Early Identification and Management of Cervical Impairments in Pediatric Patients With Concussion May Reduce Risk of Delayed Recovery.

OBJECTIVE: Previous research, including high-quality systematic reviews, has found that cervical injury, which often accompanies concussive head injury, can delay recovery from concussion. One pilot randomized controlled trial found that focused cervical assessment and appropriate intervention in children and young adults with persisting postconcussive symptoms (PPCS) improved recovery outcomes. Our sports medicine clinics adopted this approach early (within 2 weeks) in children (aged 10-18 years) after concussion. This study describes our clinical management protocol and compares the recovery trajectories in children after concussion with and without a concomitant cervical injury. DESIGN: Prospective cohort study. SETTING: Three university-affiliated outpatient sports medicine clinics from September 2016 to December 2019. PATIENTS: One-hundred thirty-four concussed children with cervical impairment (mean age 14.9 years, 65% male, and 6.2 days since concussion) were compared with 130 concussed children without cervical impairment (mean age 14.9 years, 57% male, and 6.0 days since concussion). INDEPENDENT VARIABLES: Examination findings related to the cervical spine (range of motion, cervical spasm, and cervical tenderness). MAIN OUTCOME MEASURES: Recovery time (measured in days), concussion symptom burden (Postconcussion Symptom Scale), and incidence of PPCS. RESULTS: Children with cervical impairment reported a higher initial symptom burden; however, there were no differences in recovery time (33.65 [28.20-39.09] days vs 35.98 [27.50-44.45] days, P = 0.651) or incidence of PPCS (40.0% vs 34.3%, P = 0.340). CONCLUSIONS: We conclude that within this pediatric population, early identification and management of cervical injuries concomitant with concussion may reduce the risk of delayed recovery.

Adolescents With a High Burden of New-Onset Mood Symptoms After Sport-Related Concussion Benefit From Prescribed Aerobic Exercise, a Secondary Analysis of 2 Randomized Controlled Trials.

OBJECTIVE: Approximately 20% of students with sport-related concussion (SRC) report new symptoms of anxiety and depression which may be associated with delayed recovery and increased risk for developing a mood disorder. Early prescribed aerobic exercise facilitates recovery in athletes with concussion-related exercise intolerance. We studied the effect of aerobic exercise treatment on new mood symptoms early after SRC. DESIGN: Exploratory secondary analysis of 2 randomized controlled trials (RCT). SETTING: Sports medicine clinics associated with UB (Buffalo, NY), CHOP (Philadelphia, PA), and Boston Children's Hospital (Boston, MA). PARTICIPANTS: Male and female adolescents (aged 13-18 years) diagnosed with SRC (2-10 days since injury). INTERVENTIONS: Participants were randomized to individualized targeted heart rate aerobic exercise (n = 102) or to a placebo intervention designed to mimic relative rest (n = 96). MAIN OUTCOME MEASURES: Incidence of Persisting Post-Concussive Symptoms (PPCS, symptoms ≥28 days). RESULTS: First RCT recruited from 2016 to 2018 and the second from 2018 to 2020. Of 198 adolescents, 156 (79%) reported a low burden (mean 1.2 ± 1.65/24) while 42 (21%) reported a high burden (mean 9.74 ± 3.70/24) of emotional symptoms before randomization. Intervention hazard ratio for developing PPCS for low burden was 0.767 (95% CI, 0.546-1.079; P = 0.128; ß = 0.085) and for high burden was 0.290 (95% CI, 0.123-0.683; P = 0.005; ß = 0.732). CONCLUSIONS: High burden of mood symptoms early after injury increases risk for PPCS, but the sports medicine model of providing early targeted aerobic exercise treatment reduces it. Nonsports medicine clinicians who treat patients with a high burden of new mood symptoms after concussion should consider prescribing aerobic exercise treatment to reduce the risk of PPCS and a mood disorder.

An Exploratory Analysis of Physical Examination Subtypes in Pediatric Athletes With Concussion.

