Temporal Changes in Fixational Eye Movements After Concussion in Adolescents and Adults: Preliminary Findings

Concussions often involve ocular impairment and symptoms such as convergence insufficiency, accommodative insufficiency, blurred vision, diplopia, eye strain, and pain. Current clinical assessments of ocular function and symptoms rely on subjective symptom reporting and/or involve lengthy administration time. More objective, brief assessments of ocular function following concussion are warranted. The purpose of this study was to evaluate changes in fixational eye movements (FEMs) and their association with clinical outcomes including recovery time, symptoms, cognitive and vestibular/ocular motor impairment. Thirty-three athletes (13-27 years of age; 54.5% female) within 21 days of a diagnosed concussion participated in the study. A tracking scanning laser ophthalmoscope (TSLO) evaluated FEMs metrics during fixation on a center and corner target. Participants completed symptom (Post-Concussion Symptom Scale [PCSS]), cognitive (Immediate Post-concussion Assessment and Cognitive Testing [ImPACT], and Vestibular/Ocular Motor Screening (VOMS) evaluations. All measures were administered at the initial visit and following medical clearance, which was defined as clinical recovery. Changes in FEMs were calculated using paired-samples t tests. Linear regression (LR) models were used to evaluate the association of FEMs with clinical recovery. Pearson product-moment correlations were used to evaluate the associations among FEMs and clinical outcomes. On the center task, changes across time were supported for average microsaccade amplitude (p = 0.005; Cohen's d = 0.53), peak velocity of microsaccades (p = 0.01; d = 0.48), peak acceleration of microsaccades (p = 0.02; d = 0.48), duration of microsaccade (p < 0.001; d = 0.72), and drift vertical (p = 0.017; d = -0.154). The LR model for clinical recovery was significant (R2 = 0.37; p = 0.023) and retained average instantaneous drift amplitude (β = 0.547) and peak acceleration of microsaccade (β = 0.414). On the corner task, changes across time were supported for drift proportion (p = 0.03; d = 0.43). The LR model to predict clinical recovery was significant (R2 = 0.85; p = 0.004) and retained average amplitude of microsaccades (β = 2.66), peak velocity of microsaccades (β = -15.11), peak acceleration of microsaccades (β = 12.56), drift horizontal (β = 7.95), drift vertical (β = 1.29), drift amplitude (β = -8.34), drift proportion (β = 0.584), instantaneous drift direction (β = -0.26), and instantaneous drift amplitude (β = 0.819). FEMs metrics were also associated with reports of nausea and performance within the domain of visual memory. The FEMs metric were also associated with PCSS, ImPACT, and VOMS clinical concussion outcomes, with the highest magnitude correlations between average saccade amplitude and VOMS symptoms of nausea and average instantaneous drift speed and ImPACT visual memory, respectively. FEMs metrics changed across time following concussion, were useful in predicting clinical recovery, and were correlated with clinical outcomes. FEMs measurements may provide objective data to augment clinical assessments and inform prognosis following this injury.

The Vestibular/Ocular Motor Screening-Child (VOMS-C) tool for concussion evaluation in 5- to 9-year-old pediatric patients: preliminary evidence

OBJECTIVE

Vestibular and ocular motor dysfunction occurs in an estimated 60%-90% of concussion patients. The Vestibular/Ocular Motor Screening (VOMS) tool is validated for use in concussion patients older than 9 years. The goal of the current study was to adapt the current VOMS tool for a pediatric sample of children aged 5-9 years and establish its clinical utility in this patient population.

METHODS

In this case-control study, 80 symptomatic concussion patients (n = 33 [41%] female) aged 5-9 years (mean age 7.40 ± 1.09 years) and 40 (n = 18 [45%] female) age- and sex-matched uninjured controls (mean age 7.10 ± 1.26 years) completed the VOMS-Child (VOMS-C), a version of the VOMS adapted for younger patients. Differences in binary "yes" or "no" symptom provocation for headache, dizziness, and nausea/"tummy ache" across the 7 items of the VOMS-C, and near point of convergence (NPC) distance, were examined. Logistic regression (LR) models were built to classify concussion and controls. Predicted probabilities were generated from the LR model and entered into receiver operating characteristic (ROC) curve models to generate area under the curve (AUC) values.

