15 Dec Traumatic Brain Injury: Dietary Therapy

MedicalResearch.com Interview with: Miranda M. Lim, MD, PhD Assistant Professor, Sleep Medicine Division of Pulmonary and Critical Care Portland VA Medical Center and Oregon Health & Science University MedicalResearch.com: What are the main findings of the study? Dr. Lim: People with traumatic brain injury (TBI) often have persistent sleep-wake disturbances including excessive daytime sleepiness and nighttime insomnia, yet the link between a hard blow to the head and drowsiness remains a mystery. We report that a dietary supplement containing branched chain amino acids helps keep mice with TBI awake and alert. The findings suggest that branched chain amino acids, something all humans produce from foods in their normal diets, could potentially alleviate sleep problems associated with TBI. In experiments with brain-injured mice that had trouble staying awake, we found that feeding the animals a dietary supplement enriched with branched chain amino acids improved wakefulness. Treated mice not only stayed continuously awake for longer periods of time, they also showed more orexin neuron activation, neurons known to be involved in maintaining wakefulness. (Previous studies have shown that people with narcolepsy lose significant amounts of orexins.) Branched chain amino acids are the building blocks of neurotransmitters, the chemicals released by neurons in the brain, including glutamate and GABA. We believe that branched chain amino acids act to restore the excitability of orexin neurons after brain injury, which could potentially promote wakefulness. Further studies are needed to pinpoint the exact mechanism of branched chain amino acids effect on sleep pathways in the brain, and to determine any side effects.