Diagnosis of Concussion: The Role of Imaging Now and in the Future

Review of Media Representation of Sport Concussion and Implications for Youth Sports

Participation in sport can incur a risk of sport-related concussion (SRC). Media representation of SRC is frequently at odds with up-to-date scientific data. Our findings confirm a significant amount of false, confusing, or misleading terminology used in reporting on the topic, which is concerning as media is as a major source of SRC information. Individuals have a variable base of knowledge pertaining to this injury, and accurate understanding of SRC does not always correlate to appropriate action. Inaccurate portrayal of SRC media may contribute to the confusion surrounding it. Popular media presents an opportunity to convey evidence-based information on SRC.

Positive Head Computed Tomography Findings in the Setting of Sport Head Injuries: Can These Athletes Return-to-Play?

BACKGROUND

The literature on athletes with positive head computed tomography (HCT) findings in the setting of sport head injuries remains sparse.

OBJECTIVE

To report the proportions of athletes with a positive HCT and compare acute injury characteristics and recovery between those with and without a positive HCT.

METHODS

A retrospective, single-institution, cohort study was performed with all athletes aged 12 to 23 years seen at a regional concussion center from 11/2017 to 04/2022. The cohort was dichotomized into positive vs negative HCT (controls). Acute injury characteristics (ie, loss of consciousness and amnesia) and recovery, as measured by days to return-to-learn (RTL), symptom resolution, and return-to-play (RTP) were compared. χ 2 and Mann-Whitney U tests were performed.

RESULTS

Of 2061 athletes, 226 (11.0%) received an HCT and 9 (4.0%) had positive findings. HCT findings included 4 (44.4%) subdural hematomas, 1 (11.1%) epidural hematoma, 2 (22.2%) facial fractures, 1 (11.1%) soft tissue contusion, and 1 (11.1%) cavernous malformation. All 9 (100.0%) athletes were treated nonoperatively and successfully returned-to-play at a median (IQR) of 73.0 (55.0-82.0) days. No differences in loss of consciousness or amnesia were seen between positive HCT group and controls. The Mann-Whitney U test showed differences in RTL (17.0 vs 4.0 days; U = 45.0, P = .016) and RTP (73.0 vs 27.0 days; U = 47.5, P = .007) but not in symptom resolution. Our subanalysis showed no differences across all recovery metrics between acute hemorrhages and controls.

CONCLUSION

Among athletes seen at a regional concussion center who underwent an acute HCT, positive findings were seen in 4%. Although athletes with a positive HCT had longer RTL and RTP, symptom resolution was similar between those with a positive and negative HCT. All athletes with a positive HCT successfully returned to play. Despite a more conservative approach to athletes with a positive HCT, clinical outcomes are similar between those with and without a positive HCT.

Advanced neuroimaging of mild traumatic brain injury

This article focuses on advancements in neuroimaging techniques, compares the advantages of each of the modalities in the evaluation of mild traumatic brain injury, and discusses their contribution to our understanding of the pathophysiology as it relates to prognosis. Advanced neuroimaging techniques discussed include anatomic/structural imaging techniques, such as diffusion tensor imaging and susceptibility-weighted imaging, and functional imaging techniques, such as functional magnetic resonance imaging, perfusion-weighted imaging, magnetic resonance spectroscopy, and positron emission tomography.

An overview of the basic science of concussion and subconcussion: where we are and where we are going

There has been a growing interest in the diagnosis and management of mild traumatic brain injury (TBI), or concussion. Repetitive concussion and subconcussion have been linked to a spectrum of neurological sequelae, including postconcussion syndrome, chronic traumatic encephalopathy, mild cognitive impairment, and dementia pugilistica. A more common risk than chronic traumatic encephalopathy is the season-ending or career-ending effects of concussion or its mismanagement. To effectively prevent and treat the sequelae of concussion, it will be important to understand the basic processes involved. Reviewed in this paper are the forces behind the primary phase of injury in mild TBI, as well as the immediate and delayed cellular events responsible for the secondary phase of injury leading to neuronal dysfunction and possible cell death. Advanced neuroimaging sequences have recently been developed that have the potential to increase the sensitivity of standard MRI to detect both structural and functional abnormalities associated with concussion, and have provided further insight into the potential underlying pathophysiology. Also discussed are the potential long-term effects of repetitive mild TBI, particularly chronic traumatic encephalopathy. Much of the data regarding this syndrome is limited to postmortem analyses, and at present there is no animal model of chronic traumatic encephalopathy described in the literature. As this arena of TBI research continues to evolve, it will be imperative to appropriately model concussive and even subconcussive injuries in an attempt to understand, prevent, and treat the associated chronic neurodegenerative sequelae.

Understanding the neuroinflammatory response following concussion to develop treatment strategies

Mild traumatic brain injuries (mTBI) have been associated with long-term cognitive deficits relating to trauma-induced neurodegeneration. These long-term deficits include impaired memory and attention, changes in executive function, emotional instability, and sensorimotor deficits. Furthermore, individuals with concussions show a high co-morbidity with a host of psychiatric illnesses (e.g., depression, anxiety, addiction) and dementia. The neurological damage seen in mTBI patients is the result of the impact forces and mechanical injury, followed by a delayed neuroimmune response that can last hours, days, and even months after the injury. As part of the neuroimmune response, a cascade of pro- and anti-inflammatory cytokines are released and can be detected at the site of injury as well as subcortical, and often contralateral, regions. It has been suggested that the delayed neuroinflammatory response to concussions is more damaging then the initial impact itself. However, evidence exists for favorable consequences of cytokine production following traumatic brain injuries as well. In some cases, treatments that reduce the inflammatory response will also hinder the brain's intrinsic repair mechanisms. At present, there is no evidence-based pharmacological treatment for concussions in humans. The ability to treat concussions with drug therapy requires an in-depth understanding of the pathophysiological and neuroinflammatory changes that accompany concussive injuries. The use of neurotrophic factors [e.g., nerve growth factor (NGF)] and anti-inflammatory agents as an adjunct for the management of post-concussion symptomology will be explored in this review.

The young brain and concussion: imaging as a biomarker for diagnosis and prognosis

Concussion (mild traumatic brain injury (mTBI)) is a significant pediatric public health concern. Despite increased awareness, a comprehensive understanding of the acute and chronic effects of concussion on central nervous system structure and function remains incomplete. Here we review the definition, epidemiology, and sequelae of concussion within the developing brain, during childhood and adolescence, with current data derived from studies of pathophysiology and neuroimaging. These findings may contribute to a better understanding of the neurological consequences of traumatic brain injuries, which in turn, may lead to the development of brain biomarkers to improve identification, management and prognosis of pediatric patients suffering from concussion.