OBJECTIVE: Pediatric athletes with concussion present with a variety of impairments on clinical assessment and require individualized treatment. The Buffalo Concussion Physical Examination is a brief, pertinent clinical assessment for individuals with concussion. The purpose of this study was to identify physical examination subtypes in pediatric athletes with concussion within 2 weeks of injury that are relevant to diagnosis and treatment. DESIGN: Secondary analysis of a published cohort study and clinician consensus. SETTING: Three university-affiliated sports medicine centers. PARTICIPANTS: Two hundred seventy children (14.9 ± 1.9 years). INDEPENDENT VARIABLES: Orthostatic intolerance, horizontal and vertical saccades, smooth pursuits, vestibulo-ocular reflex, near-point convergence, complex tandem gait, neck range of motion, neck tenderness, and neck spasm. MAIN OUTCOME MEASURES: Correlations between independent variables were calculated, and network graphs were made. k-means and hierarchical clustering were used to identify clusters of impairments. Optimal number of clusters was assessed. Results were reviewed by experienced clinicians and consensus was reached on proposed subtypes. RESULTS: Physical examination clusters overlapped with each other, and no optimal number of clusters was identified. Clinician consensus suggested 3 possible subtypes: (1) visio-vestibular (horizontal and vertical saccades, smooth pursuits, and vestibulo-ocular reflex), (2) cervicogenic (neck range of motion and spasm), and (3) autonomic/balance (orthostatic intolerance and complex tandem gait). CONCLUSIONS: Although we identified 3 physical examination subtypes, it seemed that physical examination findings alone are not enough to define subtypes that are both statistically supported and clinically relevant, likely because they do not include symptoms, assessment of mood or cognitive problems, or graded exertion testing.

Does Physiologic Post-Concussion Disorder Cause Persistent Post-Traumatic Headache?

PURPOSE OF REVIEW: One system classifies patients with symptoms after concussion into physiologic, vestibulo-ocular, cervicogenic, and mood/cognition post-concussion disorders (PCD) based upon the preponderance of specific symptoms and physical impairments. This review discusses physiologic PCD and its potential relationship to the development of persistent post-traumatic headaches (PPTH). RECENT FINDINGS: Headache is the most reported symptom after a concussion. Headaches in physiologic PCD are suspected to be due to abnormal cellular metabolism, subclinical neuroinflammation, and dysfunction of the autonomic nervous system (ANS). These abnormalities have been linked to the development of migraine-like and neuralgia-related PPTH. Physiologic PCD is a potential cause of PPTH after a concussion. Future research should focus on how to prevent PPTH in patients with physiologic PCD.

Adults are not older adolescents: comparing physical therapy findings among adolescents, young adults and older adults with persistent post-concussive symptoms.

OBJECTIVE: Individuals with persistent post-concussive symptoms (PPCS) may present with a myriad of physical symptoms. There is limited research available comparing the presence of examination findings among individuals with PPCS from different age groups. METHODS: Retrospective case-control chart review of 481 patients with PPCS and 271 non-trauma controls. Physical assessments were categorized as ocular, cervical, and vestibular/balance. Differences in presentation were compared between PPCS and controls as well as between individuals with PPCS in three age groups: adolescents, young adults, and older adults. RESULTS: All three PPCS groups had more abnormal oculomotor findings than their age-matched counterparts. When comparing PPCS patients from different age groups, no differences were seen in prevalence of abnormal smooth pursuits or saccades; however, adolescents with PPCS had more abnormal cervical findings and a lower prevalence of abnormal NPC, vestibular and balance findings. CONCLUSION: Patients with PPCS presented with a different constellation of clinical findings based on their age. Adolescents were more likely to demonstrate evidence of cervical injury compared to younger and older adults, and adults were more likely to present with vestibular findings and impaired NPC. Adults with PPCS were more likely to present with abnormal oculomotor findings compared to adults with non-traumatic causes of dizziness.

Practical Management: A Standardized Aerobic Exercise Program for Adolescents With Concussion in the Absence of Graded Exercise Testing.

