Post-Concussion Syndrome: The Risks and Potential Longer-Term Impacts of a Knock on the Head
With football and soccer season in full swing, and the risk of falls due to icy winter weather ahead, there is no time like the present to discuss the potential implications of head injuries, and effective approaches that may help mitigate injury-related consequences.
As many parents and sport-enthusiasts line the fields to cheer for their kids and favorite sport teams, we not only bring with us the excitement for the sport, but a continuously increasing awareness of the potential short and long-term impacts of head injuries. When we watch a player go down, or see an impact that is even more dramatic, we can’t help but gasp at times, knowing that there is no avoiding an injury with these high momentum collisions. Hands clenched, and breath held, we hope the player will get up, upon which we all cheer and breathe a sigh of relief. But even if he or she does get up, an injury may have occurred to the brain that is not immediately obvious, and that may have long-term consequences
Awareness in the medical community of post-concussion syndrome and chronic traumatic encephalopathy--the brain-related changes associated with chronic trauma to the head – has skyrocketed in recent years, with PubMed indexed publications on these topics increasing between 3 to 10-fold since 2010. A very recent study, highlighted in Scientific American, brought even further interest to the topic, as it was shown that the impact of head injuries on females is even greater than the impacts on men. This study looked at the medical records of 110 male and 102 female athletes who had a sport-related concussion injury, and found that the median recovery time for female athletes was 28 days – more than double the 11 days necessary for the males to recover.1
Males experienced a higher incidence of loss of consciousness and anterograde amnesia (defined as the ability to create new memories after the event that caused the amnesia, leading to a partial or complete inability to recall the recent past), symptoms which many would associate with a more significant injury. Yet, surprisingly, this had no impact on the time to recovery from post-concussion symptoms. Other studies also have not shown a loss of consciousness and amnesia at the time of injury to be associated with symptom duration.2 Prior toconcussion, females had a significantly higher history of migraines than males, a symptom which has previously been associated with an increase in time to recovery fromconcussion. However, there was no significant difference in recovery time between females with or without a pre-concussion history of migraines.3
Mechanisms and Symptoms of Concussion-Related Damage
Various potential explanations have been offered for the differences between males and females, including hormones, musculoskeletal variations, glucose metabolism, and gender differences in reporting physical symptoms.4,5,6 In females, symptoms of anxiety and depression and higher stress levels are also more frequent, and also may be a contributing factor.7 Overall, the pathophysiology of concussion is complex, and factors such as disruption of neurons known as axons, alterations in neurotransmitter release (due to impact-related effects, such as depolarization), neuroinflammation, and related excitotoxicity have been shown to play a role.8Concussions also impact the integrity of the blood-brain barrier, which may additionally contribute to neuroinflammation and related oxidative stress as bloodborne neurotransmitters and mediators of inflammation also can then pass into the central nervous system.9 Elevated plasma levels of C-reactive protein (CRP), a marker of inflammation, have also been shown to be related to an increased incidence of post-concussion syndrome.10
In recognizing post-concussion syndrome, it is important to be aware that loss of consciousness does not indicate the severity of impact, and a broad range of physical, cognitive, and emotional symptoms may manifest. This can include headache, dizziness, hypersomnia or insomnia, difficulty with concentration and/or memory, depression, anxiety, and mood liability. Thus, anyone experiencing these types of symptoms with a recent head injury should question the potential of post-concussion syndrome, and should seek medical evaluation.
Support for Recovery from Post-Concussion Syndrome
The primary interventions which are important for post-concussion syndrome are rest, and abstinence from activities which put one at a high risk for a subsequent injury. However, in addition, neurocognitive, or brain, rest is also important. Any activities including physical activity or cognitive effort which worsen symptoms should be avoided.11 This even includes seemingly restful activities such as reading a book or watching television, as these actually require cognitive effort. Cognitive activities increase metabolic processes, and thus alter neurotransmitter levels and other aspects of central nervous system balance.
