Convergence Insufficiency Identifies Athletes at Risk of Prolonged Recovery From Sport-Related Concussion

Optimizing the Combination of Common Clinical Concussion Batteries to Predict Persistent Postconcussion Symptoms in a Prospective Cohort of Concussed Youth

BACKGROUND

Studies have evaluated individual factors associated with persistent postconcussion symptoms (PPCS) in youth concussion, but no study has combined individual elements of common concussion batteries with patient characteristics, comorbidities, and visio-vestibular deficits in assessing an optimal model to predict PPCS.

PURPOSE

To determine the combination of elements from 4 commonly used clinical concussion batteries and known patient characteristics and comorbid risk factors that maximize the ability to predict PPCS.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

We enrolled 198 concussed participants-87 developed PPCS and 111 did not-aged 8 to 19 years assessed within 14 days of injury from a suburban high school and the concussion program of a tertiary care academic medical center. We defined PPCS as a Post-Concussion Symptom Inventory (PCSI) score at 28 days from injury of ≥3 points compared with the preinjury PCSI score-scaled for younger children. Predictors included the individual elements of the visio-vestibular examination (VVE), Sport Concussion Assessment Tool, 5th Edition (SCAT-5), King-Devick test, and PCSI, in addition to age, sex, concussion history, and migraine headache history. The individual elements of these tests were grouped into interpretable factors using sparse principal component analysis. The 12 resultant factors were combined into a logistic regression and ranked by frequency of inclusion into the combined optimal model, whose predictive performance was compared with the VVE, initial PCSI, and the current existing predictive model (the Predicting and Prevention Postconcussive Problems in Pediatrics (5P) prediction rule) using the area under the receiver operating characteristic curve (AUC).

RESULTS

A cluster of 2 factors (SCAT-5/PCSI symptoms and VVE near point of convergence/accommodation) emerged. A model fit with these factors had an AUC of 0.805 (95% CI, 0.661-0.929). This was a higher AUC point estimate, with overlapping 95% CIs, compared with the PCSI (AUC, 0.773 [95% CI, 0.617-0.912]), VVE (AUC, 0.736 [95% CI, 0.569-0.878]), and 5P Prediction Rule (AUC, 0.728 [95% CI, 0.554-0.870]).

CONCLUSION

Among commonly used clinical assessments for youth concussion, a combination of symptom burden and the vision component of the VVE has the potential to augment predictive power for PPCS over either current risk models or individual batteries.

The Ability of Vestibular and Oculomotor Screenings to Predict Recovery in Patients After Concussion: A Systematic Review of the Literature

OBJECTIVE

The objective of this systematic review was to investigate if a positive vestibular or oculomotor screening is predictive of recovery in patients after concussion.

DATA SOURCES

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to search through PubMed, Ovid MEDLINE, SPORTDiscus, and the Cochrane Central Register of Controlled Trials (CENTRAL) and hand searches of included articles.

STUDY SELECTION

Two authors evaluated all articles for inclusion and assessed their quality using the Mixed Methods Assessment Tool.

DATA EXTRACTION

After quality assessment was completed, the authors extracted recovery time, vestibular or ocular assessment results, study population demographics, number of participants, inclusion and exclusion criteria, symptom scores, and any other outcomes of assessments reported in the included studies.

DATA SYNTHESIS

Data were critically analyzed by 2 of the authors and categorized into tables regarding the ability of researchers of each article to answer the research question. Many patients who have vision, vestibular, or oculomotor dysfunction appear to have longer recovery times than patients who do not.

CONCLUSIONS

Researchers routinely reported that vestibular and oculomotor screenings are prognostic of time to recovery. Specifically, a positive Vestibular Ocular Motor Screening test appears to consistently predict longer recovery.

Baseline Computerized Neurocognitive Testing and Oculomotor Measures are not Altered by Hormonal Contraceptive Use

OBJECTIVE

Neurocognitive testing and oculomotor assessment have been an integral component to provide objective measures for sport-related concussion (SRC) detection and management. Hormonal contraceptive (HC) use is common among collegiate female athletes and may modify baseline SRC performance. The purpose was to examine the effects of HC use on baseline computerized neurocognitive testing (CNT) and oculomotor testing in college-aged individuals.

METHOD

A total of 63 participants (22 HC using females, 22 non-HC using females, 19 males) completed a baseline SRC battery consisting of CNT, near point of convergence (NPC), and the King-Devick (KD) test. CNT measures were composite scores of verbal and visual memory, visual motor processing speed and reaction time, impulse control, and cognitive efficiency index (CEI). NPC was measured as the average convergence distance across three trials. KD time was recorded as total time for each of the two trials and best trial marked as baseline.

RESULTS

There were no group differences between HC, non-HC, and male control groups on all baseline CNT composite scores (p = .13-.98), impulse control (p = .47), and CEI (p = .49). NPC distance was similar between groups (p = .41), as well as KD time by trial (Trial 1 p = .65; 2 p = .48) and best time (p = .49).

CONCLUSIONS

HC use does not appear to influence baseline SRC measures of neurocognition and oculomotor assessment. Clinicians should continue to consider the effects of modifying factors at baseline and post-concussion. Additional research is needed to better understand sex hormone levels and SRC performance measures.

When should an athlete retire or discontinue participating in contact or collision sports following sport-related concussion? A systematic review

OBJECTIVE

To systematically review the scientific literature regarding factors to consider when providing advice or guidance to athletes about retirement from contact or collision sport following sport-related concussion (SRC), and to define contraindications to children/adolescent athletes entering or continuing with contact or collision sports after SRC.

