Persistent Concussion Symptoms Research Articles

Exploring Female University Athlete Experiences of Coping With Protracted Concussion Symptoms

Concussions result in a multitude of somatic, cognitive, and/or emotional symptoms as well as physical and behavior changes and disturbances in balance, cognition, and sleep. Moreover, some concussed athletes can experience these symptoms, changes, and disturbances for extended periods of time. This qualitative study explored the coping skills used by five female university athletes who suffered persistent concussion symptoms for more than 6 weeks. Our analysis of the interview data indicated that the athletes used emotion-focused coping strategies, such as avoidance and acceptance, throughout their recovery. In addition, the lack of perceived control over their injuries, a lack of a symptom-specific treatment protocol, and the type of social support they received influenced their coping abilities. These results add to the limited, yet growing, body of literature on the psychology of sport-related concussions, particularly with respect to identifying the types of resources that athletes may use to cope and manage concussion symptoms.

Sports-Related Concussions in Adults Presenting to Canadian Emergency Departments.

To document the occurrence and recovery outcomes of sports-related concussions (SRCs) presenting to the Emergency Department (ED) in a community-based sample. A prospective observational cohort study was conducted in 3 Canadian hospitals. Emergency Department. Adults (≥17 years) presenting with a concussion to participating EDs with a Glasgow Coma Scale score ≥13 were recruited. Patient demographics (eg, age and sex), clinical characteristics (eg, history of depression or anxiety), injury characteristics (eg, injury mechanisms and loss of consciousness and duration), and ED management and outcomes (eg, imaging, consultations, and ED length of stay) were collected. Patients' self-reported persistent concussion symptoms, return to physical activity status, and health-related quality of life at 30 and 90 days after ED discharge. Overall, 248 patients were enrolled, and 25% had a SRC. Patients with SRCs were younger and reported more physical activity before the event. Although most of the patients with SRCs returned to their normal physical activities at 30 days, postconcussive symptoms persisted in 40% at 90 days of follow-up. After adjustment, there was no significant association between SRCs and persistent symptoms; however, patients with concussion from motor vehicle collisions were more likely to have persistent symptoms. Although physically active individuals may recover faster after a concussion, patients returning to their physical activities before full resolution of symptoms are at higher risk of persistent symptoms and further injury. Patient-clinician communications and tailored recommendations should be encouraged to guide appropriate acute management of concussions.

Do Cognitive Behavioral Therapy Techniques Reduce Symptom Duration in Children and Adolescents Who Have Sustained a Mild Traumatic Brain Injury?

Focused Clinical Question: Does cognitive behavioral therapy (CBT) reduce concussion symptoms among children and adolescents following mild traumatic brain injury? Clinical Bottom Line: Based on the results of this critically appraised topic, there is moderate evidence to support the use of CBT as a treatment intervention to reduce complaints of persistent concussion symptoms in children and adolescents.

Characterizing Sleep and Wakefulness in the Acute Phase of Concussion in the General Population: A Naturalistic Cohort from the Toronto Concussion Study.

Growing literature links concussion to changes in sleep and wakefulness in humans and in rodent models. Sleep has been linked with synaptic reorganization under other conditions; however, the characterization and role of sleep after acute concussion remains poorly understood. While much research has focused on insomnia among patients with chronic or persistent concussion symptoms, there is limited understanding of sleep and acute concussion, its potential role in recovery, and associated risk factors for the development of chronic sleep disturbance. Studies to date are limited by small sample sizes of primarily athlete or military populations. Additional studies among the general population are critical to inform best practice guidelines. We examined the sleep and daytime wakefulness of 472 adults from a naturalistic general population cohort (mean age, 33.3 years, females = 60.8%) within seven days of diagnosed concussion, using a validated, condition-specific measure, the Sleep and Concussion Questionnaire. Participants identified immediate changes in sleep characterized by hypersomnia and difficulty maintaining daytime wakefulness; 35% considered these changes as moderate to severe and 79% required monitoring or follow-up. Females experienced significantly greater severity of changes in sleep compared with males. Positive correlations between severity of sleep and pain and headache were identified. Differences by sex are an important consideration for early intervention and long-term monitoring. Because sleep was compromised by pain, pain management is also an integral part of early intervention. Our findings suggest that assessment of sleep beginning in the acute stage is a critical component of concussion management in the general population.

