Pathophysiologic Mechanisms of Concussion, Development of Chronic Traumatic Encephalopathy, and Emerging Diagnostics: A Narrative Review

Abstract

Pathophysiological mechanisms and cascades take place after a mild traumatic brain injury (mTBI) that can cause long-term sequelae, including chronic traumatic encephalopathy in patients with multiple concurrent TBIs. As diagnostic imaging has become more advanced, microanatomical changes present after mTBI may now be more readily visible. In this narrative review, the authors discuss emerging diagnostics and findings in mTBI through advanced imaging, electroencephalograms, neurophysiologic processes, Q2 biochemical markers, and clinical tissue tests in an effort to help osteopathic physicians to understand, diagnose, and manage the pathophysiology behind mTBI, which is increasingly prevalent in the United States.

Immunomodulatory Effect of Electromagnetic Field in the Treatment of Traumatic Brain Injury

“…Failure of the normal homeostatic mechanisms of the BBB cause the release of excess neurotransmitters that have been implicated in TBI. Of these, glutamate is notable as failure of glutamate transporters has been implicated in the TBI cascade of events [ 12 - 13 ]. With release, glutamate and its associated metabolites bind to glutamate receptors causing activation and inducing excitotoxicity [ 8 ].…”

A Review of Glymphatics and the Impact of Osteopathic Manipulative Treatment in Alzheimer's Disease, Concussions, and Beyond

“…The mechanical energy not absorbed by the CSF is transmitted throughout the brain tissue, disrupts the cytoskeletal architecture, impairs organelle structure and function, and ultimately affects the biochemical function of the brain. This cascade interferes with the function of neurotransmitters [ 3 ].…”

“…While PCS can begin shortly after injury, it is usually delayed and can persist for many months. Further confirming the diagnosis and effective testing for PCS is limited [ 3 ].…”

“…CTE can take several years for its progressive effects to become evident, sometimes only after cognitive and psychiatric impairments significantly interfere with a patient's life and their ability to work resulting in an unemployment rate 60% higher than the general population. Further symptoms include increased rates of depression and 3-4 times increased rates of suicide than the general population [ 3 ].…”

“…Many patients, particularly as demonstrated in boxers, have developed a Parkinsonian-like disease attributed to blunt force trauma to the head. These individuals demonstrate higher incidences of depression, anxiety, and psychosis [ 3 ]. Similar to concussions, CTE continues to highlight this concept of a buildup of toxic metabolites in the brain.…”