Balance Markers and Saccadic Eye-Movement Measures in Adolescents With Postconcussion Syndrome.

CONTEXT: Deficits in both balance and oculomotor function, including impairments in saccadic eye movements, are observed in approximately 30% of patients postconcussion. Whereas balance and saccadic eye movements are routinely assessed separately, growing evidence suggests that they should be assessed concurrently. OBJECTIVE: To compare balance measures and saccades between adolescents 1 to 3 months postconcussion and healthy uninjured adolescents. DESIGN: Case-control study. SETTING: Concussion clinic and 2 private schools. PATIENTS OR OTHER PARTICIPANTS: Twenty-five adolescents (10 boys, 15 girls; median [interquartile range (IQR)] age = 14 years [11.5-16 years]) between 1 and 3 months postconcussion (median [IQR] time since injury = 39.5 days [30-56.75 days]) and 33 uninjured adolescents (18 boys, 15 girls; median [IQR] age = 13 years [11.5-14 years]). MAIN OUTCOME MEASURE(S): The center-of-pressure 95% ellipse area and medial-lateral and anterior-posterior velocity and the number of saccades in the dual-task balance conditions including a high cognitive load (cognitive condition), a low cognitive load and a gaze-shifting component (visual condition) or both a high cognitive load and a gaze-shifting component (combined condition). RESULTS: Concussion-group participants swayed over larger center-of-pressure ellipse areas in the visual (P = .02; effect size = 0.73) and combined (P = .005; effect size = 0.86) conditions but not in the cognitive condition (P = .07; effect size = 0.50). No group differences were identified for anterior-posterior (F1,56 = 2.57, P = .12) or medial-lateral (F1,56 = 0.157, P = .69) velocity. Concussion-group participants also did not perform more saccades than the control-group participants (F1,56 = 2.04, P = .16). CONCLUSIONS: Performing dual-task balance conditions for which the secondary task involved a gaze-shifting component or both a gaze-shifting component and a high cognitive load resulted in greater sway amplitude in adolescents with concussion. However, these larger amounts of postural sway were not associated with increased saccadic eye movements.

Concussed athletes walk slower than non-concussed athletes during cognitive-motor dual-task assessments but not during single-task assessments 2 months after sports concussion: a systematic review and meta-analysis using individual participant data.

OBJECTIVES: To determine whether individuals who sustained a sports concussion would exhibit persistent impairments in gait and quiet standing compared to non-injured controls during a dual-task assessment . DESIGN: Systematic review and meta-analysis using individual participant data (IPD). DATA SOURCES: The search strategy was applied across seven electronic bibliographic and grey literature databases: MEDLINE, EMBASE, CINAHL, SportDISCUS, PsycINFO, PsycARTICLES and Web of Science, from database inception until June 2017. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Studies were included if; individuals with a sports concussion and non-injured controls were included as participants; a steady-state walking or static postural balance task was used as the primary motor task; dual-task performance was assessed with the addition of a secondary cognitive task; spatiotemporal, kinematic or kinetic outcome variables were reported, and; included studies comprised an observational study design with case-control matching. DATA EXTRACTION AND SYNTHESIS: Our review is reported in line with the Preferred Reporting Items for Systematic review and Meta-Analyses-IPD Statement. We implemented the Risk of Bias Assessment tool for Non-randomised Studies to undertake an outcome-level risk of bias assessment using a domain-based tool. Study-level data were synthesised in one of three tiers depending on the availability and quality of data: (1) homogeneous IPD; (2) heterogeneous IPD and (3) aggregate data for inclusion in a descriptive synthesis. IPD were aggregated using a 'one-stage', random-effects model. RESULTS: 26 studies were included. IPD were available for 20 included studies. Consistently high and unclear risk of bias was identified for selection, detection, attrition, and reporting biases across studies. Individuals with a recent sports concussion walked with slower average walking speed (χ2=51.7; df=4; p<0.001; mean difference=0.06 m/s; 95% CI: 0.004 to 0.11) and greater frontal plane centre of mass displacement (χ2=10.3; df=4; p=0.036; mean difference -0.0039 m; 95% CI: -0.0075 to -0.0004) than controls when evaluated using a dual-task assessment up to 2 months following concussion. SUMMARY/CONCLUSIONS: Our IPD evidence synthesis identifies that, when evaluated using a dual-task assessment, individuals who had incurred a sports concussion exhibited impairments in gait that persisted beyond reported standard clinical recovery timelines of 7-10 days. Dual-task assessment (with motion capture) may be a useful clinical assessment to evaluate recovery after sports concussion. PROTOCOL PRE-REGISTRATION: This systematic review was prospectively registered in PROSPERO CRD42017064861.

