Assessing Brain Processing Deficits Using Neuropsychological and Vision-Specific Tests for Concussion.

INTRODUCTION: Since verbal memory and visual processing transpire within analogous cerebral regions, this study assessed (i) if a visual function can predict verbal memory performance. It also hypothesized whether neurocognitive (e.g., ImPACT) tests focusing on the Visual Memory and Cognitive Efficacy Index will predict Verbal Memory scores and (ii) if vision metrics and age can identify individuals with a history of concussion. Finally, it also hypothesized that King-Devick and near point of convergence scores alongside age considerations will identify candidates with a prior reported history of concussion. MATERIALS AND METHODS: This observational cohort assessed 25 collegiate ice hockey players prior to the competitive season considering age (19.76 ± 1.42 years) and BMI (25.9 ± 3.0 kg/cm2). Hypothesis 1 was assessed using a hierarchical (sequential) multiple regression analysis, assessing the predictive capacity of Visual Memory and Cognitive Efficacy Index scores in relation to Verbal Memory scores. Hypothesis 2 utilized a binomial logistic regression to determine if King-Devick and near point of convergence scores predict those with a prior history of concussion. RESULTS: Hypothesis 1 developed two models, where Model 1 included Visual Memory as the predictor, while Model 2 added the Cognitive Efficacy Index as a predictor for verbal memory scores. Model 1 significantly explained 41% of the variance. Results from Model 2 suggest that the Cognitive Efficacy Index explained an additional 24.4%. Thus, Model 2 was interpreted where only the Cognitive Efficacy Index was a significant predictor (p = 0.001). For every 1 unit increase in the Cognitive Efficacy Index, Verbal Memory increased by 41.16. Hypothesis 2's model was significant, accounting for 37.9% of the variance in those with a history of concussion. However, there were no significant unique predictors within the model as age (Wald = 1.26, p = 0.261), King-Devick (Wald = 2.31, p = 0.128), and near point of convergence (Wald = 2.43, p = 0.119) were not significant predictors individually. CONCLUSIONS: The conflicting findings of this study indicate that baseline data for those with a history of concussion greater than one year may not be comparable to the same metrics during acute concussion episodes. Young athletes who sustain a concussion may be able to overcompensate via the visual system. Future prospective studies with larger sample sizes are required using the proposed model's objective metrics.

Short-Term Benefits from Manual Therapy as an Adjunct Treatment for Persistent Postural-Perceptual Dizziness Symptoms: A Preliminary Prospective Case Series.

Persistent dizziness and balance deficits are common, often with unknown etiology. Persistent Postural-Perceptual Dizziness (3PD) is a relatively new diagnosis with symptoms that may include dizziness, unsteadiness, or non-vertiginous dizziness and be persistent the majority of time over a minimum of 90 days. The purpose of this case series was to investigate short-term outcomes of reducing dizziness symptoms using a manual therapy intervention focused on restoring mobility in the fascia using a pragmatically applied biomechanical approach, the Fascial Manipulation® method (FM®), in patients with 3PD. The preliminary prospective case series consisted of twelve (n = 12) patients with persistent complaints of dizziness who received systematic application of manual therapy to improve fascial mobility after previously receiving vestibular rehabilitation. The manual therapy consisted of strategic assessment and palpation based on the model proposed in the FM® Stecco Method. This model utilizes tangential oscillations directed toward the deep fascia at strategic points. Six males (n = 6) and females (n = 6) were included with a mean age of 68.3 ± 19.3 years. The average number of interventions was 4.5 ± 0.5. Nonparametric paired sample t-tests were performed. Significant improvements were observed toward the resolution of symptoms and improved outcomes. The metrics included the Dizziness Handicap Inventory and static and dynamic balance measures. The Dizziness Handicap Inventory scores decreased (i.e., improved) by 43.6 points (z = -3.1 and p = 0.002). The timed up and go scores decreased (i.e., improved) by 3.2 s (z = -2.8 and p = 0.005). The tandem left increased (i.e., improved) by 8.7 s (z = 2.8 and p = 0.005) and the tandem right increased (i.e., improved) by 7.5 s (z = 2.8 and p = 0.005). Four to five manual therapy treatment sessions appear to be effective for short-term improvements in dizziness complaints and balance in those with 3PD. These results should be interpreted with caution as future research using rigorous methods and a control group must be conducted.