DATA SOURCES

Medline, Embase, SPORTSDiscus, APA PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials were searched systematically.

STUDY ELIGIBILITY CRITERIA

Studies were included if they were (1) original research, (2) reported on SRC as the primary source of injury, (3) evaluated the history, clinical assessment and/or investigation of findings that may preclude participation in sport and (4) evaluated mood disturbance and/or neurocognitive deficits, evidence of structural brain injury or risk factors for increased risk of subsequent SRC or prolonged recovery.

RESULTS

Of 4355 articles identified, 93 met the inclusion criteria. None of the included articles directly examined retirement and/or discontinuation from contact or collision sport. Included studies examined factors associated with increased risk of recurrent SRC or prolonged recovery following SRC. In general, these were low-quality cohort studies with heterogeneous results and moderate risk of bias. Higher number and/or severity of symptoms at presentation, sleep disturbance and symptom reproduction with Vestibular Ocular Motor Screen testing were associated with prolonged recovery and history of previous concussion was associated with a risk of further SRC.

CONCLUSION

No evidence was identified to support the inclusion of any patient-specific, injury-specific or other factors (eg, imaging findings) as absolute indications for retirement or discontinued participation in contact or collision sport following SRC.

PROSPERO REGISTRATION NUMBER

CRD42022155121.

Longitudinal Associations of Clinical and Biochemical Head Injury Biomarkers With Head Impact Exposure in Adolescent Football Players

Importance

Consequences of subconcussive head impacts have been recognized, yet most studies to date have included small samples from a single site, used a unimodal approach, and lacked repeated testing.

Objective

To examine time-course changes in clinical (near point of convergence [NPC]) and brain-injury blood biomarkers (glial fibrillary acidic protein [GFAP], ubiquitin C-terminal hydrolase-L1 [UCH-L1], and neurofilament light [NF-L]) in adolescent football players and to test whether changes in the outcomes were associated with playing position, impact kinematics, and/or brain tissue strain.

Design, Setting, and Participants

This multisite, prospective cohort study included male high school football players aged 13 to 18 years at 4 high schools in the Midwest during the 2021 high school football season (preseason [July] and August 2 to November 19).

Exposure

A single football season.

Main Outcomes and Measures

The main outcomes were NPC (a clinical oculomotor test) and serum levels of GFAP, UCH-L1, and NF-L. Participants' head impact exposure (frequency and peak linear and rotational accelerations) was tracked using instrumented mouthguards, and maximum principal strain was computed to reflect brain tissue strain. Players' neurological function was assessed at 5 time points (preseason, post-training camp, 2 in season, and postseason).

Results

Ninety-nine male players contributed to the time-course analysis (mean [SD] age, 15.8 [1.1] years), but data from 6 players (6.1%) were excluded from the association analysis due to issues related to mouthguards. Thus, 93 players yielded 9498 head impacts in a season (mean [SD], 102 [113] impacts per player). There were time-course elevations in NPC and GFAP, UCH-L1, and NF-L levels. Compared with baseline, the NPC exhibited a significant elevation over time and peaked at postseason (2.21 cm; 95% CI, 1.80-2.63 cm; P < .001). Levels of GFAP and UCH-L1 increased by 25.6 pg/mL (95% CI, 17.6-33.6 pg/mL; P < .001) and 188.5 pg/mL (95% CI, 145.6-231.4 pg/mL; P < .001), respectively, later in the season. Levels of NF-L were elevated after the training camp (0.78 pg/mL; 95% CI, 0.14-1.41 pg/mL; P = .011) and midseason (0.55 pg/mL; 95% CI, 0.13-0.99 pg/mL; P = .006) but normalized by the end of the season. Changes in UCH-L1 levels were associated with maximum principal strain later in the season (0.052 pg/mL; 95% CI, 0.015-0.088 pg/mL; P = .007) and postseason (0.069 pg/mL; 95% CI, 0.031-0.106 pg/mL; P < .001).

Conclusions and Relevance

The study data suggest that adolescent football players exhibited impairments in oculomotor function and elevations in blood biomarker levels associated with astrocyte activation and neuronal injury throughout a season. Several years of follow-up are needed to examine the long-term effects of subconcussive head impacts in adolescent football players.

Incidence of Remote Near-Point of Convergence in University Athletes After Sport-Related Concussion

OBJECTIVE

Near-point of convergence (NPC) testing is an attractive screening tool in the sport setting because it is rapid, requires few resources, and is easy to administer. Remote NPC has been reported after sport-related concussion (SRC), although the incidence among a university-aged population is not well defined. The purpose of the study was to examine the incidence of remote NPC after SRC in a cohort of Canadian interuniversity athletes.

DESIGN

Cross-sequential.

SETTING

University.

PARTICIPANTS

One hundred thirty-two university athletes [SRC, n = 68; musculoskeletal (MSK) injury, n = 64] were tested before the beginning of their competitive season and again after their injury.

INDEPENDENT VARIABLES

Healthy athletes measured preseason were compared with athletes after SRC or MSK injury using both longitudinal and cross-sectional designs.

MAIN OUTCOME MEASURES

Remote NPC (pass/fail), measured at 6 cm or greater, repeated 3 times.

RESULTS

After SRC, 22% of athletes failed their test postinjury (95% CI, 14%-33%). Comparatively, in the MSK group, 3% of athletes failed their test postinjury (95% CI, 1%-7%). A direct comparison of both injury groups yielded a mean 19% higher prevalence of failed NPC tests after SRC versus MSK injury (95% CI, 10%-30%). There seems to be no relationship between reported symptom burden and NPC performance after SRC.

