Systematic review of the balance error scoring system

The Role of Physical Therapy in Concussion Rehabilitation

A complex diagnosis such as concussion requires a multidisciplinary patient-centered approach to maximize health outcomes. There is growing evidence to support the role of the Physical Therapist as a key member of the team of healthcare professionals managing children and adolescents with a protracted recovery following concussion. Symptoms such as headache, dizziness, neck pain, gaze instability, balance dysfunction, and fatigue can be addressed through a multimodel approach. This article provides an overview of the targeted pathways of examination and treatment of individuals with a concussion through vestibular rehabilitation, cervicogenic rehabilitation, exertional training, and patient education.

Level of Agreement Between Human-Rated and Instrumented Balance Error Scoring System Scores

Clinicians have used the Balance Error Scoring System (BESS) to quantify postural control for concussion management. However, the reliability of the human rated BESS has varied prompting the development of instrumented BESSs. A cross-sectional design was used to determine the level of agreement (LOA) between human rated and instrumented BESS scores. Sixty participants completed the BESS on video. An instrumented mat was used to quantify BESS errors while a live human rater simultaneously scored the BESS. A second human rated BESS performance via video. Bland-Altman LOA analyses evaluated agreement between scoring methods (Mat-Human, Mat-Video, Video-Live) for each stance. Mean biases between scores, for each stance, with 95% confidence intervals (95%CIs) were calculated. Agreement between scoring methods was not assessed for the Firm-Double-Limb stance because very few errors were recorded. Agreement between both human raters and the mat was poor based on mean bias estimates > ± 1 and/or wide 95%CIs for all stances including BESS-Total. Agreement between the human raters was better, having displayed consistently smaller mean bias estimates and tighter 95%CIs for all stances and BESS Total. As a result, human rated and instrumented BESS scores may not be comparable. One method should be used to measure BESS errors for consistency.

Clinical predictors of symptom resolution for children and adolescents with sport-related concussion

OBJECTIVE

The goal of this study was to determine which variables assessed during an initial clinical evaluation for concussion are independently associated with time until symptom resolution among pediatric patients.

METHODS

Data collected from a prospective clinical registry of pediatric patients with concussion were analyzed. The primary outcome variable was time from injury until symptom resolution. Predictor variables assessed within 10 days after injury included preinjury factors, Health and Behavior Inventory scores, headache severity, and balance, vestibular, and oculomotor test performances. The researchers used univariate Cox proportional models to identify potential predictors of symptom resolution time and constructed a multivariate Cox proportional hazards model in which total duration of concussion symptoms remained the outcome variable.

RESULTS

The sample consisted of 351 patients (33% female, mean age 14.6 ± 2.2 years, evaluated 5.6 ± 2.6 days after concussion). Univariate Cox proportional hazards models indicated that several variables were associated with a longer duration of symptoms, including headache severity (hazard ratio [HR] 0.90 [95% CI 0.85-0.96]), headache frequency (HR 0.83 [95% CI 0.71-0.96]), confusion (HR 0.79 [95% CI 0.69-0.92]), forgetfulness (HR 0.79 [95% CI 0.68-0.92]), attention difficulties (HR 0.83 [95% CI 0.72-0.96]), trouble remembering (HR 0.84 [95% CI 0.72-0.98]), getting tired often (HR 0.86 [95% CI 0.76-0.97]), getting tired easily (HR 0.86 [95% CI 0.76-0.98]), dizziness (HR 0.86 [95% CI 0.75-0.99]), and abnormal performance on the Romberg test (HR 0.59 [95% CI 0.40-0.85]). A multivariate Cox proportional hazards model indicated that an abnormal performance on the Romberg test was independently associated with a longer duration of symptoms (HR 0.65 [95% CI 0.44-0.98]; p = 0.038).

CONCLUSIONS

For children and adolescents evaluated within 10 days after receiving a concussion, abnormal performance on the Romberg test was independently associated with a longer duration of symptoms during recovery. In line with findings of other recent studies investigating predictors of symptom resolution, postural stability tests may provide useful prognostic information for sports medicine clinicians.

POST-CONCUSSIVE CHANGES IN BALANCE AND POSTURAL STABILITY MEASURED WITH CANESENSE™ AND THE BALANCE ERROR SCORING SYSTEM (BESS) IN DIVISION I COLLEGIATE FOOTBALL PLAYERS: A CASE SERIES

INTRODUCTION

Impairments in postural stability have been identified following sports-related concussion. CaneSense™ is a recently developed mobile lower limb motion capture system and mobile application for movement assessment which provides an objective measure of postural stability. One of the components within CaneSense™ is the Post-Concussive Excursion Index (PCEI), a measure of postural stability expressed as a percentage of symmetry between lower limbs.

PURPOSE

The purpose of this case series is to examine pre- and post-concussion differences using two separate measures, CaneSense™, and a known test, the Balance Error Scoring System (BESS), in Division I collegiate football players.

METHODS

A convenience sample of eight football players diagnosed with a concussion, were the subjects in this case series. All subjects underwent baseline testing prior to the start of pre-season camp consisting of the single limb stance (SLS) test with CaneSense™ and the BESS test. Twenty-four to 72 hours following their concussion, SLS with CaneSense™ test and the BESS test, were administered. Segmental excursions for the thigh and shank segments for each lower limb were combined into the Post-Concussion Excursion Profile (PCEP), which represents each segment's maximum excursion in the medial-lateral and anterior-posterior direction. The PCEI is a single metric generated to quantify differences within subjects by comparing the PCEP value between lower limbs during SLS where 100% suggests absolute symmetry.

RESULTS

The PCEI value decreased significantly post-concussion (41.43 ± 15.53% vs. 87.41 ± 6.05%, p < 0.001) demonstrating a 52.6% decrease in inter-limb symmetry when compared to baseline values. There was an unanticipated 36.36% improvement in composite BESS performance post-concussion (10.5 ± 4.87 errors vs. 16.5 ± 8.49 errors, p = 0.10).

CONCLUSIONS

Differences in inter-limb postural stability were found in subjects post-concussion. By assessing postural stability in both lower limbs individually, using the PCEI, impairments were detected that otherwise would have likely gone undiagnosed using the BESS test alone.

LEVELS OF EVIDENCE

Therapy, Level 4.

Trouble Falling Asleep After Concussion Is Associated With Higher Symptom Burden Among Children and Adolescents

Our objective was to identify factors associated with trouble falling asleep postconcussion. Patients seen for care after sport-related concussion were assessed ≤10 days postinjury and were between 6 and 19 years of age. Outcomes included symptoms (Post-Concussion Symptom Scale), postural steadiness, missed school, and medical history. There were 261 patients (49% female; mean age=14.8±2.5 years): 45% reported trouble falling asleep. A greater proportion of patients who reported trouble falling asleep missed ≥2 days of school (64% vs 49%; P = .02). Patients who reported trouble falling asleep endorsed more severe symptom severity than those who did not (median=38 vs 18; P < .001). After covariate adjustment, confusion (aOR = 1.95, 95% CI = 1.131-3.375), missing ≥2 days of school (aOR = 4.52, 95% CI = 1.553-13.16), and noise sensitivity (aOR = 1.48, 95% CI = 1.1.042-2.010) were independently associated with trouble falling asleep. Sleep disturbances are associated with poorer clinical outcomes after concussion. Inclusion of sleep assessments may help to provide early therapeutic pathways for pediatric concussion patients.

Can Functional Movement Assessment Predict Football Head Impact Biomechanics?

PURPOSE

The purposes of this study was to determine functional movement assessments' ability to predict head impact biomechanics in college football players and to determine whether head impact biomechanics could explain preseason to postseason changes in functional movement performance.