ABSTRACT: Aerobic exercise is safe and beneficial for adolescent athletes recovering from sport-related concussion (SRC). The results of systematic graded exercise testing are used to create individualized, subsymptom heart rate threshold (HRt) aerobic exercise treatment programs for adolescents after SRC. Many clinicians, however, do not have access to graded exercise tests. This article presents a safe, systematic, evidence-based exercise program that clinicians can prescribe, progress, and modify to help manage acute pediatric SRC without the need for formal exercise testing. The exercise prescription accounts for sex and days since injury but not age because our analysis indicates age does not significantly affect the HRt on graded exercise testing. This article provides clinicians without access to graded exercise testing a viable option for prescribing exercise treatment to adolescents in the early phase after SRC.

Exercise-Induced Vision Dysfunction Early After Sport-Related Concussion Is Associated With Persistent Postconcussive Symptoms.

OBJECTIVE: The purpose of this study was to determine if exercise-induced vision dysfunction [reduced performance and/or symptom exacerbation on a post-exercise King-Devick (KD) test] in adolescents early after sport-related concussion was associated with increased risk of persistent post-concussive symptoms (PPCS, recovery >28 days). We used exercise as a provocative maneuver before the KD test, hypothesizing that concussed adolescents with exercise-induced vision dysfunction would be more likely to develop PPCS. DESIGN: Secondary analysis of data from a multi-center, randomized clinical trial comparing KD test performance before and after the Buffalo Concussion Treadmill Test in adolescents within 10 days of sport-related concussion who were randomized to aerobic exercise or placebo stretching program. SETTING: Three university-associated sports medicine clinical programs. PARTICIPANTS: Ninety-nine adolescents with sport-related concussion (exercise group: n = 50, 15.3 ± 1 years, 60% M, 22% with PPCS; stretching group: n = 49, 15.9 ± 1 years, 65% M, 35% with PPCS) tested a mean of 6 ± 2 days from injury. INDEPENDENT VARIABLE: King-Devick test performed immediately before and 2 minutes after Buffalo Concussion Treadmill Test. MAIN OUTCOME MEASURE: Persistent post-concussive symptoms. RESULTS: Adolescents who demonstrated exercise-induced vision dysfunction upon initial evaluation developed PPCS at a significantly greater rate when compared with adolescents who did not (71% vs 34%, P < 0.001). Exercise-induced vision dysfunction corresponded to a relative risk of 3.13 for PPCS. CONCLUSIONS: Adolescents with exercise-induced vision dysfunction had a 3-fold greater relative risk of developing PPCS than those without exercise-induced vision dysfunction.

Norm-Based Cutoffs as Predictors of Prolonged Recovery After Adolescent Sport-Related Concussion.

OBJECTIVES: To identify predictors of prolonged recovery (ie, >28 days) using patient demographic factors and healthy, norm-based cutoffs on a multimodal test battery in adolescents after sport-related concussions (SRCs). DESIGN: Retrospective cohort. Patients were deemed recovered after successful completion of return-to-play/school protocols and received medical clearance. SETTING: Community concussion clinic. PATIENTS: Male and female adolescent student athletes diagnosed with a SRC and evaluated within 1 week of injury. INDEPENDENT VARIABLES: Patient demographics, medical history, injury description, computerized neurocognitive testing, vestibular/ocular testing, and symptoms at initial clinical visit. MAIN OUTCOME MEASURES: Performance on clinical testing to predict recovery duration, classified as normal (<28 days) or prolonged (>28 days). RESULTS: A total of 201 adolescent student athletes (age = 15.3 ± 1.4 years) were included (female 35%). Average recovery duration for the entire cohort was 22.3 ± 13.3 days, with 22% (n = 45) of adolescent student athletes taking >28 days to recover. The final model was 88.3% accurate in classifying normal and prolonged recovery. Predictor variables included sex, loss of consciousness, history of ocular disorder, history of concussion, performance on visual motor speed composite, visual motion sensitivity symptom provocation and near point of convergence distance, number-naming total time, and symptom count. CONCLUSIONS: These findings suggest that using norm-based cutoffs from cognitive, oculomotor, and vestibulo-ocular testing and symptom reporting, clinicians can accurately predict a prolonged recovery (sensitivity = 81%) and normal recovery (specificity = 83%) in an adolescent, SRC cohort.

