Describing the evidence linking interprofessional education interventions to improving the delivery of safe and effective patient care: a scoping review.

Empirical evidence indicates that collaborative interprofessional practice leads to positive health outcomes. Further, there is an abundance of evidence examining student and/or faculty perceptions of learning or satisfaction about the interprofessional education (IPE) learning experience. However, there is a dearth of research linking IPE interventions to patient outcomes. The objective of this scoping review was to describe and summarize the evidence linking IPE interventions to the delivery of effective patient care. A three-step search strategy was utilized for this review with articles that met the following criteria: publications dated 2015-2020 using qualitative, quantitative or mixed methods; the inclusion of healthcare professionals, students, or practitioners who had experienced IPE or training that included at least two collaborators within coursework or other professional education; and at least one of ten Centers for Medicare & Medicaid Services quality measures (length of stay, medication errors, medical errors, patient satisfaction scores, medication adherence, patient and caregiver education, hospice usage, mortality, infection rates, and readmission rates). Overall, n=94 articles were identified, providing overwhelming evidence supporting a positive relationship between IPE interventions and several key quality health measures including length of stay, medical errors, patient satisfaction, patient or caregiver education, and mortality. Findings from this scoping review suggest a critical need for the development, implementation, and evaluation of IPE interventions to improve patient outcomes.

When Particle Repositioning Maneuvers Just Will Not Stick: Clinical Considerations for Persistent Benign Paroxysmal Positional Vertigo.

PURPOSE: Although benign paroxysmal positional vertigo (BPPV) is often considered benign and easily treatable, aberrant cases of persistent BPPV can be challenging to manage. Detailed differential diagnosis is essential as central-, vascular-, and cervical-related etiologies may mirror the presentation of persistent BPPV. In addition, an understanding of alternative noninvasive treatment options is important as persistent BPPV is often refractory to traditional particle repositioning maneuvers (PRMs). This article reviews clinical considerations for persistent BPPV. METHOD: A case of a 68-year-old male diagnosed with posterior semicircular canal BPPV (PC-BPPV) and received various unsuccessful PRMs treatments is described. His clinical presentation is referenced alongside various possible etiologies to discern the most likely diagnosis. Nonsurgical treatment options for intractable PC-BPPV will also be reviewed. CONCLUSIONS: BPPV recalcitrant to PRM treatment warrants investigation of other etiologies; however, key elements of the case history and objective examination are helpful for differential diagnosis. Brandt-Daroff exercises may facilitate habituation of symptoms secondary to persistent BPPV. More research is needed to understand the use of multiaxial repositioning chairs for the treatment of intractable BPPV.

Benign paroxysmal positional vertigo: Effective diagnosis and treatment.

Benign paroxysmal positional vertigo (BPPV), caused by wayward crystals ("rocks") in the semicircular canals of the inner ear, is the most common cause of brief symptoms of vertigo secondary to head and body movements. Diagnosing and treating it are simple to do in the medical office. This article reviews the differential diagnosis for patients presenting with dizziness and vertigo, the pathophysiology of BPPV, how to diagnose it using maneuvers to elicit symptoms and nystagmus, how to interpret the nystagmus pattern to determine where the rocks are, and how to treat it using different maneuvers to reposition ("roll") the rocks back where they belong.

Age Effects of Bone Conduction Vibration Vestibular-evoked Myogenic Potentials (VEMPs) Using B81 and Impulse Hammer Stimuli.