METHODS

Participants (N = 44; mass, 109.0 ± 20.8 kg; age, 20.0 ± 1.3 yr) underwent two preseason and postseason functional movement assessment screenings: 1) Fusionetics Movement Efficiency Test and 2) Landing Error Scoring System (LESS). Fusionetics is scored 0 to 100, and participants were categorized into the following movement quality groups as previously published: good (≥75), moderate (50-75), and poor (<50). The LESS is scored 0 to 17, and participants were categorized into the following previously published movement quality groups: good (≤5 errors), moderate (6-7 errors), and poor (>7 errors). The Head Impact Telemetry (HIT) System measured head impact frequency and magnitude (linear acceleration and rotational acceleration). An encoder with six single-axis accelerometers was inserted between the padding of a commercially available Riddell football helmet. We used random intercepts general linear-mixed models to analyze our data.

RESULTS

There were no effects of preseason movement assessment group on the two Head Impact Telemetry System impact outcomes: linear acceleration and rotational acceleration. Head impact frequency did not significantly predict preseason to postseason score changes obtained from the Fusionetics (F1,36 = 0.22, P = 0.643, R = 0.006) or the LESS (F1,36 < 0.01, P = 0.988, R < 0.001) assessments.

CONCLUSIONS

Previous research has demonstrated an association between concussion and musculoskeletal injury, as well as functional movement assessment performance and musculoskeletal injury. The functional movement assessments chosen may not be sensitive enough to detect neurological and neuromuscular differences within the sample and subtle changes after sustaining head impacts.

Influence of biological maturity on static and dynamic postural control among male youth soccer players

BACKGROUND

Peak height velocity has been reported to be associated with the phenomenon of adolescent awkwardness, a temporary disruption in motor skills, and an increase in injuries in some adolescents. To date, it is not entirely clear which motor abilities are deficient during the phase of rapid growth.

RESEARCH QUESTION

We hypothesized that static as well as dynamic postural control is influenced by biological maturation.

METHODS

The study was conducted in a prospective, cross-sectional design. Maturity offset, a somatic indicator for biological maturation was captured for n = 99 male soccer players (13.7 ± 0.5 years). Static and dynamic balance were assessed by the Balance Error Scoring System (BESS) and the Y-Balance Test (YBT), respectively. Influences of biological maturation on balance performances have been analyzed by linear mixed models.

RESULTS

Linear mixed model analyses revealed that biological maturation is significantly associated with the total BESS score (p = 0.022, b = 2.195) as well as the YBT anterior (right leg: p = 0.023, b = -0.022; left leg: p = 0.015, b = -0.024) and posteromedial reach directions (left leg: p = 0.02, b = -0.029). No significant associations were found for the other YBT distances.

SIGNIFICANCE

Based on our results, maturation seems to have a considerable influence on postural control. It might be that deficits in balance performance contribute to the phenomenon of adolescent awkwardness and therefore lead to an increased injury risk during the adolescent growth spurt. To possibly prevent injuries in youth soccer, biological maturation should be taken into consideration in youth sport coaching.

The effect of cervical spine subtypes on center of pressure parameters in a large asymptomatic young adult population

BACKGROUND

Recent research highlighted that non-lordotic subtypes are common within an asymptomatic population of young adults. The potential mechanisms responsible for the decreased postural control witnessed in healthy participants exhibiting non-lordotic cervical alignment are unclear.

RESEARCH QUESTION

Therefore, the aim of this study is to compare and contrast asymptomatic radiographically derived sagittal cervical alignment subtypes with Center of Pressure (CoP) parameters.

METHODS

In this cross-sectional study strict asymptomatic inclusion criteria were met by 150 of the original 182 volunteers. All radiographs were assessed using a multi-method subtype system with participants classified into lordotic and non-lordotic groups. Participants performed 90s narrow stance trials with their eyes closed whilst standing on both a firm surface (FS) and compliant surface (CS) (3 trials per surface). CoP parameters were recorded from a force platform sampling at 100 Hz. Nonparametric statistical tests were conducted to assess differences between groups for each surface type and to determine differences in CoP parameters between FS and CS types.

RESULTS

Significant differences were found between groups on both surfaces for the anterior to posterior range (FS: p = 0.013; CS: p = 0.023), total excursion (FS: p = 0.029; CS: p = 0.005) and mean velocity of total excursion (FS: p = 0.032; CS: p = 0.004).

SIGNIFICANCE

Our data suggest that sagittal plane cervical alignment is a measure capable of distinguishing between the postural control of asymptomatic lordotic and non-lordotic young adult participants on both surfaces types. Furthermore, decreased postural control is present in asymptomatic participants across all non-lordotic subtypes and is not isolated exclusively to those with forward head posture. Consequently, future research endeavours should investigate the clinical significance of these non-lordotic findings in relation to both the potential for early cervical osseous degeneration and the transitional stages of non-specific pain sufferers from previously asymptomatic young adults.

Kinesio Taping Improves Perceptions of Pain and Function of Patients With Knee Osteoarthritis: A Randomized, Controlled Trial

Context: Although increasingly used for therapeutic treatment, only limited evidence exists regarding the effects of kinesio taping on patients with knee osteoarthritis (OA). Objective: To determine the effects of kinesio taping on pain, function, gait, and neuromuscular control concerning patients with knee OA. Design: Randomized sham-controlled trial. Setting: University laboratory. Participants: A total of 141 patients (65.1 [7.0] y) with a clinical and radiographic diagnosis of knee OA. Intervention: Kinesio tape, sham tape, or no tape for 3 consecutive days. Main Outcome Measures: Self-reported pain, stiffness, and function were measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Further tests included the Balance Error Scoring System, 10-m walk test, the maximum voluntary isometric contraction force of the quadriceps femoris, and knee active range of motion. Results: At baseline, there were no differences in all outcomes between groups except for knee flexion. Significant effects were found for WOMAC pain (tape vs sham, P = .05; tape vs control, P = .047), stiffness (tape vs sham, P = .01; tape vs control, P ≤ .001), and physical function (tape vs sham, P = .03; tape vs control P = .004). No interactions were found for balance, muscle strength, walking speed, or active range of motion. Conclusion: Wearing kinesio tape for 3 consecutive days had beneficial effects regarding self-reported clinical outcomes of pain, joint stiffness, and function. This emphasizes that kinesio taping might be an adequate conservative treatment for the symptoms of knee OA.

Fat-Free Mass and the Balance Error Scoring System Predict an Appropriate Maximal Load in the Unilateral Farmer's Walk

This study quantified and compared unilateral farmer’s walk (UFW) performance in recreationally active males and females, and determined if additional variables allowed for the prediction of a maximal safe load. Anthropometric (height, body weight (BW), body mass index, body fat percentage, fat-free mass (FFM), and fat mass), muscular endurance (maximal duration side bridge), and balance (Balance Error Scoring System (BESS)) tests were completed. Participants performed a series of 20 s UFW trials (non-dominant side) at a cadence of 66 beats/min. The initial load was 10% of BW and increased by 10% per trial until deviations in spinal alignment or compromised gait patterns were noted, and the series was terminated. The highest load carried before technical failure was recorded. Descriptive and comparative statistics and a stepwise linear regression analysis were utilized to determine relationships between UFW performance and anthropometric, muscular endurance, and balance tests. Males (N = 25) were significantly taller (177.3 ± 6.7 vs. 164.7 ± 7.2 cm, p < 0.05), heavier (81.7 ± 7.0 vs. 62.0 ± 9.4 kg, p < 0.05), and leaner (14.4 ± 4.4 vs. 22.4 ± 4.8%, p < 0.05) than females (N = 26). Further, males had a higher amount of FFM (p < 0.05) than females. The males (52.2 ± 9.0, 64% BW) carried a higher average UFW load than the females (32.5 ± 7.1 kg, 53% BW, p < 0.05). FFM was strongly predictive of UFW load (load = −9.88876 + 0.88679 × (FFM); r² = 0.774, p < 0.0001). The addition of the BESS test further increased the accuracy of the prediction equation (r² = 0.800, p < 0.0001). There are differences in UFW performance ability between males and females. As our method does not account for all potential confounding variables, the use of these equations should be combined with technique analysis and participant feedback to ensure an appropriate workload.

