Sideline Concussion Assessment: The King-Devick Test in Canadian Professional Football

Performance of current tools used for on-the-day assessment and diagnosis of mild traumatic brain injury in sport: a systematic review

Objective

The monitoring and diagnosis of sports-related mild traumatic brain injury (SR-mTBI) remains a challenge. This systematic review summarises the current monitoring tools used for on-the-day assessment and diagnosis of SR-mTBI and their performance.

Design

Systematic review, using Quality Assessment of Diagnostic Accuracy Studies assessment.

Data sources

Embase via Ovid, IEEEXplore, Medline via Ovid, Scopus and Web of Science were searched up to June 2024.

Eligibility criteria

Peer-reviewed English-language journal articles which measured athletes using the index test within a day of injury and provided a performance measure for the method used. Studies of all designs were accepted, and no reference methods were required.

Results

2534 unique records were retrieved, with 52 reports included in the review. Participants were 76% male, when reported, and the mean injury-to-measurement time was reported in 10% of reports. 46 different methods were investigated. 38 different reference methods were used, highlighting the lack of gold standard within the field. Area under the curve (AUC), sensitivity and specificity were the most frequent outcome metrics provided. The most frequent index test was the King-Devick (KD) test. However, there were large variations in accuracy metrics between reports for the KD test, for instance, the range of AUC: 0.51-0.92.

Conclusion

Combinations of existing methods and the KD test were most accurate in assessing SR-mTBI, despite the inconsistent accuracy values related to the KD test. The absence of a gold-standard measurement hampers our ability to diagnose or monitor SR-mTBI. Further exploration of the mechanisms and time-dependent pathophysiology of SR-mTBI could result in more targeted diagnostic and monitoring techniques. The Podium Institute for Sports Medicine and Technology funded this work.

PROSPERO registration number

CRD42022376560.

Smartphone-Based Pupillometry Using Machine Learning for the Diagnosis of Sports-Related Concussion

Background: Quantitative pupillometry has been proposed as an objective means to diagnose acute sports-related concussion (SRC). Objective: To assess the diagnostic accuracy of a smartphone-based quantitative pupillometer in the acute diagnosis of SRC. Methods: Division I college football players had baseline pupillometry including pupillary light reflex (PLR) parameters of maximum resting diameter, minimum diameter after light stimulus, percent change in pupil diameter, latency of pupil constriction onset, mean constriction velocity, maximum constriction velocity, and mean dilation velocity using a smartphone-based app. When an SRC occurred, athletes had the smartphone pupillometry repeated as part of their concussion testing. All combinations of the seven PLR parameters were tested in machine learning binary classification models to determine the optimal combination for differentiating between non-concussed and concussed athletes. Results: 93 football athletes underwent baseline pupillometry testing. Among these athletes, 11 suffered future SRC and had pupillometry recordings repeated at the time of diagnosis. In the machine learning pupillometry analysis that used the synthetic minority oversampling technique to account for the significant class imbalance in our dataset, the best-performing model was a random forest algorithm with the combination of latency, maximum diameter, minimum diameter, mean constriction velocity, and maximum constriction velocity PLR parameters as feature inputs. This model produced 91% overall accuracy, 98% sensitivity, 84.2% specificity, area under the curve (AUC) of 0.91, and an F1 score of 91.6% in differentiating between baseline and SRC recordings. In the machine learning analysis prior to oversampling of our imbalanced dataset, the best-performing model was k-nearest neighbors using latency, maximum diameter, maximum constriction velocity, and mean dilation velocity to produce 82% accuracy, 40% sensitivity, 87% specificity, AUC of 0.64, and F1 score of 24%. Conclusions: Smartphone pupillometry in combination with machine learning may provide fast and objective SRC diagnosis in football athletes.

Clinical Utility of Ocular Assessments in Sport-Related Concussion: A Scoping Review

Background/objectives: Ocular tools and technologies may be used in the diagnosis of sport-related concussions (SRCs), but their clinical utility can vary. The following study aimed to review the literature pertaining to the reliability and diagnostic accuracy of such assessments. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) extension for scoping reviews was adhered to. Reference standard reliability (RSR ≥ 0.75) and diagnostic accuracy (RSDA ≥ 0.80) were implemented to aid interpretation. Results: In total, 5223 articles were screened using the PCC acronym (Population, Concept, Context) with 74 included in the final analysis. Assessments included the King-Devick (KD) (n = 34), vestibular-ocular motor screening (VOMs) and/or near point of convergence (NPC) (n = 25), and various alternative tools and technologies (n = 20). The KD met RSR, but RSDA beyond amateur sport was limited. NPC met RSR but did not have RSDA to identify SRCs. The VOMs had conflicting RSR for total score and did not meet RSR in its individual tests. The VOMs total score did perform well in RSDA for SRCs. No alternative tool or technology met both RSR and RSDA. Conclusion: Ocular tools are useful, rapid screening tools but should remain within a multi-modal assessment for SRCs at this time.

