Test Performance and Test-Retest Reliability of the Vestibular/Ocular Motor Screening and King-Devick Test in Adolescent Athletes During a Competitive Sport Season

Utility of the Vestibular/Ocular Motor Screening in Military Medicine: A Systematic Review

INTRODUCTION

The Vestibular/Ocular Motor Screening (VOMS) was created as a brief clinical screening tool for identifying vestibular and ocular motor symptoms and impairments post-concussion. It was found to have predictive validity in correctly identifying concussed athletes from healthy controls. In 2018, the Military Acute Concussion Evaluation 2 (MACE2) replaced the original Military Acute Concussion Evaluation (MACE); the most prominent change between the MACE and MACE2 was the addition of the VOMS. Despite its adoption into military medicine, it is not known if the addition of the VOMS to the MACE2 is acutely helpful, and if it provides additional information for diagnosis, prognosis, and/or management. The purposes of this systematic review were: (1) to determine the utility of the VOMS in correctly identifying concussed individuals, particularly as it pertains to military medicine; (2) to explore the extent to which the VOMS can inform concussion prognosis; and (3) to establish the value of the VOMS as a measure for monitoring the evolution of symptoms throughout a service member's course of care.

MATERIALS AND METHODS

A comprehensive search of PubMed was performed from January 1, 2014 through August 16, 2023. Articles were included if they researched concussion or a related health condition or healthy controls and administered the VOMS. Articles were excluded if they discussed health conditions other than concussion; did not administer the VOMS; or were written in languages other than English. The tools used to assess methodological quality and risk of bias varied according to study design. Articles were classified into three primary domains: diagnosis, prognosis, and/or rehabilitation/recovery over time.

RESULTS

A total of 231 articles were retrieved and 3 were duplicates, leaving 228 articles for review. Of the 228 articles screened, 100 relevant full-text articles were assessed for eligibility. Fifty-nine articles met our inclusion and exclusion criteria while the other 41 articles were rejected. Thirty-two articles helped to inform diagnosis, 15 prognosis, and 16 rehabilitation/recovery over time.

CONCLUSIONS

The VOMS had excellent internal consistency and moderate to good test-retest reliability; however, a false-positive rate of 21.9% was found. Most studies indicated that a positive VOMS was associated with a delayed recovery. Several studies indicated that VOMS scores improved with targeted, active interventions and/or a symptom-guided progressive return to activity. The greatest limitation was the paucity of published evidence in the military population. More research is needed on the use of the VOMS in service members.

Long-term test-retest reliability of the vestibular/ocular motor screening for concussion in child athletes: A preliminary study

The Vestibular/Ocular Motor Screening (VOMS) is a sport-related concussion screening tool that assesses vestibular ocular reflex (VOR) and oculomotor symptom provocation. Long-term test-retest reliability of the VOMS over multiple athletic seasons has not yet been established in a pediatric population. Fifty-one child athletes (females = 28, 54.9%) 8-13 years of age, completed a baseline VOMS assessment at two timepoints, 18 months apart. Cronbach's alpha was used to examine the internal consistency at both time points. Two-way mixed intra-class correlation coefficients and Cohen's Kappa statistics were used to evaluate test-retest reliability. High internal consistency existed at both initial (α = 0.91) and follow-up (α = 0.95) for VOMS symptom provocation items. Strong inter-item correlations were noted between vertical VOR (r = ≥0.70) and visual motion sensitivity (VMS) (r = ≥0.70). Fair agreement was produced for convergence (κ = 0.23, vertical VOR (κ = 0.25) and VMS (κ = 0.25), as well as reliability on NPC distance (ICC2,k = 0.31). All other VOMS scores yielded poor agreement between time points. Symptom provocation was the same for 49% of athletes between timepoints, while 31.4% had a decrease in scoring at follow-up. Symptom provocation from VOMS tasks lessened with increasing age and time; therefore, clinicians should consider annual baseline testing to improve accuracy for concussion evaluation and management in pediatrics.

Clinical Utility of Ocular Assessments in Sport-Related Concussion: A Scoping Review

Background/objectives: Ocular tools and technologies may be used in the diagnosis of sport-related concussions (SRCs), but their clinical utility can vary. The following study aimed to review the literature pertaining to the reliability and diagnostic accuracy of such assessments. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) extension for scoping reviews was adhered to. Reference standard reliability (RSR ≥ 0.75) and diagnostic accuracy (RSDA ≥ 0.80) were implemented to aid interpretation. Results: In total, 5223 articles were screened using the PCC acronym (Population, Concept, Context) with 74 included in the final analysis. Assessments included the King-Devick (KD) (n = 34), vestibular-ocular motor screening (VOMs) and/or near point of convergence (NPC) (n = 25), and various alternative tools and technologies (n = 20). The KD met RSR, but RSDA beyond amateur sport was limited. NPC met RSR but did not have RSDA to identify SRCs. The VOMs had conflicting RSR for total score and did not meet RSR in its individual tests. The VOMs total score did perform well in RSDA for SRCs. No alternative tool or technology met both RSR and RSDA. Conclusion: Ocular tools are useful, rapid screening tools but should remain within a multi-modal assessment for SRCs at this time.

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.

Preliminary Baseline Vestibular Ocular Motor Screening Scores in Pediatric Soccer Athletes

CONTEXT

The utility of baseline vestibular and ocular motor screening (VOMS) in high school and collegiate athletes is demonstrated throughout the literature; however, baseline VOMS data at the youth level are limited. In addition, with the recent adoption of the change scoring method, there is a need to document baseline VOMS total and change scores in a pediatric population.

OBJECTIVE

To document baseline VOMS total and change scores and to document the internal consistency of the VOMS in pediatric soccer athletes. We hypothesized that the VOMS would demonstrate strong internal consistency in pediatric soccer athletes.

DESIGN

Cross-sectional study.

METHODS

Pediatric soccer athletes (N = 110; range = 5-12 y) completed the VOMS at baseline. Descriptive statistics summarized demographic information, VOMS total scores, and VOMS change scores. Cronbach α assessed internal consistency for VOMS total scores and change scores.

