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

Abstract

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.

Key Points

• A positive Vestibular Ocular Motor Screening (VOMS) consistently demonstrated to be an indicator of longer recovery compared to a negative test.

• Clinicians should incorporate vestibular and ocular motor screenings into their assessment for concussion as it is a prognostic factor of prolonged recovery from concussion and reliably elicits concussive symptoms in patients.

Patients who are diagnosed with a concussion often present with vestibular and oculomotor symptoms during the initial diagnosis. Specific symptoms of the vestibular and oculomotor system include eye movement abnormalities such as saccadic¹ and eye-tracking dysfunction^2,3 and vision abnormalities including vision reaction time⁴ and pupillary light reflex.⁵ Rates of vision dysfunction have been reported at 62%,⁶ oculomotor dysfunction at 21% to 69%,^1,6 and vestibular dysfunction at 81%⁷ after concussion. Although these rates include patients who sustained a concussion during a motor vehicle accident or accident at the home, school, or work, most patients sustained a sport-related concussion.^1,6 Several symptoms are indicative of vestibular or oculomotor dysfunction, including blurred vision, visual problems, and double vision.⁸ Some researchers have reported dizziness in approximately 50% to 80% of diagnosed concussions.^9,10

Vision and vestibular symptoms have been investigated as prognostic factors for recovery from concussive injury,¹¹ with researchers of one scoping review suggesting that vestibular and oculomotor testing can indicate the need for further testing that could predict recovery.¹² Other injury characteristics reported in one systematic review to be associated with recovery were total symptom severity, headache severity, and dizziness severity. Symptom severity is the most frequently studied and strongest predictor of time to recovery.¹³ It is difficult for clinicians to gain a full picture of the symptoms and dysfunctions that a patient is presenting with and to give patients a prognosis without considering the multisystemic nature of concussive injury.

Often during a clinical evaluation, a multimodal assessment will appropriately inform clinical decision-making. Vestibular and visual symptoms are often present in patients after concussion, and clinicians can assess impairments related to these systems. Several tools are available to clinicians to assess the vestibulospinal, vestibulo-ocular, and oculomotor systems. To assess the vestibulospinal system, clinicians often use the Balance Error Scoring System,¹⁴ sensory organization test,^15,16 Romberg test,¹⁷ Concussion Balance Test,¹⁸ or the tandem gait test.¹⁹ Some of these tests are included in the most recent sideline concussion assessment tool (SCAT5)²⁰ and have been previously validated.^14,17 Similar to the vestibulospinal system, the vestibulo-ocular system has multiple tests that clinicians can use to assess patients. Clinicians can assess horizontal and vertical vestibular ocular reflex (VOR) and visual motion sensitivity to challenge the vestibulo-ocular system. Finally, the oculomotor system can be assessed using horizontal and vertical saccades, near point of convergence (NPC), accommodation, smooth pursuit, and pupillometry. Currently no single test is suitable to screen patients for all these subdomains of vestibulo-ocular and oculomotor systems.

The Vestibular Ocular Motor Screening tool (VOMS) enables clinicians to assess many of the subdomains of the vestibulo-ocular and oculomotor systems. The VOMS has demonstrated that it is reliable and functionally allows clinicians to measure most of the vestibular system and monitor a patient’s vestibular system recovery.²¹ Thus, when clinicians use the VOMS, they can gain a substantial understanding of which symptoms are provoked after each oculomotor task and which symptoms patients may be the most sensitive to. However, to date, no investigators have specifically examined (via a systematic review or meta-analysis) the ability of the VOMS or vestibular or oculomotor assessments within the VOMS to predict recovery from concussion. Thus, our question is as follows: Do patients who present with a positive vestibular or oculomotor screening, or single test within a vestibular or oculomotor screening, after concussion have a longer recovery time than patients with a negative vestibular or oculomotor screening?

METHODS

Search Strategy

This systematic review was completed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.²² This review was registered in PROSPERO (no. CRD42022306344). The databases searched include PubMed, Ovid MEDLINE, SPORTDiscus, and the Cochrane Central Register of Controlled Trials (CENTRAL). The search terms used include VOMS, concussion, recovery, vestibular, vision, saccades, NPC, visual motion sensitivity, and King-Devick. The specific searches were concussion AND VOMS AND recovery, concussion and King-Devick AND recovery, and concussion AND vestibular OR vision OR saccades OR near point convergence OR visual motion sensitivity. In addition to the searches of databases, hand searches of reference lists of all relevant articles were conducted. The initial searches were conducted in January 2022. Follow up searches of PubMed were conducted in July 2022.

Selection Criteria and Quality Assessment

The inclusion criteria were studies of humans in which researchers assessed patients with the VOMS or another vestibular or oculomotor screening, recorded duration of recovery from concussion, English language, limited to the past 10 years (2012 to 2022), and level 4 evidence or higher based on the Centre for Evidence-Based Medicine scale.²³ Exclusion criteria were studies in which researchers examined rehabilitation effects on recovery. The results from the database searches were exported and inputted into Covidence systematic reviewer software (Veritas Health Innovation). Once the results were imported, 2 authors (M.B. and T.V.M.) screened the titles, abstracts, and full text for inclusion. The Mixed-Methods Appraisal Tool²⁴ was used to assess the quality of studies and was performed within Covidence (Veritas Health Innovation).

Data Extraction

The primary data extracted from the studies included recovery time, vestibular or oculomotor scores, and other objective or subjective measures taken by clinicians or reported by patients, such as postconcussion symptom score, patient-report outcome measures, and cognitive or balance assessments. Secondary data extracted from the studies included the number of patients, patient demographics, study design, start and end date, inclusion and exclusion criteria, and method of recruitment. The data extraction was performed through Covidence and was organized by individual study. Each of the articles was evaluated, and the data were extracted and inputted into the individual data extraction tables in Covidence. If it was impractical to extract the data from within Covidence, such as that embedded in a large table, an Excel spreadsheet was used.

Data Synthesis and Analysis

Once data were extracted, the authors critically evaluated each of the articles for commonalities and differences, focusing specifically on the extracted variables. The data from included studies were reviewed for a possible meta-analysis; however, the methods and statistical analyses used in individual studies did not allow for the extraction of similar data to perform a meta-analysis. A qualitative synthesis of the findings was used to summarize the conclusions. Articles were categorized into 2 groups based on the study design and comparators used. The groups included studies comparing typical and prolonged recovery and studies assessing recovery over time with a positive or negative initial vestibular or oculomotor screening finding.