Reference values for the Balance Error Scoring System as measured by the Tekscan MobileMat™ in a physically active population

OBJECTIVES

The Balance Error Scoring System (BESS) is commonly used to measure postural stability; however, it has demonstrated inconsistent reliability values when administered by humans. The Tekscan MobileMat™ was developed to automate the assessment of BESS errors and eliminate rater subjectivity. The objective of this study was to report reference values for the BESS, as measured by the MobileMat™, and examine the effect of sex, concussion history, and competitive sport level on BESS performance.

METHODS

Four hundred and forty participants performed the BESS on the MobileMat™. Participants were asked to maintain each stance with their eyes closed for 20 s. The MobileMat™ was used to quantify the number of errors.

RESULTS

Concussion history (p = 0.279-0.979) and competitive sport level (p = 0.422-0.979) did not affect BESS performance. Males performed significantly better than females for the single-limb foam stance (p = 0.032). No sex differences were detected for the other BESS stances or BESS total score (p = 0.067-0.744).

CONCLUSIONS

Previously reported reference values in collegiate athletes and adolescents were slightly higher thus highlighting the value in establishing population norms and in developing new technologies to objectively quantify BESS performance. Furthermore, sex, concussion history, and competitive sport level do not appear to influence BESS performance as measured by the MobileMat™.

Influence of rearfoot alignment on static and dynamic postural stability

Background/Aims:

It has been postulated that foot alignment affects postural stability. However, previous studies reported contradicting results regarding the association between foot alignment and postural stability.

Methods:

A total of 216 healthy participants aged 15 to 24 years were recruited. Their rearfoot alignment was measured in non-weight bearing and weight-bearing positions. Their static balance was assessed using Balance Error Scoring System and dynamic balance by Star Excursion Balance Test. The relationship between the data obtained were analysed using SPSS version 22 software.

Findings:

A Pearson correlation with a 95% confidence interval reported that there was: (i) no significant difference in the rearfoot alignment between both genders; (ii) no significant relationship between the rearfoot alignment measured in prone lying and unilateral stance position; (iii) a weak negative correlation between the rearfoot alignment measured in prone lying position to dynamic balance on medial, posterior, lateral, anterolateral and posteromedial direction; (iv) no significant relationship between the rearfoot alignment measured in unilateral stance position to both static and dynamic postural balance.

Conclusions:

Rearfoot alignment measured in non-weight bearing position plays some role in postural stability and therefore should be considered in sports rehabilitation. However, this can be overlooked in rehabilitation for individuals whose postural stability is not the primary concern.

COMPARISON OF CORE STABILITY AND BALANCE IN ATHLETES WITH AND WITHOUT SHOULDER INJURIES

BACKGROUND

Relationships between core stability and lower extremity injuries have been described in the literature; however, evidence of the relationship between upper extremity injuries and core stability and balance is limited.

HYPOTHESIS/PURPOSE

The purpose of this study was to compare clinical measures of core stability and balance between athletes with and without non-traumatic shoulder injuries.

STUDY DESIGN

Cross sectional.

METHODS

Eighty athletes (54 males, age: 21.2 + 3.3 years) participated in this study. Forty athletes with a current shoulder injury were matched to healthy athletes by age, gender, BMI, and sport. Athletes completed clinical core stability tests including flexor and extensor endurance tests, double leg lower test (°) and balance tests including single leg stance under eyes open and eyes closed conditions, and the Y-balance test. MANOVAs were used to assess group differences.

RESULTS

No statistically significant differences existed between athletes with and without shoulder injuries for clinical tests of core stability, F(1,78)=0.97, p=0.41; η2 = 0.04. No statistically significant differences existed between injured athletes with and without shoulder injuries for static and dynamic balance measures, F(1,78)=0.86, p=0.53; η2 = 0.07.

CONCLUSIONS

Although core stability is widely incorporated in rehabilitation of athletes with shoulder injuries, performance on these clinical tests did not differ in the group of athletes assessed in this study.

LEVEL OF EVIDENCE

3.

Neuromuscular Control Deficits and the Risk of Subsequent Injury after a Concussion: A Scoping Review

An emerging area of research has identified that an increased risk of musculoskeletal injury may exist upon returning to sports after a sport-related concussion. The mechanisms underlying this recently discovered phenomenon, however, remain unknown. One theorized reason for this increased injury risk includes residual neuromuscular control deficits that remain impaired despite clinical recovery. Thus, the objectives of this review were: (1) to summarize the literature examining the relationship between concussion and risk of subsequent injury and (2) to summarize the literature for one mechanism with a theorized association with this increased injury risk, i.e., neuromuscular control deficits observed during gait after concussion under dual-task conditions. Two separate reviews were conducted consistent with both specified objectives. Studies published before 9 December, 2016 were identified using PubMed, Web of Science, and Academic Search Premier (EBSCOhost). Inclusion for the objective 1 search included dependent variables of quantitative measurements of musculoskeletal injury after concussion. Inclusion criteria for the objective 2 search included dependent variables pertaining to gait, dynamic balance control, and dual-task function. A total of 32 studies were included in the two reviews (objective 1 n = 10, objective 2 n = 22). According to a variety of study designs, athletes appear to have an increased risk of sustaining a musculoskeletal injury following a concussion. Furthermore, dual-task neuromuscular control deficits may continue to exist after patients report resolution of concussion symptoms, or perform normally on other clinical concussion tests. Therefore, musculoskeletal injury risk appears to increase following a concussion and persistent motor system and attentional deficits also seem to exist after a concussion. While not yet experimentally tested, these motor system and attentional deficits may contribute to the risk of sustaining a musculoskeletal injury upon returning to full athletic participation.

Identifying Persistent Postconcussion Symptom Risk in a Pediatric Sports Medicine Clinic

BACKGROUND

Although most children report symptom resolution within a month of a concussion, some patients experience persistent postconcussion symptoms (PPCS) that continues for more than 1 month. Identifying patients at risk for PPCS soon after an injury can provide useful clinical information.

PURPOSE

To determine if the Predicting Persistent Post-concussive Problems in Pediatrics (5P) clinical risk score, an emergency department (ED)-derived and validated tool, is associated with developing PPCS when obtained in a primary care sports concussion setting.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We conducted a study of patients seen at a pediatric sports medicine concussion clinic between May 1, 2013, and October 1, 2017, who were <19 years of age and evaluated within 10 days of a concussion. The main outcome was PPCS, defined as symptoms lasting >28 days. Nine variables were used to calculate the 5P clinical risk score, and we assessed the association between the 5P clinical risk score and PPCS occurrence. The secondary outcome was total symptom duration.

RESULTS

We examined data from 230 children (mean age, 14.8 ± 2.5 years; 50% female; mean time from injury to clinical assessment, 5.6 ± 2.7 days). In univariable analyses, a greater proportion of those who developed PPCS reported feeling slowed down (72% vs 44%, respectively; P < .001), headache (94% vs 72%, respectively; P < .001), sensitivity to noise (71% vs 43%, respectively; P < .001), and fatigue (82% vs 51%, respectively; P < .001) and committed ≥4 errors in tandem stance (33% vs 7%, respectively; P < .001) than those who did not. Higher 5P clinical risk scores were associated with increased odds of developing PPCS (adjusted odds ratio [OR], 1.62 [95% CI, 1.30-2.02]) and longer symptom resolution times (β = 8.40 [95% CI, 3.25-13.50]). Among the individual participants who received a high 5P clinical risk score (9-12), the majority (82%) went on to experience PPCS. The area under the curve for the 5P clinical risk score was 0.75 (95% CI, 0.66-0.84). After adjusting for the effect of covariates, fatigue (adjusted OR, 2.93) and ≥4 errors in tandem stance (adjusted OR, 7.40) were independently associated with PPCS.