RESULTS

Twenty-one (19.1%) participants had at least one total score above clinical cutoffs (≥2 on any VOMS component and ≥5 cm on average near point convergence). Forty (36.4%) participants had at least one change score above clinical cutoffs (≥1 on any VOMS component and ≥3 cm on average near point convergence). The internal consistency was strong for total scores with all VOMS components included (Cronbach α = .80) and change scores (Cronbach α = .89).

CONCLUSIONS

Although results suggest VOMS items measure distinct components of the vestibular and ocular motor systems, caution should be taken when interpreting VOMS total and change scores in pediatric athletes, as overreporting symptoms is common, thereby impacting the false-positive rate.

Mixed Martial Arts: Comparing the King-Devick and Sport Concussion Assessment Tool 5 in knockouts, technical knockouts and choke holds

Objective

To compare validity indices of the King-Devick (KD) test and Sport Concussion Assessment Tool 5 (SCAT5) for traumatic events in MMA, and to determine if perfusion events (alterations in consciousness as the result of choke holds) cause similar changes in KD/SCAT5 scores.

Design

A prospective cohort study in MMA fighters who completed KD and SCAT5 assessments before and after a match. Outcomes were categorized as non-event, traumatic event, or perfusion event. KD/SCAT5 changes were compared between all athletes.

Participants

One hundred forty MMA athletes (7 women, 133 men), mean age=27.1 ± 4.9 years.

Intervention

N/A.

Main outcome measures

King-Devick (KD) test and Sport Concussion Assessment Tool 5 (SCAT5).

Results

Among the 140 athletes, 19 sustained traumatic and 15 perfusion events. Testing provided sensitivities/specificities of 21.05%/93.39% (KD) and 77.78%/52.99% (SCAT5) in detecting a traumatic event. KD and SCAT5 Symptom Severity scores differed between athletes with and without traumatic events (P=.041 and .014). KD and SCAT5 Symptoms Score changes were observed between athletes with and without traumatic events (P=.023 and .042). Neither KD nor SCAT5 differed significantly between athletes with and without perfusion events.

Conclusions

The KD test provides high specificity and the SCAT5 demonstrates reasonable sensitivity when detecting a traumatic event. Of the SCAT5, symptoms-related scores may most effectively identify a traumatic event. A traumatic event may cause KD/SCAT5 changes similar to a concussion, while perfusion events did not.

Reliability of a Smooth Pursuit Eye-Tracking System (EyeGuide Focus) in Healthy Adolescents and Adults

Mild traumatic brain injury (mTBI) is the most common brain injury, seen in sports, fall, vehicle, or workplace injuries. Concussion is the most common type of mTBI. Assessment of impairments from concussion is evolving, with oculomotor testing suggested as a key component in a multimodality diagnostic protocol. The aim of this study was to evaluate the reliability of one eye-tracking system, the EyeGuide Focus. A group of 75 healthy adolescent and adult participants (adolescents: n = 28; female = 11, male = 17, mean age 16.5 ± 1.4 years; adults n = 47; female = 22; male = 25, mean age 26.7 ± 7.0 years) completed three repetitions of the EyeGuide Focus within one session. Intraclass correlation coefficient (ICC) analysis showed the EyeGuide Focus had overall good reliability (ICC 0.79, 95%CI: 0.70, 0.86). However, a familiarization effect showing improvements in subsequent trials 2 (9.7%) and 3 (8.1%) was noticeable in both cohorts (p < 0.001) with adolescent participants showing greater familiarization effects than adults (21.7% vs. 13.1%). No differences were observed between sexes (p = 0.69). Overall, this is the first study to address the concern regarding a lack of published reliability studies for the EyeGuide Focus. Results showed good reliability, suggesting that oculomotor pursuits should be part of a multimodality assessment protocol, but the observation of familiarization effects suggests that smooth-pursuit testing using this device has the potential to provide a biologically-based interpretation of the maturation of the oculomotor system, as well as its relationship to multiple brain regions in both health and 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.

Exploring Vestibular Ocular Motor Screening in Adults With Persistent Complaints After Mild Traumatic Brain Injury

OBJECTIVE

The purpose of this study was to (1) explore differences in vestibular ocular motor screening (VOMS) symptoms between healthy adults and adults with persistent symptoms after mild traumatic brain injury (mTBI), and (2) explore the relationships between VOMS symptoms and other measures (self-reported vestibular symptoms, clinical measures of balance and gait, and higher-level motor ability tasks).

SETTING

Research laboratory setting.

PARTICIPANTS

Fifty-three persons with persistent symptoms (>3 weeks) following mTBI and 57 healthy controls were recruited. Eligibility for participation included being 18 to 50 years of age and free of medical conditions that may affect balance, with the exception of recent mTBI for the mTBI group.

DESIGN

Cross-sectional.

MAIN MEASURES

The primary outcomes were the VOMS symptom scores and near point of convergence (NPC) distance. Secondary outcomes included the Dizziness Handicap Inventory (DHI) total and subdomain scores, sway area, Functional Gait Analysis total score, gait speed, and modified Illinois Agility Task completion time, and Revised High-Level Mobility Assessment Tool total score.

RESULTS

The mTBI group reported more VOMS symptoms ( z range, -7.28 to -7.89) and a further NPC ( t = -4.16) than healthy controls (all P s < .001). DHI self-reported symptoms (total and all subdomain scores) were strongly associated with the VOMS symptom scores (rho range, 0.53-0.68; all P s < .001). No significant relationships existed between VOMS symptoms and other measures.

CONCLUSION

Significant group differences support the relevance of the VOMS for mTBI in an age-diverse sample with persistent symptoms. Furthermore, strong association with DHI symptoms supports the ability of the VOMS to capture vestibular complaints in this population.

Norm-Based Cutoffs as Predictors of Prolonged Recovery After Adolescent Sport-Related Concussion

OBJECTIVES

To identify predictors of prolonged recovery (ie, >28 days) using patient demographic factors and healthy, norm-based cutoffs on a multimodal test battery in adolescents after sport-related concussions (SRCs).