A-129 The Association between Parental Migraine History and Persistent Post Traumatic Headaches

Abstract Objective Literature indicates persistent concussive symptoms beyond the typical recovery time of days or weeks are attributable to factors other than concussion or mild traumatic brain injury (mTBI) (Scott et al., 2020). Post traumatic headaches (PTH) are a frequent complaint of pediatric patients who have sustained a mTBI. Research have indicated that parental migraine and mTBI may put children at risk for PTH (Whitecross, 2020). This systematic review aims to further investigate the relationship between parental history of migraine and PTH in pediatric patients who have sustained a concussion. Data Selection A search was conducted using, Medline, PubMed, and Google Scholar databases with the terms “pediatric”, “concussion”, “parental”, and “headache” between 2011 and 2021. A total of 200 relevant articles were screened and 14 were selected for this review. Exclusion criteria included studies unrelated child migraines, concussion or mTBI diagnosis, and parental history. Data Synthesis A review of literature indicates a 42% heritability and earlier onset of migraine diagnosis for children with parental migraine history (Dao et al., 2018; Eidlitz-Markus et al 2015). This indicates a significant risk factor for persistent post concussive symptoms and possibly direct implications in the slower rate of recovery (Sufrinko et al., 2018). Conclusion Overall, this systematic review strongly suggests that a genetic predisposition for migraines may serve as a catalyst for onset and duration of PTH and the earlier diagnosis of pediatric migraines. Consideration of these predispositions can aid the multidisciplinary approach to improve cognitive and neurobehavioral health in the pediatric population.

Diagnosing and managing paediatric concussion: Key recommendations for general paediatricians and family doctors.

Concussion in children and adolescents is an important health concern. Most paediatric patients fully recover in 1 month or less following an acute concussion. However, some experience prolonged or persistent concussion symptoms for months. Those with prolonged post-concussion-related symptoms may have impaired quality of life, and limited involvement in social, academic, and physical activities with associated mental health implications. In this review, we share key updated clinical recommendations from the Living Guideline for Diagnosing and Managing Pediatric Concussion that will improve the way general paediatricians and family doctors diagnose and manage paediatric patients with suspected concussion.

Frequency of oculomotor disorders in adolescents 11 to 17 years of age with concussion, 4 to 12 weeks post injury

The purpose of the study was to determine the frequency of vision diagnoses after concussion in adolescents and evaluate the sensitivity and specificity of physician-administered screening for detecting convergence and accommodative disorders post-concussion. We enrolled participants 11 to 17 years old, assessed 4 to 12 weeks following a diagnosed concussion. During the initial concussion examination, a sports medicine physician measured the near point of convergence (NPC), monocular accommodative amplitude (AA), and symptoms using the Convergence Insufficiency Symptom Survey (CISS). A comprehensive oculomotor evaluation was performed by an optometrist. One hundred and thirteen adolescents were enrolled, with a mean age of 15.2 years. Seventy-nine of the 113 (70%) participants had at least one oculomotor diagnosis after concussion, with the most common problems being vergence disorders (60%) and accommodative disorders (57%). The most common vergence disorder was convergence insufficiency (35%). Among accommodative disorders, the most common problem was accommodative insufficiency (35%). In all, 47% of the participants had more than one oculomotor diagnosis following concussion. The sensitivity of physician screening using measures of NPC, AA, and CISS for detecting convergence and accommodative insufficiency was 63%, 43%, 48%, respectively. The results of this study provide additional evidence that vision problems are common in adolescents with persistent concussion symptoms in the sub-acute phase 4 to 12 weeks post-concussion, and current physician screening methods using the NPC, AA, or the CISS underperform. Thus, it is prudent that adolescents with post-concussion symptoms lasting more than 4 weeks post injury receive a comprehensive oculomotor examination.

Predictors of persistent concussion symptoms in adults with acute mild traumatic brain injury presenting to the emergency department.