RESULTS

Figure 1 presents the flow diagram based on the PRISMA guidelines. The literature search retrieved 1612 articles published between January 1, 2012, and January 2, 2022. We removed 684 duplicates and screened 937 studies. After we screened titles and abstracts, we assessed 42 articles for inclusion based on their full text. Two articles were included in the full text screening after a review of the author’s personal article databases. After a full text evaluation, we included 18 articles in the review (Tables 1–3).

Figure.

PRISMA flow diagram.

Table 1.

Studies Comparing Typical and Prolonged Recovery

Study	Design	Inclusion Criteria	Exclusion Criteria	Group Differences	Outcome Measures	Conclusions
Cheever et al28	Prospective cohort	Diagnosed with SRC, 11 to 20 y old, assessed within 14 days of concussion.	Vestibular or ocular motor pathologic condition; brain surgery; ophthalmic surgery; neurological, cognitive, or behavioral disorders; or TBI graded more severe than concussion	Years experience: Healthy control, 10.55 ± 5.4 y Acute concussion, 6.11 ± 6.2 y Prolonged recovery, 6.88 ± 3.1 y Previous concussions: Healthy control, 0.34 ± 0.8 Acute concussion, 0.95 ± 1.1 Prolonged recovery, 4 ± 3.3	Healthy vs prolonged recovery: NPC at initial visit, P = .004 NPC at 2 weeks postinjury, P = .01 NPC at 6 weeks postinjury, P = .043	Vestibular and oculomotor assessments demonstrate continued impairment after clinical recovery particularly in patients with a prolonged recovery.
DuPrey et al29	Case control		Lost to follow up; strabismus, amblyopia, ocular surgery, intracranial hemorrhage, neurologic or ocular surgery, vestibular disorder, substance abuse, migraine headache, learning disability (including ADD/ADHD), psychiatric or mood disorder (not including depression and anxiety), and NPC greater than 15 cm at time of recovery measured in the office after SRC.	Normal NPC 49.6%, n = 134 Abnormal NPC 50.4%, n = 136 Days to initial evaluation: Normal NPC, 4.6 ± 3.3 days Abnormal NPC, 5.8 ± 4.9 Symptom severity: Normal NPC, 14.5 ± 4.6 Abnormal NPC, 43.1 ± 9.5 Number of symptoms: Normal NPC, 7.8 ± 3.3 Abnormal NPC, 15.1 ± 4.2	Recovery: Normal NPC, 19.2 ± 14.7 days Abnormal NPC, 51.6 ± 53.9 days NPC at initial visit: Normal NPC, 4.1 ± 1.3 cm Abnormal NPC, 12.3 ± 4.7cm Prolonged recovery: Normal NPC, 11.9% (n = 16) Abnormal NPC, 62.5% (n = 85)	When measuring convergence insufficiency, it may predict prolonged recovery and can be a useful tool for assessing concussion.
Eagle et al30	Retrospective chart review	Patients between 12 and 17 y of age with a diagnosed, symptomatic concussion per current consensus guidelines (n = 232).	Patients with a moderate-to-severe TBI, neurological disorder, or preexisting vestibular disorder.	% Female: Early, 43 (30%) Late, 49 (60%) History of motion sickness: Early, 38 (26%) Late, 17 (21%) Anxiety or depression: Early, 19 (13%) Late, 9 (11%) ADHD or learning disability: Early, 9 (6%) Late, 5 (6%) Headache or migraine history: Early, 52 (36%) Late, 30 (37%)	Adjusted OR for prolonged recovery: VMS, 5.18; 95% CI = 1.52, 17.60	Patients with a positive VMS were 5 times more likely to have a prolonged recovery than those who did not.
Ellis et al27	Retrospective cross sectional	Patient aged 19 y or younger, diagnosis of acute SRC or of persistent symptoms.	Patients with intracranial hemorrhage or traumatic structural spinal injury. Patients who suffered a second concussion during follow-up for a previous symptomatic concussion. Patients with coexistent neuroopthalmological conditions. Patients in whom other coexistent medical conditions that prevented return to play.	Mean age: Acute SRC, 13.7 ± 2.2 y PCS, 16 ± 1.6 y % Female: Acute SRC, 30% (n = 23) PCS, 63% (n = 15) VOD: Acute SRC, 29% (n = 22) PCS, 63% (n = 15) Previous concussion: Acute SRC, 47% (n = 36) PCS, 54% (n = 13) Median PCS score: Acute SRC, 10 (3–25 range) PCS, 33 (14.5–47.5 range)	Association between length of recovery and VOD. Displayed as OR (95% CI): Crude, VOD only 8.89 (2.61, 26.29) Age, 8.92 (2.73, 29.11) Female, 8.41 (2.62, 27.07) Previous concussion, 9.45 (2.97, 30.06) Previous migraine, 9.94 (3.06, 32.32) Amnesia, 7.17 (2.15, 23.83) LOC, 8.29 (2.6, 26.44)	Patients who presented with a vestibular oculomotor dysfunction were 8 times more likely to have persistent symptoms after recovery than patients who did not.
Knell et al31	Prospective case series	Patients aged 8–18 y, participating in a sport at time of injury, diagnosed with an SRC and evaluated within 7 days from initial date of injury	Previous diagnosis of developmental delay, diagnosis of comorbid neck or spine injuries, previous diagnosis of congenital or acquired neurological defect or injury not related to the concussion injury, inability to understand the premise of the study due to language barriers.	Median recovery time (IQR): Normal recovery, 18 (13–23) days Protracted recovery ,43 (35–52) days Median time since injury (IQR): Normal recovery, 2 (1–4) days Prolonged recovery, 3 (2–5) days Age: Normal recovery: 8–12 y, 29.7% (n = 121); 13–18 y, 70.3% (n = 286) Prolonged recovery: 8–12 y, 21.8% (n = 31); 13–18 y, 78.2% (n = 111) Female sex: Normal recovery, 39.7% (n = 162) Prolonged recovery, 53.3% (n = 76) Sport: Normal recovery, noncontact, 10.3% (n = 43); contact, 39.1% (n = 159); collision, 42.5% (n = 172) Prolonged recovery, noncontact, 18.3% (n = 26); contact, 43% (n = 61); collision, 8.5% (n = 12)	1-Unit increase in symptoms from VOMS: Males, Exp(0.3223846) = 1.38 days longer recovery or unit increase (P < .001) Females, Exp(0.548789) = 1.73 days longer recovery or unit increase (P < .001) Symptom provocation, mean ± SD, Males: Smooth pursuits, 0.89 ± 1.58 Horizontal saccades, 1.65 ± 2.43 Vertical saccades, 2.02 ± 2.75 Convergence, 2.27 ± 4.34 Horizontal VOR, 2.96 ± 3.56 Vertical VOR, 3.01 ± 3.78 VMS, 4.05 ± 4.44 Symptom provocation, mean ± SD, females Smooth pursuits, 1.37 ± 2.01) Horizontal saccades 2.20 ± 2.91 Vertical saccades 2.62 ± 3.14 Convergence, 3.02 ± 4.49 Horizontal VOR 3.57 ± 3.54 Vertical VOR, 3.82 ± 3.7 VMS, 4.62 ± 3.99	In patients who do not test positive on the VOMS, they have a 90% chance for a normal recovery.
Leddy et al26	Prospective cohort	Patients with acute concussion (AC) included male and female adolescent athletes (aged 13–19 years) who sustained SRC within 1–10 days of initial visit at the University Concussion Management Clinic and were evaluated by a study physician who diagnosed the concussion according to the 4th International Conference on Concussion in Sport	(1) Evidence of focal neurological deficit; (2) inability to exercise on the treadmill due to other injury; (3) known heart disease or increased cardiac risk; (4) current diagnosis of ADHD, learning disorder, depression, or anxiety; (5) history of moderate or severe TBI; (6) use of medications that affect cardiac output (eg, beta blockers); or (7) greater than 3 prior concussions (because this is associated with delayed recovery).	Days to recovery, mean ± SD: Acutely concussed, 26.19 ± 38.27 days Normal recovery, 13 ± 6.82 days Delayed recovery, 75.36 ± 62.55 days Mean ± SD symptom score, visit 1: Acutely concussed, 31.25 ± 22.89 Normal recovery, 25.22 ± 19.16 Delayed recovery, 53.73 ± 22.23 Mean ± SD symptom score, visit 2: Acutely concussed, 8.31 ± 15.06 Normal recovery, 2.54 ± 5.93 Delayed recovery, 29.82 ± 19.26	Initial visit delayed vs normal recovery physical exam findings Convergence OR, 5.5352 (1.1022, 37.7497), P = .019 Second visit delayed vs normal recovery physical exam findings Smooth pursuits OR, 41.8147 (4.0001–2221.5053), P = .0001 Convergence OR, 19.8356 (3.1593–173.7532), P = .0002 Tandem gait OR, 70.2308 (3.4588–1426.0205), P = .0002	Patients who tested positive on the smooth pursuits or near point convergence at the second visit were 41 times and 19 times more likely, respectively, to have a delayed recovery than those who did not.