DESIGN

Retrospective cohort. Patients were deemed recovered after successful completion of return-to-play/school protocols and received medical clearance.

SETTING

Community concussion clinic.

PATIENTS

Male and female adolescent student athletes diagnosed with a SRC and evaluated within 1 week of injury.

INDEPENDENT VARIABLES

Patient demographics, medical history, injury description, computerized neurocognitive testing, vestibular/ocular testing, and symptoms at initial clinical visit.

MAIN OUTCOME MEASURES

Performance on clinical testing to predict recovery duration, classified as normal (<28 days) or prolonged (>28 days).

RESULTS

A total of 201 adolescent student athletes (age = 15.3 ± 1.4 years) were included (female 35%). Average recovery duration for the entire cohort was 22.3 ± 13.3 days, with 22% (n = 45) of adolescent student athletes taking >28 days to recover. The final model was 88.3% accurate in classifying normal and prolonged recovery. Predictor variables included sex, loss of consciousness, history of ocular disorder, history of concussion, performance on visual motor speed composite, visual motion sensitivity symptom provocation and near point of convergence distance, number-naming total time, and symptom count.

CONCLUSIONS

These findings suggest that using norm-based cutoffs from cognitive, oculomotor, and vestibulo-ocular testing and symptom reporting, clinicians can accurately predict a prolonged recovery (sensitivity = 81%) and normal recovery (specificity = 83%) in an adolescent, SRC cohort.

Vestibulo-ocular dysfunction in mTBI: Utility of the VOMS for evaluation and management – A review

BACKGROUND: Individuals who have suffered a concussion/mild traumatic brain injury (mTBI) frequently report symptoms associated with vestibular and/or oculomotor dysfunction (VOD) like dizziness, nausea, fatigue, brain fog, headache, gait and neurocognitive impairments which are associated with the development of chronic symptoms. The Vestibular/Ocular Motor Screening (VOMS) tool has been established as a reliable and clinically relevant complement to use alongside a battery of post-concussion tests to improve screening and referral for further evaluation and treatment of VOD. OBJECTIVES: This paper will review the pathoanatomy and symptomatology of common vestibular and oculomotor disorders after concussion, as well as the utility of the VOMS to assist in diagnosis, referral, and management. METHODS: Primary articles were identified using a search via PubMed, Google Scholar, OneSearch, and CINAHL. Search key terms were combinations of “mild traumatic brain injury” or “concussion” or “pursuit” or “accommodation” or “vergence” or “convergence insufficiency” or “saccades” or “vestibulo-ocular reflex” or “vestibular ocular motor screen” or “vestibular rehabilitation”, or “vision rehabilitation” including adult and pediatric populations that were published in print or electronically from 1989 to 2021 in English. Classic papers on anatomy of eye movements, vestibular system and pathological changes in mTBI were also included, regardless of publication date. RESULTS: Objective impairments are commonly found during testing of smooth pursuit, saccades, vergence, accommodation, vestibular ocular reflex, and visual motion sensitivity after mTBI. These deficits can be actively treated with vestibular physical therapy and oculomotor/neuro-optometric vision therapy. VOMS is an efficient and reliable tool that can be used by all healthcare and rehabilitation providers to aid in diagnosis of post-concussion VOD, to help facilitate the decision to refer for further evaluation and treatment to expedite symptomatic post-concussion recovery. CONCLUSIONS: VOD is common after concussion in acute, post-acute, and chronic phases. Once areas of impairments are identified through proper assessment, clinicians can maximize recovery by referring to vestibular physical therapy and/or neuro-optometry to design a targeted treatment program to address individual deficits.

Recovery of symptoms, neurocognitive and vestibular-ocular-motor function and academic ability after sports-related concussion (SRC) in university-aged student-athletes: a systematic review

BACKGROUND

Physiological differences between a maturing and matured brain alters how Sports-Related Concussion (SRC) affects different age groups; therefore, a review specific to university-aged student-athletes is needed.

OBJECTIVES

Determine time to recovery for symptom burden, neurocognitive and Vestibular-Ocular-Motor (VOM) function and academic impact in university-aged student-athletes.

METHODS

Searches were conducted in PubMed, SpringerLink, PsycINFO, Science Direct, Scopus, Cochrane, Web of Science and EMBASE. Articles were included if they contained original data collected within 30 days in university-aged student-athletes, analysed SRC associated symptoms, neurocognitive or VOM function or academic ability and published in English. Two reviewers independently reviewed sources, using the Oxford Classification of Evidence-Based Medicine (CEBM) and the Downs and Black checklist, and independently extracting data before achieving consensus.

RESULTS

58 articles met the inclusion criteria. Recovery of symptoms occurred by 7 and 3-5.3 days for neurocognition. The evidence base did not allow for a conclusion on recovery time for VOM function or academic ability. Few papers investigated recovery times at specified re-assessment time-points and have used vastly differing methodologies.

CONCLUSIONS

To fully understand the implication of SRC on the university-aged student-athlete' studies using a multi-faceted approach at specific re-assessments time points are required.Systematic review registration number: CRD42019130685.

The acute, systemic effects of aerobic exercise in recently concussed adolescent student-athletes: preliminary findings

OBJECTIVES

Examine the acute effects (pre-, during, post-intervention) of two different intensities of aerobic exercise or rest on autonomic, oculomotor, and vestibular function and symptom burden in patients with a recent sport-related concussion (SRC) and compare their responses to sex-matched, age-stratified, non-concussed (HEALTHY) student-athletes.

METHODS

Student-athletes between the ages of 13 and 18 that presented to the sports medicine clinic within Day 3-7 post-SRC and from local schools were recruited for a randomized controlled trial (RCT). The participants were administered the Vestibular/Ocular Motor Screening (VOMS), King-Devick (K-D), and Post-Concussion Symptom Scale (PCSS) before and after the intervention. Heart rate variability (HRV) and mean arterial pressure (MAP) were collected before, during, and after the intervention. The intervention was either a single, 20-min session of treadmill walking at 40% (40HR) or 60% of age-predicted max heart rate (60HR), or seated, rest (NOEX).