OBJECTIVE: Recently developed, the Radioear B81 bone oscillator allows for higher bone conduction vibration output; however, normative data are lacking regarding its use in vestibular-evoked myogenic potential (VEMP) testing. The purpose of this study was to examine the effect of age on cervical and ocular VEMP (c- and oVEMP) responses using the B81 and to compare with air conduction stimuli (ACS) and impulse hammer (IH) VEMP response characteristics. DESIGN: c- and oVEMP were completed with ACS, B81, and IH stimuli in healthy participants (age range = 10 to 87 years, n = 85). RESULTS: Regardless of stimulus type, c- and oVEMP amplitudes and response rates decreased with age. For cVEMP response rates, ACS performed better or equal to B81, which was superior to the IH. For cVEMP corrected amplitude, ACS had significantly higher amplitudes compared with B81 and IH. There was no difference in cVEMP corrected amplitude between B81 and IH. For oVEMP, response rates were comparable between stimuli with the largest disparity in response rates occurring in the oldest groups where IH outperformed both ACS and B81. For oVEMP amplitude, IH had significantly higher amplitudes compared with B81 and ACS. There was no difference in oVEMP amplitude between B81 and ACS. CONCLUSIONS: Age significantly affected c- and oVEMP amplitudes regardless of stimulus type (ACS, B81, IH). All stimuli are appropriate for eliciting c- and oVEMP in the young individuals. While ACS resulted in higher cVEMP corrected amplitudes, either ACS or B81 are appropriate for older individuals. However, for oVEMPs, higher response rates and larger amplitudes were noted for IH followed by B81 and ACS. Overall, the B81 performed well across the lifespan for c- and oVEMPs and may be a reasonable bone conduction vibration option for patients with absent ACS VEMPs, but at this time is not recommended as a replacement to ACS.

Using Functional Ability Measures to Assess Fall Risk in Acute Care.

Currently, it is not known whether integration of functional performance measures is sensitive and feasible for use in acute care settings. This cross-sectional study explored the subjective and objective measures of the risks of falling, falls efficacy, and functional abilities for inpatients in an adult acute care unit. The Morse Fall Scale (n = 30) and Timed Up and Go (TUG; n = 10) had excellent sensitivity (100%) for identifying participants with prior fall histories, while the St. Thomas Risk Assessment Tool in Falling Elderly Inpatients only had good sensitivity (87.5%). Study findings suggest that implementation of feasible functional ability measures in conjunction with subjective fall risk measures could enhance accuracy and performance in identifying inpatient risks of falling in acute care settings.

BASIC Training: A Pilot Study of Balance/Strengthening Exercises in Heart Failure.

PURPOSE: The aim of this pilot study was to evaluate the effect of a multicomponent balance and resistance training intervention on physical function, balance, and falls in older (≥65 years) community-dwelling heart failure (HF) patients. DESIGN: Randomized, two-group repeated-measures experimental design. METHODS: The intervention involved once weekly supervised group sessions with home sessions encouraged twice weekly. Focus groups held pre/post intervention. Outcome variables included measures of physical function, balance confidence, and falling risk. FINDINGS: In a sample size of 33, the Dynamic Gait Index change from baseline to 12 weeks was significantly different in the groups (p = .029). The number of reported falls declined from 0.92 to 0.54 per participant. CONCLUSIONS: A supervised group session intervention can increase mobility and gait and reduce fall rate for HF patients. CLINICAL RELEVANCE: This study was designed to improve lower extremity strength, balance, and falls in elderly HF patients, thus reducing costs and improving quality of life for this population.

Clinical Utility of Oculomotor and Electrophysiological Measures in Identifying Concussion History.

OBJECTIVE: To examine whether oculomotor and electrophysiological measures improve the clinical performance of the typical concussion protocol for classifying collegiate athletes with a history of concussion. DESIGN: Cross-sectional. SETTING: University Athletic Medicine and Research Facility. PARTICIPANTS: Forty-five varsity collegiate athletes. INDEPENDENT VARIABLES: Collegiate varsity athletes with or without a history of a diagnosed concussion. MAIN OUTCOME MEASURES: Multivariate receiver operating curve and area under the curve (AUC) analyses tested the clinical performance of the typical concussion protocol (symptoms, postural control, neuropsychological abilities). We examined differences in clinical performance between this protocol and after adding reflexive saccade and event-related potential (ERP) indices. Hypotheses were formed after data collection. RESULTS: Significant AUCs were demonstrated for the typical concussion protocol (model 1: AUC = 0.75, P = 0.007), after adding reflexive saccade eye excursion gain (model 2: AUC = 0.80, P = 0.001), and ERPs (model 3: AUC = 0.79, P = 0.002). The AUC for reflexive saccades and ERPs was significant (model 4: AUC = 0.70, P = 0.030). Model 2's increased clinical performance compared with model 1 was nonsignificant, χ(2) = 1.871, P = 0.171. CONCLUSIONS: All 4 models demonstrated adequate sensitivity and specificity for classifying athletes with a previous concussion. Adding reflexive saccades and ERPs did not significantly increase clinical performance of the typical concussion protocol. Future research should determine the clinical utility of saccades and ERPs for acute postconcussion assessments.