CONCLUSION

Our findings extend the potential use for an ED-derived clinical risk score for predicting the PPCS risk into the sports concussion clinic setting. While not all 9 predictor variables of the 5P clinical risk score were independently associated with the PPCS risk in univariable or multivariable analyses, the combination of factors used to calculate the 5P clinical risk score was significantly associated with the odds of developing PPCS. Thus, obtaining clinically pragmatic risk scores soon after a concussion may be useful for early treatments or interventions to mitigate the PPCS risk.

Effects of Kinesiology Tape on Non-linear Center of Mass Dispersion During the Y Balance Test

Static taping of the ankle or knee joint is a common method of reducing risk of injury by providing mechanical stability. An alternative taping technique employs kinesiology tape, which has the additional benefit of improving functionality by stimulating proprioception. There is substantial disagreement whether kinesiology tape shows significant differences in proprioception and postural stability as compared to rigid/static tape when applied at the lower limb. The current study investigated the effects of kinesiology tape and static tape during a Y Balance Test on center of mass as an indicator for postural stability. Forty-one individuals, free of injury, performed the Y Balance Test under the three conditions; no tape, kinesiology tape, and static tape applied at the lower limb to the quadriceps, triceps surae and ankle joint. All participants completed the Y Balance Test to determine whether any significant differences could be observed using center of mass movement as a surrogate measure for balance and proprioception. The Minkowski-Bouligand and box-counting fractal dimension analyses were used as measures of the dynamic changes in the center of mass whilst undertaking the Y Balance Test. Statistical analyses included the Kruskal Wallis test to allow for non-normally distributed data and a Bonferroni corrected pairwise T-test as a post hoc test to ascertain pairwise differences between the three taping conditions. Significance was set at 0.05. The fractal analyses of the dynamic changes in center of mass showed significant differences between the control and both the static tape and kinesiology tape groups (p = 0.021 and 0.009, respectively). The current study developed a novel measure of dynamic changes in the center of mass during a set movement that indicated real-time processing effects during a balance task associated with the type of taping used to enhance postural stability.

No change in plasma tau and serum neurofilament light concentrations in adolescent athletes following sport-related concussion

Sport-related concussion (SRC), a mild form of traumatic brain injury (TBI), is a common injury in contact sports. Health care professionals rely on subjective criteria (e.g., symptoms), as there is no objective marker for identification of athletes with SRC. Blood-based biomarkers have shown promise as diagnostic and prognostic tools following TBI and SRC. In the present study, we examined plasma tau and serum NF-L, two biomarkers for neuronal/axonal injury, concentrations at preseason and following SRC in contact sport athletes (n = 11) using ultrasensitive single molecule array (Simoa) assays. Preseason baseline samples were collected, and post-concussion samples were obtained at 6- and 14-days following injury. We found no difference between baseline, 6-day and 14-day post-concussion concentrations of tau (p = 0.14) or NF-L (p = 0.53). Further, no difference was found between preseason baseline and all post-SRC samples for tau (p = 0.22) or NF-L (p = 0.98). The total number of symptoms reported on the Standardized Assessment of Concussion– 3^rd Edition (SCAT3) and associated symptom severity scores increased from preseason to 6-days post-SRC but returned to baseline values at 14-days (p = 0.02 and p = 0.003, respectively). These results suggest that the severity of neuronal injury in this cohort of contact sport athletes with clinical uncomplicated SRC was too low to be detected by tau and NF-L measurements in blood samples obtained at 6- and 14-days post-injury.

Clinical Findings in a Multicenter MRI Study of Mild TBI

Background: Uncertainty continues to surround mild traumatic brain injury (mTBI) diagnosis, symptoms, prognosis, and outcome due in part to a lack of objective biomarkers of injury and recovery. As mTBI gains recognition as a serious public health epidemic, there is need to identify risk factors, diagnostic tools, and imaging biomarkers to help guide diagnosis and management. Methods: One hundred and eleven patients (15-50 years old) were enrolled acutely after mTBI and followed with up to four standardized serial assessments over 3 months. Each encounter included a clinical exam, neuropsychological assessment, and magnetic resonance imaging (MRI). Chi-square and linear mixed models were used to assess changes over time and determine potential biomarkers of mTBI severity and outcome. Results: The symptoms most frequently endorsed after mTBI were headache (91%), not feeling right (89%), fatigue (86%), and feeling slowed down (84%). Of the 104 mTBI patients with a processed MRI scan, 28 (27%) subjects had white matter changes which were deemed unrelated to age, and 26 of these findings were deemed unrelated to acute trauma. Of the neuropsychological assessments tested, 5- and 6-Digit Backward Recall, the modified Balance Error Scoring System (BESS), and Immediate 5-Word Recall significantly improved longitudinally in mTBI subjects and differentiated between mTBI subjects and controls. Female sex was found to increase symptom severity scores (SSS) at every time point. Age ≥ 25 years was correlated with increased SSS. Subjects aged ≥ 25 also did not improve longitudinally on 5-Digit Backward Recall, Immediate 5-Word Recall, or Single-Leg Stance of the BESS, whereas subjects < 25 years improved significantly. Patients who reported personal history of depression, anxiety, or other psychiatric disorder had higher SSS at each time point. Conclusions: The results of this study show that 5- and 6-Digit Backward Recall, the modified BESS, and Immediate 5-Word Recall should be considered useful in demonstrating cognitive and vestibular improvement during the mTBI recovery process. Clinicians should take female sex, older age, and history of psychiatric disorder into account when managing mTBI patients. Further study is necessary to determine the true prevalence of white matter changes in people with mTBI.

Stochastic Resonance Training Improves Balance and Musculoskeletal Well-Being in Office Workers: A Controlled Preventive Intervention Study

Sixty-two office workers in a Swiss federal department were randomly assigned to a training and a control group. While the training group was instructed to complete 3 stochastic resonance whole-body vibration (SR-WBV) exercises every week for 4 weeks, the control group received no treatment. During this time all participants answered a daily questionnaire concerning their surefootedness, sense of balance, musculoskeletal well-being, and muscle relaxation. Before and after the 4-week SR-WBV intervention, balance was tested with a single-leg stance on a foam mat of the Balance Error Scoring System (BESS) using a SwayStar™-System measuring Total Angle Area (TotAngArea) and Total Velocity Area (TotVelArea). Multilevel results highlighted a significant increase over time for surefootedness and sense of balance (t = 2.491, p = .016), as well as for musculoskeletal well-being and muscle relaxation (t = 2.538, p = .014) in the training group but not in the control group. Balance tests showed improvement of balance in the training group (TotAngArea: Z = 2.550, p = .011; TotVelArea: Z = 3.334, p = .001) but not in the control group. SR-WBV exercise indicated a high compliance during this study (3.87±0.45 trainings per week) underlining its benefits for the working context. Especially office workers who spend most of their time in sitting position could profit from SR-WBV exercise to improve balance and reduce the risk of falls.

Using sideline concussion tests in the emergency department

Purpose

Traumatic brain injury (TBI) is a significant cause of death and disability in the United States. Many patients with TBI are initially treated in the emergency department (ED), but there is no evidence-based method of detecting or grading TBI in patients who have normal structural neuroimaging. This study aims to evaluate the validity of two common sideline concussion tests. The Concussion Symptom Severity Score (CSSS) and modified Balance Error Scoring System (mBESS) tests are well-validated sideline tests for concussion, but have not been validated in the setting of non-sport-related concussion, in settings other than the sideline or athletic training room or in moderate or severe TBI.

Patients and methods

One hundred forty-eight subjects who had sustained a TBI within the previous 72 hours and 53 healthy control subjects were enrolled. CSSS and mBESS were administered. Clinical outcomes were followed up prospectively.

