title: Early childhood gender differences in anterior and posterior cerebral blood flow velocity and autoregulation.
abstract: OBJECTIVE
  We aimed to describe gender differences in blood flow velocity and autoregulation of the anterior and posterior cerebral circulations in prepubertal children.
  
  
  METHODS
  A prospective observational cohort study was performed at Harborview Medical Center's Cerebrovascular Laboratory after institutional review board approval, consent, and assent procedures. Children underwent measurement of middle cerebral and basilar artery flow velocities and cerebral autoregulation testing of the middle cerebral and basilar arteries. Cerebral autoregulation was quantified using the autoregulatory index, and estimated cerebrovascular resistance was calculated. Autoregulatory index <0.4 reflects impaired cerebral autoregulation. Data are presented as mean +/- SD. Patients were healthy 4- to 8-year-old children.
  
  
  RESULTS
  Forty-eight children (24 boys and 24 girls) 4 to 8 years of age (mean: 6 +/- 2 years) were enrolled. Middle cerebral artery flow velocity was higher than basilar artery flow velocity (96 +/- 13 vs 65 +/- 11 cm/s). Girls had higher middle cerebral artery flow velocity (99 +/- 11 vs 91 +/- 13 cm/s) and basilar artery flow velocity (70 +/- 10 vs 61 +/- 9 cm/s) than boys. Cerebral autoregulation was intact in all children. There was no gender difference in autoregulation between the middle cerebral artery (boys: 0.97 +/- 0.07; girls: 0.94 +/- 0.11) or basilar artery (boys: 0.94 +/- 0.13; girls: 0.94 +/- 0.11).
  
  
  CONCLUSIONS
  Similar to older children and adults, girls between 4 and 8 years of age had higher middle cerebral and basilar artery flow velocity than age-matched boys. This difference may reflect inherent differences in cerebral metabolic rate and/or estimated cerebrovascular resistance between the genders.
authors.affiliation: Anesthesiology, University of Washington, Seattle, Washington, USA.
authors.forename: Nuj
authors.initials: N
authors.lastname: Tontisirin
authors.forename: Saipin L
authors.initials: SL
authors.lastname: Muangman
authors.forename: Pilar
authors.initials: P
authors.lastname: Suz
authors.forename: Catherine
authors.initials: C
authors.lastname: Pihoker
authors.forename: Dana
authors.initials: D
authors.lastname: Fisk
authors.forename: Anne
authors.initials: A
authors.lastname: Moore
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Lam
authors.forename: Monica S
authors.initials: MS
authors.lastname: Vavilala
mesh_terms: D000367:Age Factors; D020771:Anterior Cerebral Artery / Q000502:physiology*; D001488:Basilar Artery / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000502:physiology; D020769:Posterior Cerebral Artery / Q000502:physiology*; D011187:Posture / Q000502:physiology; D011446:Prospective Studies; D012727:Sex Characteristics