Pediatric vestibular testing: Tolerability of test components in children.

INTRODUCTION: Objective of the study is to define rates of successful completion of components of pediatric vestibular testing (VT). METHODS: Retrospective review of VT performed on patients less than 18 years of age from 2004 to 2015. RESULTS: 188 pediatric patients (mean age: 13.9 ±â€¯3.56 years old, range 2-17 years) underwent testing. Thirty-five (18.6%) had abnormal test results. Pediatric patients unable to complete all aspects of VT could still complete an average of 7.9 ±â€¯4.0 of 12 test components. The optokinetic tracking test was the most commonly omitted component of the vestibular tests. In a multivariate analysis, failure to perform Nylen-Barany positional testing (χ2 27.5, p < 0.0001) or Dix-Hallpike (5.66, p = 0.0174) testing was associated with inability to obtain final diagnosis on VT. CONCLUSIONS: Interpretable VT may be obtained in most children, even in those that do not tolerate the full testing protocol. Spontaneous and gaze-evoked nystagmus testing maybe considered as part of initial testing protocol before attempting less well-tolerated components such as bithermal calorics or components that require VNG goggles.

Video Head Impulse Test (vHIT): The Role of Corrective Saccades in Identifying Patients With Vestibular Loss.

OBJECTIVE: 1) Characterize corrective saccades (CS) in normal controls, and 2) examine the sensitivity of the video head impulse test (vHIT) for identifying vestibular loss using both gain and CS. STUDY DESIGN: Prospective combined with retrospective review. SETTING: Tertiary referral center. PATIENTS: Seventy subjects with normal vestibular function served as controls (mean age, 44.1 yr; range, 10-78) and data from 49 patients with unilateral and bilateral vestibular loss was retrospectively reviewed (mean age, 50; range, 7-81). INTERVENTION: vHIT; individual horizontal head impulses were then analyzed in MATLAB. MAIN OUTCOME MEASURES: Horizontal vHIT gain, CS peak velocity, frequency, and latency. RESULTS: There was not an age effect for CS velocity or latency, and only a weak relationship between CS frequency and age in the control group. Gain and CS latency were the only parameters affected by impulse side, demonstrating higher gain and longer latency on the right. The group with vestibular loss had significantly lower mean vHIT gain, higher mean CS frequency, higher mean CS velocity, earlier CS latency, and smaller mean CS standard deviations of the latency compared with the control group.When all factors were analyzed separately by logistic regression, vHIT gain provided the best classification (83.8%), closely followed by CS frequency (83.1%). Using a two variable approach (both gain and CS frequency) yielded the best diagnostic accuracy (overall classification = 84.6%). CONCLUSIONS: Along with gain, incorporating CS frequency in interpreting vHIT improves diagnostic accuracy. A repeatable CS (>81.89%) and/or low gain (<0.78) indicate vestibular loss.

Functional Measures for Fall Risk in the Acute Care Setting: A Review.

This review explores the evidence pertaining to the use of functional ability measures for fall risk in the acute care setting. We included studies from six bibliographic databases that investigated fall risk functional ability measures in hospitalized older adults (≥55 years). We utilized the following search terms: acute care, subacute care, critical care, inpatient, fall, and fall prevention. Nineteen articles met the inclusion criteria. Timed "Up and Go" (TUG) was identified as a feasible fall risk functional ability measure for clinicians; it demonstrated clinical performance of fair sensitivity (56%-68%) and good specificity (74%-80%). Clinical performance of other measures (Berg Balance Scale and Functional Reach test) was not as favorable as the TUG. Functional ability measures are underutilized in the acute care setting, potentially due to limited knowledge and training on administration. Combining functional measures with subjective screening tools may optimize performance and accuracy of identifying fall risk identification.

Effects of Device on Video Head Impulse Test (vHIT) Gain.