Results

The CSSS was collected in 147 TBI subjects but only 51 TBI subjects were able to complete the mBESS. The CSSS was collected for all 53 control subjects, and the mBESS was completed for 51 control subjects. The mean CSSS for TBI and control subjects was 32.25 and 2.70, respectively (P < 0.001). The average mBESS for TBI and control subjects was 7.43 and 7.20, respectively (P = 0.82). CSSS greater than 5.17 was 93.43% sensitive and 69.84% specific for TBI.

Conclusion

The mBESS is poorly tolerated and, among those who can complete the test, not sensitive to TBI in the ED. The CSSS is both sensitive to TBI and well tolerated.

Perceptual-cognitive three-dimensional multiple-object tracking task can help the monitoring of sport-related concussion

Objectives

While the rate of sport-related concussion is increasing, more effective tools are needed to help monitor the diagnosis and return to play of athletes. The three-dimensional multiple-object tracking (3D-MOT) exercise is a perceptual-cognitive task that has shown predictive power towards the dynamic requirements of real-world activities such as sport. This study introduced the use of the 3D-MOT task, along with the Standardized Assessment of Concussion (SAC) and Modified Balance Error Scoring System (M-BESS) tests, for diagnosis and return to play in professional sports.

Methods

Fifty-nine professional athletes were tested with the 3D-MOT, SAC and M-BESS tests at 48 hours following the injury. The same measures were employed to evaluate the return to play following the standard concussion management protocol. The SAC and M-BESS tests were also performed in pre-season (baseline) in 32 out of the 59 athletes.

Results

The injured athletes exhibited poor performance on 3D-MOT at 48 hours post injury compared with return to play (p<0.001) as well as compared with healthy professionals' performance scores (p<0.001). Importantly, learning rate, which participants are thought to have an expert advantage on this perceptual-cognitive task, was totally disrupted at 48 hours post injury compared with healthy professionals (p<0.001). The 3D-MOT performance was also correlated to the total number of symptoms (p=0.020), SAC (p=0.031) and M-BESS (p=0.004) scores at 48 hours. Not surprisingly, SAC and M-BESS tests' usefulness for monitoring concussion was found to be weak, particularly when test performance following the injury was compared to baseline (p=0.056 and 0.349 for SAC and M-BESS, respectively).

Conclusion

3D-MOT could help monitor sport-related concussion in professional athletes. The discussion also covers the critical importance of perceptual-cognitive assessment following concussion in the athletic population.

Effects of barefoot and footwear conditions on learning of a dynamic balance task: a randomized controlled study

PURPOSE

Although barefoot balancing has shown to be more challenging compared to shod balancing, it is still unclear whether this may also influence the balance learning effects. The purpose of this study was to explore the impact of barefoot and shod exercising on learning of a dynamic balance task.

METHODS

Sixty healthy and physically active adults (mean age 25.3 ± 3.4 years) were randomly allocated into one of three groups (barefoot, shod and controls). The barefoot and shod intervention groups exercised once weekly over 7 weeks on a stability platform with an unstable surface. Each training session included 15 trials over 30 s. Before and after the intervention period, all participants completed two balance tests (stability platform and Balance Error Scoring System = BESS) under barefoot and shod conditions. Group effects in stability gains (pre to post-test differences) were analysed using ANOVA. Development of balance learning curves during the intervention period was analysed using a mixed effects model.

RESULTS

Balance times improved in both intervention groups (p < 0.001, 95% CI barefoot 5.82-9.22 s, shod 7.51-10.92 s) compared to controls. The barefoot intervention group showed a significantly less sloped balance learning curve compared to the shod intervention group (p = 0.033). No changes over time or differences between groups were found for the BESS test.

CONCLUSIONS

Improvements in the dynamic balance task did not differ between individuals exercising barefoot or with footwear although the progression was slower in the barefoot group. The lack of changes in the BESS supports the task-specificity of balance learning effects.

TEST-RETEST RELIABILITY OF THE LIMITS OF STABILITY TEST PERFORMED BY YOUNG ADULTS USING NEUROCOM® VSR SPORT

BACKGROUND

A reliable measure of dynamic postural control is needed for inclusion in the sports-related concussion assessment battery. Currently, there is not a clinical gold standard. The Limits of Stability (LOS) test has potential to be a useful tool to collect objective data on important dynamic postural stability variables. Psychometric properties of the LOS test with healthy young adults are yet to be established.

HYPOTHESIS/PURPOSE

The purpose of this study was to examine the intra-session and test-retest reliability for the LOS on the NeuroCom® VSR Sport when performed by young adults.

STUDY DESIGN

Reliability study.

METHODS

Twenty-seven healthy university students completed four trials of the LOS in each of two testing sessions one week apart. Relative reliability was measured within each session with an intraclass correlation coefficient (ICC[3,k]) for Session 1 and Session 2, respectively, on each of the five dependent variables (movement velocity [MVL], directional control [DCL], maximum excursion [MXE], endpoint excursion [EPE], and reaction time [RT]) provided by the Neurocom. Test-retest reliability was assessed using a repeated-measures analysis of variance along with an ICC (3,k) for relative reliability. An ICC value of 0.90 or higher was defined as having a high reliability, moderate reliability for ICC values between 0.80-0.89, and below 0.80 as questionable.

RESULTS

The reliability within each session for LOS composite scores for MVL, DCL, and MXE was moderate to high (ICC[3,k]=0.89-0.95). These same three variables also had high levels of test-retest reliability (ICC[3,k]=0.95-0.96). EPE and RT had moderate reliability over time (ICC[3,k]=0.88) but differences for within session reliability.

CONCLUSIONS

LOS provides a reliable measure of dynamic postural control for young adults. Two trials are recommended at baseline with the first being an adaptation trial to ensure accuracy of findings. Care needs to be taken when interpreting EPE and DCL scores on post-injury tests due to a learning effect for those variables.

LEVEL OF EVIDENCE

2c.

Balance- and Strength-Training Protocols to Improve Chronic Ankle Instability Deficits, Part I: Assessing Clinical Outcome Measures

CONTEXT

  Functional rehabilitation may improve the deficits associated with chronic ankle instability (CAI).

OBJECTIVE

  To determine if balance- and strength-training protocols improve the balance, strength, and functional performance deficits associated with CAI.

DESIGN

  Randomized controlled clinical trial.

SETTING

  Athletic training research laboratory.

PATIENTS OR OTHER PARTICIPANTS

  Participants were 39 volunteers with CAI, which was determined using the Identification of Functional Ankle Instability Questionnaire. They were randomly assigned to 1 of 3 groups: balance-training protocol (7 males, 6 females; age = 23.5 ± 6.5 years, height = 175.0 ± 8.5 cm, mass = 72.8 ± 10.9 kg), strength-training protocol (8 males, 5 females; age = 24.6 ± 7.7 years, height = 173.2 ± 9.0 cm, mass = 76.0 ± 16.2 kg), or control (6 males, 7 females; age = 24.8 ± 9.0 years, height = 175.5 ± 8.4 cm, mass = 79.1 ± 16.8 kg).

INTERVENTION(S)

  Each group participated in a 20-minute session, 3 times per week, for 6 weeks. The control group completed a mild to moderately strenuous bicycle workout.

MAIN OUTCOME MEASURE(S)

  Participants completed baseline testing of eccentric and concentric isokinetic strength in each ankle direction (inversion, eversion, plantar flexion, and dorsiflexion) and the Balance Error Scoring System (BESS), Star Excursion Balance Test (SEBT), and side-hop functional performance test. The same variables were tested again at 6 weeks after the intervention. Two multivariate repeated-measures analyses of variance with follow-up univariate analyses were conducted. The α level was set a priori at .05.

