“New testing is available using biomarkers”
Mark Studin, William J. Owens (2016)
Concussion, also known as mild traumatic brain injury (mTBI) has been a poorly understood condition known to most healthcare providers as difficult to objectify and manage. It is understandable as historically there has been no definitive testing available to conclude an accurate diagnosis in a region that is imaging dependent. In the absence of objective imaging findings of bleeding in the brain, a diagnosis of “mild traumatic brain injury” has been affixed to the condition, whereas if there is evidence of traumatic bleeding the diagnosis “traumatic brain injury” is applied. Although Hartvigsen, Boyle, Cassidy and Carroll (2014) reported that 600 out of 100,000 Americans are affected every year by concussion, Jeter et al, (2012) reported that close to 40% of people experiencing a mild brain injury do not report it to their doctor, making accurate statistics very difficult to conclude. Despite potential under reporting in the population, we recognize concussion an issue that has significant negative consequences from both a clinical outcome and whole life perspective and we cannot afford to ignore this condition any longer.
Mild traumatic brain injury or concussion results from transfer of mechanical energy from the outside environment to the brain from traumatic events where there is a sudden acceleration and then a sudden deceleration of the head and brain, such as in a Coup/Contrecoup injury during a whiplash scenario. In a Coup/Contrecoup event, the head is rapidly moving in one direction, but then suddenly changes direction. As the brain is freely moving to some degree as it is only surrounded by cerebral spinal fluid, the brain continues moving in the original direction and as the head “whips” rapidly in the opposite direction, the brain bounces off elements of the inner skull, which in turn is the catalyst for the brain to rebound shortly after the head changes direction. This is one easily defined mechanism of mTBI that does not cause gross bleeding, yet leaves the brain injured through direct compression or overstretching (axonal shearing) of central nervous system elements.
Although this has been examined extensively in the military, it has been more recently investigated in professional sports, where after numerous lawsuits and lives ruined, there are now definitive “concussion protocols” in place. Part of those protocols as reported by the British Journal of Sports Medicine (2016) is the Sports Concussion Assessment Tool 2 or SCAT2 that has been adopted by numerous professional sports leagues. However, the majority of concussion victims are not active participants in the military or a professional sports team and many find their way into chiropractic practices as a result of similar sports injuries, car accidents, slip and falls and every other type of head trauma etiology. Although the mechanisms may vary, the traumatically induced end results are the same.
Generalized patient intake protocols, based on both Medicare and academia standards, a questionnaire outlining a review of body systems is mandated, and part of those questions center on brain function. Therefore, as reported by Jeter et al neurological, cognitive and behavioral symptoms collectively referred to as post-concussion symptoms which are reported on standard patient intake questionnaires, require consideration of a diagnosis of concussion. Prominent neurological symptoms of concussion include headache, vomiting, nausea, balance issues, vision, dizziness, fatigue, drowsiness, light or noise sensitivity and sleep disturbances. Cognitive symptoms include deficits in attention, concentration, memory, mental processing speed, and working memory or decision making. Common behavioral symptoms include anxiety, depression, irritability, aggression and depression. The researchers went on to report that approximately 25% of these cases can have these symptoms persist.
As a profession, chiropractic is a critical part of the rehabilitation for the concussion population as the post-traumatic patient typically presents to the average chiropractic practice. As chiropractors (along with all healthcare providers), if you combine the history with the above symptoms inclusive of neurological, cognitive and behavioral traits, you then have the direction or “triage road map” of how to conclusively differentially diagnose your patient, including what tests to consider conducting in order to do so. The first line of testing is to consider advanced imaging to rule out bleeding and ensure the patient does not need an immediate neurosurgical consultation. With the above set of signs and symptoms, treating blindly can put your patient at possible extreme risk.
Imaging of the brain necessitates either MRI or CAT scans, MRI being the more sensitive, and in the absence of bleeding, the diagnosis is limited to mTBI or concussion (used interchangeably). More recently, diffusion tensor imaging (DTI) has been a tool available to image mTBI victims that uses tissue water diffusion rates to determine bleeding at a very small level giving demonstrable evidence to brain injury. As reported by Soares, Marques, Alves, and Sousa, (2013), DTI has multiple issues to overcome to certify accuracy including, but not limited to, tissue type, integrity, barriers and quantitative diffusion rates that are required to infer molecular diffusion rates. Currently, DTI is a model based upon assumption with a very promising outlook as a reliable tool.
