Gregory F. Marchetti

The Effect of Age on Vestibular Rehabilitation Outcomes

Objective The purpose of the retrospective chart review was to compare vestibular rehabilitation outcomes in young versus older adults.

A comparison of accelerometry and center of pressure measures during computerized dynamic posturography: A measure of balance

Accelerometry (ACC) shows promise as an easily implemented clinical measure of balance. The purpose of the study was to estimate test-retest reliability of ACC measures and determine the relationship between ACC measured at the pelvis and underfoot center of pressure (COP) measures during sensory organization test (SOT) conditions. Eighty-one subjects were recruited from the community with no known orthopedic or vestibular deficits (19-85 years). Subjects completed three consecutive, ninety second trials for each of the six SOT conditions, while wearing the accelerometer. ACC and COP time series were described by calculating the normalized path length, root mean square (RMS), and peak-to-peak values. The test-retest reliability of the three measures within each SOT condition was estimated over three trials using the intraclass correlation coefficient. ACC and COP test-retest reliability were similar, ranging from 0.63 to 0.80 using ACC and 0.42 to 0.81 using COP for the measure of normalized path length. Linear regression between ACC and COP measures showed significant correlation under almost every SOT condition using both single and average measures across trials. The degree of association between COP and ACC was equivalent when using the first trial or the 3-trial average, suggesting that one trial may be sufficient. The use of accelerometry may have value in estimating balance function and minimizing clinical evaluation time.

Construction and Validation of the 4-Item Dynamic Gait Index

Background and Purpose. People with balance disorders often have difficulty walking. The purpose of this study was to develop and test the psychometric properties of a short form of the Dynamic Gait Index (DGI) for the clinical measurement of walking function in people with balance and vestibular disorders. Subjects. A total of 123 subjects with such disorders (test subjects) and 103 control subjects were included in this study. Methods. Rasch and factor analyses were used to create a short form of the DGI. Internal consistency and discriminative validity for test subjects versus control subjects and for falling versus nonfalling test subjects were evaluated. Results. Four items were selected for the shorter version of the test: gait on level surfaces, changes in gait speed, and horizontal and vertical head turns. Discussion and Conclusion. The clinical psychometric properties of the 4-item DGI were equivalent or superior to those of the 8-item test. The 4-item DGI can be used by clinicians to measure gait in people with balance and vestibular disorders without compromising important clinical measurement characteristics.

Usefulness of the dizziness handicap inventory in the screening for benign paroxysmal positional vertigo.

Objective: The purpose of the study was to determine whether a newly developed subscale of the Dizziness Handicap Inventory (DHI) could assist in the screening of benign paroxysmal positional vertigo (BPPV). Study Design: Retrospective case review. Setting: Tertiary balance referral center. Patients: Charts of 383 patients (mean age, 61 yr) with a variety of vestibular diagnoses (peripheral and central) were reviewed. Interventions: Patients completed the DHI before the onset of physical therapy intervention. Main Outcome Measures: A newly developed BPPV subscale developed from current DHI items was computed to determine whether the score could assist the practitioner in identifying individuals with BPPV. Results: Individuals with BPPV had significantly higher mean scores on the newly developed BPPV subscale of the DHI (p < 0.01). The five-item BPPV score was a significant predictor of the likelihood of having BPPV (χ2 = 8.35; p < 0.01). On the two-item BPPV scale, individuals who had a score of 8 of 8 were 4.3 times more likely to have BPPV compared with individuals who had a score of 0. Conclusion: Items on the DHI appear to be helpful in determining the likelihood of an individual having the diagnosis of BPPV.

