Advance MR imaging in sports‐related concussion and mild traumatic brain injury – ready for clinical use? (Commentary on Tremblay et al. 2017)

Abstract

Sports-related concussion -including chronic traumatic encephalopathy in adult professional American football players -has recently attracted considerable interest, even in the general media. The Hollywood movie entitled 'Concussion' is one recent example. Furthermore, discussion about brain abnormalities as a consequence of sports injuries should also include younger players (Bahrami et al., 2016). It remains to be explored how traumatic brain injury in the youth may alter the normal trajectory of brain development. In Europe, more attention is paid to sports-related concussion in the commonly played game of soccer (Koerte et al., 2012;Lipton et al., 2013). Likewise, there is growing interest in brain abnormalities related to mild traumatic brain injury (MTBI) resulting from minor accidents (e.g. whip-lash injury), particularly with respect to medico-legal and insurance-related issues. In both sports-related concussion and MTBI, conventional CT and MR imaging results generally do not reveal clear abnormalities. However, advanced imaging techniques, including diffusion tensor imaging (DTI) (Bahrami et al., 2016) In 'Defining a multimodal signature of remote sports concussions ', Tremblay et al. (2017) used DTI and MRS to characterize white matter changes in aging, retired athletes with a history of sports-related MTBI. Using machine learning approaches, the authors achieved up to 90% accuracy in identifying former athletes on the basis of their white matter profiles. While this research is certainly promising, there are several concerns that require strict and careful consideration before such automated classification techniques can be used clinically. Regional specific pattern of brain abnormalities?Advanced imaging techniques have been used in the domain of neurodegeneration, particularly in Alzheimer's dementia and its prodromal stages, with the same basic aim -to detect subtle brain abnormalities not evident using standard imaging techniques. There is, however, a fundamental difference between trauma-related and neurodegenerative abnormalities. Neurodegenerative diseases typically share common, disease-specific patterns of brain changes. For example, Alzheimer's dementia is characterized by atrophy particularly within the hippocampal and parietal regions, while behavioral variant fronto-temporal dementia is typically associated with a predominantly fronto-temporal atrophy (Haller et al., 2013). For post-traumatic changes, we may assume that some traumatic mechanisms are more common than others, and that trauma-related changes are more or less widespread in the brain. Therefore, trauma-related changes will overlap to a certain degree. However, the individual trauma-related changes are variable depending on the site, direction and velocity of the impact, and consequently trauma-related variability is larger than the more stereotypical neurodegeneration-related brain alterations. This implies that several patterns of trauma-related brain abnormalities should be defined, and the best-suited reference dataset for...

Prognostic imaging markers for sports-related concussion: a review

“…In such situations, banning the athlete from continued participation in sports could facilitate long-term neurologic regression and reduce the proportion of athletes who experience long-term deficits. Traditional neuroimaging cannot reveal structural abnormalities in classic SRCs [4,5]. The focus of current research has been to investigate advanced neuroimaging techniques to identify typical alterations in brain structure and function.…”