title: Relationships between ophthalmic artery flow direction and cognitive performance in patients with unilateral carotid artery stenosis.
abstract: BACKGROUND
  Cerebral hypoperfusion is responsible for cognitive impairment in patients with severe carotid artery stenosis (CAS). The manifestation of reversed ophthalmic artery flow (ROAF) is not uncommon in patients with CAS, suggesting a state of intensified cerebral hypoperfusion. This study aimed to examine whether the presence of ROAF can exacerbate cognitive impairment in patients with severe unilateral CAS.
  
  
  METHODS
  One-hundred-and-two patients with CAS and 37 age-matched volunteers participated in this case-control study. Depending on the side of CAS and occurrences of ROAF, the patients were allocated to four groups: left CAS groups with ROAF (n=28) or without ROAF (n=22), and right CAS groups with ROAF (n=26) or without ROAF (n=26). All subjects underwent a battery of neuropsychological tests.
  
  
  RESULTS
  All patients performed worse than the control group on most tests. No significant differences were observed between patient groups (ps>0.05), except for inferior performance on psychomotor speed and visuospatial tests in the right ROAF group (ps<0.03). Hierarchical regression analyses indicated strong contributions of estimated premorbid intelligence to performance on most tests (ps<0.05). The severity of left and right CAS was distinctively associated with different functions. To a lesser extent, the severity of infarcts was also associated with impairment of psychomotor speed and some executive functions (ps<0.05). The contributions of ROAF to performance on most tests were negligible.
  
  
  CONCLUSIONS
  Patients with unilateral CAS may present with specific cognitive impairment relevant to the ipsilateral hemispheric functions. However, the manifestation of ROAF does not necessarily imply more extensive or severe cognitive impairment.
authors.affiliation: Stroke Center and Department of Neurology, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Kuo-Lun
authors.initials: KL
authors.lastname: Huang
authors.affiliation: Stroke Center and Department of Neurology, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ting-Yu
authors.initials: TY
authors.lastname: Chang
authors.affiliation: Stroke Center and Department of Neurology, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Chang
authors.affiliation: Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ho-Ling
authors.initials: HL
authors.lastname: Liu
authors.affiliation: Stroke Center and Department of Neurology, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yeu-Jhy
authors.initials: YJ
authors.lastname: Chang
authors.affiliation: Stroke Center and Department of Neurology, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chi-Hung
authors.initials: CH
authors.lastname: Liu
authors.affiliation: Stroke Center and Department of Neurology, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address: thlee@adm.cgmh.org.tw.
authors.forename: Tsong-Hai
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Clinical Psychology Program, c/o Department of Occupational Therapy, Chang Gung University, Taoyuan, Taiwan. Electronic address: myho@mail.cgu.edu.tw.
authors.forename: Meng-Yang
authors.initials: MY
authors.lastname: Ho
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000473:pathology / Q000502:physiology*; D016037:Single-Blind Method
keywords: Carotid artery stenosis; Cerebral infarcts; Cerebrovascular disease; Cognition; Neuropsychology; Ophthalmic artery blood flow