Martinez et al34	Retrospective cohort	Adolescent- and college-aged patients who self-presented or referred to the sports concussion clinic at the Duke Sport Sciences Institute between July 2013 and January 2015. Medical diagnosis of concussion and willingness to receive a battery of questionaries and follow-up.	None disclosed.	Gender (n): Delayed recovery: F = 34, M = 46 Nondelayed recovery: F = 23, M = 60 Age (y): Delayed recovery, 16.47 ± 4.36 Nondelayed recovery, 16.02 ± 2.81 Neck disability index score (%): Delayed recovery, 21.08 ± 14.3 Nondelayed recovery, 21.21 ± 26.23 Dizziness handicap inventory (%): Delayed recovery, 30.47 ± 17.97 Nondelayed recovery, 28 ± 25.7 Symptom number: Delayed recovery, 9.57 ± 7.38 Nondelayed Recovery, 4.7 ± 5.88 Time from injury to exam (days): Delayed recovery, 17.1 ± 37.43 Nondelayed recovery, 4.07 ± 6.43	Clinical symptoms and delayed recovery OR (95% CI) Headache, 3.53 (1.08, 11.47), P = .04 Dizziness, 2.14 (1.13, 4.02), P = .02 Cognitive impairments, 2.72 (1.4, 5.28), P < 0.01 Clinical exam findings and delayed recovery (OR): Cognitive testing, 3.52 (1.08, 11.48), P = .04 Visual testing, 2.98 (1.31, 6.8), P < .01 Vestibular testing, 4.28 (2.18, 8.43), P < .01	Some symptoms and parts of a comprehensive clinical exam can identify patients who are more likely to have a delayed recovery. Vestibular testing and cognitive impairments at initial examination were the most consistent predictors of delayed recovery.
Price et al11	Retrospective cohort	None disclosed	Developmental delays other than ADDs or learning disabilities (ie, autism spectrum disorder, muscular dystrophy), comorbid neck or spine injuries, and congenital or acquired neurological defects not related to the concussion injury (ie, brain tumor, epilepsy).	Recovery time (IQR) 19 days (14–28): Protracted recovery No, 77.2% (n = 88) Yes, 22.8% (n = 26) Sex Male, 64% (n = 73) Female, 36% (n = 41) Sport: Nonsport, 2.6% (n = 3) Noncontact, 7.9% (n = 9) Contact, 58.8% (n = 67) Collision, 30.7% (n = 35) Hx concussion: No, 75.4% (n = 86) Yes, 24.6% (n = 28) Time to presentation (IQR): 2 days (2–4)	Incidence rate ratio (95% CI): Positive VOMS Fully adjusted, 1.31 (1.05, 1.63) Age adjusted, 1.22 (0.96, 1.55) Crude 1.22 (0.96, 1.55) Positive King-Devick Fully adjusted, 1.02 (0.85, 1.24) Age adjusted, 1.09 (0.88, 1.34) Crude, 1.08 (0.87, 1.33)	A positive VOMS screening resulted in a 1.31-day longer recovery than those who had a negative VOMS screening. A negative VOMS screening was a useful predictor of normal recovery.
Sufrinko et al32	Cohort study	Athletes between the ages of 12 and 22 years, who had sustained their SRC during an organized sports practice or competition within the past 7 days.	Athletes with no clear mechanism of injury, prior brain surgery, neurological disorder, vestibular or ocular motor condition, treatment for substance abuse, psychiatric condition.	Age: ≤14 day recovery, 15.7 ± 2.1 y 15–29 day recovery, 15.2 ± 1.7 y 30–90 day recovery, 15.0 ± 1.9 y Male sex: ≤14 day recovery, 81% (n = 22) 15–29 day recovery, 64% (n = 16) 30–90 day recovery, 76% (n = 13) Time until presentation: ≤14 day recovery, 3.3±1.9 days 15–29 day recovery, 3.6 ± 1.9 days 30–90 day recovery, 4.2 ± 1.8 days No hx of concussion: ≤14 day recovery, 52% (n = 14) 15–29 day recovery, 72% (n = 18) 30–90 day recovery, 71% (n = 12) Migraine: ≤14 day recovery, 15% (n = 4) 15–29 day recovery, 12% (n = 3) 30–90 day recovery, 12% (n = 2)	VOMS 30–90 day recovery predictors: Smooth pursuits: β = .405; SE= 0.565; P < .001; OR, 1.5; 95% CI = 1.19, 1.9 Horizontal saccades: β = .404; SE = 0.117; P = .001; OR, 1.5; 95% CI = 1.19, 1.88 Vertical saccades: β = .356; SE = 0.105; P = .001; OR, 1.43; 95% CI = 1.16, 1.75 Convergence distance: β = .192; SE = 0.088; P = .029; OR, 0.12; 95% CI = 1.02, 1.44 Horizontal VOR: β = .271; SE = 0.086; P = .002; OR, 1.31; 95% CI = 1.11, 1.55 Vertical VOR: β = .253; SE = 0.079; P = .001; OR, 1.29; 95% CI = 1.10, 1.51 VMS: β = .21; SE = 0.063; P = .001; OR, 1.23; 95% CI = 1.09, 1.4	Vertical saccades were a good predictor or concussion recovery. However, vestibular and oculomotor testing were not as robust predictors of recovery as symptom clusters.
Walker et al33	Retrospective cross sectional	Patients with a concussion if they were <19 y of age and presented to clinic for evaluation within 14 days of injury	Patients who sustained a concussion from a non-sports-like related mechanism, had trauma-related pathology on neuroimaging, or sustained a second head injury before full recovery from the index concussion.	Age: Normal NPC, 15.7 ± 1.7 y Receded NPC, 14.9 ± 1.5 y Female sex: Normal NPC, 46% (n = 21) Receded NPC, 47% (n = 36) Time until presentation: Normal NPC, 6.8 ± 3.1 days Receded NPC, 7 ± 3.6 days Hx previous concussion: Normal NPC, 59% (n = 27) Receded NPC, 45% (n = 35) ADHD: Normal NPC, 4% (n = 2) Receded NPC, 16% (n = 12) Hx anxiety Normal NPC, 4% (n = 2) Receded NPC, 16% (n = 12)	Symptom severity: Normal NPC, 15.8 Receded NPC, 23.7 NPC break point: Normal NPC, 3.7 ± 1.8 cm Receded NPC, 11.1 ± 6.2 cm NPC recovery point: Normal NPC, 6.2 ± 2.1 cm Receded NPC, 13.9 ± 7.1 cm mBESS errors: Normal NPC, 5.2 ± 4.1 errors Receded NPC, 7.2 ± 5.2 errors Single-task tandem gait time: Normal NPC, 21.9 ± 8.7 seconds Receded NPC, 23.8 ± 8.4 seconds Dual-task tandem gait time: Normal NPC, 32.3 ± 15.2 seconds Receded NPC, 33.0 ± 12.6 seconds	When assessing patients within 14 days of concussive injury, a receded NPC appears predictive of symptom burden and possible longer recovery.
Worts et al39	Retrospective cohort	Athletes aged 13 to 18 y old sustaining a sport-related concussion and presented for evaluation within 7 days of injury to an outpatient clinic between November 2013 and April 2019.	It was later determined that their initial visit occurred >7 days since their injury (n = 25), they did not return for full medical clearance (n = 47), or it was determined that their injury occurred outside the context of sport participation (n = 2).	Recovery duration: Normal recovery, 16.5 ± 5.8 days Prolonged recovery, 42.4 ± 12.3 days Time until presentation: Normal recovery, 3.5 ± 1.8 days Prolonged recovery, 4 ± 1.9 days Age: Normal recovery, 15.3 ± 1.3 y Prolonged recovery, 15.1 ± 1.5 y Male sex: Normal recovery, 72% (n = 112/156) Prolonged recovery, 40% (n = 18/45) Hx migraine: Normal recovery, 10% (n = 15/153) Prolonged recovery, 9% (n = 4/45) Hx mood disorder: Normal recovery, 5% (n = 8/154) Prolonged recovery, 16% (n = 7/45) Loss of consciousness: Normal recovery, 16% (n = 25/152) Prolonged recovery, 2% (n = 1/44)	Smooth pursuits symptom provocation: Normal recovery, 0.4 ± 1.4 Prolonged recovery, 1.2 ± 1.7 Horizontal saccades symptom provocation: Normal recovery, 1.1 ± 1.9 Prolonged recovery, 2.3 ± 2.1 Vertical saccades symptom provocation: Normal recovery, 1.5 ± 2 Prolonged recovery, 2.4 ± 3.1	Symptom provocation from smooth pursuits, horizontal saccades, and vertical saccades at initial presentation is predictive of prolonged recovery in patients after a concussion.