RESULTS

30 participants completed the intervention with the SRC group treated 4.5 ± 1.3 days post-injury. Pre-exercise HRV and MAP were significantly different (p's < 0.001) during treatment but returned to pre-exercise values within 5 min of recovery in both the SRC and HEALTHY groups. Both the SRC and HEALTHY groups exhibited similar reductions pre- to post-intervention for symptom severity and count (p's < 0.05), three VOMS items (p's < 0.05) but not K-D time.

CONCLUSIONS

To date, this is the first adolescent RCT to report the acute, systemic effects of aerobic exercise on recently concussed adolescent athletes. The interventions appeared safe in SRC participants, were well-tolerated, and provided brief therapeutic benefit.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier NCT03575455.

Assessment of Saccades and Gaze Stability in the Diagnosis of Pediatric Concussion

OBJECTIVE

To evaluate the discriminatory ability of different repetition increments of saccades and gaze stability testing for diagnosing concussion in adolescents.

DESIGN

Cross-sectional.

SETTING

Suburban high school and academic pediatric tertiary care center.

PARTICIPANTS

Sixty-nine adolescent athletes within 28 days of a sports- or recreation-related concussion and 69 adolescent athletes without recent concussion.

ASSESSMENT OF INDEPENDENT VARIABLES

Symptom provocation with horizontal and vertical saccades and gaze stability testing performed up to 30 repetitions.

MAIN OUTCOME MEASURES

Sensitivity and specificity at 10-repetition increments (≤10, ≤20, ≤30) and area under the receiver operating characteristic curves (AUC) of a visio-vestibular examination (VVE) subscore, scored 0 to 4 based on the number of assessments with symptom provocation, at each repetition increment.

RESULTS

Sensitivity improved when increasing from ≤10 to ≤20 to ≤30 repetitions for horizontal (25% to 50% to 69%) and vertical (32% to 52% to 74%) saccades and horizontal (19% to 45% to 71%) and vertical (23% to 45% to 72%) gaze stability. Specificity was comparable at ≤10 and ≤20 repetitions, but decreased at ≤30 repetitions across assessments. For a VVE subscore (0-4) based on the number of symptomatic assessments, the discriminatory ability of the test was highest at ≤20 repetitions (AUC of 0.79) with an optimal subscore of one (sensitivity 59%, specificity 96%).

CONCLUSIONS

A VVE including a higher threshold level of repetitions for saccades and gaze stability has improved discriminatory ability for concussion, with an optimized AUC of 0.79 at ≤20 repetitions.

CLINICAL RELEVANCE

The findings in this study suggest that a higher threshold level of repetitions of 2 commonly used visio-vestibular assessments enables clinicians to more accurately diagnose youth concussion.

Vestibular/Ocular Motor Screening is Independently Associated With Concussion Symptom Severity in Youths

OBJECTIVE

To examine the independent contributions of the Vestibular/Ocular Motor Screening (VOMS) to concussion symptom severity in youths while controlling for computerized neurocognitive screening performance, demographics, and medical history.

STUDY DESIGN

Cross-sectional.

SETTING

Concussion specialty clinic.

PARTICIPANTS

A retrospective review of 278 concussed youths clinical charts resulted in a total of 158 participants (16.5 ± 2.8 years, 46.8% women, 4.3 ± 3.3 days post-injury) when exclusionary criteria (ie, neurological or substance use disorders, age >21, >14 days since injury, and missing/incomplete data) were applied.

INDEPENDENT VARIABLES

Vestibular/Ocular Motor Screening items and computerized neurocognitive test scores.

MAIN OUTCOME MEASURES

Standardized postconcussion symptom scale scores.

RESULTS

At the univariate level, all VOMS items were positively associated with concussion symptom severity at small to medium effect sizes (r range 0.26-0.42). Women and individuals with a concussion history and/or Attention Deficit Disorder/Attention Deficit Hyperactivity Disorder diagnosis reported higher VOMS item scores (Ps < 0.10). In a multiple hierarchical regression, the contribution of VOMS item scores was significant and explained 9.6% of the variance in concussion symptom severity after adjustment for sex, baseline VOMS symptom ratings, and ImPACT scores [F(6, 141) = 3.90, P = 0.001]. Vertical saccades (b = 2.22, P = 0.003) and vertical vestibulo-ocular reflex (VOR; b = -1.46, P = 0.004) VOMS items significantly contributed to concussion symptom severity in the multivariable model.

CONCLUSIONS

Findings from this study provide support for the independent contributions of the VOMS items, particularly vertical saccades and vertical VOR, to acute concussion symptom severity in youths. Further work is warranted for a comparison of the VOMS to the full gold standard of concussion testing (ie, clinical interview, physical examination, balance testing, and neurocognitive assessment).

Minimum detectable change and false positive rates of the vestibular/ocular motor screening (VOMS) tool: an NCAA-DoD care consortium analysis

OBJECTIVE

To derive minimum detectable change (MDC) across individual Vestibular-Ocular Motor Screening (VOMS) items and VOMS overall score in 17-25 years old collegiate athletes and to examine false positive rates.

METHOD

Participants (n = 378) completed VOMS pre-season for two consecutive years. MDC was identified for individual VOMS symptom items and NPC distance (cm). Both total and change methods of VOMS scoring were included in analysis.

RESULTS

Regarding total scoring, MDC for ocular VOMS symptom items was 1 and MDC for vestibular VOMS symptoms items was 2. MDC for NPC was 4 cm and for VOMS overall score was 10. Regarding change scoring, MDC for each VOMS symptom item was 1, and for VOMS overall score was 8. False positives ranged from 5.3% to 15.9%.

CONCLUSIONS

This study presents MDCs for each VOMS item and overall VOMS score, using total and change scoring. These values can be considered true change outside measurement error with 95% confidence in a 17-25 year old collegiate athlete population.