Mixed Martial Arts: Comparing the King-Devick and Sport Concussion Assessment Tool 5 in knockouts, technical knockouts and choke holds

Objective

To compare validity indices of the King-Devick (KD) test and Sport Concussion Assessment Tool 5 (SCAT5) for traumatic events in MMA, and to determine if perfusion events (alterations in consciousness as the result of choke holds) cause similar changes in KD/SCAT5 scores.

Design

A prospective cohort study in MMA fighters who completed KD and SCAT5 assessments before and after a match. Outcomes were categorized as non-event, traumatic event, or perfusion event. KD/SCAT5 changes were compared between all athletes.

Participants

One hundred forty MMA athletes (7 women, 133 men), mean age=27.1 ± 4.9 years.

Intervention

N/A.

Main outcome measures

King-Devick (KD) test and Sport Concussion Assessment Tool 5 (SCAT5).

Results

Among the 140 athletes, 19 sustained traumatic and 15 perfusion events. Testing provided sensitivities/specificities of 21.05%/93.39% (KD) and 77.78%/52.99% (SCAT5) in detecting a traumatic event. KD and SCAT5 Symptom Severity scores differed between athletes with and without traumatic events (P=.041 and .014). KD and SCAT5 Symptoms Score changes were observed between athletes with and without traumatic events (P=.023 and .042). Neither KD nor SCAT5 differed significantly between athletes with and without perfusion events.

Conclusions

The KD test provides high specificity and the SCAT5 demonstrates reasonable sensitivity when detecting a traumatic event. Of the SCAT5, symptoms-related scores may most effectively identify a traumatic event. A traumatic event may cause KD/SCAT5 changes similar to a concussion, while perfusion events did not.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

OBJECTIVES

To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6).

DATA SOURCES

Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation.

ELIGIBILITY CRITERIA

(1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC.

DATA EXTRACTION

Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool.

RESULTS

Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children.

CONCLUSION

Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

Do Sideline Tests of Vestibular and Oculomotor Function Accurately Diagnose Sports-Related Concussion in Adults? A Systematic Review and Meta-analysis

BACKGROUND

Sports-related concussion (SRC) assessment tools are primarily based on subjective assessments of somatic, cognitive, and psychosocial/emotional symptoms. SRC symptoms remain underreported, and objective measures of SRC impairments would be valuable to assist diagnosis. Measurable impairments to vestibular and oculomotor processing have been shown to occur after SRC and may provide valid objective assessments.

PURPOSE

Determine the diagnostic accuracy of sideline tests of vestibular and oculomotor dysfunction to identify SRC in adults.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Electronic databases and gray literature were searched from inception until February 12, 2020. Physically active individuals (>16 years of age) who participated in sports were included. The reference standard for SRC was a combination of clinical signs and symptoms (eg, the Sport Concussion Assessment Tool [SCAT]), and index tests included any oculomotor assessment tool. The QUADAS tool was used to assess risk of bias, with the credibility of the evidence being rated according to GRADE.

RESULTS

A total of 8 studies were included in this review. All included studies used the King-Devick test, with no other measures being identified. Meta-analysis was performed on 4 studies with a summary sensitivity and specificity of 0.77 and 0.82, respectively. The overall credibility of the evidence was rated as very low.

CONCLUSION

Caution must be taken when interpreting these results given the very low credibility of the evidence, and the true summary sensitivity and specificity may substantially differ from the values calculated within this systematic review. Therefore, we recommend that clinicians using the King-Devick test to diagnose SRC in adults do so in conjunction with other tools such as the SCAT.

PROSPERO REGISTRATION

CRD42018106632.

