Average symptom severity and related predictors of prolonged recovery in pediatric patients with concussion

The Concussion, Exercise, and Brain Networks (ConExNet) study: a cohort study aimed at understanding the effects of sub-maximal aerobic exercise on resting state functional brain activity in pediatric concussion

BACKGROUND

Recent scientific evidence has challenged the traditional "rest-is-best" approach for concussion management. It is now thought that "exercise-is-medicine" for concussion, owing to dozens of studies which demonstrate that sub-maximal, graded aerobic exercise can reduce symptom burden and time to symptom resolution. However, the primary neuropathology of concussion is altered functional brain activity. To date, no studies have examined the effects of sub-maximal aerobic exercise on resting state functional brain activity in pediatric concussion. In addition, although exercise is now more widely prescribed following concussion, its cardiopulmonary response is not yet well understood in this population. Our study has two main goals. The first is to understand whether there are exercise-induced resting state functional brain activity differences in children with concussion vs. healthy controls. The second is to profile the physiological response to exercise and understand whether it differs between groups.

METHODS

We will perform a single-center, controlled, prospective cohort study of pediatric concussion at a large, urban children's hospital and academic center. Children with sport-related concussion (aged 12-17 years) will be recruited within 4-weeks of injury by our clinical study team members. Key inclusion criteria include: medical clearance to exercise, no prior concussion or neurological history, and no implants that would preclude MRI. Age- and sex-matched healthy controls will be required to meet the same inclusion criteria and will be recruited through the community. The study will be performed over two visits separated by 24-48 h. Visit 1 involves exercise testing (following the current clinical standard for concussion) and breath-by-breath gas collection using a metabolic cart. Visit 2 involves two functional MRI (fMRI) scans interspersed by 10-minutes of treadmill walking at an intensity calibrated to Visit 1 findings. To address sub-objectives, all participants will be asked to self-report symptoms daily and wear a waist-worn tri-axial accelerometer for 28-days after Visit 2.

DISCUSSION

Our study will advance the growing exercise-concussion field by helping us understand whether exercise impacts outcomes beyond symptoms in pediatric concussion. We will also be able to profile the cardiopulmonary response to exercise, which may allow for further understanding (and eventual optimization) of exercise in concussion management.

TRIAL REGISTRATION

Not applicable.

Association between days for concussion recovery and initial specialty clinic evaluation within 48 hours

BACKGROUND

Researchers have highlighted the importance of early access to concussion care within one week of injury in reducing recovery times. However, a persisting question for concussion researchers is "just how early is important?" The purpose of this study was to examine differences in recovery time as predicted by the number of days elapsed since injury (DSI) to initial evaluation among patients who had access to a specialty concussion clinic within seven days. We hypothesized that DSI group membership, even within seven days, would significantly predict risk of protracted recovery (i.e., beyond 21 days).

METHODS

In this archival study, retrospective data were gathered from electronic medical records between September 2020 to March 2022. Records of participants between ages 12-18, those diagnosed with a sports-related concussion based on initial clinic visit diagnosis by a medical provider and those who established care within seven days of injury at a large pediatric specialty concussion clinic were examined. Participants were divided into three DSI groups (patients seen in < 48 h: "acute", patients seen between 49 h < and < 96 h: "sub-acute", and patients seen between 97 < and < 168 h: "post-acute"). A general linear model was constructed to examine relationships between relevant concussion factors (e.g., Post Concussion Scale Score, neurodevelopmental history, psychiatric history, concussion history, migraine history, overall VOMS change score, cognitive testing, sex, age, race, and ethnicity) that were either significant in the preliminary analysis or in clinical judgement and recovery time. Adjusted odds ratios (OR) were derived from a binary logistic regression model, in which recovery time was normal (≤ 21 recovery days) or protracted (> 21 recovery days).

