The Challenges of Concussion Diagnosis, Prognosis and Treatment: The Most Complicated Disease of the Most Complex Organ of the Body
A review published in the September 2017 issue of Frontiers in Neurology proposes use of “systems science” to better understand concussion diagnosis and prognosis. This is a discipline that analyzes complex problems as whole systems and integrates research findings from different disciplines. In explaining the need for a systems approach, the reviewers note one description of concussion that is uniformly recognized – that it is a highly heterogeneous phenomenon, with numerous factors interacting dynamically to influence an individual’s recovery trajectory. (This concept is highlighted in the title of one of the Concussion WebCasts made available by the American Association of Family Physicians : “If you have seen one concussion, you have seen one concussion.”)
As discussed in the review, there are many reasons for this heterogeneity. One is the mode of injury. Traumatic biomechanical forces can occur in infinitely different ways, with different consequences for the most complex organ of the body. Biomechanics and other injury characteristics also interact with individual variation in physiology (particularly idiosyncrasies in brain topography and connectivity), along with other personal characteristics such as age, sex, pre-injury diseases and medications and genetics. Research has also described wide heterogeneity in the complaints and impairments following concussion – physical complaints are more common in some cases, in other cases the predominant complaints are cognitive or emotional. The severity and duration of all of the potential impairments varies from concussion to concussion and is largely unpredictable.
Adding even further to the complexity of this condition is the increasing recognition that it can be a chronic condition rather than isolated event or fixed injury, with evolving dynamic changes occurring over days, weeks, months or even years. (MediVisuals produces an extraordinary science based animation demonstrating how traumatic axonal injury can result in delayed or progressive symptoms.) The types and extent of injuries currently included under the umbrella of concussion, the authors note, are so different from one another that a diagnosis of “concussion” alone is not very useful for informing treatment. Put into the context of litigation, when an insurance company disputes an injury claim because it does not have the “typical” characteristics of a concussion, it is choosing to ignore how complex and heterogeneous this condition is.
The authors of the review propose a multi-scale framework for approaching diagnosis, treatment and prognosis of concussion. The “scales” proposed are “cellular”, “network”, “experiential” and “social”.
- The cellular scale measures the structure and function of neuron, glia, vasculature, and cytoarchitecture and considers biomarkers of tissue damage.
- The network scale looks at connectivity, timing and functioning brain networks (including use of advanced imaging, QEEG analysis, eye tracking, balance and gait measures, neurological assessments, etc.)
- The experiential scale looks at symptoms and deficits in cognitive, psychological and emotional functioning.
- The social scale looks at the strength of social relationships and social functioning, factors also influencing resilience and recovery.
The authors point out that these scales do not operate in isolation; a variable in one scale can influence a variable in another scale (for example what is occurring in the network, experiential and social scales can impact what is occurring in the cellular scale and visa versa.)
This new model for understanding concussion highlights for treatment providers the importance of considering all of the many factors impacting the course of a concussion in constructing a treatment plan, and highlights for patients the importance of exploring a wide range of treatment options delivered by knowledgeable providers.