Temporal Differences in Concussion Symptom Factors in Adolescents following Sports-Related Concussion

Applying Dynamical Systems Theory to Improve Personalized Medicine Following Mild Traumatic Brain Injury

A sizable proportion of patients with mild traumatic brain injury (mTBI) have persistent symptoms and functional impairments months to years following injury. This phenomenon is continually observed despite an explosion of research and interest in improving mTBI clinical outcomes over the last two decades. All pharmacological clinical trials to date have failed to demonstrate improved outcomes for mTBI. One possible explanation for these continued failures is an overly myopic approach to treating mTBI (i.e., testing the effect of a single drug with a specific mechanism on a group of people with highly heterogenous injuries). Clinical presentation and prognosis of mTBI vary considerably between patients, and yet we continue to assess group-level effects of a homogenized treatment. We need to utilize an equally complex treatment approach to match the extraordinary complexity of the human brain. Dynamical systems theory has been used to describe systems composed of multiple subsystems who function somewhat independently but are ultimately interconnected. This theory was popularized in the motor control literature as an overarching framework for how the mind and body connect to interact and move through the environment. However, the human body can be viewed as a dynamical system composed of multiple subsystems (i.e., organ systems) who have isolated functions, which are also codependent on the health and performance of other interconnected organ systems. In this perspective piece, we will use the example of mTBI in the obese patient to demonstrate how broadening our approach to treatment of the individual (and not necessarily the injury) may ultimately yield improved outcomes. Furthermore, we will explore clinical and pre-clinical evidence demonstrating multiple system interactions in the context of obesity and TBI and discuss how expanding our understanding of the mechanistic interplay between multiple organ systems may ultimately provide a more personalized treatment approach for this mTBI patient subpopulation.

The Association Among Clinical Profiles, Modifiers, and Prolonged Recovery in Adolescents With Sport-Related Concussion

OBJECTIVE

The purposes were to (1) describe the prevalence of clinical profiles and modifiers, (2) examine the association between clinical profiles and prolonged recovery, and (3) examine the interaction between clinical profiles and modifiers and prolonged recovery in adolescents with sport-related concussion (SRC).

DESIGN

Retrospective, cross-sectional.

SETTING

Interdisciplinary specialty sports concussion clinic.

PATIENTS

Patients (n = 299) aged 12 to 19 years who were diagnosed with SRC within 30 days of injury.

INDEPENDENT VARIABLES

Clinical profiles and modifiers were decided by the clinical judgment of the clinical neuropsychologist and sports medicine physician, using data from the Clinical Profile Screen and information gathered from the clinical interview, neurocognitive, and vestibular and ocular motor testing.

MAIN OUTCOME MEASURES

Prolonged recovery was defined as ≥28 days from the date of injury to the date of clearance.

RESULTS

The most common clinical profiles were migraine (34.8%) and cognitive-fatigue (23.4%). There were no significant relationships between clinical profiles and prolonged recovery (Wald = 5.89, df = 4, P = 0.21). The presence of a modifier did not significantly affect the relationship between clinical profiles and prolonged recovery ( = 6.5, df = 5, P = 0.26). The presence of any modifier yielded a 10-day increase in median recovery time within the cognitive/fatigue clinical profile (Wilcoxon rank-sum = 268.5, P = 0.01).

CONCLUSIONS

Although patients with a clinical profile and modifier may not experience prolonged recovery, they may experience longer recovery time than patients with a clinical profile and no modifier.

Association of obesity with mild traumatic brain injury symptoms, inflammatory profile, quality of life and functional outcomes: a TRACK-TBI Study

OBJECTIVES

Obesity is associated with chronic inflammation, which may impact recovery from mild traumatic brain injury (mTBI). The objective was to assess the role of obesity in recovery of symptoms, functional outcome and inflammatory blood biomarkers after mTBI.

METHODS

TRACK-TBI is a prospective study of patients with acute mTBI (Glasgow Coma Scale=13-15) who were enrolled ≤24 hours of injury at an emergency department of level 1 trauma centres and followed for 12 months. A total of 770 hospitalised patients who were either obese (body mass index (BMI) >30.0) or healthy mass (BMI=18.5-24.9) were enrolled. Blood concentrations of high-sensitivity C reactive protein (hsCRP), interleukin (IL) 6, IL-10, tumour necrosis factor alpha; Rivermead Post-Concussion Symptoms Questionnaire (RPQ), Quality of Life After Brain Injury and Glasgow Outcome Score-Extended reflecting injury-related functional limitations at 6 and 12 months were collected.

RESULTS

After adjusting for age and gender, obese participants had higher concentrations of hsCRP 1 day after injury (mean difference (MD)=0.65; 95% CI: 0.44 to 0.87, p<0.001), at 2 weeks (MD=0.99; 95% CI: 0.74 to 1.25, p<0.001) and at 6 months (MD=1.08; 95% CI: 0.79 to 1.37, p<0.001) compared with healthy mass participants. Obese participants had higher concentrations of IL-6 at 2 weeks (MD=0.37; 95% CI: 0.11 to 0.64, p=0.006) and 6 months (MD=0.42; 95% CI: 0.12 to 0.72, p=0.006). Obese participants had higher RPQ total score at 6 months (MD=2.79; p=0.02) and 12 months (MD=2.37; p=0.049).

CONCLUSIONS

Obesity is associated with higher symptomatology at 6 and 12 months and higher concentrations of blood inflammatory markers throughout recovery following mTBI.

Validation of the Gait Disorientation Test in children with concussion

BACKGROUND

Mild traumatic brain injury (mTBI) or concussion is a complex injury that is difficult to diagnose and assess. There are negative impacts on cognition, balance, and mobility after a concussion. The Gait Disorientation Test (GDT) is an objective measure that assesses a person's balance ability by comparing the walking time with eyes open and the walking time with eyes closed in a standardized walking task. The purpose of this study was to assess the validity and the diagnostic properties of the GDT in children with concussions.

METHODS

Thirty-six children with concussions, and 91 controls aged between 9 and 18 years old participated in the study. Participants completed demographics, the GDT, the Functional Gait Assessment (FGA), the Pediatric Vestibular Symptom Questionnaire (PVSQ), and the Pediatric Visually Induced Dizziness Questionnaire (PVID).

RESULTS

Children with concussions showed higher (worse) GDT scores (M = 2.18 ± 1.93 s) than healthy controls (M = 1.13 ± 0.95 s), which was statistically significant (P = 0.014).

CONCLUSION

The GDT was able to distinguish between children with concussions and healthy controls. Given the simplicity of the GDT, it can be used to assist in discriminating between children with and without concussion.