RESULTS

A total of 856 participants were eligible. Adolescents in the acute group (M = 15.12, SD = 8.04) had shorter recovery times in days compared to those in the sub-acute (M = 17.98, SD = 10.18) and post-acute (M = 21.12, SD = 10.12; F = 26.00, p < .001) groups. Further, participants in the acute (OR = 4.16) and sub-acute (OR = 1.37) groups who accessed specialty concussion clinics within 48 h were 4 times more likely to have a normal recovery and recovered approximately 6 days faster than the post-acute care group.

CONCLUSIONS

Earlier concussion care access predicted recovery times and was associated with lower risk for protracted recovery.

Injury Incidence, Outcomes, and Return to Competition Times after Sports-Related Concussions during One Professional Ice Hockey Season: A Prospective Cohort Study

OBJECTIVE

The objective of this study was to analyze the incidence and characteristics of sports-related concussions (SRCs) for a professional ice hockey team during one regular season in the International Central European Hockey League.

BACKGROUND

Repeated concussions are a common cause of long periods of absence in team contact sports, with a wide range of potential short- and long-term consequences for the affected athlete. Questions mainly regarding early diagnosis and ideal follow-up treatment remain unanswered, especially regarding the timing of return to sports (RTS).

METHOD

A prospective data analysis for a professional ice hockey team during a regular season was conducted. Firstly, concussions per 1000 athlete exposure (AE) and average time loss due to SRC were calculated. Secondly, the data from ImPACT Applications were analyzed for those players who were diagnosed with an SRC.

RESULTS

Five SRCs were evaluated during the regular season, which resulted in 1.35 concussions/1000 AEs, a maximum of 17 missed games, and a median of three games per SRC. The average symptom count was 9.6, with the most common symptoms being headache, sensitivity to light, and dizziness.

CONCLUSIONS

SRCs sustained in professional ice hockey are a common in-competition injury, while practices play a subsidiary role. The duration of RTS is highly individual and can be associated with symptoms lasting days to months.

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.

Effects of prior concussion on symptom severity and recovery time in acute youth concussion

OBJECTIVE

Many studies have identified factors associated with increased symptom burden and prolonged recovery after pediatric and adolescent concussion. Few have systematically examined the effects of prior concussion on these outcomes in patients with concussion due to any mechanism. An improved understanding of the short- and long-term effects of a multiple concussion history will improve counseling and management of this subgroup of patients.

METHODS

A retrospective review of adolescent and young adult acute concussion patients presenting to the multidisciplinary concussion clinic between 2018 and 2019 was conducted at a single center. Patient demographic data, medical history including prior concussion, initial symptom severity score (SSS), injury mechanisms, and recovery times were collected. Univariate and multivariable analyses were conducted to identify associations of history of prior concussion and patient and injury characteristics with symptom score and recovery time.

RESULTS

A total of 266 patients with an average age of 15.4 years (age range 13-27 years) were included. Prior concussion was reported in 35% of patients. The number of prior concussions per patient was not significantly associated with presenting symptom severity, recovery time, or recovery within 28 days. Male sex and sports-related concussion (SRC) were associated with lower presenting SSS and shorter recovery time on univariate but not multivariable analysis. However, compared to non-sport concussion mechanisms, SRC was associated with 2.3 times higher odds of recovery within 28 days (p = 0.04). A history of psychiatric disorders was associated with higher SSS in univariate analysis and longer recovery time in univariate and multivariable analyses. Multivariable log-linear regression also demonstrated 5 times lower odds of recovery within 28 days for those with a psychiatric history.

CONCLUSIONS

The results of this study demonstrated that an increasing number of prior concussions was associated with a trend toward higher presenting SSS after youth acute concussion but did not show a significant association with recovery time or delayed (> 28 days) recovery. Presence of psychiatric history was found to be significantly associated with longer recovery and lower odds of early (≤ 28 days) recovery. Future prospective, long-term, and systematic study is necessary to determine the optimal counseling and management of adolescent and young adult patients with a history of multiple concussions.