To identify risk factors associated with persistent concussion symptoms in adults presenting to the emergency department (ED) with acute mild traumatic brain injury (TBI). This was a secondary analysis of a randomized controlled trial conducted in three Canadian EDs whereby the intervention had no impact on recovery or healthcare utilization outcomes. Adult (18-64years) patients with a mild TBI sustained within the preceding 48h were eligible for enrollment. The primary outcome was the presence of persistent concussion symptoms at 30days, defined as the presence of ≥ 3 symptoms on the Rivermead Post-concussion Symptoms Questionnaire. Of the 241 patients who completed follow-up, median (IQR) age was 33 (25 to 50) years, and 147 (61.0%) were female. At 30days, 49 (20.3%) had persistent concussion symptoms. Using multivariable logistic regression, headache at ED presentation (OR: 7.7; 95% CI 1.6 to 37.8), being under the influence of drugs or alcohol at the time of injury (OR: 5.9; 95% CI 1.8 to 19.4), the injury occurring via bike or motor vehicle collision (OR: 2.9; 95% CI 1.3 to 6.0), history of anxiety or depression (OR: 2.4; 95% CI 1.2 to 4.9), and numbness or tingling at ED presentation (OR: 2.4; 95% CI 1.1 to 5.2), were found to be independently associated with persistent concussion symptoms at 30days. Five variables were found to be significant predictors of persistent concussion symptoms. Although mild TBI is mostly a self-limited condition, patients with these risk factors should be considered high risk for developing persistent concussion symptoms and flagged for early outpatient follow-up.

Effects of Persistent Concussion Symptoms on Executive Function in Working-aged Adults using a Novel Sensorimotor Assessment Tool

To examine neurocognitive performance of persistent concussion symptom patients using a novel sensorimotor technology. In patients with persistent concussion symptoms, neurocognitive deficits have been routinely identified; however, most of the current literature focuses on athletes and military veterans. Middle aged community members face unique challenges related to jobs, family, and transportation which can all be adversely affected by neurocognitive deficits. Thirteen adults (44.3 ± 12.6 years) with self-reported persistent-concussion symptoms (PCS) at least 3 months post-injury, and thirteen sex and age matched healthy controls (37.5 ± 8.8 years) were recruited. Participants performed the Trail-Making Test A (TMT-A) and Trail-Making Test B (TMT-B) on a novel sensorimotor assessment tool, the KINARM (BKIN Technologies, Kingston, ON, Canada). Using their dominant hand, TMT-A required participants to connect numbered dots in ascending order as quickly as possible. TMT-B required connecting dots with either a number or letter inside, in an alternating number-letter fashion (i.e.,: 1-A-2-B-3-C…). Total number of symptoms and a symptom severity score were assessed using the Rivermead Post Concussion Symptoms Questionnaire (RPQ). An independent samples t-test was used to analyze group differences of total time to completion, dwell time, and number of errors. As expected, PCS patients had a significantly higher number of symptoms and severity score (PCS: 13.4 ± 2.3 and 36.2 ± 14.5, respectively; Controls: 3.4 ± 3.7 and 5.3 ± 5.6, respectively, p < 0.001). PCS patients were significantly slower on TMT-A (46.3 ± 20.1 sec; and 34.7 ± 6.5 sec respectively, p = 0.047). There were no group differences in TMT-B. Our results suggest that neurocognitive function may remain unaffected by persistent concussion symptoms in working-aged adults. The lack of task performance differences may be a result of neurocognitive function recovery, or the need for a more sensitive task to assess neurocognitive function in this population.

Saliva microRNA Biomarkers of Cumulative Concussion.

Recurrent concussions increase risk for persistent post-concussion symptoms, and may lead to chronic neurocognitive deficits. Little is known about the molecular pathways that contribute to persistent concussion symptoms. We hypothesized that salivary measurement of microribonucleic acids (miRNAs), a class of epitranscriptional molecules implicated in concussion pathophysiology, would provide insights about the molecular cascade resulting from recurrent concussions. This hypothesis was tested in a case-control study involving 13 former professional football athletes with a history of recurrent concussion, and 18 age/sex-matched peers. Molecules of interest were further validated in a cross-sectional study of 310 younger individuals with a history of no concussion (n = 230), a single concussion (n = 56), or recurrent concussions (n = 24). There was no difference in neurocognitive performance between the former professional athletes and their peers, or among younger individuals with varying concussion exposures. However, younger individuals without prior concussion outperformed peers with prior concussion on three balance assessments. Twenty salivary miRNAs differed (adj. p < 0.05) between former professional athletes and their peers. Two of these (miR-28-3p and miR-339-3p) demonstrated relationships (p < 0.05) with the number of prior concussions reported by younger individuals. miR-28-3p and miR-339-5p may play a role in the pathophysiologic mechanism involved in cumulative concussion effects.

Characteristics and Outcomes for Delayed Diagnosis of Concussion in Pediatric Patients Presenting to the Emergency Department.