Association of Concussion History and Prolonged Recovery in Youth.

OBJECTIVE: To determine the number of prior concussions associated with increased incidence of persistent postconcussive symptoms (PPCS) in a cohort of acutely concussed pediatric patients. DESIGN: Prospective observational cohort study. SETTING: Three university-affiliated concussion clinics. PARTICIPANTS: Two hundred seventy participants (14.9 ± 1.9 years, 62% male, 54% with prior concussion) were assessed within 14 days of concussion and followed to clinical recovery. Participants with a second head injury before clinical recovery were excluded. MEASURES AND MAIN OUTCOME: Concussion history, current injury characteristics, recovery time, and risk for prolonged recovery from current concussion. RESULTS: There was no statistically significant change in PPCS risk for participants with 0, 1 or 2 prior concussions; however, participants with 3 or more prior concussions had a significantly greater risk of PPCS. Twelve participants sustained a subsequent concussion after clinical recovery from their first injury and were treated as a separate cohort. Our secondary analysis found that these participants took longer to recover and had a greater incidence of PPCS during recovery from their latest concussion. CONCLUSION: Pediatric patients with a history of 3 or more concussions are at greater risk of PPCS than those with fewer than 3 prior concussions.

Rehabilitation of Concussion and Persistent Postconcussive Symptoms.

Concussion and persistent postconcussive symptoms (PPCS) are encountered by clinicians in sports medicine, pediatrics, neurology, physiatry, emergency medicine, and primary care. Clinical management may require a multidisciplinary approach. This article presents a structured method for the diagnosis of concussion and PPCS in the outpatient setting, which includes a history, physical examination, and additional tests as clinically indicated to help identify underlying symptom generators. Treatment for concussion and PPCS should be individualized, based on predominant signs and symptoms, and can include subsymptom threshold aerobic exercise, cervical physical therapy, vestibulo-ocular rehabilitation, behavioral and cognitive psychotherapy, and some symptom-specific pharmacological therapies.

Practical Management: Prescribing Subsymptom Threshold Aerobic Exercise for Sport-Related Concussion in the Outpatient Setting.

ABSTRACT: Exercise intolerance is an objective biomarker of the physiological dysfunction after sport-related concussion (SRC). Several trials have established the safety and clinical efficacy of subsymptom threshold aerobic exercise prescribed within 1 week of injury as treatment for SRC. Clinicians, however, may not be comfortable prescribing aerobic exercise after SRC. This article presents 3 methods of exercise prescription for patients with SRC. The first requires a graded exertion test plus a home-based exercise program requiring a heart rate (HR) monitor. The second requires a graded exertion test but no HR monitor for home-based exercise. The third requires solely an HR monitor to safely progress through the home-based exercise prescription. Patients are encouraged to keep a symptom and exercise diary and return for re-evaluation every 1 to 2 weeks. Delayed recovery should prompt the clinician to evaluate for other potential symptom generators (eg, cervical, vestibular, oculomotor, mood, or migraine disorders).

Derivation of a Focused, Brief Concussion Physical Examination for Adolescents With Sport-Related Concussion.

OBJECTIVE: To describe the derivation of a brief but pertinent physical examination (PE) for adolescents who have sustained sport-related concussion (SRC). DESIGN: Prospective cohort. SETTING: University concussion management clinic. PARTICIPANTS: Acutely concussed (AC, n = 52, 15.5 ± 1.4 years, 4.4 ± 2 days since injury, 26.2 ± 38 days to recovery, 71% males) and healthy control (HC) adolescents (n = 30, 15.8 ± 1.4 years, 73% males). INTERVENTION: Acutely concussed had a PE on visit 1 and were retested at visit 2 (13.6 ± 1 day after visit 1). Acutely concussed were further characterized as normal recovery (NR, n = 41, 15.5 ± 1.5 years, recovery time 13.0 ± 7 days) and delayed recovery (DR, n = 11, 15.5 ± 1.2 years, recovery time 75.4 ± 63 days). MAIN OUTCOME MEASURE: Physical examination findings, including cervical, vestibular, and oculomotor systems. RESULTS: Visit 1 abnormal PE signs were significantly greater in AC versus HC (2.79 ± 2.13 vs 0.07 ± 0.37, P < 0.0001) but not in NR versus DR (2.61 ± 2.2 vs 3.45 ± 1.8, P = 0.246). Visit 2 abnormal PE signs differentiated NR versus DR (0.17 ± 0.7 vs 2.45 ± 2.1, P < 0.0001). CONCLUSIONS: A brief focused PE can help to diagnose SRC, establish recovery, and may have prognostic value.