RESULTS

  We observed time-by-group interactions in concentric ( P = .02) and eccentric ( P = .01) inversion, eccentric eversion ( P = .01), concentric ( P = .001) and eccentric ( P = .03) plantar flexion, BESS ( P = .01), SEBT ( P = .02), and side hop ( P = .004). With pairwise comparisons, we found improvements in the balance- and strength-training protocol groups in concentric and eccentric inversion and concentric and eccentric plantar flexion and the BESS, SEBT, and side hop (all P values = .001). Only the strength-training protocol group improved in eccentric eversion. The control group did not improve in any dependent variable.

CONCLUSIONS

  Both training protocols improved strength, balance, and functional performance. More clinicians should incorporate hop-to-stabilization exercises into their rehabilitation protocols to improve the deficits associated with CAI.

Motion analysis evaluation of adolescent athletes during dual-task walking following a concussion: A multicenter study

BACKGROUND

Research suggests that dynamic balance in adolescents is compromised following concussion and may worsen if patients return to sport (RTS) too soon. Understanding if there are ongoing dynamic balance deficits in adolescents at the time of RTS clearance would determine if more complex motor tasks are necessary to facilitate safe RTS decisions.

RESEARCH QUESTION

The purpose of this study was to determine if there were remaining dynamic balance deficits in concussed adolescents at the time of clearance for RTS.

METHODS

Sixteen concussed adolescent athletes (age 14.6 ± 1.8 years; 9 males; 57 ± 46 days post injury) performed a simple walking task as well as two split attention gait tasks (reciting months backwards and audio Stroop). The center of mass (COM) movement and walking velocity during these tasks was compared to a control group of 15 healthy non-concussed adolescent athletes (age 13.8 ± 1.4 years; 9 male).

RESULTS

The results indicated that there were no statistically significant differences between the two groups for any of the tasks. Height-normalized walking speed did not differ between groups during walking alone (control: 0.757 ± 0.119, concussed: 0.739 ± 0.108, p = 0.34), with the recitation task (control: 0.555 ± 0.095, concussed: 0.557 ± 0.143, p = 0.72), or with the Stroop task (control: 0.589 ± 0.129, concussed: 0.567 ± 0.141, p = 0.43). Similarly, height-normalized medial-lateral COM displacement did not differ between groups during walking alone (control: 0.027 ± 0.007, concussed: 0.028 ± 0.007, p = 0.98, with the recitation task (control: 0.037 ± 0.012, concussed: 0.0.037 ± 0.016, p = 0.82), or with the Stroop task (control: 0.032 ± 0.014, concussed: 0.033 ± 0.009, p = 0.891).

SIGNIFICANCE

These findings indicate that the patients were returned to sport when their dynamic balance was similar to controls suggesting that this cohort had recovered from their concussion. However, large variability in dynamic balance measures in both the patient and control groups may reflect ongoing neuromuscular development and requires further exploration.

Is There a Relationship Between the Functional Movement Screen, Star Excursion Balance Test, and Balance Error Scoring System?

OBJECTIVE

To evaluate associations between the Functional Movement Screen (FMS), Star Excursion Balance Test (SEBT), and Balance Error Scoring System (BESS) scores.

DESIGN

Correlational.

SETTING

College athletic training facilities.

PARTICIPANTS

Fifty-two intercollegiate athletes (men = 36 and women = 16) representing 8 sports and cleared for unrestricted sport participation.

INTERVENTIONS

Participants completed the FMS, SEBT, and BESS, in random order, during 1 testing session. Testing order was randomized to control for fatigue and learning effects.

MAIN OUTCOME MEASURES

Composite and item scores for the FMS, SEBT, and BESS.

RESULTS

A fair, negative correlation was found between FMS asymmetry and SEBT composite (r = -0.31, P = 0.03) scores. Fair, positive correlations were reported for FMS rotary stability task and SEBT anterior (r = 0.37-0.41, P ≤ 0.007) and posteromedial (r = 0.31, P = 0.03) reaches. Fair, negative correlations were reported for FMS deep squat and BESS single-leg firm (r = -0.33, P = 0.02), double-leg foam (r = -0.34, P = 0.02) and tandem foam (r = -0.40, P = 0.003), FMS inline lunge and BESS single-leg firm (r = -0.39, P = 0.004), FMS trunk stability pushup and tandem foam (r = -0.31, P = 0.025), and FMS composite and BESS single-leg firm (r = -0.37, P = 0.007). Little-to-no correlations were reported for remaining comparisons.

CONCLUSIONS

Results indicate that each instrument provides distinct information about function, with only small areas of overlap. Associations between the FMS asymmetry score and SEBT composite score may indicate a relationship between movement asymmetry and postural stability. Associations between the FMS deep squat and BESS foam tasks may be related to underlying neuromuscular control factors.

The role of subconcussive impacts on sway velocities in Division I men's lacrosse players

Head impacts resulting in a concussion negatively affect the vestibular system, but little is known about the effect of subconcussive impacts on this system. This study's objective was to determine if subconcussive head impacts sustained over one competitive lacrosse season, effect sway velocity. Healthy Division I male lacrosse players (n = 33; aged 19.52 ± 1.20 years) wore instrumented helmets to track head impact exposures. At the beginning and end of the season the players completed an instrumented Balance Error Scoring System assessment to assess sway velocity. Score differentials were correlated to the head impact exposure data collected via instrumented helmets when averaged within participant. Paired samples t-tests revealed a post-season increase in sway velocity on the double leg stance, firm surface (p = 0.002, d = 0.59); tandem stance, firm surface (p = 0.033, d = 0.39) and double leg, foam surface (p = 0.014, d = 0.45) A significant correlation was found between change in tandem stance, firm surface sway velocities and linear acceleration (p < 0.001, r = 0.65). It appears subconcussive impacts may result in tandem stance balance deficits. Repetitive head impacts may negatively affect sway velocity, even in the absence of a diagnosed concussion injury.

A Preliminary Report on Brain-Derived Extracellular Vesicle as Novel Blood Biomarkers for Sport-Related Concussions

The purpose of the study was to test the utility of unique panel of blood biomarkers as a means to reflect one’s recovery process after sport-related neurotrauma. We established a panel of biomarkers that reacted positive with CD81 (extracellular vesicle marker) and various neuron- and glia-specific antigens [e.g., neurofilament light polypeptide (NF-L), tau, synaptosome-associated protein 25 (SNAP25), glial fibrillary acidic protein, and myelin basic protein]. We first evaluated test–retest reliabilities of brain-derived exosome markers, followed by an application of these markers in eight professional ice hockey players to detect cumulative neuronal burden from a single ice hockey season. During the season, two players were diagnosed with concussions by team physician based on an exhibition of symptoms as well as abnormality in balance and ocular motor testing. One player reached symptom-free status 7 days after the concussion, while the other player required 36 days for symptoms to completely resolve. Blood samples and clinical assessments including balance error scoring system and near point of convergence throughout recovery process were obtained. Biomarkers indicative of axonal damage, neuronal inflammation, and glial activation showed excellent test–retest reliabilities (intraclass correlation coefficient: 0.713–0.998, p’s < 0.01). There was a statistically significant increase in the NF-L marker at post-season follow-up compared to pre-season baseline (Z = −2.100, P = 0.036); however the statistical significance did not withstand Bonferroni correction for multiple comparisons. In concussion cases, neuronal and microglia markers notably increased after concussions, with the unique expression patterns being similar to that of concussion recovery process. These longitudinal data coupled with excellent test–retest reliabilities of novel array of blood biomarkers potentially reflect the damage in neural cell structures and metabolic crisis due to concussion. However, future studies with larger sample size and appropriate control groups to evaluate sensitivity and specificity of these markers are needed. This preliminary case report suggests the potential utility of multimodal blood biomarkers for concussion prognosis and recovery assessment.