Concussions are common pediatric injuries. Previous studies have found concussed youth may be underdiagnosed in the emergency department (ED), but outcomes for those with delayed diagnosis have yet to be described. Our aim was to compare visit characteristics and outcomes of patients who present to the ED with head injury who receive immediate vs. delayed diagnosis. Retrospective chart review of patients aged 6 to 18years diagnosed with concussion on their first ED or urgent care (UC) visit and patients requiring a second visit for diagnosis between July 1, 2017 and June 20, 2019. We compared demographic information, ED or UC visit features, and recovery outcomes using χ2 tests, Student's t-tests, and Wilcoxon rank-sum tests. Overall, we included 85 patients with delayed concussion diagnosis and 159 with immediate diagnosis. Those with immediate diagnosis had more symptoms inquired at initial visit (5 vs. 4; p=0.003) and a higher likelihood of receiving concussion-specific physical examinations (80% vs. 36.5%; p<0.001); 76.5% of delayed diagnosis patients had at least 1 symptom at follow-up visit that was not inquired about at initial visit. Those with delayed diagnosis had more medical visits during recovery (3 vs. 2; p<0.001), longer average time to symptom resolution (21 vs. 11days; p=0.004), and a higher likelihood of having persistent concussion symptoms (odds ratio 2.9; 95% confidence interval 1.4-5.9). Concussed children evaluated acutely for head injury who do not receive an immediate diagnosis may be at risk for persistent symptoms. Performance of a concussion-specific physical examination and use of a standardized symptom scale may aid in identification of concussed youth acutely.

Blunted Cardiac Parasympathetic Activation in Student Athletes With a Remote History of Concussion: A Pilot Study.

Introduction: Blunted cardiac autonomic nervous system (ANS) responses, quantified using heart rate variability (HRV), have been reported after sport-related concussion (SRC). Research suggests this persists beyond clinical recovery. This study compared cardiac parasympathetic responses in student athletes with a remote history of SRC (> 1-year ago, Concussion History: CH) with those who reported no lifetime history of SRC (Concussion Naïve: CN).Design: Retrospective nested case-control.Setting: University laboratory.Patients or Other Participants: CH (n = 9, 18.3 ± 2 years, 44% male, median 2 years since injury) were student athletes with a remote history of concussion(s) from more than 1 year ago. CN (n = 21, 16.7 ± 3 years, 67% male) were student athletes with no lifetime history of concussion. Exclusion criteria included taking medications that could affect ANS function, history of concussion within the past year, persistent concussion symptoms, lifetime history of moderate to severe brain injury, and lifetime history of more than 3 concussions.Material and Methods: Participants performed the Face Cooling (FC) test for 3-min after 10-min of supine rest while wearing a 3-lead electrocardiogram in a controlled environment.Outcome Measures: Heart rate (HR), R-R interval (RRI), root mean square of the successive differences (RMSSD) of RRI, high frequency (HF) and low frequency to HF (LF:HF) ratios.Results: At baseline, CH had a lower resting HR than CN (62.3 ± 11 bpm vs. 72.9 ± 12, p = 0.034). CH had a different HR response to FC than CN (+8.9% change from baseline in CH vs. −7.5% in CN, p = 0.010). CH also had a smaller RMSSD increase to FC than CN (+31.8% change from baseline in CH vs. +121.8% in CN, p = 0.048). There were no significant group differences over time in RRI (p = 0.106), HF (p = 0.550) or LF:HF ratio (p = 0.053).Conclusion: Asymptomatic student athletes with a remote history of concussion had a blunted cardiac parasympathetic response to FC when compared with athletes with no lifetime history of concussion. These data suggest that an impaired autonomic response to a physiological stressor persists after clinical recovery from SRC for longer than previously reported.

Mood-related changes in children and adolescents with persistent concussion symptoms following a six-week active rehabilitation program

ABSTRACT Primary objective The purpose of this study is to explore changes in mood in youth with persistent post-concussion symptoms following participation in a six-week active rehabilitation program. Research design A pre-post test design was used. Methods and procedures Participants (N = 40 children and adolescents with concussion symptoms >2 weeks post-injury) were recruited from the concussion services at an urban children’s rehabilitation hospital and the community. The program consisted of individualized low-intensity aerobic exercise, sport-specific drills, relaxation exercises and comprehensive education and support. The 6 week program was completed by participants in their home or local community with weekly check-ins with the research team. Data were analyzed using descriptive statistics and linear regressions. Main outcomes and results Outcome measures included the Beck Youth Inventories (youth), and the Child Behavior Checklist (parents). Results indicated significant improvements in anger and anxiety post-intervention with anger reduction being more pronounced in girls. Conclusions Active rehabilitation interventions may have positive effects on mood in youth recovering from concussion. Clinicians may wish to consider addressing anxiety and anger management strategies as part of comprehensive concussion management in youth.