Abbreviations: ADDs, attention-deficit disorders; ADHD, attention-deficit/hyperactivity disorder; Hx, History IQR, interquartile range; LOC, level of consciousness; PCS, pelvic congestion syndrome; TBI, traumatic brain injury; VOD, veno-occlusive disease.

Table 3.

Studies Examining Natural Recovery of Vestibular and Oculomotor Screenings

Study	Design	Inclusion Criteria	Exclusion Criteria	Group Differences	Outcome Measures	Conclusions
Büttner et al35	Prospective longitudinal	Diagnosed with a concussion by emergency department physician.	Sustaining a concussion in the previous 12 months; a history of greater than 3 lifetime concussions; loss of consciousness greater than 1 minute after the current sport-related concussion; a history of vestibular disorder; or any visual abnormality not correctible by lenses	Concussion history: Concussion group, 52% (n = 26) Control group, 36% (n = 18) Learning disability: Concussion group, 12% (n = 6) Control group, 2% (n = 1)	VOMS measures Time to return to activity Symptom severity	The VOMS has a high negative predictive value and may be useful for ruling out concussion soon after injury.
Glendon et al36	Prospective cohort	Rugby athletes who sustained a concussion during the 2019–2020 season.	None disclosed	Age: All athletes, 20.5 ± 1.5 y SRC, 20.62 ± 3.5 y Male sex: All athletes, 65.7% (n = 92) SRC, 61.4% (n = 25) Previous concussion: All athletes, 75% (n = 90) SRC, 73.8% (n = 31) Learning disability: All athletes, 25% (n = 35) SRC, 14.3% (n = 6)	Wilcoxon sign rank testing (median VOMS score after concussion): 2 days, 3.0 (0–20.5), z = −4.375, P = .000 4 days, 3.0 (0–12.25), z = −4.707, P = .000 8 days ,0.0 (0–3), P < 0.005	University athlete’s symptom burden after concussion returned to near baseline around 8 days postconcussion along with vestibular and oculomotor functioning.
Henry et al25	Prospective case series	Patients aged 14–22 y and had suffered a SRC within 7 days of initial assessment.	History of special education; history of neurological or psychiatric disorders; previous moderate-to-severe TBI (Glasgow Coma Scale, <13); previous brain surgery; current use of central nervous system-affecting medications; history of 3 or more concussions; or previous concussion within the past 6 months	Mean age, 16.5 ± 1.9 y Male, 64% Sport played: Football, n = 16 Soccer, n = 13 Hockey, n = 10 Softball, n = 6 Lacrosse, n = 5 Basketball, n = 4 Cheer, n = 4 Volleyball, n = 3 Ski or snowboarding, n = 2 Wrestling, n = 2 Field hockey, n = 1	VOMS score: Week 1, 11.0 ± 9.9 (n = 61) Week 2, 5.0 ± 8.1 (n = 63) Week 3, 3.0 ± 7.4 (n = 58) Week 4, 2.1 ± 6.9 (n = 54) F2,73 = 29.26, P < .001, n = 50 Dizziness interview score: Week 1, 9.5 ± 8.2 (n = 61) Week 2, 4.6 ± 6.3 (n = 62) Week 3, 2.1 ± 5.5 (n = 56) Week 4, 1.8 ± 5.4 (n = 54) F2,82 = 29.97, P < .001, n = 48	Dizziness and vestibular-oculomotor symptoms had significantly decreased after 4 weeks compared to 1 week and 2 weeks postconcussion.