The Utility of the King-Devick Test in Evaluating Professional Ice Hockey Players With Suspected Concussion

OBJECTIVE

The purpose of this study was to (1) examine the diagnostic utility of the King-Devick (KD) in professional ice hockey players and (2) determine whether the KD provides unique variance in predicting a diagnosis of concussion when given in combination with the SCAT-5.

STUDY DESIGN

Cohort Study.

SETTING

Primary care.

PATIENTS/PARTICIPANTS

Professional ice hockey players.

INDEPENDENT VARIABLES

Diagnosis versus no diagnosis of concussion.

MAIN OUTCOME MEASURES

King-Devick and SCAT-5 component scores.

METHODS

In part 1, players suspected of having a concussion were evaluated at baseline and acutely with the KD and either the SCAT-3 or the SCAT-5. Players evaluated and not diagnosed with concussion served as active controls. In part 2, a separate group of players suspected of having a concussion was evaluated acutely with both the KD and SCAT-5.

RESULTS

In part 1 of this study, 53 concussed players declined in performance on the KD from baseline to acute evaluation, whereas the performance of 76 active controls improved significantly. In part 2 of the study, 75 players were diagnosed with concussion and compared with 80 active controls who were evaluated and not diagnosed with concussion. Concussed players revealed a decline in KD performance from baseline to acute evaluation when compared with controls. However, the KD did not account for significant unique variance in predicting a diagnosis of concussion after accounting for SCAT-5 data.

CONCLUSIONS

The KD is useful in differentiating concussed and not concussed athletes acutely, but the KD does not seem to add additional diagnostic value over and above the SCAT-5.

Diversifying sport-related concussion measures with baseline balance and ocular-motor scores in professional Zambian football athletes

PURPOSE

Normative values of common sport-related concussion assessment tools may assist clinical diagnosis and management. However, current baseline normative values are not representative of athletic participants across international domains. This study develops healthy baseline norms on the Balance Error Scoring System (BESS), and King-Devick (K-D), providing baseline reference values for professional Zambian football athletes.

METHODS

Of the 125 male participants (aged 24.48 ± 5.41 years) screened for this study, 9 (7.2%) reported a previous history of concussion, 98 (78.4%) completed the Balance Error Scoring System and 88 (70.4%) completed the King-Devick. Descriptive statistics calculated for the BESS and the K-D test included mean, standard deviation, median, interquartile range (IQR), and percentiles ranks.

MAIN FINDINGS

Participants scored a mean ± standard deviation of 10.15 ± 5.6 and a median [IQR] of 9 [6-12.25] errors on the total BESS and completed the K-D test in a mean ± standard deviation 56.85 ± 10.55 seconds and a median [IQR] 55.28 [48.7-64.8] seconds.

CONCLUSIONS

Cross-cultural awareness and management of sport-related concussion are continuously improving the safety and well-being of athletic participants around the world. The diverse representation in these data may aid in interpretation of post-injury performance during sport-related concussion management in Zambia. This study develops baseline reference values currently lacking within African cultures and demonstrates the feasibility and global clinical utility of two sport-related concussion assessment resources.

Head and Neck Injury Patterns among American Football Players

IMPORTANCE

American football is a popular high-impact sport, leading to 2.7 million injuries in the United States annually. Recent evidence in football-related neurological damage has spurred national interest in player-safety. Football players injure their head and neck in up to 26% of total injuries. Variation in injury patterns between age groups and correlated hospitalizations for football-related head and neck injury has yet to be characterized.

OBJECTIVE

Our aim is to evaluate injury patterns among American-football related head and neck trauma.

METHODS

A retrospective cohort study of patients with football-related head and neck injury in the National Electronic Injury Surveillance System (NEISS).

RESULTS

Nearly 100 000 ED visits for football-related head and neck injuries occur annually. Males comprised 95% of patients, with a median age of 13. The head comprised 70% of injuries followed by the face (13%). The most common diagnoses were concussions (39%), internal organ injury (26%), and lacerations (11%). Pediatric patients were more likely to sustain concussions while adults experienced more lacerations (P < .05%). Fractures and nerve damage were rare injuries but caused a disproportionate share of hospitalizations.

CONCLUSION

Pediatric males are most likely to present for emergency care from football-related injury to the head and neck. Evaluating physicians can anticipate concussions, internal organ injury, and lacerations among presenting patients. Concussions, facial fractures, and nerve damage are injuries most likely to lead to hospitalization.