Person-Specific Methods for Characterizing the Course and Temporal Dynamics of Concussion Symptomatology: A Pilot Study

Better characterization of acute concussion symptomatology is needed in order to advance clinical and scientific understanding of persistent concussion symptoms. This paper aims to illustrate a novel framework for conceptualizing, collecting, and analyzing concussion symptom data. To that end, we describe the temporal and structural dynamics of acute concussion symptoms at the individual-patient level. Ten recently concussion adolescents and young adults completed 20 days of ecological momentary assessment (EMA) of post-concussion symptoms. Follow-up assessments were completed at 3 months post-injury. Network modeling revealed marked heterogeneity across participants. In the overall sample, temporal patterns explained the most variance in light sensitivity (48%) and the least variance in vomiting (5%). About half of the participants had symptom networks that were sparse after controlling for temporal variation. The other individualized symptom networks were densely interconnected clusters of symptoms. Networks were highly idiosyncratic in nature, yet emotional symptoms (nervousness, emotional, sadness), cognitive symptoms (mental fogginess, slowness), and symptoms of hyperacusis (sensitivity to light, sensitivity to noise) tended to cluster together across participants. Person-specific analytic techniques revealed a number of idiosyncratic features of post-concussion symptomatology. We propose applying this framework to future research to better understand individual differences in concussion recovery.

The Role of Subsymptom Threshold Aerobic Exercise for Persistent Concussion Symptoms in Patients With Postconcussion Syndrome: A Systematic Review.

In recent years, there has been a shift away from rest until total symptom resolution after concussion, due to the potential adverse consequences of inactivity. Aerobic exercise has been increasingly investigated for the treatment of postconcussion syndrome, whereby symptoms persist beyond 4 wks. The aim of this review was to systematically review the literature on subsymptom threshold aerobic exercise as a treatment for postconcussion syndrome. We conducted systematic literature searches in databases: MEDLINE (Ovid), CINAHL, PubMed, and Embase. After thorough review, 12 articles met the eligibility criteria and were included in the systematic review. The quality of selected studies was low to moderate. Subsymptom threshold aerobic exercise was associated with improvement in symptoms in patients with postconcussion syndrome for all included studies. The most commonly used protocols incorporated 20 mins of exercise at 80% of the heart rate that provoked symptoms, 5-6 days per week, with no adverse events documented. However, there was considerable variation in exercise protocols, and many studies incorporated subsymptom threshold aerobic exercise as part of a broader rehabilitation plan. Evidence supports subsymptom threshold aerobic exercise as a promising treatment for postconcussion syndrome. Further studies are required to delineate the optimal intensity, duration, and frequency of exercise for postconcussion syndrome in a variety of populations.

Pediatric Concussion: Managing Persistent Symptoms With an Interdisciplinary Approach.

We outline the development of a clinic that works directly with youth clients, their caregivers, and family members to help address symptoms that are persisting long after the youth sustained a concussion. Client referral characteristics are described, as well as general clinic flow and procedures. Particular emphasis is placed on a novel interdisciplinary team assessment pathway designed with input from clients and families to help provide consistent treatment plans, education, direction, and conclusions for those clients with complex psychosocial, cognitive, and physical presentations. The Persistent Concussion Clinic at Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada. Youth with persistent concussion symptoms have limited access to interdisciplinary clinics and supports. This article outlines the practices of a large, hospital-based interdisciplinary clinic whose model can inform clinical care pathways and practices for this underserved population. Facilitators and barriers to access are discussed and future directions for the clinic and persistent concussion care in Ontario and internationally are reviewed.

A Qualitative Inquiry of Social and Emotional Support for Students with Persistent Concussion Symptoms

ABSTRACTStudents who sustain concussions often struggle with social and emotional symptoms. Such symptoms can interfere with students’ academic performance, relationships, and overall sense of well-being. This qualitative study involved interviews with eight adolescents and young adults who sustained concussions as youths and experienced significant social and emotional symptoms; six of the participants’ parents were also interviewed. Grounded theory methodology was used to code the data, construct categories and identify themes, and develop a theoretical model of students’ post-concussion social and emotional issues and potential sources of support. Categories of issues emerging from the interviews included anxiety/stress, depression/sadness, interpersonal difficulties/isolation, and irritability/moodiness. An exploration of barriers and facilitators of recovery revealed themes related to: factors at school, factors at home, medical care, and level of involvement with sports and athletic personnel. The theoretical model highlights important areas for development in school-based consultation to ameliorate students’ post-concussion social and emotional symptoms.