CONCLUSION

Remote NPC occurs in approximately 1 of 5 athletes after SRC and is rarely observed after MSK injury.

Concussion Recovery in Children and Adolescents: A Retrospective Study

Background

Concussion is a common injury among children and adolescents, with a growing body of literature supporting a variety of diagnostic and treatment modalities. Recovery is variable and depends on multiple factors that can be evaluated through a clinic visit: a thorough history, physical examination, and use of the Post-concussion Symptom Scale (PCSS).

Purpose/Hypothesis

The purpose of this study was to evaluate factors associated with overall recovery from concussion in children and adolescents in the clinical setting. It was hypothesized that the presence of 1 of a number of pre- or postinjury characteristics will be associated with poor concussion recovery.

Study Design

Case-control study; Level of evidence, 3.

Methods

We conducted a retrospective chart review of adolescents and children aged 6 to 17 years with a diagnosis of concussion who were evaluated at a single sports medicine center between January 2015 and December 2019. Cases were categorized into recovered (PCSS <7) and poorly recovered (PCSS ≥7) cohorts based on the last PCSS scores during clinical follow-ups for concussion management.

Results

Of the 162 charts reviewed, 110 cases met inclusion criteria. Significant statistical differences were found between the recovered and poorly recovered cohorts regarding mean days from injury to last clinic visit, previous migraine diagnosis, and emergency room (ER) visit before the first clinic visit (P < .01 for all). Binary logistic regression analysis revealed that the most predictive factors associated with poorer recovery were having an ER visit before the first clinic evaluation (P = .01) and previous migraine diagnosis (P = .04).

Conclusion

While many factors may contribute to overall recovery from concussion in pediatric populations, our study suggested that a history of migraine and an ER visit before clinic evaluation may be associated with poor recovery of concussive symptoms.

Examination of Near Point of Convergence Scores in High-School Athletes: Implications for Identifying Binocular Vision Dysfunction After Concussion Injury

OBJECTIVE

To identify normative near point of convergence (NPC) data for healthy high-school-aged athletes (13-19 years old) and determine the percentage of individuals with NPC scores that fall outside the currently accepted clinical cutoff value of 5 cm. Another objective was to determine the relationship between sex, concussion history, and attention deficit disorder/attention deficit hyperactivity disorder (ADD/ADHD) with NPC scores, if any.

DESIGN

Case series.

SETTING

High-school sports medicine clinic.

PATIENTS OR PARTICIPANTS

Near point of convergence was assessed in 718 high-school student athletes (141 females and 577 males) with an average age of 15.96 ± 1.16 years.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

An accommodation convergence ruler was used to measure NPC. Near point of convergence scores were repeated a total of 3 times and the mean used for all statistical analyses.

RESULTS

The NPC scores for all participants averaged 3.58 cm, and the intraclass correlation coefficient for the 3 repeated measurements was 0.956. Approximately 20% of mean NPC scores were above the accepted upper limit of 5 cm. Although a statistically significant effect for sex was identified, the difference between them was considered clinically insignificant. No relationship between NPC and history of concussion or ADD/ADHD was identified.

CONCLUSIONS

Results indicate that in high-school-aged subjects, approximately 20% of individuals may have NPC values that fall outside the current critical cutoff value and may lead to incorrect diagnosis of ocular dysfunction. In addition, NPC does not seem to be affected by the history of concussion or a diagnosis of ADD/ADHD.

Premorbid Primary Headache and Vestibular and Oculomotor Baseline Assessments in Collegiate Athletes

OBJECTIVE

The purpose of this study was to determine the effects of premorbid headache status on vestibular and oculomotor baseline tests in collegiate club athletes.

DESIGN

Retrospective case-control study.

SETTING

Sport Concussion Laboratory.

PATIENTS OR PARTICIPANTS

Collegiate club athletes with a self-reported premorbid headache history (n = 32, 19.50 ± 1.98 years, and 31% women) and age-sex-sport-matched controls (n = 32, 19.56 ± 1.47 years, and 31% women) without a self-reported headache history were included.

INTERVENTIONS

Participants were grouped based on a self-reported headache history at baseline. Controls were randomly matched to self-reported headache participants by age, sex, and sport.

MAIN OUTCOME MEASURES

Vestibular/ocular motor screen (VOMS) baseline symptoms, symptom provocation, near point of convergence (NPC) distance, and King-Devick (K-D) test time were compared between groups.

RESULTS

Athletes with a self-reported headache history at baseline are 3.82 times more likely to have abnormal NPC scores (P = 0.032) and 4.76 times more likely to have abnormal K-D test times (P = 0.014) than those without a headache history. There was no difference in VOMS baseline symptoms or symptom provocation between groups (P > 0.05).

CONCLUSIONS

Club collegiate athletes with a headache history were more likely to screen as abnormal during a vestibular/ocular motor function assessment than athletes without a history of headaches. Healthcare professionals should screen for pre-existing headache during baseline concussion assessments before test interpretation.

CLINICAL RELEVANCE

A premorbid headache history at preseason baseline assessment may influence vestibular and oculomotor function, and care should be taken when interpreting these individuals' tests.

Effect of Sleep-Related Symptoms on Recovery From a Sport-Related Concussion

Background

Sleep issues are commonly reported in athletes after a sport-related concussion (SRC). Further studies are needed to evaluate screening methods for sleep disturbances and the risk of persisting symptoms after an SRC.