Practical Management: Brief Physical Examination for Sport-Related Concussion in the Outpatient Setting.

This article presents a brief, focused physical examination [PE, the Buffalo Concussion Physical Examination (BCPE)] for sport-related concussion (SRC) to be considered for use in the outpatient setting by sports medicine physicians, pediatricians, and primary-care physicians. This companion paper describes how to perform the PE, which was derived in a separate study presented in this journal. It is envisioned for use at the initial and follow-up outpatient visits both for acute concussions and in patients with prolonged symptoms. A pertinent PE, combined with other assessments, can help identify specific treatment targets in those with persistent symptoms after SRC. The BCPE includes orthostatic vital signs and examinations of the cranial nerves, oculomotor/ophthalmologic, cervical, and vestibular systems. Supplementary tests, including testing for exercise tolerance and neurocognitive function, may be performed if indicated. It is recommended that a PE be performed at the initial visit and every 1 to 2 weeks after SRC. On return of symptoms, cognition, and the PE to baseline, as well as normalization of any supplementary tests, patients can begin a return to play program.

Comparison of Rest to Aerobic Exercise and Placebo-like Treatment of Acute Sport-Related Concussion in Male and Female Adolescents.

OBJECTIVE: To compare a sample of adolescents with sport-related concussion (SRC) who were prescribed rest with 2 arms of a randomized controlled trial comparing aerobic exercise with placebo-like stretching. We also compared sex differences across the 3 approaches to treatment. DESIGN: Quasi-experimental trial. SETTING: University concussion management clinics. PARTICIPANTS: Adolescent athletes (aged 13-18 years) presenting within 10 days of SRC (mean, 5 days after injury) received a recommendation for rest (rest group [RG], n=48, 15.4±1y, 25% female). Their outcomes were compared with matched samples of adolescents assigned to aerobic exercise (exercise group [EG], n=52, 15.3±2y, 46% female) or placebo-like stretching (placebo group [PG], n=51, 15.4±2y, 47% female) (N=151). MAIN OUTCOME MEASURES: The primary outcome was median days from injury to recovery. The secondary outcome was proportion classified as normal recovery (<30d) or delayed recovery (≥30d). RESULTS: The RG recovered in 16 days (interquartile range, 9.25-23.25d), which was significantly delayed (P=.020) compared with EG (13d; interquartile range, 10-18.5d). The PG recovered in 17 days (interquartile range, 13-23d). Four percent of the EG, 14% of the PG, and 13% of the RG had delayed recovery (P=.190). There was no difference in recovery time or delayed recovery between male participants and female participants across groups. Female participants prescribed rest experienced an increase in symptoms vs the other groups (P=.013). CONCLUSION: Relative rest and a placebo-like stretching program were very similar in days to recovery and symptom improvement pattern after SRC. Both conditions were less effective than subsymptom threshold aerobic exercise. Female adolescents appear to be susceptible to symptom increase when prescribed rest.

Physician Medical Assessment in a Multidisciplinary Concussion Clinic.