Historically, mTBI was exclusively diagnosed by an omission of advanced imaging findings and the presence and persistence of the neurology, cognitive and behavioral signs and symptoms. Today, brain-derived neurotrophic factors (BDNF) offer answers about post-traumatic brain pathology that is both conclusive and reproducible. According to Korley et al. (2015), brain-derived neurotrophic factors is a secreted autocrine (chemical hormone or messenger in blood) that promotes the development, maintenance, survival, differentiation and regeneration of neurons. BDNF also is important for synaptic plasticity (strengthening of synapses over time) and memory processing. Germane to mTBI and concussion, BDNF has been implicated in reducing secondary brain injury, with elevations providing neuro-protection and restoring connectivity traumatic brain injury.
Korley went on to report that BDNF levels were the highest in the normal group with lower values in mTBI and even lower in traumatic brain injury (TBI) subjects. In addition, very low BDNF values were associated with incomplete recovery of mTBI patients than moderate or severe TBI patients. As a result, it has been determined that BDNF has a higher prognostic value for identifying mTBI related sequelae at 6 months.
Korley et al. continued, BDNF is the most abundantly secreted brain neurotrophin and as a secreted protein and can be readily measured using well-established immune-assay techniques, identifying it as a non-necrosis brain injury biomarker. This distinguishes BDNF from other protein-based biomarkers that are structural components of neurons and myelin based proteins among other neurologic structures. In order for structural proteins to be found in high abundance in circulation, sufficient cellular necrosis and damage to the blood barrier membrane must be observed, however BDNF does not require cellular damage or necrosis to be observed in circulation allowing DDNF to be more abundant in circulation than structural proteins.
After a traumatic brain event, BDNF supports synaptic reorganization and restoration during the brain circuitry “reconnection” phase. Therefore, lowered BDNF values indicate a better prognosis. In patients with a co-morbidity of BDNF of anxiety, depressive disorders and schizophrenia low BDNF values on the day of injury predispose this population to incomplete recovery as a risk factor. Korley et al. concluded that serum BDNF discriminates between mTBI and TBI cases with excellent diagnostic accuracy. Additionally, lowered BDNF values are associated with incomplete recovery and useful in identifying patients that are likely to retain symptoms 6-months post-trauma.
Simply put, a blood test could assist providers in concluding the presence and/or severity of traumatic brain injury or mild traumatic brain injury. The results afford an early diagnosis so that you can devise a treatment plan inclusive of altering activities of daily living to prevent further damage and maximize the repair process with minimizing further physical, chemical or emotional stressors.
Based upon interviews with leading neurologists and neurosurgeons who understand and have first-hand experience of both receiving chiropractic care and managing and treating mTBI patients, it is recommended that until the signs and symptoms of the neurologic, cognitive and behavioral abate that high-velocity rotational cervical adjustments be avoided to allow the brain to “repair and rewire” the connections without further possibilities of and Coup/ Contrecoup energy to the brain. This is a recommendation that we concur while recognizing that chiropractic care should not be avoided, just adapted to allow the brain to heal.
1. Hartvigsen, J., Boyle, E., Cassidy, J. D., & Carroll, L. J. (2014). Mild traumatic brain injury after motor vehicle collision: What are the symptoms and who treats them? A population-based 1-year inception cohort study. Archives of Physical Medicine and Rehabilitation, 95(Suppl. 3), S286-S294.
2. Jeter, C. B., Hergenroeder, G. W., Hylin, M. J., Redell, J. B., Moore, A. N., & Dash, P. K. (2013). Biomarkers for the diagnosis and prognosis of mild traumatic brain injury/concussion. Journal of Neurotrauma, 30(8), 657-670.
3. British Journal of Sports Medicine. (2016). Sport concussion assessment tool 2. Retrieved from http://bjsm.bmj.com/content/43/Suppl_1/i85.full.pdf
4. Soares, J. M., Marques, P., Alves, V., & Sousa, N. (2013). A hitchhiker’s guide to diffusion tensor imaging. Frontiers in Neuroscience, 7(31), 1-14.
5. Korley, F. K., Diaz-Arrastia, R., Wu, A. H. B., Yue, J. K., Manley, G. T., Sair, H. I., Van Eyk, J., Everett, A. D., Okonkwo, D. O., Valadka, A. B., Gordon, W. A., Maas, A. I., Mukherjee, P., Yuh, E. L., Lingsma, H. F., Puccio, A. M., & Schnyer, D. M., (2015). Circulating brain-derived neurotrophic factor has diagnostic and prognostic value in traumatic brain injury. Journal of Neurotrauma, 32, 1-11.