title: Time course for autoregulation recovery following severe traumatic brain injury.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the time course for cerebral autoregulation (AR) recovery following severe traumatic brain injury (TBI).
  
  
  METHODS
  Thirty-six patients (27 males and 9 females, mean +/- SEM age 33 +/- 15.1 years) with severe TBI underwent serial dynamic AR studies with leg cuff deflation as a stimulus, until recovery of the AR responses was measured.
  
  
  RESULTS
  The AR was impaired (AR index < 2.8) in 30 (83%) of 36 patients on Days 3-5 after injury, and in 19 individuals (53%) impairments were found on Days 9-11 after the injury. Nine (25%) of 36 patients exhibited a poor AR response (AR index < 1) on postinjury Days 12-14, which eventually recovered on Days 15-23. Fifty-eight percent of the patients with a Glasgow Coma Scale score of 3-5, 50% of those with diffuse brain injury, 54% of those with elevated intracranial pressure, and 40% of those with poor outcome had no AR recovery in the first 11 days after injury.
  
  
  CONCLUSIONS
  Autoregulation recovery after severe TBI can be delayed, and failure to recover during the 2nd week after injury occurs mainly in patients with a lower Glasgow Coma Scale score, diffuse brain injury, elevated ICP, or unfavorable outcome. The finding suggests that perfusion pressure management should be considered in some of the patients for a period of at least 2 weeks.
authors.affiliation: Department of Neurological Surgery, Rambam Medical Center, The Technion, Israel Institution of Technology, Haifa, Israel. sviri@u.washington.edu
authors.forename: Gill E
authors.initials: GE
authors.lastname: Sviri
authors.forename: Rune
authors.initials: R
authors.lastname: Aaslid
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Douville
authors.forename: Anne
authors.initials: A
authors.lastname: Moore
authors.forename: David W
authors.initials: DW
authors.lastname: Newell
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001930:Brain Injuries / Q000175:diagnosis* / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D015600:Glasgow Coma Scale; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors; D015599:Trauma Severity Indices; D055815:Young Adult