This is a double-blind, randomized, placebo-controlled feasibility trial of DHA for the treatment of pediatric concussion related to sports-injury. The definition used for concussion is from the Consensus Statement on Concussion in Sport: the 3rd International Conference on Concussion in Sport (Br J Sports Med 2009;43:Suppl 1 i76-i84 doi:10.1136/bjsm.2009.058248) and will meet the following criteria:
1. Direct blow to the head, face, neck or a blow elsewhere on the body with an "impulsive" force transmitted to the head.
2. Rapid onset of short-lived impairment of neurologic function in one or more of the following clinical domains that resolves spontaneously:
1. symptoms: somatic (eg, headache), cognitive (eg, feeling like in a fog) and/or emotional symptoms (eg, lability).
2. physical signs (eg, loss of consciousness, amnesia).
3. behavioural changes (eg, irritability).
4. cognitive impairment (eg, slowed reaction times).
5. sleep disturbance (eg, drowsiness).
3. No abnormality on standard structural neuroimaging studies, if such neuroimaging studies are completed for a clinically-indicated reason. Note: neuroimaging is not a part of this study protocol. Study participants will not undergo neuroimaging as part of this study.
Subjects will be randomized in a 1:1 fashion. DHA is an omega-3 fatty acid that occurs naturally in fish oil and algae. There are many dietary supplements containing DHA available in the marketplace. Martek Biosciences provides an algae-based DHA compound which minimizes the side effects of "fishiness" in both flavor and "fish burps." The DHA produced by Martek Biosciences is also used for many infant formula companies in the US. DHA and identical placebo will be provided by Martek Biosciences.
The DHASCO capsules are supplied as 950 mg capsules with an effective dose of 500 mg DHA per capsule. The placebo capsules are supplied as 950 mg capsules consisting of 475 mg corn oil and 475 mg soy oil. Both DHA and placebo are flavored with sweet orange flavoring and masking agents.
They are supplied in sealed white plastic bottles containing 100-200 capsules per bottle, depending on dose. Each bottle has the lot number stamped on it. The capsules will be stored in a dry, locked compartment at room temperature (60 to 75 F). Martek's Quality Assurance department completes regularly scheduled chemical and long-term stability analyses on each lot of capsules. If shipments will occur during warmer months, arrangements will be made for capsules to be shipped with ice packs or other temporary refrigeration. Capsules will be dispensed to subjects in separate bottles in quantities sufficient to last until their next appointment. Any unused capsules will be returned to the PI or research staff and sent to the pharmacy for destruction in compliance with Children's regulations.
Subjects will be randomized to 2 g of DHA or matched placebo for 12 weeks. In order to achieve this dose of DHA, subjects will receive 2 950 mg capsules twice a day. Subjects who cannot tolerate the divided dose of 2000 mg per day will be discontinued from the study.
Although much of our knowledge of the pathophysiology of concussion comes from animal models, it is believed that the mechanical trauma to the brain causes a sudden disruption in the ionic balances, leading to an increase in calcium and an increase in glucose metabolism as cells try to compensate for the potassium/calcium imbalance. This is followed by a period of decreased glucose metabolism which may last up to 4 weeks in humans, resulting in continued high levels of calcium which interfere with mitochondrial oxidative metabolism. This decrease in mitochondrial oxidative metabolism appears to be biphasic, with improvement seen at 2, followed by a decrease which bottoms out on day 5 and recovers around day 10. Other important aspects of the concussive trauma include free radical production, initiation of inflammatory responses, and altered neurotransmission.
DHA has several important functions in the brain with relatively few side effects, making it a good option for concussion treatment. DHA is helpful in modulating ion channels; higher levels of DHA are associated with higher levels of sodium pump activity, so it is possible that providing DHA post-injury may help the cells reduce the calcium balance more quickly or efficiently. DHA also has an apparent anti-inflammatory action. DHA interferes with the inflammatory arachidonic acid cascade by reducing the affinity of platelet thromboxane A2/prostaglandin H2 (TxA2/PGH2) receptor for its ligand. Additionally, higher levels of DHA in the cerebral cortex cause significantly higher levels of the anti-oxidant enzymes catalase, glutathione and glutathione peroxidase -- resulting in decreased cerebral levels of lipid peroxides. DHA reduces formation of the peroxynitrite free radical and reduces formation of pro-inflammatory cytokines by inhibiting transcription factor NF-κB and inducible nitric oxide synthetase. Finally, DHA is highly concentrated in synapses, indicating a role in synaptic signal transduction. DHA appears to address many different aspects of how we believe concussive injury affects the brain.
The primary outcomes of this feasibility trial are to determine the willingness of patients to be randomized, the expected rate of enrollment based on the clinic population, and protocol adherence of enrolled study participants. We anticipate the results from this study will provide data to inform a larger randomized trial of DHA for the treatment of pediatric sports concussion. Secondary outcomes are time to clearance to return to play (in days) and improvement in balance, as assessed by the Balance Error Scoring System (BESS) which is a component of the Sport Concussion Assessment Tool 3 (SCAT-3). Time to clearance to return to play was chosen as a clinically significant measurement for medical professionals in the sports medicine field. The investigators will determine clearance for return to full competitive game play (Stage 6 of graduated return to play protocol) according to Consensus Statement guidelines and following the law in Texas, House Bill 2038. Criteria for return to play include complete clinical recovery from the concussion including returning to baseline symptoms, exam and neurocognitive function and successful completion of a gradual return to play progression. The BESS was chosen because it is a relatively simple assessment that has been noted by the investigators to be a good predictor of neurological recovery.
In addition to time to return to play and the BESS, the SCAT-3 and Immediate Post Concussion Assessment and Cognitive Testing (ImPACT) computerized neurocognitive testing programs will be used to evaluate recovery. The SCAT-3 is a standardized method of evaluating injured athletes for concussion and can be used in athletes aged from 10 years and older. The ImPACT program is a computerized exam that helps to quantify the degree of symptom, injury, or dysfunction that occurs after a sports related concussion. Although this test is utilized by many professionals, college, and high school sports programs throughout the country, it is unclear if its use contributes to a safer or more expedited return to activity.
Finally, information on side effects will be collected at every visit in order to track the rate and severity of side effects in this patient population.
We plan to enroll 40 subjects for this study, which consists of 20 subjects to be treated with DHA and 20 subjects to be treated with placebo. In order to achieve enrollment of 40 total subjects, we anticipate screening 80 subjects in order to consent 40. Because this is a pilot study, information on early withdrawals is important to us and no extra subjects will be consented due to this. We anticipate that it will take approximately 12 months to complete enrollment, with an additional 3 months for patient follow-up once the last patient has been enrolled. We anticipate that it will take approximately 6-9 months to complete data clean-up, analysis, and manuscript submission for total study duration of 2 years.
Subjects who are non-compliant with the protocol either by not keeping appointments or by not taking study pills as directed may be discontinued from the study. Subjects who do not tolerate the minimum dose of 2000 mg of DHA per day or who experience intolerable side effects will be discontinued. Subjects who choose to withdraw consent will be discontinued early.