Does Exercise Increase Vestibular and Ocular Motor Symptom Detection After Sport-Related Concussion?

BACKGROUND AND PURPOSE

Postconcussive vestibular and ocular motor symptoms are common and contribute to longer recovery. The Vestibular/Ocular Motor Screening (VOMS) is used to detect such symptoms, but a VOMS performed at rest may miss symptoms that are only provoked by exertion. Supervised exercise challenges (SECs) have been shown to detect concussion-related symptoms provoked by physical exertion. The purpose of this study was to determine whether athletes undergoing an SEC will exhibit greater symptom provocation with the VOMS compared to a VOMS performed at rest prior to an SEC.

METHODS

Thirty-six athletes (58.3% male) between ages 10 and 18 years and within 30 days of concussion were included. All participants completed VOMS assessments at rest and immediately after an SEC. VOMS total symptom score increases were calculated for both pre- and post-SEC assessments compared using Wilcoxon ranked sum tests. The frequencies of positive assessments for each VOMS item were compared using McNemar's test.

RESULTS

There were significant increases in post-SEC symptom provocation scores compared with pre-SEC scores for all VOMS items. The post-SEC VOMS identified 29 participants (80.6%) as positive in at least 1 VOMS item compared with 21 participants (58.3%) identified as positive pre-SEC (P = 0.008). For all VOMS items, the post-SEC VOMS identified participants who were previously negative on a pre-SEC VOMS but became positive after the SEC.

DISCUSSION AND CONCLUSIONS

An SEC performed prior to a VOMS assessment may increase the detection of vestibular and ocular motor symptoms that may be missed if the VOMS was performed only at rest.Video Abstract available for more insight from the authors (see the Video Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A342).

Preseason Vestibular Ocular Motor Screening in Children and Adolescents

OBJECTIVES

The primary purpose of this study was to examine vestibular/ocular motor screening (VOMS) test performance in a sample of healthy youth ice hockey players. A particular focus was to investigate the potential effects of age and pre-existing health conditions, including concussion history, attention-deficit/hyperactivity disorder (ADHD), learning disability (LD), headaches/migraines, and depression/anxiety on preseason baseline VOMS performance, including the near point of convergence (NPC) distance.

DESIGN

Cross-sectional cohort.

SETTING

Outpatient physiotherapy clinic.

PARTICIPANTS

Three hundred eighty-seven male youth hockey players, with an average age of 11.9 years (SD = 2.2, range = 8-17), completed the VOMS and responded to self- or parent-reported demographic and medical history questionnaires during preseason baseline assessments.

INDEPENDENT VARIABLES ASSESSED

Age, sex, and mental and physical health history including ADHD, headaches, depression, anxiety, migraine, and LD.

OUTCOME MEASURE

Vestibular/ocular motor screening.

RESULTS

The large majority of boys scored within normal limits on the VOMS, ie, they reported no symptom provocation of more than 2 points on any VOMS subset (89%) and had a normal NPC distance, ie, <5 cm (78%). The individual VOMS subtests had low abnormality rates, and demographic and pre-existing health conditions, such as age, headache or migraine history, previous neurodevelopmental conditions, or mental health problems, were not associated with clinically meaningful symptom provocation during the VOMS.

CONCLUSIONS

There was a low rate of abnormal findings for the individual VOMS subtests, with the exception of NPC distance, among male youth hockey players during preseason assessment.

The Current Status of Concussion Assessment Scales: A Critical Analysis Review

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Concussion is a complex pathophysiologic process that affects the brain; it is induced by biomechanical forces, with alteration in mental status with or without loss of consciousness.

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Concussion assessment tools may be broadly categorized into (1) screening tests such as the SAC (Standardized Assessment of Concussion), the BESS (Balance Error Scoring System), and the King-Devick (KD) test; (2) confirmatory tests including the SCAT (Sport Concussion Assessment Tool), the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing), and the VOMS (Vestibular Oculomotor Screening); and (3) objective examinations such as brain network activation (BNA) analysis, imaging studies, and physiologic markers.

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The KD, child SCAT3 (cSCAT3), child ImPACT (cImPACT), and VOMS tests may be used to evaluate for concussion in the pediatric athlete.

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Future work with BNA, functional magnetic resonance imaging, diffusion tensor imaging, and serum biomarkers may provide more objective assessment of concussion, neurologic injury, and subsequent recovery.

Is near point of convergence associated with symptom profiles or recovery in adolescents after concussion?

Our purpose was to compare the clinical and injury characteristics of concussion patients with a receded near point of convergence (NPC) vs those without a receded NPC. Concussion patients were seen within 14 days of injury. We compared those with receded a NPC (>6 cm) break point distance and those with a normal NPC distance on symptom, behavioral, and clinical assessments. We also compared NPC break points between those who did/did not recover within 28 days of injury. 123 patients completed the assessment. 77/123 (63%) of participants demonstrated a receded NPC when tested within 14 days of injury. Those with receded a NPC break point (n = 77; mean = 14.9, SD = 1.5 years; 47% female) were significantly younger than those with a normal NPC break point (n = 46; mean = 15.7, SD = 1.7 years; 46% female). The receded NPC break point group had a significantly greater proportion of patients reporting headaches (86% vs. 61%), as well as significantly greater cognitive (mean = 13.4, SD = 8.7 vs. mean = 8.8, SD = 8.6), somatic (mean = 10.0, SD = 5.9 vs. mean = 6.9, SD = 6.6), and overall (mean = 23.7, SD = 13.6 vs. mean = 15.8, SD = 14.4) symptom severity. Our multivariable model indicated among all potential predictor variables, more severe somatic symptoms were significantly associated with a greater NPC break point (β = 0.26; 95% CI = 0.01, 0.52). The group who went onto experience persistent symptoms had a significantly greater NPC break point at initial evaluation than those without persistent symptoms (mean = 9.7, SD = 7.5 cm vs. mean = 7.0, SD = 4.0 cm). Those with a receded NPC break point at initial evaluation showed an increased symptom burden, most notable with somatic symptoms, compared with those without a receded NPC break point.