Table 2.

Studies Assessing Continuous Recovery After Positive Vestibular or Oculomotor Screening

Study	Design	Inclusion Criteria	Exclusion Criteria	Group Differences	Outcome Measures	Conclusions
Anzalone et al40	Prospective cohort	Diagnosed with SRC, 11 to 20 y old, assessed within 14 days of concussion.	Vestibular or ocular motor pathologic condition; brain surgery; ophthalmic surgery; neurological, cognitive, or behavioral disorders; or TBI graded more severe than concussion	Boys, 58.7% (n = 98) Girls, 41.3% (n = 69) Prior concussion, 29.9 % (n = 50) Sport participation: Basketball, 11.4% (n = 19) Football, 42.5% (n = 71) Soccer, 19.2% (n = 32) Other, 27% (n = 45)	VOMS measures, Univariate HR: Smooth pursuits, 0.65 (0.47–0.9) Horizontal saccades, 0.68 (0.5–0.94) Vertical saccades, 0.55 (0.4–0.75) Horizontal VOR, 0.68 (0.49–0.94) Vertical VOR, 0.6 (0.44–0.83) NPC, 0.7 (0.46–1.08) Accommodation, 0.79 (0.55–1.16) Vestibular 0.55 (0.4–0.76) Ocular motor 0.45 (0.32–0.63) Recovery time: Negative VOMS recovery, 13.4 ± 8.2 days Positive VOMS recovery, 23.0 ± 13.4 days	Any positive test on the VOMS except accommodation and NPC was associated with an increased recovery time.
Glendon et al36	Prospective cohort	Rugby athletes who sustained a concussion during the 2019–2020 season.	None disclosed	Age: All athletes, 20.5 ± 1.5 y SRC, 20.62 ± 3.5 y Male sex: All athletes, 65.7% (n = 92) SRC, 61.4 (n = 25) Previous concussion: All athletes, 75% (n = 90) SRC, 73.8% (n = 31) Learning disability: All athletes, 25% (n = 35) SRC, 14.3% (n = 6)	Wilcoxon sign rank testing (median VOMS score after concussion): 2 days, 3.0 (0–20.5), z = −4.375, P = .000 4 days, 3.0 (0–12.25), z = −4.707, P = .000 8 days, 0.0 (0–3), P < .005	University athletes’ symptom burden after concussion returned to near baseline around 8 days postconcussion along with vestibular and oculomotor functioning.
Master et al41	Retrospective cohort	A total of 432 randomly selected pediatric patients out of a total 3430 patients, representing a 13% sample, aged 5 to 18 y who presented within 1 y of injury with a new diagnosis of concussion using the International Classification of Diseases, Ninth Revision codes 850.0, 850.1, 850.11,850.12, 850.2, 850.3, 850.4, 850.5, or 850.9 to The Children’s Hospital of Philadelphia Minds Matter Concussion Program between July 1, 2014, and June 1, 2016.	Patients with intracranial hemorrhage or previous neurologic surgery	Sex: Females, 59% (n = 253) Males, 41% (n = 179) Age: 14 (IQR 12–16) Comorbidities: Motion sickness, 28% (n = 123) Migraine, 18% (n = 80) Anxiety, 16% (n = 69) Depression, 11% (n = 47) ADD, 9% (n = 39) Physical exam deficits at presentation: Saccades, 82% (n = 355) Balance, 68% (n = 285) Smooth pursuits, 66% (n = 285) VOR, 66% (n = 275) NPC, 35% (n = 147) Accommodation, 22% (n = 93) Time to resolution, 86 (IQR 40–146)	Median time to recovery +VOR, 107 days −VOR, 53, days +Balance, 107 days −Balance, 47 days +Accommodative amplitude, 150 days −Accommodative amplitude, 81 days +Smooth pursuits, 95 days −Smooth pursuits, 60 days	Patients who present with NPC, accommodation, VOR, smooth pursuits, or saccadic dysfunction were significantly more likely to take longer to recover than patients who did not.
Sinnott et al37	Prospective case series	Complete a clinical assessment within 10 days of injury; second clinical visit at 11–21 days after concussion; medical clearance evaluation as determined by treating physician.	Concurrent cervical spine injury or positive neuroimaging	Groups: None, n = 20 Improve, n = 12 Persist, n = 17 Age: None, 14.3 ± 1.9 y Improve, 15.8 ± 2.3 y Persist, 15.6 ± 2.1 y Female: None, 20% (n = 4) Improve, 58.3% (n = 7) Persist, 58.8% (n = 10) Previous concussion None 12.2% n = 6 Improve 2% n = 1 Persist 14.3% n = 7 Motion sickness: None, 15% (n = 3) Improve, 50% (n = 6) Persist, 35.3 (n = 6) Migraine: None, 15% (n = 3) Persist, 29.4% (n = 5)	Mean days until recovery: None, 22.95 days Improve, 26.42 days Persist, 34.94 days	Patients who have vestibular symptoms compared to patients who do not have a significantly longer recovery.
Whitney et al38	Prospective cohort	An athlete who sustained a concussion while attending a participating institution in the CARE consortium who opted to collect VOMS data.	None disclosed	Age: 19 ± 1.2 y Male sex: 72% (n = 49) Race: White, 69% (n = 47) African American, 22% (n = 15) Asian, 2% (n = 1) Multiracial, 4% (n = 3) Unknown, 3% (n = 2) Sport classification: Contact, 79.4% (n = 54) Limited contact, 16.2% (n = 11) Noncontact, 4.4% (n = 3) ADHD: 7% (n = 5) Hx migraines: 13% (n = 9)	Survival curve for abnormal VOMS predicting recovery (Kaplan-Meier log-rank Chi-square): Smooth pursuits, 4.98, P = .026 Horizontal saccades, 5.04, P = .025 Vertical saccades, 4.8, P = .028 Convergence, 4.64, P = .031 Initial VOMS assessment symptoms (mean ±SD, % abnormal test) Smooth pursuits, 7.9 ± 6.2; 81% Horizontal saccades, 8.4 ± 6.6; 82% Vertical saccades, 8.3 ± 6.6; 82% Convergence, 8.3 ± 6.8; 81% VOR-horizontal 8.3 ± 6.7; 83% VOR-vertical 8.4 ± 6.8; 85% Visual motion sensitivity, 8.4 ± 7.3; 82%	In patients who had a 2-point or more symptom increase, the length of recovery was significantly longer than patients who had less than a 2-point symptom increase after the VOMS screening. Symptom increase of 2 or more on the VOMS was associated with a 3.5-day longer recovery.