Diagnostic accuracy and reliability of sideline concussion evaluation: a prospective, case-controlled study in college athletes comparing newer tools and established tests

OBJECTIVE

To assess diagnostic accuracy and reliability of sideline concussion tests in college athletes.

METHODS

Athletes completed baseline concussion tests including Post-Concussion Symptom Scale, Standardised Assessment of Concussion (SAC), modified Balance Error Scoring System (m-BESS), King-Devick test and EYE-SYNC Smooth Pursuits. Testing was repeated in athletes diagnosed acutely with concussion and compared to a matched teammate without concussion.

RESULTS

Data were collected on 41 concussed athletes and 41 matched controls. Test-retest reliability for symptom score and symptom severity assessed using control athletes was 0.09 (-0.70 to 0.88) and 0.08 (-1.00 to 1.00) (unweighted kappa). Intraclass correlations were SAC 0.33 (-0.02 to 0.61), m-BESS 0.33 (-0.2 to 0.60), EYE-SYNC Smooth Pursuit tangential variability 0.70 (0.50 to 0.83), radial variability 0.47 (0.19 to 0.69) and King-Devick test 0.71 (0.49 to 0.84). The maximum identified sensitivity/specificity of each test for predicting clinical concussion diagnosis was: symptom score 81%/94% (3-point increase), symptom severity score 91%/81% (3-point increase), SAC 44%/72% (2-point decline), m-BESS 40%/92% (5-point increase), King-Devick 85%/76% (any increase in time) and EYE-SYNC Smooth Pursuit tangential variability 48%/58% and radial variability 52%/61% (any increase). Adjusted area under the curve was: symptom score 0.95 (0.89, 0.99), symptom severity 0.95 (95% CI 0.88 to 0.99), SAC 0.66 (95% CI 0.54 to 0.79), m-BESS 0.71 (0.60, 0.83), King-Devick 0.78 (0.69, 0.87), radial variability 0.47 (0.34, 0.59), tangential variability 0.41 (0.30, 0.54) CONCLUSION: Test-retest reliability of most sideline concussion tests was poor in uninjured athletes, raising concern about the accuracy of these tests to detect new concussion. Symptom score/severity had the greatest sensitivity and specificity, and of the objective tests, the King-Devick test performed best.

INFLUENCING FACTORS OF COLLEGE STUDENTS’ PHYSICAL HEALTH UNDER THE INTERVENTION OF FOOTBALL

ABSTRACT The current football can effectively exercise the body of college students and improve their physical health. How to use modern intelligent technology to perform quantitative research on the influencing factors of football on college students’ physical health is the current development trend. Based on this, this paper studies the influencing factors of college students’ physical health under the intervention of football. First of all, this paper puts forward an analysis model of college students’ physical health based on the sarsa algorithm. The autocorrelation function is used to simulate and process the students’ physical information. Through the maximum value of the autocorrelation function curve in the detection process, the detection signal is restored, then the error of the sarsa algorithm is analyzed. Secondly, this paper expounds the influence factors of sarsa algorithm on students’ physical health in football. Fuzzy evaluation method and analytic hierarchy process are used in the evaluation. Aiming at the shortcomings of AHP, the improved sarsa algorithm is used for comprehensive analysis, and an adaptive simulation evaluation system is established. Finally, the effectiveness of the sarsa algorithm in this system is verified by many football experiments.

Considerations for Diagnosis and Management of Concussion

Concussion is an ongoing concern for health care providers. The incidence rates continue to be high and the rate of recovery is variable due to potential risk factors. With no valid biomarkers, diagnosis and assessment of concussion remain a clinical challenge. The heterogeneity in presentation following injury provides an additional level of complexity, requiring the screening and evaluation of diverse body systems, including oculomotor, vestibular, autonomic, psychiatric, cervical, and cognitive symptoms. While a few tools, such as the Vestibular/Ocular Motor Screening and Balance Error Scoring System, have been developed specifically for concussion, the vast majority of tests are adapted from other conditions. Further complicating the process is the overlapping and interactive nature of the multiple domains of postconcussion presentation. This commentary illustrates how clinicians can conceptualize the multiple profiles that present following concussion and describes tools that are available to assist with screening and evaluation of each area. The multifaceted nature of concussion warrants broad clinical screening skills and an interdisciplinary approach to management. J Orthop Sports Phys Ther 2019;49(11):787-798. doi:10.2519/jospt.2019.8855.