Purpose

To evaluate the association between the Sport Concussion Assessment Tool 5 (SCAT5) symptoms of trouble falling asleep, fatigue (or low energy), and drowsiness and the risk of persisting symptoms (≥28 days to recovery) in adolescent athletes.

Study Design

Cohort study; Level of evidence, 3.

Methods

A total of 519 athletes aged 13 to 18 years reported any sleep-related symptoms with an SRC, scored as none (0), mild (1-2), moderate (3-4), or severe (5-6), at their initial office visit (median, 5.4 days after an SRC). Scores were correlated with the risk of persisting symptoms. A composite "sleep cluster" score (range, 0-18) was calculated by summing the SCAT5 component items for trouble falling asleep, fatigue, and drowsiness.

Results

The results indicated that, compared with athletes who reported that they did not have each symptom, (1) athletes who reported mild, moderate, or severe trouble falling asleep were 3.0, 4.6, and 6.7 times more likely to have persisting symptoms, respectively; (2) athletes reporting mild, moderate, or severe fatigue (or low energy) were 2.6, 4.8, and 7.6 times more likely to have persisting symptoms, respectively; and (3) athletes reporting mild, moderate, or severe drowsiness were 1.9, 4.6, and 6.8 times more likely to have persisting symptoms, respectively (P < .001 for all). For every 1-point increase in the sleep cluster score, there was a 1.2-fold increased risk of persisting symptoms and an additional 2.4 days of recovery required (P < .001 for both).

Conclusion

Athletes who reported mild, moderate, or severe sleep-related symptoms on the SCAT5 were at a proportionally increased risk of persisting symptoms at the initial office visit.

Pediatric Sports-Related Concussion: An Approach to Care

Sports-related concussion (SRC) is a common sports injury in children and adolescents. With the vast amount of youth sports participation, an increase in awareness of concussion and evidence that the injury can lead to consequences for school, sports and overall quality of life, it has become increasingly important to properly diagnose and manage concussion. SRC in the student athlete is a unique and complex injury, and it is important to highlight the differences in the management of child and adolescent concussion compared with adults. This review focuses on the importance of developing a multimodal systematic approach to diagnosing and managing pediatric sports-related concussion, from the sidelines through recovery.

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.

Clinical testing of mild traumatic brain injury using computerised eye-tracking tests

Traumatic brain injury (TBI) refers to the alteration of typical brain function that occurs following a blow to the head. Even a mild case of traumatic brain injury (mTBI) can lead to long-term impairment, so accurate and timely detection is vital. Visual symptoms are common following mTBI, so while it may seem to fall outside their typical scope of practice, optometrists are ideally qualified to assess the visual impacts and help with the diagnosis of mTBI. Given that mTBI is challenging to objectively diagnose and has no universally accepted diagnostic criteria, clinicians can lack confidence in diagnosing mTBI, and be hesitant in becoming involved in the management of such patients. The development of easily quantifiable techniques using eye tracking as an objective diagnostic tool provides practitioners with an easier pathway into the field, assigning numerical values to parameters which are difficult to assess using conventional optometric tests. As this evolving technology becomes increasingly integrated into optometric clinical settings, the potential for it to identify deficits accurately and reliably in patients following mTBI, and to monitor both their recovery and the effectiveness of potential treatments will increase. This paper provides an overview of clinical tests, relevant to optometrists, that can uncover oculomotor, attentional, and exteroceptive deficits following a mTBI, so that an optometrist with an interest in eye tracking can play a role in the detection and monitoring of mTBI symptoms.

Neurosensory Screening and Symptom Provocation in Pediatric Mild Traumatic Brain Injury

OBJECTIVE

To evaluate diagnostic/prognostic implications of neurosensory testing during the subacute stage in patients with pediatric mild traumatic brain injury (pmTBI).

SETTING

Recruitment from pediatric emergency department and urgent care clinics, assessment in a controlled environment.

PARTICIPANTS

In total, 146 pmTBI patients evaluated 7.4 ± 2.3 days and approximately 4 months postinjury; 104 age/sex-matched healthy controls (HCs) at equivalent time points.

DESIGN

Prospective cohort study.

MAIN MEASURES

Neurosensory examination based on sequence of 10 established tests of vestibular-ocular, oculomotor, vestibulospinal, and visual functioning.

RESULTS

The amount of symptom provocation (positive change from pretest symptomatology) was significantly increased in pmTBI relative to HCs on every subtest 1 week postinjury, as were deficits in monocular accommodative amplitude and King-Devick Test errors. However, symptom provocation did not meaningfully alter diagnostic sensitivity/specificity relative to more easily obtained pretest symptom ratings. Evidence of clinically significant symptom provocation 1 week postinjury improved sensitivity (Δ = +12.9%) of identifying patients with persistent postconcussive symptoms 4 months postinjury on an independent symptom measure.

CONCLUSIONS

The diagnostic sensitivity/specificity of neurosensory testing in acutely concussed youth may be limited at 1 week postinjury as a function of natural recovery occurring in most emergency department cohorts. Neurosensory screening may have greater utility for identifying patients who experience delayed recovery.

Discriminative Validity of Vestibular Ocular Motor Screening in Identifying Concussion Among Collegiate Athletes: A National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research, and Education Consortium Study

BACKGROUND

Vestibular and ocular motor screening tools, such as the Vestibular/Ocular Motor Screening (VOMS), are recognized as important components of a multifaceted evaluation of sport-related concussion. Previous research has supported the predictive utility of the VOMS in identifying concussion, but researchers have yet to examine the predictive utility of the VOMS among collegiate athletes in the first few days after injury.