Heart Rate Variability as a Reliable Biomarker Following Concussion: A Critically Appraised Topic.

CLINICAL SCENARIO: Recent systematic reviews show conflicting information regarding the effect of concussion on cardiac autonomic function. Controlled aerobic exercise is the most popular intervention for those recovering from a concussion. There is a gap in the literature supporting the utility of objective metrics during exertional return to play protocols and rehabilitation. CLINICAL QUESTION: Can heart rate variability (HRV) during physical exertion be a reliable biomarker over time for those who suffered a sport-related concussion? SUMMARY OF KEY FINDINGS: A literature search produced 3 studies relevant to the clinical question. One, a prospective-matched control group cohort study, reported disturbances in HRV during physical exertion in those with a history of concussion, and identified persistent HRV dysfunction after resolution of subjective complaints, return to play, and with multiple concussive events. Second, a cross-sectional cohort study found an HRV difference in those with and without a history of concussion and in HRV related to age and sex. Finally, the prospective longitudinal case-control cohort study did not find sex or age differences in HRV and concluded that, although postconcussion HRV improved as time passed, resting HRV was not as clinically meaningful as HRV during exertional activities. CLINICAL BOTTOM LINE: There is emerging evidence to support the use of HRV as an observable biomarker, over time, of autonomic function during physical exertion following a sport-related concussion. However, the meaningfulness of HRV data is not fully understood and the utility seems individualized to the level of athlete, age, and sex and, therefore, cannot be generalizable. In order to be more clinically meaningful and to assist with current clinical decision making regarding RTP, a preinjury baseline assessment would be beneficial as an individualized reference for baseline comparison. STRENGTH OF RECOMMENDATION: Although HRV is not fully understood, currently, there is grade B evidence to support the use of individualized baseline exertional HRV data as comparative objective metric to assess the autonomic nervous system function, over time, following a concussive event.

Test-Retest Reliability of Postural Control Assessment on Biodex BioSway™.

Background: Recent protocols for posturographic assessment of postural control and balance have included head shake test conditions to challenge the vestibular contributions of postural control in an effort to increase the diagnostic accuracy of identifying individuals with impaired balance. However, evidence is limited regarding the test-retest reliability of such assessment protocols. Purpose: The purpose of this study was twofold: to determine the test-retest reliability of postural control assessment on the Biodex Biosway™, an accessible and field expedient tool for posturographic assessment, and to determine the test-retest reliability of the Head Shake Sensory Interaction and Balance Test (HS-SIB), an adaptation of the modified Clinical Test of Sensory Interaction and Balance (mCTSIB) which adds two head shake conditions to challenge the vestibular contributions to postural control. Study Design. This was a correlational time series cohort study completed in a biomechanics laboratory. Methods: The sample consisted of nineteen healthy adults (10 females, 9 males). Sway Index, Equilibrium Score, and the area of the ellipse enclosing 95% of the anterior-posterior (AP) and medial-lateral (ML) center of gravity (COG) displacement (AREA95) are the 3 summary variables. Standard Error of Measurement (SEM) and Minimum Detectable Change (MDC) are also reported. Results: Test-retest reliability was generally poor with limited exceptions. Moderate to good reliability was observed for the more challenging stance conditions (ICC range 0.58-0.81), including those with head shake. Conclusions: Field-expedient systems, such as the Biodex BioSway™, may offer reliable posturographic testing where gold-standard methods are not available. Clinicians should be aware that less demanding test conditions have limited reliability; however, test-retest reliability of this assessment tool is improved with more challenged stance conditions and the inclusion of a head shake task.

Item-level and Composite-level Interrater Reliability of Functional Movement Screen™ Scores Following Condensed Training in Novice Raters.