Quality Assessment

The Mixed-Methods Appraisal Tool was used to evaluate each study for its quality (Tables 4 –6). All the included studies had representative samples of their respective populations of interest and used appropriate measurements. Most of the included studies had complete outcome data, except 4 studies.^25–28 Although most studies had complete outcome data, a few had adequate controls for confounding variables.^{26,27,29–34} Finally, for all of the studies, exposures occurred as intended with the exception of one study²⁶ in which this aspect could not be determined.

Table 4.

Quality Assessment Results: Studies Comparing Typical and Prolonged Recovery

Reference	Study Design	Level of Evidence	Q1: Representative Participants	Q2: Appropriate Measures	Q3: Complete Outcome Data	Q4: Confounders Accounted For	Q5: Intervention Administered as Intended
Cheever et al28	Prospective cohort	2	Yes	Yes	No	Can’t tell	Yes
DuPrey et al29	Case control	3	Yes	Yes	Yes	Yes	Yes
Eagle et al30	Retrospective chart review	3	Yes	Yes	Yes	Yes	Yes
Ellis et al27	Retrospective cross sectional	3	Yes	Yes	No	Yes	Yes
Knell et al31	Prospective case series	4	Yes	Yes	Yes	Yes	Yes
Leddy et al26	Quantitative RCT	2	Yes	Yes	No	Yes	Can’t tell
Martinez et al34	Retrospective cohort	2	Yes	Yes	Yes	Yes	Yes
Price et al11	Retrospective cohort	3	Yes	Yes	Yes	Can’t tell	Yes
Sufrinko et al32	Cohort study	2	Yes	Yes	Yes	Yes	Yes
Walker et al33	Retrospective cross sectional	3	Yes	Yes	Yes	Yes	Yes
Worts et al39	Retrospective cohort	3	Yes	Yes	Yes	Can’t tell	Yes

Abbreviation: RCT, randomized controlled trial.

Table 5.

Quality Assessment Results: Studies Assessing Continuous Recovery After Positive Vestibular or Oculomotor Screening

Reference	Study Design	Level of Evidence	Q1: Representative Participants	Q2: Appropriate Measures	Q3: Complete Outcome Data	Q4: Confounders Accounted For	Q5: Intervention Administered as Intended
Anzalone et al40	Prospective cohort	2	Yes	Yes	Can’t tell	Can’t tell	Yes
Glendon et al36	Prospective cohort	3	Yes	Yes	Yes	Can’t tell	Yes
Master et al41	Retrospective cohort	3	Yes	Yes	Yes	Can’t tell	Yes
Sinnott et al37	Prospective Case series	4	Yes	Yes	Yes	Can’t tell	Yes
Whitney et al38	Prospective cohort	2	Yes	Yes	Yes	Can’t tell	Yes

Table 6.

Quality Assessment Results: Studies Examining Natural Recovery of Vestibular and Oculomotor Screenings

Reference	Study Design	Level of Evidence	Q1: Representative Participants	Q2: Appropriate Measures	Q3: Complete Outcome Data	Q4: Confounders Accounted For	Q5: Intervention Administered as Intended
Büttner et al35	Prospective longitudinal	2	Yes	Yes	Yes	Can’t tell	Yes
Glendon et al36	Prospective cohort	3	Yes	Yes	Yes	Can’t tell	Yes
Henry et al25	Prospective case series	4	Yes	Yes	No	Can’t tell	Yes

Time of Assessment and Operationalization of Positive Screening

In all of the included studies, the authors conducted vestibular or oculomotor screening assessments at either the time of injury or during the initial clinic encounter. Researchers of some studies included subsequent screenings at follow-up visits. For our purposes we did not operationalize a positive or negative vestibular or oculomotor screening assessment. However, several studies (Büttner et al,³⁵ Eagle et al,³⁰ Glendon et al,³⁶ Henry et al,²⁵ Price et al,¹¹ Sinnott et al,³⁷ Whitney et al,³⁸ and Worts et al³⁹) used the VOMS cutoff of greater than a 2-symptom score increase described by Mucha et al.²¹ Other authors (Anzalone et al,⁴⁰ Leddy et al,²⁶ Master et al,⁴¹ and Martinez et al³⁴) chose to dichotomize patients based on any symptom provocation. Cheever et al,²⁸ Glendon et al,³⁶ and Sufrinko et al³² did not disclose which they used, and Knell et al³¹ examined different cut points for the VOMS.

Studies Comparing Typical and Prolonged Recovery

Researchers of nine of the included studies dichotomized patient populations into typical and prolonged recovery. The most common cutoff for typical vs prolonged recovery was less than or equal to 28 days and greater than 28 days used in 3 studies.^29,33,39 Martinez et al³⁴ used less than 29 days and greater than or equal to 29 days; Price et al,¹¹ Ellis et al,²⁷ and Eagle et al³⁰ used less than or equal to 30 days and greater than 30 days as their recovery cutoff; Leddy et al²⁶ stratified at 21 days; Cheever et al²⁸ stratified at 16 days; and Sufrinko et al³² stratified patients into groups of less than 15 days, 15 to 29 days, and greater than 29 days until recovery. For our purposes, we used the stratification by Sufrinko et al³²; we combined cutoff groups of less than 15 days and 15 to 29 days into one group of less than or equal to 29 days.