B-48 Effects of Anxiety on Response to a Subsymptom Threshold Exercise Program for Treatment of Persistent Post-Concussive Symptoms: A Pilot Randomized Clinical Trial

Abstract Objective There is a growing literature to support the use of subsymptom threshold exercise for treatment of both acute and chronic post-concussion symptoms. The present study aimed to explore the influence of anxiety on response to exercise intervention for patients with persistent post-concussive symptoms. Methods Sixteen adolescents (ages 14-18) with persistent (&gt;1 month) concussion symptoms were randomized into a light, home exercise group and a subsymptom threshold exercise group performed by PT’s (modeled after Leddy et al.,2019). Participants underwent intervention for 6 weeks and completed evaluations at Baseline, Mid-Point, and Follow-up after treatment; evaluations included State-Trait Anxiety Inventory (STAI), the Post-Concussive Scale-Revised (PCS-R), as well as additional measures of emotional functioning, balance disturbance, and neuropsychological functioning. Results Average PCS-R endorsement improved by 21 points from Baseline to Follow-up across treatment groups (PCS-R Total Change M = -21.29,SD = 13.54). There were meaningful Baseline differences between intervention groups in STAI state anxiety (p &lt; .05) and STAI trait anxiety (p = 0.51); STAI variables were used as covariates in an ANOVA comparing mean PCS-R Percent Change between treatment and control groups. After removing the influence of anxiety, the intervention groups significantly differed and showed large effect (F(3,13) = 6.94,p &lt; .05,partial eta2 = .41), with the intervention group improving (PCS-R Percent Change M = -63.3,SD = 17.4) more than the control group (PCS-R Percent Change M = -56.8,SD = 27.8). Conclusion Exercise intervention appears to be more effective than standard-of-care light activity in the treatment of persistent symptoms in adolescents; however, anxiety may alter response to intervention. Complimentary mental health treatment may augment response to exercise intervention and optimize concussion recovery trajectory in patients with persisting symptoms.

Rehabilitation Utilizing Controlled Aerobic Activity in Patients With a Concussion: A Critically Appraised Topic.

Clinical Scenario: A sport-related concussion is a common injury to the brain that may cause a variety of symptoms ranging in duration and severity. The mainstay of treatment for concussion has been rest, followed by a stepwise return to activity. This recovery process may be lengthy when symptoms persist. Aerobic exercise conducted at subsymptom and submaximal intensities has been proposed as a potential intervention for symptoms following a concussion. Therefore, the purpose of this critically appraised topic is to examine the safety of varying aerobic exercise intensities in patients with a concussion. Focused Clinical Question: Are subsymptom and submaximal exercise programs safe when implemented in a population with a symptomatic sports-related concussion when compared with traditional rest? Summary of Key Findings: Four randomized controlled trials were included for critical appraisal. The 4 studies investigated supervised and controlled aerobic exercise as early as within 1 week of with a concussion; all studies conclude that exercise is safe and may be of benefit to individuals with a concussion. Two studies support the use of submaximal exercise as a therapeutic intervention for adolescents with persistent concussion symptoms. Clinical Bottom Line: The authors conclude that controlled exercise performed within the symptom or exertion threshold of patients with concussion is safe compared with rest. It was noted that symptom changes may occur; however, the changes did not have a negative impact on long-term recovery. This research should ease concerns about prescribing physical activity when an athlete with concussion is still experiencing lingering symptoms. While specific parameters of the activity performed have not been described in detail, the individualization of each exercise program was stressed. Strength of Recommendation: Grade A.

The Role of Aerobic Exercise in Reducing Persistent Sport-related Concussion Symptoms.

Aerobic exercise has received increasing attention in the scientific literature as a component of management for individuals who sustain a concussion. Because exercise training has been reported to reduce symptoms and improve function for those experiencing persistent postconcussion symptoms, it represents a potentially useful and clinically pragmatic rehabilitation technique. However, the specific exercise parameters that best facilitate recovery from concussion remain poorly defined and unclear. This review will provide a summary of the current understanding of the role of subsymptom exercise to improve outcomes after a concussion and will describe the exercise parameters that appear to be important. The latter will take into account the three pillars of exercise dose-frequency, duration, and intensity-to examine what is currently known. In addition, we identify important gaps in our knowledge of exercise as a treatment for those who develop persistent symptoms of concussion.