Investigators will determine whether treatment with a dietary supplement containing three amino acids reduces neurocognitive problems in athletes following sports-related concussion.
Between two-four million athletes annually in this country sustain sports-related concussion. Following this traumatic brain injury (TBI), many develop enduring cognitive problems especially in learning and memory, and neurobehavioral problems. There currently are no proven therapies. While the physiological mechanisms underlying TBI are not clear, a cascade of events occurs. Among these events is an imbalance of excitation and inhibition in the brain’s hippocampus which is involved in memory and learning. The investigators hypothesize that restoring this balance may improve cognitive function following TBI. Their previous studies using experimentally induced TBI in mice found reduced levels of three amino acids (building blocks of proteins): the branched-chain amino-acids valine, isoleucine, and leucine. They are present in certain dietary supplements, and are involved in the synthesis of glutamate, an excitatory neurotransmitter. Treated mice had amino acid concentrations in the hippocampus restored, no side effects, and improved cognitive performance similar to that of non-injured mice. Subsequent administration of the three amino acids to five healthy volunteers and five people with moderate TBI produced no side effects.
This neurosurgeon and his collaborators will conduct a randomized controlled trial in 66 athletes, aged 16-33 years, who are enrolled within 24 hours of concussion. Of these, 44 will receive a dietary supplement containing the three amino acids; 22 will receive a placebo. Each group will be assessed on neurocognitive function twice daily using an on-line tool that measures processing speed, attention, learning and working memory. A physician will assess clinical symptoms. The researchers anticipate that the dietary supplement group, compared to the placebo group, will: 1) have shorter reaction time on the neurocognitive measures; 2) resolve clinical symptoms more quickly; and 3) require less time to complete a graduated return to the play protocol. If so, the investigators would then study other means to enhance the treatment effect and initiate a large-scale clinical study of the dietary supplement.
Significance: The research may lead to a simple yet effective dietary supplement treatment for athletes with sports-related TBI, and conceivably for others sustaining TBIs from other causes.