Among studies that dichotomized recovery, researchers of only 3 studies (Leddy et al,²⁶ Sufrinko et al,³² and Worts et al³⁹) investigated the association between a positive test of smooth pursuits at initial presentation and recovery. In 2 studies, the authors found a significant relationship between positive smooth pursuits at initial presentation and prolonged recovery, with Worts et al noting higher symptom provocation from smooth pursuits among the prolonged patients (P = .008)³⁹ and Sufrinko et al finding smooth pursuits had the strongest association with recovery over 30 days (odds ratio [OR] = 1.5 [95% CI = 1.19, 1.90], P < .001).³² Although Leddy et al²⁶ did not find a statistically significant relationship between a positive smooth pursuit at initial examination (1 to 10 days postinjury), upon a second visit (13.6 ± 1 days after visit 1) the authors did find a statistically significant association (P = .0001) between a positive smooth pursuit test and longer recovery at the second visit. When comparing saccadic testing and prolonged recovery, Worts et al³⁹ found that patients who had a higher symptom provocation for either horizontal or vertical saccades were more likely to be in the prolonged recovery group (horizontal saccades: P = .003, crude (unadjusted) OR = 2.087 [95% CI = 1.375, 3.167]; vertical saccades: P = .039, crude OR = 1.462 [95% CI = 0.983, 2.173]). Similarly, Sufrinko et al³² found that a positive smooth pursuit was predictive of recovery of 30 to 90 days (OR = 1.5 [95% CI = 1.19, 1.90], P < .001) and a positive smooth pursuit, horizontal or vertical saccades was predictive of a recovery of 15 to 29 days (smooth pursuits: OR = 1.25 [95% CI = 1.02, 1.55], P = .036; horizontal saccades: OR = 1.31 [95% CI = 1.06, 1.62], P = .013; vertical saccade: OR = 1.22 [95% CI = 1.01, 1.47], P = .035).

A similar assessment of saccadic functioning, the King-Devick test, was included in 4 studies within this subgroup that dichotomized recovery.^11,28,34,39 Among these studies, only Worts et al³⁹ found that patients who took longer to complete the King-Devick test were more likely to have a prolonged recovery (total time: P < .001; crude OR = 2.984 [95% CI = 1.958, 4.546]). Specifically, patients in the prolonged group took a longer (73.2 ± 21.7 seconds) time to complete the King-Devick test than those in normal recovery (56.9 ± 14.0 seconds).³⁹ Martinez et al³⁴ found that patients who had symptom provocation during the test were almost 3 times as likely to have a prolonged recovery (OR = 2.98, P < .01). Price et al¹¹ found a small but nonsignificant effect of 1.09 (95% CI = 0.88, 1.34), demonstrating a potential increased likelihood of prolonged recovery when testing took longer than the 75th percentile for the respective age group on the King-Devick test. In contrast, Cheever et al²⁸ found no statistically significant difference between performance on the King-Devick test between patients who had a prolonged vs normal recovery at initial visit or any subsequent visit (initial visit: P = .214; 2 weeks: P = .779; 6 weeks: P = .698).

A positive NPC appears to be associated with prolonged concussion recovery, according to 4 studies,^26,29,33,39 which reported statistically significant relationships. Sufrinko et al³² found a similar result comparing convergence distance predictive of a recovery of 15 to 90 days compared to a recovery of ≤14 days. Cheever et al²⁸ did not find an association between a positive NPC and the likelihood of prolonged recovery at initial visit (P = .114); however, the authors used a shorter elapsed time to dichotomize patients into prolonged and normal recovery, namely, 16 days.

Researchers of four studies^26,30,32,39 examined VOR testing with mixed results. Eagle et al³⁰ reported a significant relationship between a positive VOR and longer recovery time in both male and female patients. Sufrinko et al³² found positive horizontal and vertical VOR predictive of longer recovery with reported ORs as high as 1.31 by using the horizontal VOR test to predict a recovery of 30 to 90 days compared to a recovery less than 14 days. Interestingly, in the same study, the horizontal and vertical VOR tests were unable to predict a recovery of 15 to 29 days compared to a recovery of less than 14 days when using multinomial regressions.³² Counter to these results, researchers of 2 studies (Leddy et al²⁶ and Worts et al³⁹) found no statistically significant differences between patients with a prolonged and normal recovery when comparing results of VOR testing. Worts et al³⁹ did find numerical differences between the prolonged and normal groups on VOR testing, but the differences did not reach statistical significance.

Eagle et al,³⁰ Sufrinko et al,³² and Worts et al³⁹ examined visual motion sensitivity (VMS) with similar findings across studies that a positive VMS is related to prolonged recovery. Eagle et al³⁰ found a significant relationship between a longer recovery and positive VMS. When Worts et al³⁹ included extreme test scores in regression models, they found that VMS is likely to predict prolonged recovery with an OR of 1.54 (95% CI = 1.13, 2.09) and a crude OR of 4.36 (95% CI = 2.13, 8.93) for an adjusted OR. Sufrinko et al³² found in a multinomial regression analysis that a patient with a positive VMS was 1.23 times as likely to have a 30- to 90-day recovery relative to a recovery less than or equal to 14 days.

Finally, researchers of 5 studies^{11,27,30,34,39} reported on grouped vestibular and oculomotor testing positivity and its relationship to prolonged recovery. Worts et al³⁹ found all of the VOMS measures, except VOR, to be predictive of prolonged recovery. Price et al¹¹ reported a negative VOMS predictive of normal recovery (fully adjusted incidence rate ratio = 1.31 [95% CI = 1.05, 1.63), with a negative predictive value of 80.77%. Eagle et al³⁰ found that any increase in symptoms during VOMS testing was predictive of a longer recovery in males only, and in females, only the vestibular assessments within the VOMS was predicative of prolonged recovery. Similarly, if a patient did not have a 1-unit increase, researchers found a 90% chance that patients recovered within 30 days.³⁰ Martinez et al³⁴ found that patients were 4 times more likely to have a prolonged recovery if they had symptom provocation on any of the screening tests (OR = 4.28, P < .01). Additionally, the same study found consistently, across multiple analyses, that a positive vestibular screen was associated with a 3 to 4 times increased odds of delayed recovery in patients after concussion.³⁴ Ellis et al²⁷ noted that more than 1 subjective report of vision problems and 1 positive oculomotor or vestibular test were predictive of prolonged recovery (adjusted OR = 4.1 [95% CI = 1.04, 16.16]). A positive oculomotor or vestibular test in the previous study²⁷ included symptom provocation or an abnormal finding on a singular test. Researchers of these 5 studies demonstrated consistently that the VOMS, vestibular screenings, or oculomotor screenings may help predict recovery.