RESULTS

VOMS-C item provocation ranged from 13% to 30% for concussed patients and 3% to 20% for controls. The LR model distinguished concussed participants from controls (R2 = 0.39; p < 0.001), with significant predictors being smooth pursuits, family depression history, and NPC distance. The ROC analysis had an AUC of 0.81 (95% CI 0.73-0.89; p < 0.001) in the good range.

CONCLUSIONS

Accurate diagnosis of concussion in the clinic setting requires comprehensive evaluation in multiple domains, including detailed clinical interview, neurocognitive testing, and vestibular/ocular motor assessment, regardless of patient age. Our results provide preliminary support for the VOMS-C as a developmentally appropriate tool for concussion management.

A-01 Changes in Fixational Eye Movements (FEMs) Following Concussion

Purpose: Identify changes in fixational eye movement (FEMs) outcomes following concussion and assess the association of FEMs outcomes with clinical outcomes including symptoms, neurocognitive, and vestibular/ocular motor. Methods: Participants included thirty-three individuals (13–27 years old; 54.5% female) diagnosed with concussion within the past 21 days. Concussion diagnosis was determined using current consensus guidelines. A tracking scanning laser ophthalmoscope (TSLO) was used to measure FEMS. Participants completed ImPACT, PCSS, and VOMS. Within-subjects changes in FEMS outcomes were calculated using paired-samples t-tests. A backwards stepwise linear regression to predict days to clearance was utilized with all FEMS outcomes as predictors. Results: MeanDriftH (slope of cumulative drift regression calculated horizontally; mean difference = 0.04; p = 0.03; Cohen’s d = 0.43) and drift proportion significantly changed over time (mean difference = 0.03; p = 0.03, d = 0.44). Average peak velocity of microsaccade (MsPkVel) predicted days to recovery (R = 0.26; p = 0.045; n = 24). MsPkVel and average duration of blink correlated with select reports of nausea on VOMS. Microsaccade frequency (r = −0.36; p = 0.04) correlated with NPC fogginess. Drift amplitude (DriftAmp) correlated with NPC distance (r = −0.41; p = 0.02) and VMS headache (r = 0.35; p = 0.04). MeanDriftH was negatively correlated with verbal memory (r = −0.44; p = 0.01), whereas DriftAmp was positively correlated (r = 0.50; p = 0.003). Bivariate contour ellipse area was correlated (r = 0.43; p = 0.01) with slower reaction time on ImPACT. Conclusions: FEMs outcomes demonstrated significant change and were useful in predicting recovery time following concussion. FEMs measurements may provide brief, objective data to augment current clinical assessment and inform prognosis for recovery. Future researchers should examine FEMS outcomes from pre- to post-concussion and explore age and sex differences.

A-30 Preliminary Evidence for the Vestibular/Ocular Motor Screening-Child (VOMS-C) for Patients with Concussion (ages 5–9)

Purpose: To establish preliminary evidence (i.e., predictive validity) for the new Vestibular/Ocular Motor Screening Child Version (VOMS-C) in a sample of concussed patients and controls aged 5–9 years. A secondary purpose was to identify risk factors for false positives in healthy controls. Methods: This study included 80 patients ages 5–9 (7.40+/−1.09, 41% female) years with a concussion during the past 30 days recruited from a concussion clinic, and 40 age- and sex-matched controls (7.10+/−1.26 years, 45% female). Participants completed a clinical interview, and the VOMS-C. Groups were compared with independent samples t-tests and chi-square analyses. Backwards stepwise logistic regression (LR) was used to discriminate groups and inform a receiver operating characteristic (ROC) curve analysis with area under the curve (AUC) values. Chi-square analyses with odds ratios (OR) were conducted to examine false positives in controls. Results: VOMS-C item provocation ranged from 2.5–20% in the control group and 13.2–30.3% for the concussed group. Results from the LR discriminated concussed from controls (R2 = 0.39; p &lt; 0.001) with smooth pursuits (p = 0.047), family depression history (p = 0.02), and near-point of convergence distance (p = 0.01), as significant predictors. ROC curve analysis including these three predictors supported an AUC = 0.81 (95% CI: 0.73–0.89; p &lt; 0.001) for differentiating concussed from controls. False positives among controls were only related to family history of anxiety (OR 13.37, CI 1.45–122.88, p = 0.007). Conclusions: The findings provide preliminary support for the VOMS-C to identify concussed patients aged 5–9 years.