Self-reported balance status is not a reliable indicator of balance performance in adolescents at one-month post-concussion.

OBJECTIVES: To determine if self-reported balance symptoms can be used as a proxy for measures of the center of pressure (COP) to identify balance deficits in a group of concussed adolescents. DESIGN: Case-control. METHODS: Thirteen adolescents 1-month post-concussion who reported ongoing balance problems (Balance+), 20 adolescent 1-month post-concussion who reported no balance problems (Balance-), and 30 non-injured adolescents (control) completed a series of balance tests. Participants completed two 2-min trials standing on a Nintendo Wii Balance Board™ during which the COP under their feet was recorded: i) double-leg stance, eyes open; ii) double-leg stance, eyes closed. Participants also completed a dual-task condition combining a double-leg stance and a Stroop Colour-word test. RESULTS: Participants in both the Balance+ and Balance- group swayed over a larger ellipse area compared to the control group while completing the Eyes Closed (Balance+, p=0.002; Balance-, p=0.002) and Dual-Task (Balance+, p=0.001; Balance-, p=0.004) conditions and performed the Dual-Task condition with faster medio-lateral velocity (Balance+, p=0.003; Balance-, p=0.009). The participants in the Balance- group also swayed over a larger ellipse area compared to the control group while completing the Eyes Open condition (p=0.005). No significant differences were identified between the Balance+ and Balance- groups. CONCLUSIONS: At 1-month post-concussion, adolescents demonstrated balance deficits compared to non-injured adolescents regardless of whether they reported balance problems. These results suggest that self-reported balance status might not be an accurate reflection of balance performance following a concussion in adolescents.

Balance Markers in Adolescents at 1 Month Postconcussion.

BACKGROUND: The Balance Error Scoring System (BESS) shows that balance tends to recover within days after a concussion, whereas measures of the movement of the center of pressure (COP) show that balance deficits can persist up to 1 month after concussion. While approximately 30% of adolescents suffering concussion have functional consequences including balance deficits, evidence of the use of different balance assessments for concussion is limited within this population. PURPOSE: To compare performance on a series of balance assessments between adolescents with a diagnosed concussion at 1 month postinjury and noninjured control participants within the same age distribution. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Thirty-three adolescents 1 month postconcussion and 33 control participants completed the BESS followed by two, 2-minute trials standing on a Nintendo Wii Balance Board (WBB), during which the COP under their feet was recorded using 2 testing protocols: (1) double-leg stance, eyes open (EO) and (2) double-leg stance, eyes closed (EC). Participants then completed a dual-task condition (DT) with eyes open combining a double-leg stance and a Stroop color and word test while standing on the WBB. Three commonly used COP variables, anterior-posterior (A/P) and mediolateral (M/L) velocity and 95% ellipse, were computed for each condition performed on the WBB. RESULTS: Participants postconcussion swayed over a significantly larger ellipse area compared with the control group in the EO (P = .008), EC (P = .002), and DT (P = .003) conditions and also performed the DT condition with faster COP velocity in the M/L direction (P = .007). No significant group difference was identified for BESS total score. CONCLUSION: At 1 month postconcussion, participants continued to demonstrate balance deficits in COP control despite scoring similar to controls on the BESS. Simple COP measures of balance may identify subtle impairments not captured by the BESS.