PURPOSE

To determine the discriminative validity of individual VOMS item scores and an overall VOMS score for identifying collegiate athletes with an acute sport-related concussion (≤72 hours) from healthy controls matched by age, sex, and concussion history.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Participants (N = 570) aged 17 to 25 years were included from 8 institutions of the National Collegiate Athletic Association-Department of Defense CARE Consortium (Concussion Assessment, Research, and Education): 285 athletes who were concussed (per current consensus guidelines) and 285 healthy controls matched by age, sex, and concussion history. Participants completed the VOMS within 3 days of injury (concussion) or during preseason (ie, baseline; control). Symptoms are totaled for each VOMS item for an item score (maximum, 40) and totaled across items for an overall score (maximum, 280), and distance (centimeters) for near point of convergence (NPC) is averaged across 3 trials. Receiver operating characteristic analysis of the area under the curve (AUC) was performed on cutoff scores using Youden index (J) for each VOMS item, overall VOMS score, and NPC distance average. A logistic regression was conducted to identify which VOMS scores identified concussed status.

RESULTS

A symptom score ≥1 on each VOMS item and horizontal vestibular/ocular reflex ≥2 significantly discriminated concussion from control (AUC, 0.89-0.90). NPC distance did not significantly identify concussion from control (AUC, 0.51). The VOMS overall score had the highest accuracy (AUC, 0.91) for identifying sport-related concussion from control. Among the individual items, vertical saccades ≥1 and horizontal vestibular/ocular reflex ≥2 best discriminated concussion from control.

CONCLUSION

The findings indicate that individual VOMS items and overall VOMS scores are useful in identifying concussion in collegiate athletes within 3 days of injury. Clinicians can use the cutoffs from this study to help identify concussion in collegiate athletes.

Pre-participation Vision Screening and Comprehensive Eye Care in National Collegiate Athletic Association Athletes

SIGNIFICANCE

Pre-participation physical evaluation and its vision screenings have been the mainstay of medical clearance for competitive play for decades. The ability of screening to address athlete's sports-specific vision needs is unknown.

METHODS

Fifty-eight intercollegiate football players consented to participate in a comprehensive, sports-specific eye examination in addition to the standard pre-participation vision screening. Sensitivity, specificity, and positive and negative predictive values were determined for screening's ability to detect athletes whose vision might improve with correction, athletes who had significant ocular findings that impact safety, and either of the two conditions together. The effect no recent eye examination added to pre-participation vision screening results was evaluated for change in screening yield. Descriptive statistics of the cohort and associations with no recent comprehensive eye examination were generated.

RESULTS

The pre-participation vision screening was able to identify three athletes not meeting visual acuity requirements for medical clearance to play without a comprehensive assessment. A failed screening was poorly able to identify athletes who might benefit from improved acuity (sensitivity, 9.1%; specificity, 100%), have sports-specific significant ocular findings (sensitivity, 10.5%; specificity, 97.3%), or have either together (sensitivity, 7.5%; specificity, 100%). Sixty percent (33/55) of athletes reported never having a comprehensive examination or one within the last 10 years. Fifty-eight percent (34/58) had improved best-corrected visual acuity after comprehensive examination, and 81% (47/58) had improved acuity or a sports-specific significant finding.

CONCLUSIONS

The pre-participation vision screening was largely able to identify athletes meeting the minimum visual acuity requirement for athlete clearance. It poorly identified those who might benefit from improved vision with refractive correction and those in whom sport-specific significant eye findings were noted. Comprehensive eye care had a clear benefit for the majority of athletes tested. This benefit needs to be balanced with the potential added costs and time constraints to players and athletic department staff.

Does Vestibular-Ocular-Motor (VOM) Impairment Affect Time to Return to Play, Symptom Severity, Neurocognition and Academic Ability in Student-Athletes following acute Concussion?

Introduction: Research indicates Sports-Related Concussion (SRC) impairs Vestibular-Ocular-Motor (VOM) function. The aim was to explore if VOM impairment correlates with longer Return To Play (RTP), symptom burden, neurocognitive performance and academic capability.Participants: 40 (61.4% male) Loughborough University, UK, rugby union student-athletes who sustained 42 SRCs.Methods: Student-athletes completed an assessment battery during pre-season (baseline), 2, 4, 8 and 14 days post-SRC and prior to RTP and were managed according to the rugby Football Union' community pathway.Outcome measures: Vestibular Ocular-Motor Screening (VOMS), Immediate Post-Concussion Assessment and Cognitive Test, Post-Concussion Symptom Scale, Perceived Academic Impairment Tool questionnaire and percentage of academic activities specifically missed due to SRC.Results: VOMS scores were significantly (p < 0.005) greater than baseline at all time points except RTP. Presence of VOM dysfunction at 14 days post-SRC significantly correlated with a longer RTP, greater symptom burden and increased odds ratio at 2, 4 and 8 days and academic time loss at 2, 4 and 8 days post-SRC.Conclusion: VOM impairment is associated with an increased symptom burden and impaired academic capability, and a longer time to RTP when present at 14 days post-SRC.

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.