BACKGROUND: Numerous video head impulse test (vHIT) devices are available commercially; however, gain is not calculated uniformly. An evaluation of these devices/algorithms in healthy controls and patients with vestibular loss is necessary for comparing and synthesizing work that utilizes different devices and gain calculations. PURPOSE: Using three commercially available vHIT devices/algorithms, the purpose of the present study was to compare: (1) horizontal canal vHIT gain among devices/algorithms in normal control subjects; (2) the effects of age on vHIT gain for each device/algorithm in normal control subjects; and (3) the clinical performance of horizontal canal vHIT gain between devices/algorithms for differentiating normal versus abnormal vestibular function. RESEARCH DESIGN: Prospective. STUDY SAMPLE: Sixty-one normal control adult subjects (range 20-78) and eleven adults with unilateral or bilateral vestibular loss (range 32-79). DATA COLLECTION AND ANALYSIS: vHIT was administered using three different devices/algorithms, randomized in order, for each subject on the same day: (1) Impulse (Otometrics, Schaumberg, IL; monocular eye recording, right eye only; using area under the curve gain), (2) EyeSeeCam (Interacoustics, Denmark; monocular eye recording, left eye only; using instantaneous gain), and (3) VisualEyes (MicroMedical, Chatham, IL, binocular eye recording; using position gain). RESULTS: There was a significant mean difference in vHIT gain among devices/algorithms for both the normal control and vestibular loss groups. vHIT gain was significantly larger in the ipsilateral direction of the eye used to measure gain; however, in spite of the significant mean differences in vHIT gain among devices/algorithms and the significant directional bias, classification of "normal" versus "abnormal" gain is consistent across all compared devices/algorithms, with the exception of instantaneous gain at 40 msec. There was not an effect of age on vHIT gain up to 78 years regardless of the device/algorithm. CONCLUSIONS: These findings support that vHIT gain is significantly different between devices/algorithms, suggesting that care should be taken when making direct comparisons of absolute gain values between devices/algorithms.

Fall risk screening protocol for older hearing clinic patients.

OBJECTIVE: The primary purposes of this study were (1) to describe measures that may contrast audiology patients who fall from those who do not fall and (2) to evaluate the clinical performance of measures that could be easily used for fall risk screening in a mainstream audiology hearing clinic. DESIGN: Cross-sectional study Study sample: Thirty-six community-dwelling audiology patient participants and 27 community-dwelling non-audiology patients over 60 years of age. RESULTS: The Hearing Handicap Inventory for the Elderly (HHIE) most accurately identified patients with a recent fall (sensitivity: 76.0%), while the Dizziness Handicap Inventory (DHI) most accurately identified patients without a recent fall (specificity: 90.9%). A combination of measures used in a protocol-including HHIE, DHI, number of medications, and the Timed Up and Go test-resulted in good, accurate identification of patients with or without a recent history of falls (92.0% sensitivity, 100% specificity). CONCLUSIONS: This study reports good sensitivity and excellent specificity for identifying patients with and without a recent history of falls when measures were combined into a screening protocol. Despite previously reported barriers, effective fall risk screenings may be performed in hearing clinic settings with measures often readily accessible to audiologists.

Examining Effects of Physical Exertion on the Dynamic Visual Acuity Test in Collegiate Athletes.

