title: Impaired cerebrovascular autoregulation after hypoxic-ischemic injury in extremely low-birth-weight neonates: detection with power and pulsed wave Doppler US.
abstract: OBJECTIVE
  To evaluate regional cerebral blood flow with power and pulsed wave Doppler ultrasound (US) in extremely low-birth-weight neonates with periventricular leukomalacia (PVL), germinal matrix hemorrhage (GMH), or both.
  
  
  METHODS
  The lenticulostriate arteries of 17 preterm neonates (birth weight < or = 1,100 g) were assessed daily with Doppler US during the first 5-6 days of life. The mean arterial pressure and bilateral peak velocity, resistive index, coronal vascular cross-sectional area, and product of the peak velocity and vascular cross-sectional area were measured.
  
  
  RESULTS
  Five neonates developed PVL, GMH, or both; results of follow-up examinations in 11 patients were normal. One neonate with severe intrauterine growth retardation and renal tubular acidosis was excluded. Neonates with PVL, GMH, or both showed significantly greater mean values and more variable values of vascular cross-sectional area and product of peak velocity and cross-sectional area than neonates without PVL or GMH (P < .025). Mean resistive index was significantly lower in neonates with PVL, GMH, or both than in neonates without (P < .01). There were no significant differences between mean arterial pressure in neonates with and those without PVL, GMH, or both.
  
  
  CONCLUSIONS
  By enabling the detection of autoregulatory fluctuations in cerebral blood flow associated with hypoxic-ischemic injury, power and pulsed wave Doppler US may enable identification of preterm neonates who are at risk of developing PVL, GMH, or both during the 1st week of life.
authors.affiliation: Department of Radiology, Stanford University School of Medicine, CA 94305, USA.
authors.forename: F G
authors.initials: FG
authors.lastname: Blankenberg
authors.forename: N N
authors.initials: NN
authors.lastname: Loh
authors.forename: A M
authors.initials: AM
authors.lastname: Norbash
authors.forename: J A
authors.initials: JA
authors.lastname: Craychee
authors.forename: D M
authors.initials: DM
authors.lastname: Spielman
authors.forename: B L
authors.initials: BL
authors.lastname: Person
authors.forename: C A
authors.initials: CA
authors.lastname: Berg
authors.forename: D R
authors.initials: DR
authors.lastname: Enzmann
mesh_terms: D001783:Blood Flow Velocity; D001794:Blood Pressure; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000503:physiopathology*; D019102:Infant, Very Low Birth Weight; D007969:Leukomalacia, Periventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance