Future Advances and Areas of Future Focus in the Treatment of Sport-Related Concussion

Sports-Related Concussion: Acute Management and Chronic Postconcussive Issues

Sports-related concussion (SRC) is a common problem in youth sports. Concussion may occur after a forceful hit to the body or head, resulting in transient neuropathological changes that spontaneously resolve with relative rest and activity modification in most patients. Most SRCs are effectively managed by primary care physicians and sports medicine specialists. In some cases, symptoms may persist and the child and adolescent psychiatrist may be consulted. This article reviews important background information regarding SRC and highlights a variety of pharmacologic and nonpharmacologic treatment options that consultant psychiatrists should know.

Management of Sport-Related Concussion in the Pediatric and Adolescent Population

Concussions make up nearly 10% of all high school athletic injuries. Recent changes in concussion management guidelines and legislation aim to make concussion care more standardized and safe but simultaneously pose a challenge for the primary care and sports medicine physician. Pediatric and adolescent concussions may cause anxiety for the treating physician due to concerns over return-to-play decisions, academic issues, and the potential for second impact syndrome. Determining when to refer a patient to an emergency department acutely, to an outpatient concussion clinic, or to other subspecialists may be a difficult decision for the primary care physician. The aim of this article is to review current evidence regarding concussion treatment and return-to-school and return-to-play recommendations to provide the primary care and sports medicine physician with practical guidelines for managing concussions.

Follow-up issues in children with mild traumatic brain injuries

OBJECTIVE Concerns about mild traumatic brain injury (mTBI) have increased in recent years, and neurosurgical consultation is often requested for patients with radiographic abnormalities or clinical findings suspicious for mTBI. However, to the authors' knowledge, no study has used the Acute Concussion Evaluation (ACE) tool to systematically evaluate the evolution of symptoms in patients with mTBI during neurosurgical follow-up. The goal in this study was to evaluate symptom progression in pediatric patients referred for neurosurgical consultation by using the ACE, as endorsed by the Centers for Disease Control and Prevention. METHODS The authors performed a retrospective review of records of consecutive pediatric patients who had presented to the emergency department, were diagnosed with possible mTBI, and were referred for neurosurgical consultation. Outpatient follow-up for these patients included serial assessment using the ACE. Data collected included the mechanisms of the patients' injuries, symptoms, follow-up duration, and premorbid conditions that might potentially contribute to protracted recovery. RESULTS Of 91 patients identified with mTBI, 58 met the inclusion criteria, and 33 of these had sufficient follow-up data to be included in the study. Mechanisms of injury included sports injury (15 patients), isolated falls (10), and motor vehicle collisions (8). Ages ranged from 5 to 17 years (mean age 11.6 years), and 29 of the 33 patients were male. Six patients had preinjury developmental and/or psychiatric diagnoses such as attention deficit hyperactivity disorder. Seventeen had negative findings on head CT scans. The first follow-up evaluation occurred at a mean of 30 days after injury. The mean number of symptoms reported on the ACE inventory at first follow-up were 3.2; 12 patients were symptom free. Patients with positive head CT findings required longer follow-up: these patients needed 14.59 weeks, versus 7.87 weeks of follow-up in patients with negative findings on head CT scans (p < 0.05). CONCLUSIONS The data suggest that patients with mTBI, particularly those with developmental and/or psychiatric comorbidities and concurrent cerebral or extracranial injury, often report symptoms for several weeks after their initial injury. Serial ACE assessment permits systematic identification of patients who are experiencing continued symptoms, leading to appropriate patient management and referral.

Developmental and gender influences on executive function following concussion in youth hockey players

BACKGROUND

Concussion is the most common athletic injury in youth who are simultaneously undergoing rapid developmental changes in the brain, specifically the development of executive functions (EF). The developing brain is more vulnerable to concussive injury with a protracted and different trajectory of recovery than that of adults. Thus, there is a critical need to enhance understanding of how concussion affects EF in youth.

OBJECTIVE

To investigate the effects of age, gender and concussion history (i.e. concussion incidence, recency, severity) on EF in youth hockey players.

METHODS

This 3-year cross-sectional and longitudinal multiple cohort study examined data from 211 hockey players of 8-15 years of age. Mixed-effects modelling was used to examine the influence of age, gender and concussion on EF in youth athletes.

FINDINGS

Baseline analyses revealed significant age and gender effects on measures of EF. Multiple effects of concussion history on measures of cognitive flexibility (F = 2.48, p = 0.03) and psychomotor speed (F = 2.59, p = 0.04) were found.