Frequency of oculomotor disorders in adolescents 11 to 17 years of age with concussion, 4 to 12 weeks post injury

The purpose of the study was to determine the frequency of vision diagnoses after concussion in adolescents and evaluate the sensitivity and specificity of physician-administered screening for detecting convergence and accommodative disorders post-concussion. We enrolled participants 11 to 17 years old, assessed 4 to 12 weeks following a diagnosed concussion. During the initial concussion examination, a sports medicine physician measured the near point of convergence (NPC), monocular accommodative amplitude (AA), and symptoms using the Convergence Insufficiency Symptom Survey (CISS). A comprehensive oculomotor evaluation was performed by an optometrist. One hundred and thirteen adolescents were enrolled, with a mean age of 15.2 years. Seventy-nine of the 113 (70%) participants had at least one oculomotor diagnosis after concussion, with the most common problems being vergence disorders (60%) and accommodative disorders (57%). The most common vergence disorder was convergence insufficiency (35%). Among accommodative disorders, the most common problem was accommodative insufficiency (35%). In all, 47% of the participants had more than one oculomotor diagnosis following concussion. The sensitivity of physician screening using measures of NPC, AA, and CISS for detecting convergence and accommodative insufficiency was 63%, 43%, 48%, respectively. The results of this study provide additional evidence that vision problems are common in adolescents with persistent concussion symptoms in the sub-acute phase 4 to 12 weeks post-concussion, and current physician screening methods using the NPC, AA, or the CISS underperform. Thus, it is prudent that adolescents with post-concussion symptoms lasting more than 4 weeks post injury receive a comprehensive oculomotor examination.

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.

The impact of high- and moderate-intensity exercise on near-point of convergence metrics

Background: Near point of convergence (NPC) assesses the vergence ability of the visuo-oculomotor system; however, little is known regarding: the extent and duration exercise impacts NPC and the between- and within-day reliability of NPC metrics.Methods: An accommodative ruler with a miniature Snellen chart was placed upon the philtrum (upper lip). Participants (n=9) focused upon a 'V' sized 20/20, while the chart was moved at ~1-2 cm/s toward and away from the eyes (twice in each direction). Testing commenced at 8:00am with NPC measures being collected at baseline before three randomized conditions with serial follow-ups occurring at six post-condition timepoints (0-8 hours following). The conditions consisted of 25-minutes high-intensity intervals (10, one-minute intervals at ~85-90% heart-rate reserve), 45-minutes of moderate-intensity exercise (at ~50-60% heart-rate reserve), and a control condition (30-minutes quiet rest).Results: NPC was not impacted across any of the three conditions (all p > .59). Additionally, NPC measures between baseline conditions and across the control condition displayed very high levels of within-day and between-day reliability (coefficient of variation <3.8%).Conclusions: Future NPC measures using an accommodative ruler can be taken immediately following exercise and may be pertinent as a complementary tool in the future sideline screening of concussion.

First-time sports-related concussion recovery revisited: management changes and impact on recovery

Context

Concussion is among the most common injuries in athletes. Over the past 10 years, concussion knowledge has expanded, and guidelines for management have changed. Recent changes include recommendations against strict mental and physical rest after sustaining a concussion, a better recognition of preexisting conditions predisposing protracted concussion recovery, and the addition of preliminary patient counseling and education about the expected course of concussion recovery.

Objective

To assess the impact of changes in concussion management on the duration of symptoms in middle school and high school athletes after sustaining a first-time, sports-related concussion.

Methods

A retrospective review was performed of medical records of athletes who sustained a concussion between 2016 and 2018 and were treated by the same primary care physician (J.M.N) using the revised approach to concussion management described. Patients were included if they were 11 to 18 years old and had a diagnosis of first-time concussion sustained while playing organized sports. Athletes who sustained a concomitant injury or sustained a concussion outside of organized sports were excluded from the study; athletes lost to follow-up or with incomplete forms were also excluded. Each athlete's length of symptomatic time from his or her concussion was calculated. This data was then compared with a previously-published data set of athletes who sustained a concussion between 2011 and 2013, with the same inclusion criteria but a different approach to concussion management.

Results

A total of 110 male and 72 female athletes (N=182) met the study's eligibility criteria. Collectively, athletes of both sexes from the 2016-2018 data set reported a higher incidence of preexisting conditions associated with prolonged concussion recovery compared with the data set of 2011-2013 athletes. However, both sexes from the 2016-2018 data set also reported a shorter median duration of concussion symptoms compared with the 2011-2013 athletes (median duration 5 vs. 11 days for male athletes and 7 vs. 28 days for female athletes, respectively; p<0.001).

Conclusion

Recent changes in concussion management have led to decreased duration of symptoms among 11- to 18-year-old athletes with first-time, sports-related concussions. These management changes include advocating for early activity, recognizing preexisting conditions, and educating athletes about the realities of concussion recovery.

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.

Near Point of Convergence Deficits and Treatment Following Concussion: A Systematic Review

CONTEXT

Convergence dysfunction following concussion is common. Near point of convergence (NPC) is a quick and easy assessment that may detect oculomotor dysfunction such as convergence insufficiency (CI), but NPC measurements are rarely reported. Convergence dysfunction is treatable in otherwise healthy patients; the effectiveness of oculomotor therapy following concussion is unclear.

OBJECTIVES

The purpose of this article was to systematically review the literature and answer the following clinical questions: (1) Is performance on NPC negatively affected in patients diagnosed with a concussion compared with pre-injury levels or healthy controls? (2) In patients diagnosed with concussion, what is the effect of oculomotor/vision therapy on NPC break measurements?

EVIDENCE ACQUISITION

The search was conducted in CINAHL, SPORTDiscus, MEDLINE, and PubMed using terms related to concussion, mild traumatic brain injury, convergence, vision, and rehabilitation. Literature considered for review included original research publications that collected measures of NPC break in concussion patients, with a pretest-posttest comparison or comparison with a healthy control group. A literature review was completed; 242 relevant articles were reviewed, with 18 articles meeting criteria for inclusion in the review.