Concussive brain injury (CBI) is encountered by clinicians in sports medicine, pediatrics, neurosurgery, neurology, physiatry, and primary care. There is no gold standard diagnostic test for CBI, nor is there consensus on what neuromusculoskeletal physical examination tests should be performed on patients who have sustained CBI. This article presents an approach to the history and physical examination of the patient who has sustained a CBI that is based on a review of the literature evidence and the authors' extensive experience with this patient population. Suggested components include an elemental neurological examination that emphasizes the oculomotor/ophthalmologic and vestibular systems, as well as appropriate musculoskeletal assessment of the craniocervical and upper shoulder girdle complex. The use of supplementary tests for CBI, including assessment of exercise tolerance using the Buffalo Concussion Treadmill Test and tests of neurocognitive function, can aid in the differential diagnosis of CBI. The proposed protocol is envisioned for initial and follow-up assessments in the clinic after CBI, as well as for those with more protracted signs or symptoms. If symptoms persist beyond 2 weeks in adults or 4 weeks in adolescents, then referral to a multidisciplinary center that focuses on CBI is recommended.

A Preliminary Study of the Effect of Early Aerobic Exercise Treatment for Sport-Related Concussion in Males.

OBJECTIVE: To study the effect of early prescribed aerobic exercise versus relative rest on rate of recovery in male adolescents acutely after sport-related concussion (SRC). DESIGN: Quasi-experimental design. SETTING: University sports medicine centers. PARTICIPANTS: Exercise group (EG, n = 24, 15.13 ± 1.4 years, 4.75 ± 2.5 days from injury) and rest group (RG, n = 30, 15.33 ± 1.4 years, 4.50 ± 2.1 days from injury). INTERVENTIONS: Exercise group performed a progressive program of at least 20 minutes of daily subthreshold aerobic exercise. Rest group was prescribed relative rest (no structured exercise). Both groups completed daily online symptom reports (Postconcussion Symptom Scale) for 14 days. MAIN OUTCOME MEASURES: Days to recovery after treatment prescription. Recovery was defined as return to baseline symptoms, exercise tolerant, and judged recovered by physician examination. RESULTS: Recovery time from initial visit was significantly shorter in EG (8.29 ± 3.9 days vs 23.93 ± 41.7 days, P = 0.048). Mixed-effects linear models showed that all symptom clusters decreased with time and that there was no significant interaction between treatment group and time. No EG participants experienced delayed recovery (>30 days), whereas 13% (4/30) of RG participants experienced delayed recovery. CONCLUSIONS: These preliminary data suggest that early subthreshold aerobic exercise prescribed to symptomatic adolescent males within 1 week of SRC hastens recovery and has the potential to prevent delayed recovery.

A Preliminary Study of Early-Onset Dementia of Former Professional Football and Hockey Players.

OBJECTIVE: To provide an overview of 3 studies of the same population of retired professional contact sport athletes compared with age-matched noncontact sport athlete controls on cognition, executive function, behavior, and advanced brain imaging. SETTING: University Concussion Management Clinic. PARTICIPANTS: Twenty-two retired professional hockey and football athletes (average age 56 years) and 21 age-matched noncontact sport athlete controls. DESIGN: Case control. MAIN MEASURES: Participants were assessed on a broad range of neuropsychological measures that are associated with identification of mild cognitive impairment and executive function. Athletes were also assessed using self-report measures of executive function and personality. Advanced structural and functional imaging techniques were utilized as well. RESULTS: The former National Football League and National Hockey League athletes perceived themselves to have impaired executive function, but this was not confirmed by objective neurocognitive assessment. No significant differences were found when comparing contact-sport athletes with controls on the presence of mild cognitive impairment or brain structural and functional tissue injury. Contact sport athletes were more anxious and more likely to report unusual beliefs and experiences. CONCLUSION: None of the retired contact sport athletes qualified as having early-onset dementia consistent with chronic traumatic encephalopathy. There were no remarkable differences in imaging, cognition, behavior, or executive function from noncontact sport athletes. The results underscore an apparent disconnect between public perceptions and evidence-based conclusions about the inevitability of chronic traumatic encephalopathy and the potential neurodegenerative effect on former athletes from contact sports.

Evaluation of Executive Function and Mental Health in Retired Contact Sport Athletes.