IMPLICATIONS

This study highlights the impact of age, gender and concussion on EF in youth. These findings provide foundational knowledge to better manage cognitive sequelae following sports-related concussion.

The Utilization of Biomechanics to Understand and Manage the Acute and Long-term Effects of Concussion

The acute and long-term effects of concussive and subconcussive head impacts on brain health have gained tremendous attention over the past five years. The treatment and management of concussion involves multiple providers from multiple disciplines and backgrounds. Varied backgrounds and approaches to assessing cognitive and motor function before and post-concussion are limiting factors in the efficient and effective management of concussion as discipline-specific rating scales and assessments serve as a barrier to effective patient hand-offs between providers. Combining principles of motor behavior with biomechanical approaches to data analysis has the potential to improve the continuity of care across the multiple providers managing athletes with concussion. Biomechanical measures have been developed and validated using mobile devices to provide objective and quantitative assessments of information processing, working memory, set switching, and postural stability. These biomechanical outcomes are integral to a clinical management algorithm, the Concussion Care Path, currently used across the Cleveland Clinic Health System. The objective outcomes provide a common data set that all providers in the spectrum of care can access which facilitates communication and the practice of medicine and in understanding the acute and long-term effects of concussion and subconcussive exposure on neurological function.

A neuroscientific approach to the examination of concussions in student-athletes

Concussions are occurring at alarming rates in the United States and have become a serious public health concern. The CDC estimates that 1.6 to 3.8 million concussions occur in sports and recreational activities annually. Concussion as defined by the 2013 Concussion Consensus Statement "may be caused either by a direct blow to the head, face, neck or elsewhere on the body with an 'impulsive' force transmitted to the head." Concussions leave the individual with both short- and long-term effects. The short-term effects of sport related concussions may include changes in playing ability, confusion, memory disturbance, the loss of consciousness, slowing of reaction time, loss of coordination, headaches, dizziness, vomiting, changes in sleep patterns and mood changes. These symptoms typically resolve in a matter of days. However, while some individuals recover from a single concussion rather quickly, many experience lingering effects that can last for weeks or months. The factors related to concussion susceptibility and the subsequent recovery times are not well known or understood at this time. Several factors have been suggested and they include the individual's concussion history, the severity of the initial injury, history of migraines, history of learning disabilities, history of psychiatric comorbidities, and possibly, genetic factors. Many studies have individually investigated certain factors both the short-term and long-term effects of concussions, recovery time course, susceptibility and recovery. What has not been clearly established is an effective multifaceted approach to concussion evaluation that would yield valuable information related to the etiology, functional changes, and recovery. The purpose of this manuscript is to show one such multifaceted approached which examines concussions using computerized neurocognitive testing, event related potentials, somatosensory perceptual responses, balance assessment, gait assessment and genetic testing.

A community return-to-play mTBI clinic: results of a pilot program and survey of high school athletes

BACKGROUND

High school athletes who sustain a mild traumatic brain injury (mTBI) or concussion are required to be removed from play until clearance by a provider. A regional pediatric trauma center offered an mTBI clinic to evaluate students for return to play (RTP).

METHODS

An mTBI clinic was developed in collaboration with a high school district containing three schools. This program evaluated students suffering from sports-related head trauma, specifically football injuries. Community mTBI education was performed, a standardized RTP algorithm was developed, and a postseason survey was administered to football players.

RESULTS

Twenty-eight students playing football were seen by the mTBI clinic. The average time until RTP for clinic patients was 16.9 days. Four hundred five players were surveyed. Of players responding to the survey, 40 (15%) reported sustaining an mTBI during the football season. Of those sustaining an mTBI, 9 (22.5%) did not report their symptoms.

CONCLUSION

Although the mTBI rate is similar to reported rates, the unreported mTBI episodes were lower (22.5%) than previously published self-reported mTBI rates. The RTP algorithm was successful in returning athletes in 16.9 days. The algorithm and data can be utilized by other organizations in establishment of an mTBI clinic and RTP program.

Treatment with an anti-CD11d integrin antibody reduces neuroinflammation and improves outcome in a rat model of repeated concussion

Background

Concussions account for the majority of traumatic brain injuries (TBI) and can result in cumulative damage, neurodegeneration, and chronic neurological abnormalities. The underlying mechanisms of these detrimental effects remain poorly understood and there are presently no specific treatments for concussions. Neuroinflammation is a major contributor to secondary damage following more severe TBI, and recent findings from our laboratory suggest it may be involved in the cumulative properties of repeated concussion. We previously found that an anti-CD11d monoclonal antibody that blocks the CD11d/CD18 integrin and adhesion molecule interaction following severe experimental TBI reduces neuroinflammation, oxidative activity, and tissue damage, and improves functional recovery. As similar processes may be involved in repeated concussion, here we studied the effects of the anti-CD11d treatment in a rat model of repeated concussion.