EVIDENCE SYNTHESIS

Articles were categorized according to the clinical question they addressed. The patient or participant sample (number, sex, age, and health status), study design, instrumentation, or intervention used, and main results were extracted from each article.

CONCLUSIONS

The authors' main findings suggest that there is a moderate level of evidence that patients have impaired NPC up to several months postconcussion, and a low level of evidence that impairments can be successfully treated with oculomotor therapy. These findings should be cautiously evaluated; the studies are limited by weak/moderate quality, small sample sizes, varied methodology, and nonrandomized treatment groups. Future research should explore factors affecting convergence postconcussion and include randomized, controlled studies to determine if performing vision therapy improves visual measures and promotes recovery.

Oculomotor Response to Cumulative Subconcussive Head Impacts in US High School Football Players: A Pilot Longitudinal Study

Importance

Repetitive subconcussive head impacts in sports have emerged as a complex public health issue. Most of these head impacts remain asymptomatic yet have the potential to cause insidious neurological deficit if sustained repetitively. Near point of convergence (NPC) values have shown to reflect subclinical neuronal damage; however, the longitudinal pattern of NPC changes in association with subconcussive head impacts remains unclear.

Objectives

To examine the NPC response to recurring subconcussive head impacts in a single high school football season through a series of repeated measurements.

Design, Setting, and Participants

This prospective case-series study of US varsity high school football players included baseline measurements of NPC, measurements at pregame and postgame points from 6 in-season games, and postseason follow-up measurements (a total of 14 points). An accelerometer-embedded mouthguard measured head impact frequency and magnitude from all practices and games. During the 6 games, players wore chest-strap heart rate monitors to record heart rate and estimate their excess postexercise oxygen consumption, accounting for possible physical exertion effects on NPC values.

Exposures

Players participated in practices and games with no restriction.

Main Outcomes and Measures

Near point of convergence.

Results

The 12 included players were all boys, with a mean (SD) age of 16.4 (0.5) years. A total of 8009 head impacts, 177 907 g of peak linear acceleration, and 16 123 371 rad/s2 of peak rotational acceleration were recorded from the players in a single football season. There was a significant increase in NPC over time until the middle of the season (mean [SD] NPC: baseline, 5.25 [1.49] cm; pregame 3, 6.42 [1.93] cm; P = .01), which was significantly associated with subconcussive head impact frequency and magnitude (0.02 cm per 100 g of peak linear acceleration [SE, 0.0108; 95% CI, 0.0436-0.004]; P = .01; 0.023 cm per 10 000 rad/s2 of peak rotational acceleration [SE, 0.009; 95% CI, 0.041-0.0105]; P = .02). However, NPC values began to normalize toward baseline level from midseason (mean [SD] NPC: baseline, 5.25 [1.49] cm; pregame 6, 5.75 [2.23] cm; P = .32), as supported by a significant quadratic trend (β [SE], -0.002 [0.001] cm/d; P = .003), while participants continued to incur subconcussive head impacts.

Conclusions and Relevance

This longitudinal case series study suggests that NPC can be perturbed over the long term by subconcussive head impacts but may normalize over time. The oculomotor system may have an adaptational capacity to subclinical head impacts, yet the mechanism for such remains an open question and warrants further investigation.

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.

Effects of attention deficit hyperactivity disorder and learning disability on vestibular and ocular baseline concussion assessment in pediatric athletes

Vestibular and ocular motor assessment has gained popularity as a tool for sport-related concussion among healthcare professionals. With awareness of premorbid risk factors, such as attentional problems, it is imperative to understand their effects at baseline. The purpose of this study was to examine the effects of attention deficit/hyperactivity disorder (ADHD) and diagnosed learning disability (LD) on vestibular and oculomotor baseline concussion assessment in pediatrics. Pediatric athletes between the ages of 8 and 14 years with ADHD/LD (n = 30) and match controls without ADHD/LD (n = 30) completed baseline concussion testing, consisting of symptom provocation on the Vestibular/Ocular Motor Screening (VOMS) and oculomotor performance on near point of convergence (NPC) and King-Devick (K-D) tools. Those diagnosed with ADHD/LD performed worse on baseline saccades (p range = .02-.10), convergence (p = .04), vestibular ocular reflex (VOR) (p = .03) and visual motion sensitivity (VMS) (p = .04) of the VOMS. Base rate analyses revealed that 26% of athletes in the ADHD/LD group had ≥1 and 13.3% had ≥2 VOMS domains over clinical cutoff levels, compared to 3.3% (≥1 domain) and 0 (≥2 domains) of controls. Individuals with ADHD/LD also performed worse on K-D assessment (p = .005). However, no differences were reported on NPC distance (p = .19). These findings suggest worse baseline concussion assessment scores on vestibular/ocular motor assessment domains in pediatric athletes diagnosed with ADHD/LD. Additional research is needed on assessment outcomes to determine if special consideration to those diagnosed with ADHD/LD is warranted.

The Effect of Target Speed and Verbal Instruction on NPC Measures in a Young, Healthy, and Active Population

Purpose: Evaluate the effect of target speed and verbal instruction on near point of convergence (NPC) measurements in a young, healthy, and active population. Methods: NPC was measured in 20 individuals with three target speeds and two sets of verbal instruction. The target speeds used were 1 cm/s, 3 cm/s, 5 cm/s, and participant self-paced. The verbal instruction given was either to indicate when the target became “double” or “blurry”. Results: Paired-samples t-tests revealed significant differences between 5 cm/s (5.44 ± 2.01) and 1 cm/s (6.72 ± 2.39, p = .003), 3 cm/s (6.10 ± 2.36, p = .030) and self-paced (6.63 ± 2.26, p = .005). A significant difference (p < .001) was also found between the “double” (6.72 ± 2.39) and “blurry” (10.82 ± 3.08) conditions. Conclusion: For young, healthy and active individuals, target speed and verbal instruction matter when measuring NPC.