White Matter Abnormalities Associated With Prolonged Recovery in Adolescents Following Concussion

Background: Concussion symptoms in adolescents typically resolve within 4 weeks. However, 20 - 30% of adolescents experience a prolonged recovery. Abnormalities in tracts implicated in visuospatial attention and emotional regulation (i.e., inferior longitudinal fasciculus, ILF; inferior fronto-occipital fasciculus, IFOF; uncinate fasciculus; UF) have been consistently reported in concussion; yet, to date, there are no objective markers of prolonged recovery in adolescents. Here, we evaluated the utility of diffusion MRI in outcome prediction. Forty-two adolescents (12.1 - 17.9 years; female: 44.0%) underwent a diffusion Magnetic Resonance Imaging (dMRI) protocol within the first 10 days of concussion. Based on days of injury until medical clearance, adolescents were then categorized into SHORT (<28 days; N = 21) or LONG (>28 days; N = 21) recovery time. Fractional anisotropy (FA) in the ILF, IFOF, UF, and/or concussion symptoms were used as predictors of recovery time (SHORT, LONG). Forty-two age- and sex-matched healthy controls served as reference. Higher FA in the ILF (left: adjusted odds ratio; AOR = 0.36, 95% CI = 0.15 - 0.91, P = 0.030; right: AOR = 0.28, 95% CI = 0.10 - 0.83, P = 0.021), IFOF (left: AOR = 0.21, 95% CI = 0.07 - 0.66, P = 0.008; right: AOR = 0.30, 95% CI = 0.11 - 0.83, P = 0.020), and UF (left: AOR = 0.26, 95% CI = 0.09 - 0.74, P = 0.011; right: AOR = 0.28, 95% CI = 0.10 - 0.73, P = 0.010) was associated with SHORT recovery. In additional analyses, while adolescents with SHORT recovery did not differ from HC, those with LONG recovery showed lower FA in the ILF and IFOF (P < 0.014). Notably, inclusion of dMRI findings increased the sensitivity and specificity (AUC = 0.93) of a prediction model including clinical variables only (AUC = 0.75). Our findings indicate that higher FA in long associative tracts (especially ILF) might inform a more objective and accurate prognosis for recovery time in adolescents following concussion.

Does time since concussion alter the factor structure of a multidomain assessment in adolescents?

The utilization of principal component analysis (PCA) approaches to concussion is beneficial to inform the interpretation of clinical outcome data in adolescent patients. While researchers have identified factors using post-concussive symptom scales and cognitive testing, there has yet to be a PCA that incorporates vestibular or oculomotor outcomes, or that focuses exclusively on adolescents. Moreover, the role of time since injury has not been examined in relation to concussion factors in this at-risk population. PCA methods were applied to two independent samples of 237 adolescents who presented to an outpatient concussion clinic: 1) ≤7 days (n = 145), and 2) 8 days-1 month (n = 92). The two separate PCAs included nine clinical assessments comprised of: a) four symptoms factors (cognitive/fatigue/migraine, affective, somatic, sleep), b) memory and speeded cognitive performance, c) near point of convergence (NPC), d) oculomotor, and e) vestibular outcomes. A three-component model including 1) symptoms, 2) cognitive, and 3) vestibular/oculomotor factors that accounted for 69.2% of the variance was supported for the ≤7 days sample. All items except somatic symptoms loaded. A different three-component model was supported for the 8 days-1 month sample, including 1) vestibulo-ocular migraine, 2) visuo-cognitive, and 3) affective-sleep that accounted for 72.1% of the variance, with all items loading. The findings supported two different concussion factor models that highlight the influence of time since injury and importance of considering vestibular and oculomotor outcomes in adolescents. Clinicians should evaluate these different factors using a comprehensive, multi domain approach to better inform assessment and monitor recovery in adolescent patients following concussion.Abbreviations: Principal Components Analysis (PCA), Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), Post-concussion Symptom Scale (PCSS), Vestibular/Ocular Motor Screening (VOMS).