Methods

Rats were treated 2 h and 24 h after each of three repeated mild lateral fluid percussion injuries with either the CD11d antibody or an isotype-matched control antibody, 1B7. Injuries were separated by a five-day inter-injury interval. After the final treatment and either an acute (24 to 72 h post-injury) or chronic (8 weeks post-injury) recovery period had elapsed, behavioral and pathological outcomes were examined.

Results

The anti-CD11d treatment reduced neutrophil and macrophage levels in the injured brain with concomitant reductions in lipid peroxidation, astrocyte activation, amyloid precursor protein accumulation, and neuronal loss. The anti-CD11d treatment also improved outcome on tasks of cognition, sensorimotor ability, and anxiety.

Conclusions

These findings demonstrate that reducing inflammation after repeated mild brain injury in rats leads to improved behavioral outcomes and that the anti-CD11d treatment may be a viable therapy to improve post-concussion outcomes.

A pediatric perspective on concussion pathophysiology

PURPOSE OF REVIEW

According to recent Centers for Disease Control (CDC) data, the annual incidence of traumatic brain injury (TBI) in the United States is 1.6-3.2 million, of which the majority is classified as mild. Over half of these injuries occur in the pediatric population, and can often be attributed to a sports-related mechanism. Although postconcussion symptoms are usually short-lived, more lasting deficits can occur, which can be particularly disruptive to the developing brain. Recent literature detailing the pathophysiology of mild TBI (mTBI), with attention to pediatric studies, is presented.

RECENT FINDINGS

Although concussion generally does not produce any structural damage on conventional computed tomography (CT) or MRI, advanced neuroimaging modalities reveal microstructural and functional neurobiological changes. Diffuse axonal injury, metabolic impairment, alterations in neural activation and cerebral blood flow perturbations can occur and may contribute to acute symptomatology. Although these physiological changes usually recover to baseline in 7-10 days, sustaining recurrent injury before full recovery may increase the potential for persistent deficits.

SUMMARY

Understanding the pathophysiology of concussion in the pediatric population can potentially open therapeutic avenues to decrease symptom persistence and prevent further injury. Future studies in the pediatric population are necessary given the pathophysiologic differences between the developing and adult brains.

Reliability of concussion history in former professional football players

PURPOSE

The reliability of athletes to recall and self-report a concussion history has never been quantified. This study examined the reliability of the self-report concussion history measure and explored determinants of recall in the number of self-reported concussions in a group of retired professional football players.

METHODS

In 2001, a short questionnaire was administered to a cohort of former professional football players to ascertain the number of self-reported concussions they sustained during their professional playing careers. In 2010, the same instrument was readministered to a subset (n = 899) of the original cohort to assess reliability.

RESULTS

Overall reliability was moderate (weighted Cohen κ = 0.48). The majority (62.1%) reported the same number of concussions in both administrations (2001 and 2010); 31.4% reported more concussions in the second administration. Compared with the "same number reported" group, the "greater number reported" group had more deficits in the second administration in their Short Form 36 physical health (composite score combining physical functioning, role physical, bodily pain, general health) and mental health (e.g., composite score combining vitality, social functioning, role emotional) scales.

CONCLUSIONS

The self-reported concussion history had moderate reliability in former professional football players, on the basis of two administrations of the same instrument, 9 yr apart. However, changes in health status may be differentially associated with recall of concussions.

Concussions: What a neurosurgeon should know about current scientific evidence and management strategies

BACKGROUND

There has been a tremendous amount of interest focused on the topic of concussions over the past few decades. Neurosurgeons are frequently consulted to manage patients with mild traumatic brain injuries (mTBI) that have radiographic evidence of cerebral injury. These injuries share significant overlap with concussions, injuries that typically do not reveal radiographic evidence of structural injury, in the realms of epidemiology, pathophysiology, outcomes, and management. Further, neurosurgeons often manage patients with extracranial injuries that have concomitant concussions. In these cases, neurosurgeons are often the only "concussion experts" that patients encounter.

RESULTS

The literature has been reviewed and data have been synthesized on the topic including sections on historical background, epidemiology, pathophysiology, diagnostic advances, clinical sequelae, and treatment suggestions, with neurosurgeons as the intended target audience.

CONCLUSIONS

Neurosurgeons should have a fundamental knowledge of the scientific evidence that has developed regarding concussions and be prepared to guide patients with treatment plans.