Postconcussion: Receded Near Point of Convergence is not Diagnostic of Convergence Insufficiency

PURPOSE

To determine the frequency of occurrence of receded near point of convergence (NPC) in patients with chronic concussion-related symptoms and in those with receded NPC to enumerate the frequency of convergence insufficiency and other oculomotor disorders.

DESIGN

Retrospective cross-sectional study.

METHODS

Clinic charts were retrospectively reviewed for the prior 3.5 years to identify all patients < 21 years old who were > 28 days postconcussion, had chronic concussion-related symptoms, had normal visual acuity, and had received a comprehensive sensorimotor examination. The frequency of receded NPC and oculomotor diagnoses were determined.

RESULTS

Of the 83 eligible patients, 74 (89%) had receded NPC. Of these, 70 (95%) had oculomotor disorders; 30 (41%) had disorders of accommodation only; 21 (28%) had convergence insufficiency and accommodation deficits; and 6 (8%) had convergence insufficiency only. Six (8%) had a convergence deficit other than convergence insufficiency (all with concurrent accommodative disorders); 4 (5%) had both a nonspecific vergence dysfunction and accommodation deficits; 2 (3%) had convergence excess only; and 1 (1%) had both convergence excess and accommodative deficits.

CONCLUSION

A receded NPC was present in the majority of young patients with chronic postconcussion symptoms. Associated with numerous underlying oculomotor dysfunctions, the clinical finding of a receded NPC is not synonymous with the diagnosis of convergence insufficiency. Because treatment options for the various oculomotor dysfunctions differ, it is prudent that these patients undergo a thorough examination of their vergence and accommodative systems so that an accurate diagnosis can be made and appropriate treatment prescribed.

Case Studies in Neuroscience: Instability of the visual near triad in traumatic brain injury-evidence for a putative convergence integrator

Deficits of convergence and accommodation are common following traumatic brain injury, including mild traumatic brain injury, although the mechanism and localization of these deficits have been unclear and supranuclear control of the near-vision response has been incompletely understood. We describe a patient who developed profound instability of the near-vision response with inability to maintain convergence and accommodation following mild traumatic brain injury, who was identified to have a structural lesion on brain MRI in the pulvinar of the caudal thalamus, the pretectum, and the rostral superior colliculus. We discuss the potential relationship between posttraumatic clinical near-vision response deficits and the MRI lesion in this patient. We further propose that the MRI lesion location, specifically the rostral superior colliculus, participates in neural integration for convergence holding, given its proven anatomic connections with the central mesencephalic reticular formation and C-group medial rectus motoneurons in the oculomotor nucleus, which project to extraocular muscle nontwitch fibers specialized for fatigue-resistant, slow, tonic activity such as vergence holding.NEW & NOTEWORTHY Supranuclear control of the near-vision response has been incompletely understood to date. We propose, based on clinical and anatomic evidence, functional pathways for vergence that participate in the generation of the near triad, "slow vergence," and vergence holding.

Neurosensory Deficits Vary as a Function of Point of Care in Pediatric Mild Traumatic Brain Injury

Neurosensory abnormalities are frequently observed following pediatric mild traumatic brain injury (pmTBI) and may underlie the expression of several common concussion symptoms and delay recovery. Importantly, active evaluation of neurosensory functioning more closely approximates real-world (e.g., physical and academic) environments that provoke symptom worsening. The current study determined whether symptom provocation (i.e., during neurosensory examination) improved classification accuracy relative to pre-examination symptom levels and whether symptoms varied as a function of point of care. Eighty-one pmTBI were recruited from the pediatric emergency department (PED; n = 40) or outpatient concussion clinic (n = 41), along with matched (age, sex, and education) healthy controls (HC; n = 40). All participants completed a brief (∼ 12 min) standardized neurosensory examination and clinical questionnaires. The magnitude of symptom provocation upon neurosensory examination was significantly higher for concussion clinic than for PED patients. Symptom provocation significantly improved diagnostic classification accuracy relative to pre-examination symptom levels, although the magnitude of improvement was modest, and was greater in the concussion clinic. In contrast, PED patients exhibited worse performance on measures of balance, vision, and oculomotor functioning than the concussion clinic patients, with no differences observed between both samples and HC. Despite modest sample sizes, current findings suggest that point of care represents a critical but highly under-studied variable that may influence outcomes following pmTBI. Studies that rely on recruitment from a single point of care may not generalize to the entire pmTBI population in terms of how neurosensory deficits affect recovery.

Vestibular dysfunction and concussion

The assessment and treatment of sport-related concussion (SRC) often requires a multifaceted approach. Vestibular dysfunction represents an important profile of symptoms and pathology following SRC, with high prevalence and association with prolonged recovery. Signs and symptoms of vestibular dysfunction may include dizziness, vertigo, disequilibrium, nausea, and visual impairment. Identifying the central and peripheral vestibular mechanisms responsible for pathology can aid in management of SRC. The most common vestibular disturbances after SRC include benign paroxysmal positional vertigo, vestibulo-ocular reflex impairment, visual motion sensitivity, and balance impairment. A variety of evidence-based screening and assessment tools can help to identify the various types of vestibular pathology in SRC. When vestibular dysfunction is identified, there is emerging support for applying targeted vestibular rehabilitation to manage this condition.