Traumatic Brain Injury: Dietary Therapy

Miranda M. Lim, MD, PhD Assistant Professor, Sleep Medicine Division of Pulmonary and Critical Care Portland VA Medical Center and Oregon Health & Science UniversityMedicalResearch.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.
MedicalResearch.com: Were any of the findings unexpected?

Dr. Lim: Our hypothesis was that the branched chain amino acid dietary therapy would improve wakefulness, but we were surprised to find that they also seemed to improve sleep. The dietary therapy consolidated sleep bouts and improved sleep continuity in brain-injured mice.

MedicalResearch.com: What should clinicians and patients take away from your report?

Dr. Lim: It is too early to definitively say whether this will be a viable treatment for sleep-wake problems after concussion, but the potential exists. Our finding does highlight the possibility that what we consume in our diets could impact the symptoms and recovery from concussion.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Dr. Lim:We are currently in the early stages of a clinical trial testing the dietary therapy in patients; further details will be forthcoming.

Citation:

Dietary Therapy Mitigates Persistent Wake Deficits Caused by Mild Traumatic Brain Injury

Miranda M. Lim, Jaclynn Elkind, Guoxiang Xiong, Ray Galante, Jingxu Zhu, Lin Zhang, Jie Lian, Julianna Rodin, Nicholas N. Kuzma, Allan I. Pack, and Akiva S. Cohen

Sci Transl Med 11 December 2013 5:215ra173. [DOI:10.1126/scitranslmed.3007092]