Current Concepts in the Evaluation of the Pediatric Patient with Concussion

PURPOSE OF THE REVIEW

A concussion is a mild traumatic brain injury (mTBI) that results in a change in how a person feels or functions after a force transmitted to the head. Nearly 10% of all sports-related injuries are mild traumatic brain injuries. Concussion/mTBIs have accounted for more than 3 million emergency department visits between 2005 and 2009 and present as an important public health concern.

RECENT FINDINGS

Physical, cognitive, and psychological functioning are known to be affected by concussion/mTBI, and various tools are readily available to guide clinicians through the initial evaluation. Evaluation of patients with concussion/mTBI should include symptom report and balance, vestibular-ocular, and neurocognitive testing. Awareness of past medical history and pre-injury history of social, behavioral, and emotional functioning is essential to better understand the injury and to predict the expected course of recovery. No tool available can be used alone to diagnose concussion/mTBI or evaluate for recovery.

One-year test-retest reliability of ten vision tests in Canadian athletes

Background: Vision tests are used in concussion management and baseline testing. Concussions, however, often occur months after baseline testing and reliability studies generally examine intervals limited to days or one week. Our objective was to determine the one-year test-retest reliability of these tests.

Methods: We assessed one-year test-retest reliability of ten vision tests in elite Canadian athletes followed by the Institut National du Sport du Quebec. We included athletes who completed two baseline (preseason) annual evaluations by one clinician within 365±30 days. We excluded athletes with any concussion or vision training in between the annual evaluations or presented with any factor that is believed to affect the tests (e.g. migraines). Data were collected from clinical charts. We evaluated test-retest reliability using Intraclass Correlation Coefficient (ICC) and 95% limits of agreement (LoA).

Results: We examined nine female and seven male athletes with a mean age of 22.7 (SD 4.5) years. Among the vision tests, we observed excellent test-retest reliability in Positive Fusional Vergence at 30cm (ICC=0.93) but this dropped to 0.53 when an outlier was excluded in a sensitivity analysis. There was good to moderate reliability in Negative Fusional Vergence at 30cm (ICC=0.78), Phoria at 30cm (ICC=0.68), Near Point of Convergence break (ICC=0.65) and Saccades (ICC=0.61). The ICC for Positive Fusional Vergence at 3m (ICC=0.56) also decreased to 0.45 after removing two outliers. We found poor reliability in Near Point of Convergence (ICC=0.47), Gross Stereoscopic Acuity (ICC=0.03) and Negative Fusional Vergence at 3m (ICC=0.0). ICC for Phoria at 3m was not appropriate because scores were identical in 14/16 athletes. 95% LoA of the majority of tests were ±40% to ±90%.

Conclusions: Five tests had good to moderate one-year test-retest reliability. The remaining tests had poor reliability. The tests would therefore be useful only if concussion has a moderate-large effect on scores.

The King-Devick test is not sensitive to self-reported history of concussion but is affected by English language skill

OBJECTIVES

Head injuries, including concussion, are a concern in many sports. Current validated concussion assessment protocols such are problematic with suggestions that an oculomotor examination, such as the King-Devick (K-D) test, could be included. This research explores the role of the K-D test in snowsport concussion research.

DESIGN

Experienced snowsport participants were recruited through a western Canadian resort (n=75).

METHODS

Participants completed a questionnaire that included their history of prior serious head impacts and were assessed via the computer-based K-D test in English.

RESULTS

Of the 75 participants, 23 (69%) reported at least one previous serious head impact. English was the not primary language for seven participants. Independent sample t-tests revealed: significant differences in the K-D average saccade scores for those who had broken their helmets, with or without a serious head injury (̄x¯=171.23, SD=12.9) and those who had not broken a helmet (̄x¯=186.61, SD=20.18; t (70)=-2.53, p=.014, twotailed) and significant differences in the K-D time for those whose native language is English (̄x¯=47.9, SD=6.3) and those where English was not their first language (̄x¯=53.3, SD=7.4; t(73)=.48, p=.04), but no significant difference for their saccade velocities: English (̄x¯=183.64, SD=20.0) versus those where English is a second or third language (̄x¯=188.44, SD=20.1; t(70)=-.56, p=.576).

CONCLUSIONS

For subjects whose first language is not English, such as in many snowsport resorts, the K-D test may need to be conducted in a person's native language to provide a valid assessment based upon the time to complete the task.