OBJECTIVE: To compare retired professional contact sport athletes with age-matched noncontact sport athletes on measures of executive function and mental health. SETTING: The University Concussion Management Clinic. PARTICIPANTS: Twenty-one retired National Football League (NFL) and National Hockey League (NHL) players (mean age 56 years) and 21 age-matched noncontact sport athlete controls. DESIGNS: Case control. MAIN MEASURE: The self- and informant-reported Behavior Rating Inventory of Executive Function-Adult form (BRIEF-A); Wisconsin Card Sorting Test; Delis-Kaplan Executive Function System; Trail Making Part A and B; Wechsler Adult Intelligence Scale; Neuropsychological Assessment Battery; List Learning; Controlled Oral Word Association Test; Beck Depression Inventory; Beck Anxiety Inventory; and Personality Inventory of the DSM-5. RESULTS: Former NFL and NHL players perceived themselves to have some impairment in 2 of the 9 domains of executive function on the BRIEF-A; however, their informants reported no difference when compared with informants of noncontact athletes. No significant differences were found when comparing contact sport athletes with noncontact athletes on objective neuropsychological testing. Contact sport athletes qualified as clinically anxious and had more "unusual beliefs and experiences," although they remained within with age-based norms. CONCLUSION: Participation in contact sports at the professional level may not lead to later-life executive dysfunction, as the popular media and some research currently suggest.

An Exploratory Study of Mild Cognitive Impairment of Retired Professional Contact Sport Athletes.

OBJECTIVE: To test the hypothesis that mild cognitive impairment (MCI) rates are higher among retired professional contact sport athletes than in noncontact athlete controls and compare history of contact sports with other MCI risk factors. SETTING: University Concussion Management Clinic. PARTICIPANTS: Twenty-one retired National Football League and National Hockey League players and 21 aged-matched noncontact athlete controls. DESIGNS: Case-control. MAIN MEASURES: Comprehensive criteria were used to assess MCI based on the following: Wisconsin Card Sorting Test, Delis-Kaplan Executive Function System; Trail Making Parts A and B; Wechsler Adult Intelligence Scale-Third Edition subtests; Neuropsychological Assessment Battery Memory Module List Learning, Story Learning, and Naming subtests; and Controlled Oral Word Association Test. The Wide Range Achievement Test was used as a proxy measure for IQ. Atherosclerotic cardiovascular disease risk factors were self-reported and blood cholesterol was measured. Depression was measured by the Beck Depression Inventory-II (BDI). RESULTS: Eight contact sport athletes (38%) and 3 noncontact athletes (14%) met MCI criteria (P = .083). Contact sport athletes' scores were significantly worse on Letter Fluency and List B Immediate Recall. Contact athletes were more obese, had more vascular risk factors, and had higher scores on the BDI than controls. CONCLUSION: Athletes with a history of playing professional contact sports had more vascular risk factors and higher depression scores. MCI rates were somewhat higher, though not significant.

Exercise is Medicine for Concussion.

Sport-related concussion (SRC) is a physiological brain injury that produces cerebral and systemic effects, including exercise intolerance. Exercise intolerance after concussion is believed to be the result of autonomic nervous system (ANS) dysfunction. Ventilation is inappropriately low for the level of exercise intensity, raising arterial carbon dioxide (PaCO2) levels. Elevated PaCO2 increases cerebral blood flow (CBF) out of proportion to exercise intensity, which is associated with symptoms that limit exercise performance. Thus, elevated exercise PaCO2 may signal incomplete recovery from SRC. This article reviews recent observational and experimental data and presents the evidence that subthreshold aerobic exercise normalizes the cerebrovascular physiological dysfunction and is "medicine" for patients with concussion and persistent postconcussive symptoms (PPCS). It discusses the systematic evaluation of exercise tolerance after concussion using the Buffalo Concussion Treadmill Test (BCTT) and reviews the utility of the Buffalo Concussion Bike Test (BCBT), the data from which are used to establish an individualized heart rate "dose" of subthreshold exercise to safely speed recovery, which also may work in the acute recovery phase after SRC with the potential to reduce the incidence of PPCS. Evaluation and treatment approaches based on the physiology of concussion suggest that exercise is medicine for concussion, potentially adding a new dimension to concussion care to help safely speed recovery and prevent PPCS in some patients.