Concussion in the Athletic Training Room: a Team Physician Narrative

PURPOSE OF THE REVIEW

Concussion evaluation and management has changed significantly. Understanding proper recognition, evaluation, and management allows for improved provision of care to patients. This paper will approach this topic from a sideline to training room management versus the traditional clinic evaluation RECENT FINDINGS: Research is continuing to refine and examine tools to assist in proper concussion evaluation. Concussion recovery protocols are becoming more conservative as patients are taking longer to recover than previously thought. Treatment of concussion is becoming more sophisticated and patient involved. Concussion research has increased dramatically over the last 30 years changing our approach to diagnosis and treatment. The area of concussion will continue to evolve as research continues to look at effective tools and markers for diagnosis and effective treatment protocols become substantiated through research.

Longitudinal Vestibular and Oculomotor Impairments Among Amateur Athletes 1 Year Following Sport-Related Concussion: A Prospective Follow-Up

OBJECTIVES

To investigate (i) the presence of vestibular and oculomotor impairments and (ii) the self-perceived effects of concussion-associated dizziness on health-related quality of life among amateur athletes 6 months and 1 year following sport-related concussion compared with nonconcussed, control athletes.

DESIGN

Prospective, matched-cohort study.

SETTING

Clinical assessment laboratory.

PARTICIPANTS

Amateur athletes who were diagnosed with sport-related concussion within 1 week of injury, and sex-, age-, and activity-matched nonconcussed, control athletes.

MAIN MEASURES

Participants were evaluated 6 months and 1 year following sport-related concussion and enrollment in the longitudinal study using the Vestibular and Oculo-Motor Screening and the Dizziness Handicap Inventory. We performed multivariate analyses of variance and chi-square analyses to compare concussion and control group scores at each study assessment.

RESULTS

Forty-seven participants with concussion and 47 control participants completed the study. The concussion group reported similar mean symptom provocation scores on the Vestibular and Oculo-Motor Screening and exhibited a similar near-point convergence distance compared with the control group at the 6-month and 1-year study assessments. The concussion and control groups had similar perceptions of the effects of dizziness on their health-related quality of life at both study assessments.

CONCLUSION

Meaningful differences in vestibular and oculomotor symptom provocation and self-perceived effects of dizziness on everyday life were not observed between concussed and nonconcussed, control athletes 6 months and 1 year following sport-related concussion.

Utility of 1 Measurement Versus Multiple Measurements of Near Point of Convergence After Concussion

CONTEXT

Increased near point of convergence (NPC) distance is a common finding after concussion and is associated with physical symptoms and worsened neurocognitive performance. Vestibular/Ocular Motor Screening measures NPC distance across 3 trials and uses the average measurement to inform clinical care. However, whether 3 trials are necessary, are consistent, or add clinical utility is unknown.

OBJECTIVE

To investigate the consistency across 3 trials of NPC and establish the classification accuracy (ie, clinical utility) of 1 or 2 trials compared with the standardized average of 3 trials.

DESIGN

Retrospective cohort study.

SETTING

Sports medicine clinic and research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Consecutively enrolled patients aged 10 to 22 years with diagnosed concussions (74% sport related; n = 380).

MAIN OUTCOME MEASURE(S)

The previously reported clinical cutoff value of ≥5 cm across 3 trials was used. Pearson correlation and intraclass correlation coefficients were used to evaluate agreement between trials and average scores. Reliable change indices (RCIs) using 95% confidence intervals were also calculated.

RESULTS

The Pearson correlation (r = .98) and intraclass correlation (0.98) coefficients revealed excellent agreement between the first measurement and average NPC distance across 3 measurements. The RCI across all trials was 2 cm. When the first NPC measurement was ≤3 cm or ≥7 cm, agreement existed within the RCI between the first measurement and the average of 3 measurements in 99.6% of cases. When we averaged the first and second measurements, 379/380 (99.7%) participants had the same classification (ie, <5 cm = normal, ≥5 cm = abnormal) as the average NPC distance across 3 measurements.

CONCLUSIONS

Our findings suggest limited utility of multiple or average NPC distance measurements when the initial NPC distance is outside of RCI clinical cutoffs (ie, ≤3 cm or ≥7 cm). Given the high consistency between the first measurement and average NPC distance across 3 trials, only 1 measurement of NPC distance is warranted unless the first measurement is between 3 and 7 cm.

A COMPARISON OF THE PAPER AND COMPUTERIZED TABLET VERSION OF THE KING-DEVICK TEST IN COLLEGIATE ATHLETES AND THE INFLUENCE OF AGE ON PERFORMANCE

Background

Sport-related concussion is a public concern with between 1.6 and 3.8 million sport- and recreation-related injuries occurring annually. An estimated 65% to 90% of concussed athletes show oculomotor disruption such as difficulty with saccades, accommodation, smooth pursuit, and fixation. A rapid number-naming saccade test, the King-Devick (K-D) test, has shown promising results as part of a multifaceted concussion assessment tool.

Purpose

The purpose of the current study was to evaluate the two versions of the K-D in collegiate aged (18-24) athletes to determine the agreement between versions. A secondary purpose was to investigate the association of K-D scores with sport, sex, use of glasses or contacts, and age of the athlete.

Study design

Descriptive laboratory study.

Methods

Division 1 NCAA collegiate athletes across ten sports were recruited to participate in baseline concussion assessments at the beginning of their respective athletic season. Correlations and multivariable logistic regression analyses were used to investigate the association of K-D scores with sex and age.