Studies Assessing Continuous Time to Recovery After Positive Vestibular or Oculomotor Test

Although many study designs classified patients into normal and prolonged recovery, others chose to use recovery as a continuous variable. Researchers of four studies^37,38,40,41 used continuous days until recovery or return to play. Anzalone et al,⁴⁰ Master et al,⁴¹ and Whitney et al³⁸ reported on smooth pursuits and its relationship to recovery; all researchers found a significantly longer recovery in patients who had a positive smooth pursuits test than patients who had a negative test. Similarly, a positive saccades was found to be significantly associated with a longer recovery by Whitney et al³⁸ (P = .025) and Anzalone et al⁴⁰ (horizontal saccades: P = .018, vertical saccades: P < .001), a positive VOR was found by Anzalone et al⁴⁰ (horizontal VOR: P = .018, vertical VOR: P = .002) and Master et al⁴¹ (log-rank P = .001), and a positive NPC was found by Whitney et al³⁸ (P = .031).

Whitney et al³⁸ found that patients who had a VOMS symptom increase of greater than or equal to 2 had an average recovery time of 3.5 days longer than those who had a negative VOMS. Knell et al³¹ assessed symptom increase within sexes and found that (1) in males, a 1-unit increase in symptom provocation during VOMS assessment increased recovery time by 1.38 days (P < .001), and (2) in females, the recovery duration per 1-unit increase was 1.73 days (P < .001). Similarly, Price et al¹¹ reported that patients who had a 2-point increase on any VOMS test had a 1.31-day longer recovery than patients with a lesser increase. Researchers of another study found that patients who reported more than 1 vision problem and at least 1 positive oculomotor or vestibular test had a median recovery time of 40 days (interquartile range = 28.5–54 days) compared to 21 days (interquartile range = 13–32 days) in patients who did not report these symptoms and had negative oculomotor or vestibular tests.²⁷

Additionally, Sinnott et al³⁷ examined recovery among patients who had no vestibular symptoms compared to those who reported their vestibular symptoms were improving over time and patients who indicated their vestibular symptoms were persisting. In patients with improving vestibular symptoms, recovery was 3.47 days longer than patients with no vestibular symptoms. The difference reported by Sinnott et al³⁷ between patients who had no symptoms and persisting symptoms was even greater with patients experiencing persisting symptoms having a 11.99-day longer recovery than patients with no vestibular symptoms. Researchers of these studies consistently suggest that a longer recovery is associated with positive vestibular or oculomotor tests.

DISCUSSION

Researchers of 14 of the 19 included studies in this systematic review suggest that patients having a positive vestibular or oculomotor screening test is indicative of longer recovery than patients who do not test positive on these screenings. Authors of these studies consistently found that vestibular or oculomotor tests are able to predict recovery, with authors of studies reporting a difference of slightly more than 1 day.¹¹ In contrast, other authors report a 3- to 4-day difference in recovery length.^31,37,38 It appears that if patients report vestibular or oculomotor symptoms or screen positive on vestibular or oculomotor testing, they will have a longer recovery than patients who do not because these systems affect how people interact with their environment. Other researchers have found the VOMS to have relatively low false-positive rates⁴² and similar impairments between collegiate and high school athletes.⁴³ Moreover, sideline assessments of oculomotor testing, like the King-Devick test, have been found to be a good supplemental tool to traditional sideline assessment tools, such as the SCAT5.⁴⁴ Within the broader prognostic indicator literature for concussion, this review builds upon previous literature^12,13 in which authors suggest that vestibular or oculomotor dysfunction may play a role in identifying patients with persisting symptoms who have a longer recovery. As such, the vestibular and oculomotor assessments should be included as part of a multimodal concussion assessment battery.

Our findings should be interpreted in the context of several limitations. Most patients were seen in concussion specialty care; the aggregation of findings suffered from inconsistent methods, including assessment tool and timing; and outcome measures were inconsistent. Within the studies included in the systematic review in which researchers examined VOMS testing, 8 studies (Büttner et al,³⁵ Eagle et al,³⁰ Glendon et al,³⁶ Henry et al,²⁵ Price et al,¹¹ Sinnott et al,³⁷ Whitney et al,³⁸ and Worts et al³⁹) classified a positive VOMS as symptom provocation of greater than 2, as proposed in the original article for VOMS testing by Mucha et al.²¹ Authors of 4 articles (Anzalone et al,⁴⁰ Leddy et al,²⁶ Master et al,⁴¹ and Martinez et al³⁴) used any symptom provocation as a positive VOMS. This discrepancy makes it difficult to compare studies because of the different operationalizations for which some patients in the latter group of studies would test positive. In the former group, if the symptoms did not reach a threshold greater than 2, the patients would have been noted as negative. The populations studied in the included articles ranged from as young as 5 years old to 40 years old. However, only Büttner et al³⁵ included athletes who were older than collegiate athletes, and authors of 2 studies (Ellis et al²⁷ and Walker et al³³) did not exclude patients younger than 5 years old in their methods. The weighted mean age for studies that reported mean age is 16.4 years old, demonstrating that the patient population is concentrated in high school-aged patients. The adolescent age group appears to sustain an inordinate number of concussions, as supported by epidemiologic research.⁴⁵ Having most patients treated in concussion specialty care limits the clinical applicability of this review. Patients who are seen in specialty care often have access to private insurance and are of a higher socioeconomic status, and thus, they are able to seek care earlier, which has also been found to reduce recovery time.⁴⁶ Also, our findings may not be generalizable to patients in lower socioeconomic situations. Additionally, patients evaluated in specialty clinics may have had symptoms longer⁴⁷ or more severe symptoms than patients who were evaluated by only an athletic trainer or primary care provider. These patients may not represent the larger proportion of patients whose concussions do not require specialty care.

Additionally, the methods of the included studies were varied, and the authors were unable to combine the results of these studies into a meta-analysis. Furthermore, the authors reported a variety of evaluation timepoints, outcomes, and analytical approaches, including VOMS component interpretation, which limited the direct comparison of results across studies (Supplemental Table). Furthermore, recent evidence suggests that using a change score with the VOMS, rather than the total score, may improve the identification of concussion through component and overall clinical cut-offs.⁴⁸ Future researchers should use multiple variables in the concussion evaluation to help clinicians predict a prolonged recovery while using the shortest clinical examination.

CONCLUSIONS

Vestibular and oculomotor screening tests can help inform clinicians about a patient’s status. With the findings of this systematic review, we conclude that a positive vestibular or oculomotor assessment may be prognostic of a longer recovery time than a negative screening (Strength of Recommendation: B). Although researchers of most studies found that a positive vestibular or oculomotor screen was associated with a longer recovery, most of the included studies were level 3 or 4 evidence and are not generalizable to patient populations. However, clinicians in all settings should be encouraged to include vestibular or oculomotor assessments into their concussion assessment battery to inform rehabilitative efforts and monitor recovery (Strength of Recommendation: C). These assessments are cost effective, require little to no equipment, and can assist clinicians in determining dysfunction, informing rehabilitative efforts, and aiding in determining a patient’s prognosis.