ASSESSING STATIC AND DYNAMIC POSTURAL CONTROL IN A HEALTHY POPULATION

Static postural control testing is often conducted by clinicians and athletic trainers for use with athletes who have sustained a concussion. Dynamic postural control involves the body's response to perturbation of the center of mass and may offer additional insight that static testing cannot capture. The objective of this study was to assess the reliability and feasibility of a balance protocol consisting of both static and dynamic postural control assessments with a healthy, adult population. Subjects stood in both unipedal and bipedal stances on a force plate to capture quantitative data regarding the center of pressure over time. Further, subjects completed the Balance Error Scoring System (BESS), a static measure, and a modified version of the Star Excursion Balance Test (SEBT), a dynamic measure. Reliability with the BESS was limited, while moderate to strong reliability was obtained for the modified SEBT. Unipedal stances were associated with a greater variance than bipedal stances for both the BESS and force plate protocol. These assessments will be applied within a pediatric populations to determine the validity of their use. Further postural control research is necessary to determine the most viable assessments for use within an active, pediatric population.

EFFECTS OF A SEASON OF YOUTH FOOTBALL ON STATIC POSTURAL CONTROL

Concussions occur in youth football with lower frequency than observed at higher levels of play, though the effect of repetitive subconcussive head impacts resulting from participation in youth football is unknown at this point. One measure shown to be affected by concussions is athlete postural control. The objective of this study was to compare performance on the Balance Error Scoring System (BESS) and a force plate protocol at two time points within a cohort of healthy youth football players and healthy non-contact youth track or baseball athletes. In absence of a clinically-diagnosed concussion, the hypothesis was tested that a season of youth football would affect measures of static postural control and stability. Between time points, there were no significant differences observed between either BESS scores or force plate metrics. Between athlete groups, there were no significant differences observed for either the BESS or the force plate protocol. Particularly for pediatric males, postural control is still developing and current assessments may not be sensitive enough to detect changes. Continued research is necessary to determine what postural control testing may be most viable for use within an active, pediatric population.

Postural Control and Head Impact Exposure in Youth Football Players: Comparison of the Balance Error Scoring System and a Force Plate Protocol

Postural control testing is often used by clinicians and athletic trainers to assess the health of athletes during recovery from a concussion. Characterization of postural control as a clinical tool for use with youth athletes is limited though. The objective of this study was to compare performance on the Balance Error Scoring System (BESS) and a force plate protocol at the beginning and end of a season of football within a cohort of 34 healthy youth football players (average age of 9.9 ± 0.6 y). A secondary aim was to investigate if changes in measures of balance from the postseason to the preseason were correlated with head impact exposure. Players completed testing at the beginning and end of the youth football season. There were no significant differences between BESS scores before the season and after the season (P = .54). Performance on the BESS was not associated with any of the center of pressure metrics considered in this study. No correlation was observed between measures of balance and head impact exposure for the season. Further research is required to determine the viability of postural control testing with this population.

Neurological Manifestations Among US Government Personnel Reporting Directional Audible and Sensory Phenomena in Havana, Cuba

IMPORTANCE

From late 2016 through August 2017, US government personnel serving on diplomatic assignment in Havana, Cuba, reported neurological symptoms associated with exposure to auditory and sensory phenomena.

OBJECTIVE

To describe the neurological manifestations that followed exposure to an unknown energy source associated with auditory and sensory phenomena.

DESIGN, SETTING, AND PARTICIPANTS

Preliminary results from a retrospective case series of US government personnel in Havana, Cuba. Following reported exposure to auditory and sensory phenomena in their homes or hotel rooms, the individuals reported a similar constellation of neurological symptoms resembling brain injury. These individuals were referred to an academic brain injury center for multidisciplinary evaluation and treatment.

EXPOSURES

Report of experiencing audible and sensory phenomena emanating from a distinct direction (directional phenomena) associated with an undetermined source, while serving on US government assignments in Havana, Cuba, since 2016.

MAIN OUTCOMES AND MEASURES

Descriptions of the exposures and symptoms were obtained from medical record review of multidisciplinary clinical interviews and examinations. Additional objective assessments included clinical tests of vestibular (dynamic and static balance, vestibulo-ocular reflex testing, caloric testing), oculomotor (measurement of convergence, saccadic, and smooth pursuit eye movements), cognitive (comprehensive neuropsychological battery), and audiometric (pure tone and speech audiometry) functioning. Neuroimaging was also obtained.

RESULTS

Of 24 individuals with suspected exposure identified by the US Department of State, 21 completed multidisciplinary evaluation an average of 203 days after exposure. Persistent symptoms (>3 months after exposure) were reported by these individuals including cognitive (n = 17, 81%), balance (n = 15, 71%), visual (n = 18, 86%), and auditory (n = 15, 68%) dysfunction, sleep impairment (n = 18, 86%), and headaches (n = 16, 76%). Objective findings included cognitive (n = 16, 76%), vestibular (n = 17, 81%), and oculomotor (n = 15, 71%) abnormalities. Moderate to severe sensorineural hearing loss was identified in 3 individuals. Pharmacologic intervention was required for persistent sleep dysfunction (n = 15, 71%) and headache (n = 12, 57%). Fourteen individuals (67%) were held from work at the time of multidisciplinary evaluation. Of those, 7 began graduated return to work with restrictions in place, home exercise programs, and higher-level work-focused cognitive rehabilitation.

CONCLUSIONS AND RELEVANCE

In this preliminary report of a retrospective case series, persistent cognitive, vestibular, and oculomotor dysfunction, as well as sleep impairment and headaches, were observed among US government personnel in Havana, Cuba, associated with reports of directional audible and/or sensory phenomena of unclear origin. These individuals appeared to have sustained injury to widespread brain networks without an associated history of head trauma.

Sub-concussive trauma, acute concussion, and history of multiple concussions: Effects on quiet stance postural control stability

Although balance control has been studied extensively following acute concussion, little is known regarding repetitive sub-concussive head impacts or chronic exposure to multiple concussive events. Quiet stance postural control was characterized in contact sport athletes at pre-season (n = 135) and post-season (n = 48) to evaluate the effects of subconcussive trauma to the head. To determine the impact of acute concussion on postural control, athletes diagnosed with a concussion during the season (n = 12) were tested at 72-h, 2-weeks, and 1-month post-injury. Because only 4 of the concussed athletes completed baseline testing, control athletes (n = 12) matched for sport, age, body mass index (BMI), and previous concussion history served as a comparison group. Finally, the effects of previous concussion history on quiet stance postural control were determined by comparing pre-season data in contact sport athletes with either zero (Hx⁰, n = 50) or three or more (Hx³⁺, n = 25) previous concussions. A force plate was used to compare changes in centre-of-pressure root-mean-square displacement (RMSdisp) and mean-velocity (COPvel) in the anterior/posterior (AP) and medial/lateral (ML) directions. One-minute trials were performed with feet hip-width apart, hands-on-hips, and A) eyes-open and B) eyes-closed. Biomechanical head-impact exposure (impacts over 10 g) was indexed over the season using mastoid-fixed impact sensors. In acutely injured athletes, repeated-measures ANOVA revealed a significant effect of time for RMSdisp AP with increased displacement at 2 weeks compared to 72 h (p = 0.008, 95% CI: -0.180, -0.310 cm). No other COP variables were affected by acute concussion. Moreover, there was no effect of concussion history or repeated sub-concussive impacts on any quiet stance metric. Additionally, head-impact exposure metrics were not correlated with COP metrics. Taken together, the data suggests alterations in COP sway during quiet stance persist in the acute 2-week period after injury. These findings were not present with either a history of multiple concussions or exposure to sub-concussive head impacts indicating acute concussion does not have appear to have long term effects for these measures.

Visual-vestibular processing deficits in mild traumatic brain injury

BACKGROUND

The search for reliable and valid signs and symptoms of mild traumatic brain injury (mTBI), commonly synonymous with concussion, has lead to a growing body of evidence that individuals with long-lasting, unremitting impairments often experience visual and vestibular symptoms, such as dizziness, postural and gait disturbances.