BACKGROUND: Acute symptoms of dizziness and/or imbalance commonly experienced in athletes postconcussion are speculated to arise from dysfunction at multiple levels (i.e., inner ear or central vestibular system) to appropriately integrate afferent sensory information. Disruption along any pathway of the balance system can result in symptoms of dizziness, decreased postural control function (vestibulospinal reflex), and reduced vestibulo-ocular reflex function. This may also lead to decreased gaze stability with movements of the head and may account for symptoms of blurred vision or diplopia reported in almost half of athletes sustaining a concussion. Current concussion position statements include measures of postural control to examine changes to the balance system postconcussion. The Balance Error Scoring System (BESS) is a commonly used low-cost postural control measure for concussion assessment. Although this is a widely used measure for documenting balance function on both immediate (sideline) and recovery monitoring, the BESS has been shown to be affected by physical exertion. Therefore, the BESS may not be the most efficient means of examining functional changes to the balance system immediately after head injury. Dynamic Visual Acuity Test (DVAT) has been found to effectively evaluate and monitor changes to the gaze stability system postinjury. Thus, DVAT may be an additional measure in the concussion assessment battery, as well as an alternative for more immediate sideline assessment to help make objective return-to-play decisions. PURPOSE: The aim of the study was to determine the effects of physical exertion on a clinical vestibular assessment, the DVAT, in collegiate athletes, as a first step in defining the role of this measure in the concussion assessment battery. RESEARCH DESIGN: Cross-sectional, repeated-measures design. STUDY SAMPLE: Twenty-eight healthy collegiate athletes (20 males, 8 females; age = 20.25 ± 1.46 yr, range = 18-25 yr) volunteered to participate in the study. DATA COLLECTION AND ANALYSIS: Participants were randomly assigned to complete a 20-min protocol of physical exertion or rest. DVAT was completed pre-exertion or rest (pre-DVAT), immediately following the 20-min protocol (post-DVAT I), and again 10 min after the completion of the 20-min protocol (post-DVAT II). Ratings of perceived exertion (RPE) and heart rate (HR) were monitored throughout testing. Repeated-measures analysis of the variance were used to examine the effects of exertion on DVAT. Additionally, intraclass correlation coefficients were used to examine test reliability. RESULTS: No significant main effect was observed for right and left DVAT logarithm of the minimal angle of resolution loss between groups or across time points (p > 0.05). A significant main effect was observed for RPE and HR for groups and time points (p < 0.001), indicating adequate physical exertion and rest. Fair to good reliability (intraclass correlation coefficient values between 0.4 and 0.74) was observed for both rightward and leftward movements of the head across the three time points. CONCLUSIONS: Findings from this study suggest that DVAT is not affected by physical exertion and may provide a more immediate assessment of the balance system that may be of use for the sideline concussion assessment. Future studies will be performed to examine additional factors (e.g., background noise, complex visual backgrounds) that may affect DVAT performance in the sideline environment.

Modified head shake sensory organization test: Sensitivity and specificity.

The Sensory Organization Test (SOT) of Computerized Dynamic Posturography (EquiTest™ equipment) is a valuable tool for investigating how an individual uses balance system sensory input (vestibular, vision, proprioception/somatosensory) to maintain quiet stance; however, it is limited as a screening tool for identifying peripheral vestibular system dysfunction. Previous research has shown that adding horizontal head-shake to portions of the standard SOT battery improved the identification of peripheral vestibular system asymmetry; however, flaws in the methods were noted. The objective of this work was to evaluate the sensitivity and specificity of the modified head-shake SOT (HS-SOT) protocol for identification of peripheral vestibular system lesion. Fifteen patients with chief complaint of instability, vertigo, and/or lightheadedness, with and without a caloric unilateral weakness (UW) and fifteen age-matched healthy controls were included in the final analysis. Ten of the 15 patients demonstrated a caloric UW≥25%. Participants completed standard conditions 2 and 5 of SOT with head still and during four horizontal head-shaking tasks (i.e., HS-SOT2-60°/s, HS-SOT2-120°/s, HS-SOT5-15°/s, and HS-SOT5-60°/s). Average equilibrium scores decreased as condition difficulty increased (SOT2, HS-SOT2-60°/s, HS-SOT2-120°/s, SOT 5, HS-SOT5-15°/s, and HS-SOT5-60°/s) for each group; as expected, a lower decline was noted for controls (slope=-6.59) compared to patients (slope=-11.69). The HS-SOT5-15°/s condition was superior for identifying peripheral vestibular asymmetry (AUC=0.90 sensitivity=70%, specificity=100%), with the strongest correlation to caloric UW% (rs=-0.743, p=0.000006). HS-SOT5-15°/s appears to be a promising screening measure for peripheral vestibular asymmetry.

Developing a data repository of standard concussion assessment clinical data for research involving college athletes.

In sports concussion research, obtaining quality data from a sufficient number of participants to reach statistical power has been a particular problem. In addition, the necessary requirements of accessibility, informed consent, and confidentiality must be met. There is need to develop more efficient and controlled methods for collecting data to answer research questions in this realm, but the ability to collect and store these data in an efficient manner at the local level is limited. By virtue of their training, neuropsychologists can play a key role in improving data collection quality. The purpose of this paper is to describe a data repository that has been developed in the context of a university sports medicine concussion management program that includes baseline and postinjury data from student athletes. Diagnostic information, basic health information, current symptoms, neuropsychological test data, balance and vestibular data, and visual processing data are currently included in the standard of care for athletes; however, the process described need not be limited to these types of data. While a national traumatic brain injury (TBI) data repository has been developed by the National Institute of Health (NIH), local repositories have not yet become common. Thus, the description of this project is of value at the local level in the United States and internationally.

