Branched-chain amino acids enhance the cognitive recovery of patients with severe traumatic brain injury.
OBJECTIVE
To investigate whether supplementation with branched-chain amino acids (BCAAs) in patients with severe traumatic brain injury (TBI) improves recovery of cognition and influences plasma concentrations of tyrosine and tryptophan, which are precursors of, respectively, catecholamine and serotonin neurotransmitters in the brain.


METHODS
Forty patients with TBI were randomly assigned to 15 days of intravenous BCAA supplementation (19.6g/d) (n=20) or an isonitrogenous placebo (n=20).


METHODS
Tertiary care rehabilitation setting in Italy.


METHODS
Forty men (mean age, 32+/-15 y) with TBI and 20 healthy subjects (controls) matched for age, sex, and sedentary lifestyle.


METHODS
Supplementation with BCAAs.


METHODS
Disability Rating Scale (DRS) and plasma concentrations of BCAAs, tyrosine, and tryptophan.


RESULTS
Fifteen days after admission to the rehabilitation department, the DRS score had improved significantly in both the placebo group (P<.05 vs baseline) and in the BCAA-supplemented group (P<.01 vs baseline). The difference between the 2 groups was significant (P<.004). Plasma tyrosine concentration improved in the group given BCAA supplementation, and tryptophan concentration increased in patients receiving placebo.


CONCLUSIONS
Supplemental BCAAs enhance the retrieval of DRS without causing negative effects on tyrosine and tryptophan concentration.
Aquilani
Roberto
R
Servizio di Fisiopatologia Metabolico-Nutrizionale e Nutrizione Clinica.
Iadarola
Paolo
P
Contardi
Antonella
A
Boselli
Mirella
M
Verri
Manuela
M
Pastoris
Ornella
O
Boschi
Federica
F
Arcidiaco
Patrizia
P
Viglio
Simona
S
D000293:Adolescent; D000328:Adult; D000597:Amino Acids, Branched-Chain / Q000008:administration & dosage*; D001930:Brain Injuries / Q000175:diagnosis / Q000188:drug therapy*; D003072:Cognition Disorders / Q000188:drug therapy* / Q000517:prevention & control; D004185:Disability Evaluation; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007262:Infusions, Intravenous; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011336:Probability; D012016:Reference Values; D018570:Risk Assessment; D016896:Treatment Outcome
D000597:Amino Acids, Branched-Chain