Nutraceutical support also has some evidence for reducing the potential impact of post-concussion issues. Melatonin has been recommended to support sleep for post-concussion sleep difficulties,12 and as an antioxidant may be a potential agent that helps the central nervous system to recover from the injury.13,14 Lipoic acid also is a neuroprotective antioxidant, and has been shown to reduce cellular death and scarring while promoting cell proliferation and new blood vessel formation after traumatic brain injury.15 CoQ10, another antioxidant with neuroprotective effects, has been studied in other conditions associated with neuroinflammation such as Alzheimer’s and Parkinson’s disease, and may support the restoration of antioxidant balance after head injuries.16
Essential fatty acids including omega-3’s as well as phosphatidylcholine also support recovery after traumatic brain injury. Omega-3 fatty acids reduce oxidative damage and help to normalize brain derived neurotrophic factor (BDNF), a signaling factor that facilitates synaptic transmission and learning ability, restoring homeostasis at cellular and molecular levels.17,18 Phosphatidylcholine, the predominant phospholipid that forms animal and plant cell membranes, promotes cellular repair and is a precursor for the synthesis of acetylcholine, a neurotransmitter important for cognitive function.19
Restoring the balance of inhibitory and excitatory neurotransmitters is also of importance. Glutamate is released in abundance with traumatic head injuries, and is a primary excitatory neurotransmitter.20 Gamma-aminobutyric acid (GABA) is the chief inhibitory neurotransmitter that serves to balance glutamate, and shifts out of balance with glutamate subsequent to head injuries, in part due to the loss of GABA producing cells.21 Support for GABA thus also may help restore balance and homeostasis more rapidly. L-theanine, an amino acid derived from green tea, has a protective effect on the brain and supports BDNF levels, and functions complementary to GABA.22Cannabidiol (CBD), the non-psychoactive constituent of marijuana, also has neuroprotective effects, and has been shown to be a superior antioxidant in preventing glutamate toxicity.23
In summary, although protective measures such as helmets and appropriate training may help to prevent head injuries, it is important to understand the symptoms which occur post-concussion, and to take protective measures to minimize adverse outcomes. Keeping a selection of supportive supplements around the home or in the gym bag to use when needed, or even taking them in an ongoing manner for protection, may be worth consideration, depending on the sports which you or your loved ones choose to participate in.
2 Meehan WP 3rd, Mannix RC, Stracciolini A, et al. Symptom severity predicts prolonged recovery after sport-related concussion, but age and amnesia do not. J Pediatr. 2013 Sep;163(3):721-5. View Full Paper
5 Tierney RT, Sitler MR, Swanik CB, et al. Gender differences in head-neck segment dynamic stabilization during head acceleration. Med Sci Sports Exerc. 2005 Feb;37(2):272-9.
7 Hankin BL. Development of sex differences in depressive and co-occurring anxious symptoms during adolescence: descriptive trajectories and potential explanations in a multiwave prospective study. J Clin Child Adolesc Psychol. 2009 Jul;38(4):460-72. View Full Paper
10 Su SH, Xu W, Li M, et al. Elevated C-reactive protein levels may be a predictor of persistent unfavourable symptoms in patients with mild traumatic brain injury: a preliminary study. Brain Behav Immun. 2014 May;38:111-7. View Abstract
14 Barlow KM, Brooks BL, MacMaster FP, et al. A double-blind, placebo-controlled intervention trial of 3 and 10 mg sublingual melatonin for post-concussion syndrome in youths (PLAYGAME): study protocol for a randomized controlled trial. Trials. 2014 Jul 7;15(1):271. View Abstract
15 Rocamonde B, Paradells S, Barcia JM, et al. Neuroprotection of lipoic acid treatment promotes angiogenesis and reduces the glial scar formation after brain injury. Neuroscience. 2012 Nov 8;224:102-15. View Abstract
16 Beal MF. Mitochondrial dysfunction and oxidative damage in Alzheimer's and Parkinson's diseases and coenzyme Q 10 as a potential treatment. Journal of bioenergetics and biomembranes. 2004 Aug 1;36(4):381-6. View Abstract
17 Wu A, Ying Z, Gomez-Pinilla F. Dietary omega-3 fatty acids normalize BDNF levels, reduce oxidative damage, and counteract learning disability after traumatic brain injury in rats. J Neurotrauma. 2004 Oct;21(10):1457-67. View Abstract
18 Wu A, Ying Z, Gomez-Pinilla F. Omega-3 fatty acids supplementation restores mechanisms that maintain brain homeostasis in traumatic brain injury. J Neurotrauma. 2007 Oct;24(10):1587-95. View Abstract