BACKGROUND: The Functional Movement Screen™ (FMS™) is a clinical instrument designed to use movement behaviors to screen individuals for injury risk. Current rater certification programs focus on extensive, individualized training, which may not be appropriate in all screening contexts. PURPOSE: The purpose of this research was to examine the effect of a two-hour FMSTM training seminar on measures of reliability between previously untrained scorers. STUDY DESIGN: Repeated measures, descriptive cohort study. METHODS: Four novice raters completed a two-hour training course administered by an FMS™-certified, licensed physical therapist. The novices and the instructor then scored a group of 16 individuals on the seven FMS™ component tests on two separate occasions. Interrater reliability was assessed for FMS™ component scores using Fleiss' kappa and Krippendorff's α. Interrater reliability for the FMS™ composite score was assessed using a two-way ICC for agreement (a priori significance level=0.05). RESULTS: Reliability ranged from fair to almost perfect (kappa) for Deep Squat (0.61 Day 1, 0.79 Day 2), Shoulder Mobility (0.90 Day 1, 1.00 Day 2), Active Straight Leg Raise (0.53 Day 1, 0.69 Day 2), and Trunk Stability Push Up (0.48 Day 1, 0.49 Day 2) on both testing occurrences (p<0.05). Reliability (kappa) was fair for Inline Lunge (0.24 Day 1, 0.39 Day 2), and poor for Hurdle Step (Day 1 -0.01, Day 2 no result) and Rotary Stability (Day 1 -0.03, Day 2 -0.01). Results for Krippendorff's α were similar, with unacceptable interrater reliability for Hurdle Step (Day 1 -0.01, Day 2 1.00), Inline Lunge (Day 1 0.31, Day 2 0.39), and Rotary Stability (Day 1 -0.02, Day 2 -0.01). Interrater composite score reliability (ICC) was good (0.79 Day 1, 0.84 Day 2; both p<0.05). CONCLUSIONS: Findings suggest that a brief training seminar may be sufficient to ensure acceptable reliability in many, but not all, of the FMS™ component tests and composite score. LEVELS OF EVIDENCE: Level 2b.

Validity of Postural Sway Assessment on the Biodex BioSway™ Compared With the NeuroCom Smart Equitest.

CONTEXT: Current tools for sideline assessment of balance following a concussion may not be sufficiently sensitive to identify impairments, which may place athletes at risk for future injury. Quantitative field-expedient balance assessments are becoming increasingly accessible in sports medicine and may improve sensitivity to enable clinicians to more readily detect these subtle deficits. OBJECTIVE: To determine the validity of the postural sway assessment on the Biodex BioSway™ compared with the gold standard NeuroCom Smart Equitest System. DESIGN: Cross-sectional cohort study. SETTING: Clinical research laboratory. PARTICIPANTS: Forty-nine healthy adults (29 females: 24.34 [2.45] y, height 163.65 [7.57] cm, mass 63.64 [7.94] kg; 20 males: 26.00 [3.70] y, height 180.11 [7.16] cm, mass 82.97 [12.78] kg). INTERVENTION(S): The participants completed the modified clinical test of sensory interaction in balance on the Biodex BioSway™ with 2 additional conditions (head shake and firm surface; head shake and foam surface) and the Sensory Organization Test and Head Shake Sensory Organization Test on the NeuroCom Smart Equitest. MAIN OUTCOME MEASURES: Interclass correlation coefficient and Bland-Altman limits of agreement for Sway Index, equilibrium ratio, and area of 95% confidence ellipse. RESULTS: Fair-good reliability (interclass correlation coefficient = .48-.65) was demonstrated for the stance conditions with eyes open on a firm surface. The Head Shake Sensory Interaction and Balance Test condition on a firm surface resulted in fair reliability (interclass correlation coefficient = .50-.59). The authors observed large ranges for limits of agreement across outcome measures, indicating that the systems should not be used interchangeably. CONCLUSIONS: The authors observed fair reliability between BioSway™ and NeuroCom, with better agreement between systems with the assessment of postural sway on firm/static surfaces. However, the agreement of these systems may improve by incorporating methods that mitigate the floor effect in an athletic population (eg, including a head shake condition). BioSway™ may provide a surrogate field-expedient measurement tool.