Mild Traumatic Brain Injury in Translation

Abstract

This Introduction to a Special Issue on Mild Traumatic Brain Injury (mTBI) highlights the methodological challenges in outcome studies and clinical trials involving patients who sustain mTBI. Recent advances in brain imaging and portable, computerized cognitive tasks have contributed to protocols that are sensitive to the effects of mTBI and efficient in time for completion. Investigation of civilian mTBI has been extended to single and repeated injuries in athletes and blastrelated mTBI in service members and veterans. Despite differences in mechanism of injury, there is evidence for similar effects of acceleration-deceleration and blast mechanisms of mTBI on cognition. Investigation of repetitive mTBI suggests that the effects may be cumulative and that repeated mTBI and repeated subconcussive head trauma may lead to neurodegenerative conditions. Although animal models of mTBI using cortical impact and fluid percussion injury in rodents have been able to reproduce some of the cognitive deficits frequently exhibited by patients after mTBI, modeling post-concussion symptoms is difficult. Recent use of closed head and blast injury animal models may more closely approximate clinical mTBI. Translation of interventions that are developed in animal models to patients with mTBI is a priority for the research agenda. This Special Issue on mTBI integrates basic neuroscience studies using animal models with studies of human mTBI, including the cognitive sequelae, persisting symptoms, brain imaging, and host factors that facilitate recovery.

Molecular mechanisms of cognitive dysfunction following traumatic brain injury

“…For those engaged in contact sports, mild TBI's in the form of a concussion (short impairment of brain function) with or without loss of consciousness is a significant risk. While, in military population's blast induced TBI has become the “signature injury” of both the Iraq and Afghanistan conflicts (Levin and Robertson, 2012). …”

Repeated mild traumatic brain injury: potential mechanisms of damage

“…[65][66][67][68][69] Increasing amounts of head movement have also been incorporated, [70][71][72] to more closely approximate human head kinematics following mTBI. 73 As such, WD models are increasingly utilized to model repeated mTBI. To incorporate rapid translational and angular acceleration forces, the animal is rested on a Kimwipe, 72 aluminum foil 70,71 or traversable "trap door" 74 suspended on a hole in the center of the apparatus stage.…”

Found in translation: Understanding the biology and behavior of experimental traumatic brain injury

“…In addition to physical impairments that limit routine daily function, other pervasive and persistent challenges faced by TBI survivors are significant disturbances in cognitive function, such as memory loss, poor response inhibition, distractibility and the inability to acquire or store new information, particularly as it relates to prior experience or environmental feedback (Busch et al, 2005; Horneman and Emanuelson, 2009; Walker and Tesco, 2013). These disturbances occur not only in moderate to severe TBI cases, but also in patients with mild TBI who are reported to develop post-concussion symptoms characterized by cognitive impairments comorbid with other neurobehavioral symptoms such as emotional alterations (Levin and Robertson, 2012). …”