OBJECTIVE

Investigate the role of visual-vestibular processing deficits following concussion.

METHODS

A number of clinically accepted vestibular, oculomotor, and balance assessments as well as a novel virtual reality (VR)-based balance assessment device were used to assess adults with post-acute concussion (n = 14) in comparison to a healthy age-matched cohort (n = 58).

RESULTS

Significant between-group differences were found with the VR-based balance device (p = 0.001), with dynamic visual motion emerging as the most discriminating balance condition. The symptom reports collected after performing the oculomotor and vestibular tests: rapid alternating horizontal eye saccades, optokinetic stimulation, and gaze stabilization, were all sensitive to health status (p < 0.05), despite the absence of oculomotor abnormalities being observed, except for near-point convergence. The BESS, King-Devick, and Dynamic Visual Acuity tests did not detect between-group differences.

CONCLUSION

Postural and visual-vestibular tasks most closely linked to spatial and self-motion perception had the greatest discriminatory outcomes. The current findings suggest that mesencephalic and parieto-occipital centers and pathways may be involved in concussion.

The Examination of Patient-Reported Outcomes and Postural Control Measures in Patients With and Without a History of ACL Reconstruction: A Case Control Study

Context: There is a lack of literature to support the diagnostic accuracy and cut-off scores of commonly used patient-reported outcome measures (PROMs) and clinician-oriented outcomes such as postural-control assessments (PCAs) when treating post-ACL reconstruction (ACLR) patients. These scores could help tailor treatments, enhance patient-centered care and may identify individuals in need of additional rehabilitation. Objective: To determine if differences in 4-PROMs and 3-PCAs exist between post-ACLR and healthy participants, and to determine the diagnostic accuracy and cut-off scores of these outcomes. Design: Case control. Setting: Laboratory. Participants: A total of 20 post-ACLR and 40 healthy control participants. Main Outcome Measures: The participants completed 4-PROMs (the Disablement in the Physically Active Scale [DPA], The Fear-Avoidance Belief Questionnaire [FABQ], the Knee Osteoarthritis Outcomes Score [KOOS] subscales, and the Tampa Scale of Kinesiophobia [TSK-11]) and 3-PCAs (the Balance Error Scoring System [BESS], the modified Star Excursion Balance Test [SEBT], and static balance on an instrumented force plate). Mann-Whitney U tests examined differences between groups. Receiver operating characteristic (ROC) curves were employed to determine sensitivity and specificity. The Area Under the Curve (AUC) was calculated to determine the diagnostic accuracy of each instrument. The Youdin Index was used to determine cut-off scores. Alpha was set a priori at P < 0.05. Results: There were significant differences between groups for all PROMs (P < 0.05). There were no differences in PCAs between groups. The cut-off scores should be interpreted with caution for some instruments, as the scores may not be clinically applicable. Conclusions: Post-ACLR participants have decreased self-reported function and health-related quality of life. The PROMs are capable of discriminating between groups. Clinicians should consider using the cut-off scores in clinical practice. Further use of the instruments to examine detriments after completion of standard rehabilitation may be warranted.

Using concurrent gait and cognitive assessments to identify impairments after concussion: a narrative review

Understanding how a concussion affects an individual is oftentimes difficult for clinicians due to the varying symptom profiles reported by the patient and the multifaceted and heterogeneous nature of the injury. Accordingly, the interpretation of postconcussion performance can be challenging, because many different testing paradigms have been reported as potentially useful in the literature. Among the types of tests clinicians use to understand how concussion affects an individual, both gait and neurocognitive evaluations have demonstrated utility. Our purpose is to describe how combined gait and cognitive (i.e., dual task), as well as single-task gait and computerized neurocognitive examinations can assist clinical decision-making.

A Longitudinal Examination of Postural Impairments in Children With Mild Traumatic Brain Injury: Implications for Acute Testing

OBJECTIVE

To examine how postural control changes following pediatric mild traumatic brain injury.

SETTING

Urban pediatric emergency department.

PARTICIPANTS

Children 11 to 16 years old who presented within 6 hours of sustaining mild traumatic brain injury.

DESIGN

Prospective observational cohort followed for 1 month.

MAIN MEASURES

Total center of pressure path velocity and path velocity within distinct frequency bands, ranging from moderate to ultralow, were recorded by the Nintendo Wii Balance Board during a 2-legged stance. Measurements were recorded in 2 separate tests with eyes open and closed. The scores of the 2 tests were compared, and a Romberg quotient was computed.

RESULTS

Eleven children were followed for 1 month postinjury. The ultralow frequency, which reflects slow postural movements associated with exploring stability boundaries, was lower (p = .02) during the eyes closed stance acutely following injury. The Romberg quotient for this frequency was also significantly lower acutely following injury (p = .007) than at 1 month.

CONCLUSION

Following mild traumatic brain injury, children acutely demonstrate significantly more rigid sway patterns with eyes closed than with eyes open, which were highlighted by the Romberg quotient. The Romberg quotient could allow for accurate identification and tracking of postural instability without requiring knowledge of preinjury balance ability.

Posttraumatic Headache

After sustaining a concussion or mild traumatic brain injury, headaches are one of the most common complaints. The pathophysiologic changes that occur in the setting of injury likely contribute to or cause posttraumatic headaches. Posttraumatic headaches often present as migraine or tension-type headaches. Unlike pain from other types of injuries, headaches following mild traumatic brain injury are more likely to persist. Preexisting conditions such as migraine and mood disorders may influence posttraumatic headache and complicate management. Patients are at high risk to overuse abortive medications and develop medication overuse headache. Headache hygiene and early education are essential for effective management. Abortive medications include nonsteroidal anti-inflammatory drugs and triptans. Preventive medications include tricyclic antidepressants and antiepileptics. Patients who fail outpatient therapies may benefit from referral for intravenous medications in the emergency department. Patients with persistent posttraumatic headache may benefit from multimodal treatments including physical rehabilitation and pain-focused cognitive-behavioral therapies. [Pediatr Ann. 2018;47(2):e61-e68.].

Sport Concussion and the Female Athlete

Sport concussion (SC) has emerged as a major health concern in the medical community and general public owing to increased research and media attention, which has primarily focused on male athletes. Female athletes have an equal, if not increased, susceptibility to SC. An ever-growing body of research continues to compare male and female athletes in terms of SC before and after an injury. Clinicians must be cognizant of this literature to make evidence-based clinical decision when providing care to female athletes and discern between dated and/or unsupported claims in terms of SC.

Acute diesel exhaust exposure and postural stability: a controlled crossover experiment

Recent epidemiological evidence connects ambient air pollutants to adverse neurobehavioural effects in adults. In animal models, subchronic controlled exposures to diesel exhaust (DE) have also showed evidence of neuroinflammation. Evidence suggests that DE not only affects outcomes commonly associated with cognitive dysfunction, but also balance impairment. We conducted a controlled human exposure experiment with 28 healthy subjects (average age = 28 years (SD = 7.1; range = 21-49); and 40% female) who were exposed to two conditions, filtered air (FA) and DE (300 μg PM2.5/m3) for 120 min, in a double-blinded crossover study with randomized exposures separated by four weeks. Postural stability was assessed by the Balance Error Scoring System (BESS), a brief, easily-administered test of static balance. The BESS consists of a sequence of three stances performed on two surfaces. With hands on hips and eyes closed, each stance is held for 20 s. "Error" points are awarded for deviations from those stances. Pre- and immediately post-exposure BESS "error" point totals were calculated and the difference between the two timepoints were compared for each of the two exposure conditions. A mixed effect model assessed the significance of the association. While our data demonstrates a trend of reduced postural stability in response to exposure to DE, exposure was not significantly associated with BESS value. This is the first study to investigate changes in postural stability as a result of exposure to DE in human subjects.