Results

One-hundred and nine athletes (69 males, 40 females; mean age = 20.40 ± 1.38 years) were baseline tested. There was excellent agreement (ICC=0.93, 95% CI: 0.90, 0.95) between the paper and computer version. Preseason K-D scores were statistically different (r²=0.873, p<0.05) with athletes scoring a mean of 37.58 seconds on the paper version (95% CI, 36.21, 38.96) and athletes scoring a mean of 41.48 seconds for the computerized tablet version (95% CI, 40.17, 42.91). There were no significant differences in sex, sport, or use of glasses noted for both versions. Age differences were identified; eighteen-year-old athletes took statistically longer than their peers for both K-D versions. Pairwise comparisons showed statistically significant differences between 18-year olds up to the age of 21-year-olds (p<0.05) for the computer version and statistically significant differences between 18-year olds up to 22-year-olds (p<0.05) for the paper version.

Conclusion

This study supports the use of either version of the K-D test as a potential part of a multifaceted concussion assessment. The age of the athlete influences scores and therefore a K-D baseline should be repeated annually for collegiate athletes. Clinicians should not substitute K-D versions (computer vs. paper) in comparing baseline to a post-concussion K-D score as the scores are quite different.

Level of evidence

Level 3.

Military Acute Concussion Evaluation: A Report on Clinical Usability, Utility, and User's Perceived Confidence

The signs and symptoms of concussion may not always be clear. Therefore, the Military Acute Concussion Evaluation (MACE) tool was created to help deployed medics and corpsmen identify concussions, particularly in deployed settings. Since 2008, the MACE has been updated multiple times, but each new version of the tool is more complex and takes longer to complete. The objective of this study was to assess the usability, utility, and perceived confidence among military healthcare providers for the latest version, MACE 2. Therefore, a semi-structured interview, including Likert-scale and open-ended questions, was conducted among military healthcare providers at Landstuhl Regional Medical Center in order to assess the usability, utility and perceived confidence of the MACE 2. All of the providers had completed a training course on the MACE 2 and had used it for at least 3 months in their clinics. A total of 28 participants were recruited, including 22 medics, two physicians, three nurses, and one physician assistant. Average scores of usability, utility, and confidence were 5.7, 6.6, and 6.3, respectively, with 7.0 being the most positive score, and thus indicating positive assessments in all categories. The open-ended questions revealed high usability and confidence and the desire for additional training on the tool. In conclusion, despite the increased complexity and duration of the MACE 2 compared with the previous version of this tool, military providers and army medics found the new MACE 2 very useable and had a high degree of confidence in its performance.

Eye Movements, Dizziness, and Mild Traumatic Brain Injury (mTBI): A Topical Review of Emerging Evidence and Screening Measures

BACKGROUND AND PURPOSE

Eye movements may be adversely affected after mild traumatic brain injury (mTBI) and should be examined. The purpose of this topical review is to provide the clinician with the most up-to-date knowledge related to eye movement abnormalities, screening measures, and evidence related to exercise interventions that are designed to enhance outcomes in persons after mTBI.

SUMMARY OF KEY POINTS

Presence of eye misalignment such as tropias or phoria or symptoms with head/eye movements such as vestibulo-ocular reflex (VOR) × 1, saccades, or smooth pursuits may slow the person's recovery. Tools such as the Convergence Insufficiency Symptom Survey, the Vestibular/Ocular Motor Screening, the Pediatric Vestibular Symptom Questionnaire, and the Pediatric Visually Induced Dizziness questionnaire may aid in identifying visual concerns to target in the physical therapy intervention program. There is emerging evidence that vestibular rehabilitation enhances recovery in persons after mTBI.

RECOMMENDATIONS FOR CLINICAL PRACTICE

A thorough eye examination is highly recommended after mTBI to identify targeted areas for intervention.

Reliability of the visio-vestibular examination for concussion among providers in a pediatric emergency department

BACKGROUND

Visio-vestibular examination (VVE) deficits are common following pediatric concussion. Guidelines recommend assessing these deficits on all potentially concussed youth given their diagnostic and prognostic value, however test psychometrics of the VVE in the emergency department (ED) setting are unknown. Our objective was to determine the inter-rater (IRR) and test-retest reliability (TRR) of the VVE in a pediatric ED.

METHODS

We enrolled 155 patients (112 IRR; 43 TRR) age 6-18 years with head injury presenting to the ED of a tertiary care children's hospital. Exams were performed by a group of 65 attending/fellow physicians, pediatricians, and advanced practice providers. The VVE consisted of 9 maneuvers (smooth pursuits, horizontal/vertical saccades and gaze stability, binocular convergence, left/right monocular accommodation, complex tandem gait). Cohen's kappa was calculated for IRR and TRR for each element.

RESULTS

For IRR, 5/9 kappas (saccades, gaze stability, monocular accommodation) were in the moderate agreement range (0.40 to 0.60); remaining kappas showed fair agreement. For TRR, 6/9 maneuvers (saccades, horizontal gaze stability, monocular accommodation, tandem gait) showed substantial agreement (0.60 to 0.80). Kappas of 7/9 elements for subjects age 15-18 showed improved IRR and TRR.

CONCLUSIONS

The individual elements of the VVE show fair to moderate agreement between providers and moderate to substantial agreement among the same provider in the ED setting. These findings suggest a role in the VVE in evaluating concussion acutely, particularly given its previously demonstrated ability to assist in risk stratification of concussed youth and the importance of early diagnosis for improved outcomes.

Effects of exercise on symptoms, vestibular/ocular motor screening and postural stability in a college-aged sample

Aim:

To examine the effects of maximal exercise on symptoms, vestibular/ocular motor screening (VOMS) and postural stability.

Methodology:

A total of 17 college-aged individuals completed a symptom scale, VOMS and the modified Clinical Test for Sensory Interaction and Balance (m-CTSIB), followed by a graded maximal exercise treadmill test. Assessments were repeated post exercise, 20 and 40 min post-exercise.

Results:

Significant increases in total symptoms, symptom severity scores and m-CTSIB scores from baseline to immediate post exercise were reported. Following 20-min recovery, improvements were noted on symptoms, visual motion sensitivity on VOMS and m-CTSIB.

Conclusion:

Symptoms and postural stability are influenced by exercise and following 20 min of rest, returned to baseline, indicating that a period of 20 min following a suspected concussion may be needed to negate exercise effects.

