.
authors.forename: Xiangyan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Ka Sing
authors.initials: KS
authors.lastname: Wong
mesh_terms: D000368:Aged; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D020520:Brain Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016022:Case-Control Studies; D059345:Cerebral Small Vessel Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D054022:Cerebrum / Q000098:blood supply*; D005260:Female; D006706:Homeostasis; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012307:Risk Factors; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial
keywords: Cerebral autoregulation; acute ischemic stroke; blood pressure; cerebral blood flow