Audiology patient fall statistics and risk factors compared to non-audiology patients.

OBJECTIVE: To compare fall statistics (e.g. incidence, prevalence), fall risks, and characteristics of patients who seek hearing healthcare from an audiologist to individuals who have not sought such services. DESIGN: Case-control study. STUDY SAMPLE: Two groups of community-dwelling older adult patients: 25 audiology patients aged 60 years or older (M age: 69.2 years, SD: 4.5, range: 61-77) and a control group (gender- and age-matched ±2 years) of 25 non-audiology patients (M age: 69.6, SD: 4.7, range: 60-77). RESULTS: Annual incidence of falls (most recent 12 months) was higher in audiology patients (68.0%) than non-audiology patients (28.0%; p = .005). Audiology patients reported a higher incidence of multiple recent falls (p =.025) and more chronic health conditions (p = .028) than non-audiology patients. CONCLUSIONS: Significantly more audiology patients fall on an annual basis than non-audiology patients, suggesting that falls are a pervasive issue in general hearing clinics. Further action on the part of healthcare professionals providing audiologic services may be necessary to identify individuals at risk for falling.

Identifying Balance Measures Most Likely to Identify Recent Falls.

BACKGROUND AND PURPOSE: Falls sustained by older adults are an increasing health care issue. Early identification of those at risk for falling can lead to successful prevention of falls. Balance complaints are common among individuals who fall or are at risk for falling. The purpose of this study was to evaluate the clinical utility of a multifaceted balance protocol used for fall risk screening, with the hypothesis that this protocol would successfully identify individuals who had a recent fall (within the previous 12 months). METHODS: This is a retrospective review of 30 individuals who self-referred for a free fall risk screening. Measures included case history, Activities-Specific Balance Confidence Scale, modified Clinical Test of Sensory Interaction on Balance, Timed Up and Go test, and Dynamic Visual Acuity. Statistical analyses were focused on the ability of the test protocol to identify a fall within the past 12 months and included descriptive statistics, clinical utility indices, logistic regression, receiver operating characteristic curve, area under the curve analysis, effect size (Cohen d), and Spearman correlation coefficients. RESULTS AND DISCUSSION: All individuals who self-referred for this free screening had current imbalance complaints, and were typically women (70%), had a mean age of 77.2 years, and had a fear of falling (70%). Almost half (46.7%) reported at least 1 lifetime fall and 40.0% within the past 12 months. Regression analysis suggested that the Timed Up and Go test was the most important indicator of a recent fall. A cutoff score of 12 or more seconds was optimal (sensitivity: 83.3%; specificity: 61.1%). CONCLUSIONS: Older adults with current complaints of imbalance have a higher rate of falls, fall-related injury, and fear of falling than the general community-dwelling public. The Timed Up and Go test is useful for determining recent fall history in individuals with imbalance.

Effects of Hand Placement Technique on the Video Head Impulse Test (vHIT) in Younger and Older Adults.

OBJECTIVE: To investigate the effects of hand placement techniques on the video head impulse test (vHIT) responses (i.e., gain, velocity) in older and younger adults and to determine intra-rater and inter-rater reliability of the horizontal vHIT. DESIGN: Descriptive, reliability study. SETTING: University research laboratory. SUBJECTS: Forty healthy adults grouped by age with negative history of current or previous vestibular diseases between the ages of 20 and 88 years (mean = 46.60, standard deviation 23.20). MAIN OUTCOME MEASURES: Three examiners each used two hand placement techniques (chin and head) to elicit the horizontal vHIT responses. Both the examiner and hand placement orders were counterbalanced to account for order and fatigue effects. The outcome measures of interest were vHIT gain and velocity. RESULTS: A two-way between-subject factorial analysis of variance revealed a significant main effect for hand placement technique and gain response. Mean values for vHIT gain were higher for head technique. Significant main effects were observed for the velocity response for hand placement technique and age group. Mean velocity values were higher for chin technique and lower velocities were observed in the older age group. Intra- and inter-rater reliability scores were consistent for gain values; however, poor to fair inter-rater reliability scores were observed for velocity values. CONCLUSION: It is suggested that clinical sites select one hand placement technique for the measure to provide consistency of protocol. Establishing clinical norms using the one selected method to verify reliability within and across clinicians is suggested before examination with a disordered population.

