The Toronto Concussion Study: Reference Data for Balance and Gait Measures in Community-Dwelling Adults With Concussion.

OBJECTIVE: Concussion can cause deficits in balance and gait. Much of what is known about how concussion affects balance and gait has been derived from studies involving youth, high school, and university athletes. However, investigation into the effects of concussion on balance and gait in community-dwelling young, middle-age, and older aged adults is limited. This study aimed to present descriptive reference values for common balance and gait measures in community-dwelling adults between the ages of 20 and 69 years with concussion. METHODS: In this observational study, 318 participants were enrolled from a concussion care clinic at a rehabilitation hospital in an urban center and were assessed within 7 days of injury. Balance measures included the Balance Error Scoring System (BESS), modified BESS, and center-of-pressure root mean square during quiet standing. Gait measures included velocity (absolute and height adjusted), cadence, and step length during self-paced gait. Data were binned by decade-long age range. RESULTS: Mean (SD) per-decade scores for the BESS ranged from 14.8 (5.1) to 21.8 (5.6) errors and 4.0 (3.0) to 9.4 (4.6) errors for the modified BESS. Mean values for center-of-pressure root mean square in the anteroposterior direction ranged from 0.42 (0.18) to 0.52 (0.26) with the eyes open, and from 0.49 (0.19) to 0.62 (0.39) with eyes closed. Mean absolute gait velocity ranged from 98.5 (9.1) to 119.3 (21.3) cm/s. The range of step length values was 58.2 (6.8) to 66.3 (7.3) cm and cadence ranged from 102.1 (9.8) to 108.6 (10.8) steps/min across age groups. CONCLUSION: These data provide insight into the impact of concussion on balance and mobility in community-dwelling adults across the lifespan. IMPACT: Community-dwelling adults can experience concussion across the lifespan. Availability of reference values for commonly used balance and gait measures can help to inform clinical strategies and progression of recovery of balance and mobility after injury.

The Toronto concussion study: a cross-sectional analysis of balance deficits following acute concussion in community-dwelling adults.

Objective: To characterize balance deficits in community-dwelling adults following acute concussion.Design: Cross-sectional observational study.Methods: Individuals with acute concussion (n=100) and healthy controls (n=20) completed the BESS (Balance Error Scoring System) and quiet standing trials on forceplates with the eyes open, closed, or during a cognitive dual task. BESS score and centre-of-pressure root mean square and high-frequency power (0.4-3Hz) were used to characterize group differences. In a secondary analysis, participants were subdivided based on self-reported symptoms of balance problems and dizziness using the SCAT-3 (Sport Concussion Assessment Tool - Third Edition) Symptom Checklist.Results: In comparing individuals with concussion and controls, BESS score (16.0 ± 6.0 vs 12.6 ± 3.8; F(1,116) = 5.814, p = .017) and anteroposterior [F(1.78, 204.2) = 11.93, p < .001] and mediolateral [F(1, 114) = 10.05, p = .002] high-frequency power revealed significant group differences. Dividing individuals based on self-reported symptoms revealed significant differences in mediolateral high frequency power, such that participants reporting balance and dizziness problems as well as those participants not reporting balance or dizziness symptoms following concussion were less stable than controls.Conclusions: Deficits in clinical and posturographic measures of balance occur in community-dwelling adults with concussion. These measures do not align with self-reported balance symptoms. Future research and clinical practice aimed at careful selection of optimized balance assessment is recommended.

Cerebrovascular assessments to help understand brain-related changes associated with aerobic exercise after stroke.

Evidence suggests exercise is "good medicine" after stroke, yet consensus is lacking on the time to initiate, type, exertion level, and duration per session. It remains a challenge to identify outcome measures for stroke-exercise trials that are sufficiently sensitive to intervention parameters. Cerebrovascular assessments, namely cerebral blood flow and intracranial pulsatility, are herein discussed as examples of quantitative brain-specific measures that may be useful to monitor exercise-related brain changes and help to guide stroke rehabilitation interventions. Novelty: Cerebral blood flow and arterial stiffness are potential vascular targets for stroke exercise trials.

The Toronto Concussion Study: a longitudinal analysis of balance deficits following concussion in community-dwelling adults.

OBJECTIVE: To characterize recovery of balance deficits in community-dwelling adults with concussion. HYPOTHESIS: Balance measures will improve 2 weeks after injury and persist over 12 weeks. DESIGN: Prospective longitudinal observational study. METHODS: Assessments included the Balance Error Scoring System (BESS) and quiet standing during eyes open, eyes closed, and a cognitive dual task. Recovery was determined using a Hierarchical Growth Curve Model (HGCM) at Week1 (n = 61), Week2 (n = 58), Week4 (n = 53), Week8 (n = 51), and Week12 (n = 39) post-injury. Within-individual follow-up analysis was conducted using the coefficient of variation (quiet standing measures) and a reliable change index (BESS) on 28 individuals with concussion assessed at all 5 time points. RESULTS: Self-reported symptom score recovered between Week 4-8. Anteroposterior COP velocity (eyes closed) was the only variable to show statistically significant (p < .05) recovery in the HGCM. The within-individual analysis identified fewer than 43% (12/28) of participants recovered by Week 12, relative to their own Week 1 assessment. CONCLUSIONS: While recovery of balance deficits was observed in 1 variable over 12 weeks, less than half of the participants included in all assessments demonstrated improvement in balance outcomes. Future research and clinical practice should focus on the unique characteristics of community-dwelling adults with concussion to optimize recovery in this cohort.

Self-reported Balance Disturbance and Performance-Based Balance Impairment After Concussion in the General Population.

OBJECTIVE: To characterize the prevalence of, and relationship between, self-reported balance disturbance and performance-based balance impairment in the general population with concussion. SETTING: Rehabilitation hospital outpatient concussion clinic. PARTICIPANTS: One hundred six individuals with concussion (49 males, mean age = 32.4; SD = 11.5 years), mean (SD) = 5 (1.8) days postinjury. DESIGN: Cross-sectional observational study. MAIN MEASURES: SCAT3 Symptoms Subscale, Balance Error Scoring System, modified Balance Error Scoring System, and center-of-pressure root-mean-square amplitude and velocity in eyes open and closed conditions. RESULTS: The majority of participants reported balance or dizziness symptoms (54% and 63%, respectively) and demonstrated balance impairment on the Balance Error Scoring System and modified Balance Error Scoring System (66% and 58%, respectively). The prevalence of balance impairment across center-of-pressure measures varied from 32% to 48%. There was no effect of balance or dizziness symptom severity on any of the balance measures (F2,103 = 1.02; P = .44) and (F2,103 = 1.45; P = .10), respectively. There was poor agreement between self-report of balance/dizziness symptoms and identified balance impairment across all balance measures (all κ ≤ 0.26 and κ ≤ 0.20, respectively). CONCLUSIONS: There was no clear relationship between the subjective experience of balance disturbance and objective measures of balance impairment in the general population. These results have implications for clinical evaluation of postconcussive deficits and determination of recovery.