title: Plasma amino acid concentrations during late rehabilitation in patients with traumatic brain injury.
abstract: OBJECTIVE
  To investigate whether the basal plasma amino acid concentrations in patients with traumatic brain injury (TBI) have returned to levels found in healthy controls at about 17 months postinjury and to determine the effect of intake of a mixture of essential amino acids (EAA) on plasma amino acid concentrations in TBI versus healthy controls.
  
  
  METHODS
  Peripheral venous amino acid concentrations in subjects with TBI were compared with concentrations in healthy controls both at rest and for 1 hour after intake of 7g of EAA.
  
  
  METHODS
  Postacute brain injury rehabilitation center.
  
  
  METHODS
  Six men with TBI (age +/- standard deviation, 27+/-6y; months postinjury, 17+/-4) and 6 healthy men (age, 43+/-7y).
  
  
  METHODS
  Intake of a drink consisting of 7g of EAA.
  
  
  METHODS
  Individual and total plasma amino acid concentrations.
  
  
  RESULTS
  Total amino acid concentration was about 12% lower in TBI versus controls (P=.022). Valine was reduced by 33% in the TBI group versus controls (P=.003), whereas the other EAA did not differ between groups. After intake of the EAA drink, plasma non-EAA increased to a significantly higher level in controls versus TBI subjects (P=.017).
  
  
  CONCLUSIONS
  Plasma total amino acid concentration is still reduced 17 months postinjury in patients with TBI versus healthy controls, mainly because of a lower valine level. This may be of importance for both brain and muscle metabolic functions, and warrant further study. Further, ingested EAA are apparently not as readily converted to non-EAA in TBI patients as in healthy controls, suggesting that in recovery from TBI, certain non-EAA may become provisionally essential.
authors.affiliation: Department of Surgery, Metabolism Unit, Shriners Hospital for Children/UTMB, Galveston, TX 77550, USA. elborshe@utmb.edu
authors.forename: Elisabet
authors.initials: E
authors.lastname: Børsheim
authors.forename: Quynh-Uyen T
authors.initials: QU
authors.lastname: Bui
authors.forename: Robert R
authors.initials: RR
authors.lastname: Wolfe
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000097:blood*; D000601:Amino Acids, Essential / Q000008:administration & dosage*; D001628:Beverages; D001930:Brain Injuries / Q000097:blood / Q000534:rehabilitation*; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012146:Rest / Q000502:physiology; D013997:Time Factors
chemical_list: D000596:Amino Acids; D000601:Amino Acids, Essential