Test-retest reliability of the vestibular sensory-evoked potential (VsEP) in C57BL/6J mice.

BACKGROUND: The vestibular sensory-evoked potential (VsEP) is an electrical potential that provides a direct test of vestibular function in animals. VsEP recordings are carried out using subcutaneous stainless steel electrodes placed over the nuchal crest (noninverting), behind either the left or right pinna (inverting), and at the hip (ground). A noninvasive head clip is used to secure the head to a mechanical shaker for delivery of a linear vestibular stimulus measured in units of jerk (g/msec). Frequent repositioning of the noninvasive head clip and skin electrodes may be necessary during recording for particular protocols; however, the test-retest reliability of the VsEP response (latency, amplitude, and threshold) has not been determined. PURPOSE: The purpose of this study was to determine the possible effects of frequent repositioning of the noninvasive head clip and skin electrodes on VsEP response parameters (latencies, amplitudes, and thresholds). We hypothesize that the VsEP response will remain stable and reliable with such repeated measurements in a given animal across time. RESEARCH DESIGN: Linear VsEP responses were recorded from ten C57 mice (ages: 2.45 mo ±0.20; weights: 17.94 g ±1.51). Two standard threshold protocols and four repeated VsEP measurements at +6 dB re: 1.0 g/msec were performed, with four selected time points of head clip repositioning. In addition, three novice investigators performed measurements of noninverting electrode placement and head clip positioning. RESULTS: VsEP response latency, amplitude, and threshold means did not significantly change with frequent repositioning of the head clip and skin electrodes; however, increased variability was observed. CONCLUSIONS: The findings demonstrate that repositioning does not introduce significant changes in mean parameter values of the recorded VsEP response waveform; however, mean absolute difference calculations demonstrated that frequent repositioning increased response variance. For VsEP protocols requiring frequent repositioning, standardized electrode montage, optimal placement of the noninverting electrode at the nuchal crest, and increased sample size are suggested.

Gaze Stabilization Test Asymmetry Score as an Indicator of Previous Concussion in a Cohort of Collegiate Football Players.

OBJECTIVE: Vestibular dysfunction may lead to decreased visual acuity with head movements, which may impede athletic performance and result in injury. The purpose of this study was to test the hypothesis that athletes with history of concussion would have differences in gaze stabilization test (GST) as compared with those without a history of concussion. DESIGN: Cross-sectional, descriptive. SETTING: University Athletic Medicine Facility. PARTICIPANTS: Fifteen collegiate football players with a history of concussion, 25 collegiate football players without a history of concussion. INTERVENTION: Participants completed the dizziness handicap inventory (DHI), static visual acuity, perception time test, active yaw plane GST, stability evaluation test (SET), and a bedside oculomotor examination. MAIN OUTCOME MEASURES: Independent samples t test was used to compare GST, SET, and DHI scores per group, with Bonferroni-adjusted alpha at P < 0.01. Receiver operating characteristic curve analysis and area under the curve (AUC) were used to assess the clinical performance of the GST and SET. RESULTS: Athletes with previous concussion had a larger GST asymmetry score [mean (M) = 12.40, SD = 9.09] than those without concussion (M = 4.92, SD = 4.67; t (18.70) = -2.955, P = 0.008, 95% CI, -12.79 to -2.18, d = -1.37). Clinical performance of the GST (AUC = 0.77) was better than the SET (AUC = 0.61). CONCLUSIONS: Results suggest peripheral vestibular or vestibular-visual interaction deficits in collegiate athletes with a history of concussion. The results support further research on the use of GST for sport-related concussion evaluation and monitoring. CLINICAL RELEVANCE: Inclusion of objective vestibular tests in the concussion protocol may reveal the presence of peripheral vestibular or visual-vestibular deficits. Therefore, the GST may add an important perspective on the effects of concussion.