Baseline concussion testing is often completed by athletes in a rested state, prior to beginning their respective sports season. However, concussions are often sustained while the athlete has undergone physical exertion and is in a fatigued state. Therefore, it may be inaccurate to compare fatigue-state sideline assessments with resting-state baselines. The purpose of this study was to compare the effects of pre- and post-exercise performance on common concussion assessment tools. Worse performance was noted between pre- and immediately post-exercise on these tools. A duration of 20 min after exercise, performance returned to pretest levels, indicating that clinicians should wait at least 20 min before conducting a sideline examination after a sustained concussion, to cancel out the effects of exercise.

Considerations for Diagnosis and Management of Concussion

Concussion is an ongoing concern for health care providers. The incidence rates continue to be high and the rate of recovery is variable due to potential risk factors. With no valid biomarkers, diagnosis and assessment of concussion remain a clinical challenge. The heterogeneity in presentation following injury provides an additional level of complexity, requiring the screening and evaluation of diverse body systems, including oculomotor, vestibular, autonomic, psychiatric, cervical, and cognitive symptoms. While a few tools, such as the Vestibular/Ocular Motor Screening and Balance Error Scoring System, have been developed specifically for concussion, the vast majority of tests are adapted from other conditions. Further complicating the process is the overlapping and interactive nature of the multiple domains of postconcussion presentation. This commentary illustrates how clinicians can conceptualize the multiple profiles that present following concussion and describes tools that are available to assist with screening and evaluation of each area. The multifaceted nature of concussion warrants broad clinical screening skills and an interdisciplinary approach to management. J Orthop Sports Phys Ther 2019;49(11):787-798. doi:10.2519/jospt.2019.8855.

Artificial intelligence as an emerging technology in the current care of neurological disorders

BACKGROUND

Artificial intelligence (AI) has influenced all aspects of human life and neurology is no exception to this growing trend. The aim of this paper is to guide medical practitioners on the relevant aspects of artificial intelligence, i.e., machine learning, and deep learning, to review the development of technological advancement equipped with AI, and to elucidate how machine learning can revolutionize the management of neurological diseases. This review focuses on unsupervised aspects of machine learning, and how these aspects could be applied to precision neurology to improve patient outcomes. We have mentioned various forms of available AI, prior research, outcomes, benefits and limitations of AI, effective accessibility and future of AI, keeping the current burden of neurological disorders in mind.

DISCUSSION

The smart device system to monitor tremors and to recognize its phenotypes for better outcomes of deep brain stimulation, applications evaluating fine motor functions, AI integrated electroencephalogram learning to diagnose epilepsy and psychological non-epileptic seizure, predict outcome of seizure surgeries, recognize patterns of autonomic instability to prevent sudden unexpected death in epilepsy (SUDEP), identify the pattern of complex algorithm in neuroimaging classifying cognitive impairment, differentiating and classifying concussion phenotypes, smartwatches monitoring atrial fibrillation to prevent strokes, and prediction of prognosis in dementia are unique examples of experimental utilizations of AI in the field of neurology. Though there are obvious limitations of AI, the general consensus among several nationwide studies is that this new technology has the ability to improve the prognosis of neurological disorders and as a result should become a staple in the medical community.

CONCLUSION

AI not only helps to analyze medical data in disease prevention, diagnosis, patient monitoring, and development of new protocols, but can also assist clinicians in dealing with voluminous data in a more accurate and efficient manner.

On-field assessment of concussion: clinical utility of the King-Devick test

Sport-related concussion (SRC) is an important public health concern with up to 3.8 million SRCs occurring each year. As the incidence and rate of SRC increases, reliable and valid tools for diagnosis and management are needed. The King-Devick (K-D) test assesses a patient’s visual function based on reading a series of numbers as well as counting both time to completion and errors. Its rapid administration time and simplicity make the K-D test a potentially useful SRC diagnostic tool, though limitations exist in baseline testing and what constitutes an abnormal score. Additionally, the K-D tests should never be used in isolation to diagnose a concussion, but rather as one test in conjunction with additional clinical measures, as part of an individualized approach to each patient. The current review examines the clinical utility of the K-D test.

Artificial intelligence for understanding concussion: Retrospective cluster analysis on the balance and vestibular diagnostic data of concussion patients

OBJECTIVES

We propose a bottom-up, machine-learning approach, for the objective vestibular and balance diagnostic data of concussion patients, to provide insight into the differences in patients' phenotypes, independent of existing diagnoses (unsupervised learning).

METHODS

Diagnostic data from a battery of validated balance and vestibular assessments were extracted from the database of the Swiss Concussion Center. The desired number of clusters within the patient database was estimated using Calinski-Harabasz criteria. Complex (self-organizing map, SOM) and standard (k-means) clustering tools were used, and the formed clusters were compared.

RESULTS

A total of 96 patients (81.3% male, age (median [IQR]): 25.0[10.8]) who were expected to suffer from sports-related concussion or post-concussive syndrome (52[140] days between diagnostic testing and the concussive episode) were included. The cluster evaluation indicated dividing the data into two groups. Only the SOM gave a stable clustering outcome, dividing the patients in group-1 (n = 38) and group-2 (n = 58). A large significant difference was found for the caloric summary score for the maximal speed of the slow phase, where group-1 scored 30.7% lower than group-2 (27.6[18.2] vs. 51.0[31.0]). Group-1 also scored significantly lower on the sensory organisation test composite score (69.0[22.3] vs. 79.0[10.5]) and higher on the visual acuity (-0.03[0.33] vs. -0.14[0.12]) and dynamic visual acuity (0.38[0.84] vs. 0.20[0.20]) tests. The importance of caloric, SOT and DVA, was supported by the PCA outcomes. Group-1 tended to report headaches, blurred vision and balance problems more frequently than group-2 (>10% difference).

CONCLUSION

The SOM divided the data into one group with prominent vestibular disorders and another with no clear vestibular or balance problems, suggesting that artificial intelligence might help improve the diagnostic process.