title: Link between cerebral blood flow and autonomic function in survivors of internal carotid artery occlusion.
abstract: OBJECTIVE
  Symptomatic internal carotid artery occlusion (ICAO) is an important cause of cerebral ischemia with poor long-term outcome. Reductions in baroreflex function is reported in carotid atherosclerosis and implicated in increased risk of recurrent cardiovascular events. A distributed network of forebrain regions can exert modulatory influences over the cardio-vagal and baroreflex functions. The successful clinical translation of these approaches offers insights into underlying modulatory mechanisms and to possible therapeutic strategy.
  
  
  METHODS
  This study enrolled 20 symptomatic ICAO survivors, 20 patients with small vessel disease (SVD) as risk control, and 20 healthy controls. All underwent a standardized evaluation of cardiovascular autonomic function testing that included baroreflex sensitivity (BRS), Valsalva ratio (VR), and heart rate response to deep breathing (HR_DB). The regional cerebral blood flow (rCBF) of the central autonomic network (CAN) was obtained from arterial spin-labeling magnetic resonance imaging. Parameters of autonomic function between symptomatic ICAO survivors with and those without recurrent cardiovascular events were compared.
  
  
  RESULTS
  Valsalva ratio and HR_DB levels were significantly higher in the control group, followed by the SVD and ICAO groups (p=0.009 and p=0.007, respectively). Spontaneous BRS and BRS during the early phase II of Valsalva maneuver levels were both significantly higher in the control group, followed by the SVD and ICAO groups (p<0.001 and p=0.042, respectively). The rCBF of CAN inversely correlated with spontaneous BRS.
  
  
  CONCLUSIONS
  Autonomic dysregulation, including reduced BRS and impaired cardio-vagal function in the convalescent stage ICAO, can persist for a long time. Reduced BRS is inversely correlated with CAN activity.
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Ya-Ting
authors.initials: YT
authors.lastname: Chang
authors.affiliation: Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Wen-Neng
authors.initials: WN
authors.lastname: Chang
authors.affiliation: Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Nai-Wen
authors.initials: NW
authors.lastname: Tsai
authors.affiliation: Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Neurosurgery, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Hung-Chen
authors.initials: HC
authors.lastname: Wang
authors.affiliation: Department of Emergency Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chia-Te
authors.initials: CT
authors.lastname: Kung
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Yu-Jih
authors.initials: YJ
authors.lastname: Su
authors.affiliation: Department of Radiology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Wei-Che
authors.initials: WC
authors.lastname: Lin
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Hsueh-Wen
authors.initials: HW
authors.lastname: Chang
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Ben-Chung
authors.initials: BC
authors.lastname: Cheng
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Emergency Medicine, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chih-Min
authors.initials: CM
authors.lastname: Su
authors.affiliation: Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Yi-Fang
authors.initials: YF
authors.lastname: Chiang
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Neurology, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan; Department of Neurology, Xiamen Chang Gung Memorial Hospital, Xiamen, Fujian, China. Electronic address: chlu99@ms44.url.com.tw.
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Lu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001342:Autonomic Nervous System Diseases / Q000209:etiology*; D017704:Baroreflex / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002340:Carotid Artery Diseases / Q000150:complications* / Q000401:mortality*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D012307:Risk Factors; D012720:Severity of Illness Index; D013624:Taiwan; D014636:Valsalva Maneuver / Q000502:physiology
keywords: Autonomic function; Baroreflex sensitivity; Central autonomic network; Cerebral blood flow; Internal carotid artery occlusion; Valsalva ratio