Temporal and Spatial Characteristics of Gait During Performance of the Dynamic Gait Index in People With and People Without Balance or Vestibular Disorders

Background and Purpose: Understanding underlying gait characteristics during performance of the Dynamic Gait Index (DGI) could potentially guide interventions. The purpose of this study was to describe the characteristics and reliability of gait performance during the level walking items of the DGI in people with balance or vestibular dysfunction. The study was a cross-sectional investigation with 2-group comparisons. Subjects and Methods: Forty-seven subjects (mean age=59.2 years, SD=8.5, range=24–90) participated in the study; 26 were control subjects, and 21 were subjects with balance or vestibular dysfunction. Three trials of each level gait item were administered to subjects as they ambulated on an instrumented walkway. Test-retest reliability was determined by use of an intraclass correlation coefficient (3,1) 2-way random-effects model for gait parameters associated with continuous walking and the item requiring turning and stopping quickly. Mean gait parameter differences between control subjects and subjects with balance or vestibular disorders were compared by use of a multivariate analysis of variance for each gait task. Results: The reliability of most gait parameters during DGI performance were fair to excellent between trials. Subjects with balance or vestibular disorders demonstrated differences in gait characteristics compared with control subjects. The heterogeneity of the group of subjects with balance or vestibular disorders does not permit inferences to be drawn regarding the relationship between gait and any specific balance or vestibular diagnosis. The results are most pertinent to people with chronic balance or vestibular disorders. Discussion and Conclusion: Gait parameters underlying dynamic walking appeared to be relatively reliable across multiple trials and distinguished subjects with balance or vestibular disorders. Evaluating a persons performance on items of the DGI may be useful in identifying gait deviations and in evaluating gait improvements as a result of interventions.

Comparison of the Balance Accelerometer Measure and Balance Error Scoring System in Adolescent Concussions in Sports

Background: High-technology methods demonstrate that balance problems may persist up to 30 days after a concussion, whereas with low-technology methods such as the Balance Error Scoring System (BESS), performance becomes normal after only 3 days based on previously published studies in collegiate and high school athletes. Purpose: To compare the National Institutes of Health’s Balance Accelerometer Measure (BAM) with the BESS regarding the ability to detect differences in postural sway between adolescents with sports concussions and age-matched controls. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Forty-three patients with concussions and 27 control participants were tested with the standard BAM protocol, while sway was quantified using the normalized path length (mG/s) of pelvic accelerations in the anterior-posterior direction. The BESS was scored by experts using video recordings. Results: The BAM was not able to discriminate between healthy and concussed adolescents, whereas the BESS, especially the tandem stance conditions, was good at discriminating between healthy and concussed adolescents. A total BESS score of 21 or more errors optimally identified patients in the acute concussion group versus healthy participants at 60% sensitivity and 82% specificity. Conclusion: The BAM is not as effective as the BESS in identifying abnormal postural control in adolescents with sports concussions. The BESS, a simple and economical method of assessing postural control, was effective in discriminating between young adults with acute concussions and young healthy people, suggesting that the test has value in the assessment of acute concussions.

The Effects of Group Cycling on Gait and Pain-Related Disability in Individuals With Mild-to-Moderate Knee Osteoarthritis: A Randomized Controlled Trial

STUDY DESIGN Randomized controlled trial. OBJECTIVE To determine the effectiveness of a community-based program of stationary group cycling on gait, pain, and physical function in individuals with mild-to-moderate knee osteoarthritis (OA). BACKGROUND Knee pain and disability are common symptoms in individuals with knee OA. Though exercise for knee OA has acknowledged benefits, it has the potential to aggravate symptoms in some instances. METHODS Thirty-seven subjects (27 women, 10 men) with a mean ± SD age of 57.7 ± 9.8 years were randomly assigned to a cycling (n = 19) or control (n = 18) group for a 12-week intervention study. Outcome variables, measured at baseline and 12 weeks, included preferred and maximal gait velocity, a visual analog pain scale at rest and following a 6-minute walk test, muscle strength, and functional-outcome questionnaires. Data were analyzed using mixed-model analyses of variance for group and time differences. RESULTS After 12 weeks, the individuals receiving the cycling intervention showed significantly greater improvements (P<.05) for preferred gait velocity (mean difference between groups, 8.7 cm/s; 95% confidence interval [CI]: 2.2, 15.1), visual analog pain scale on the 6-minute walk test (mean difference, 16.5 mm; 95% CI: 2.1, 31.0), the Western Ontario and McMaster Universities Osteoarthritis Index pain subscale (mean difference, 14.9 points; 95% CI: 2.6, 27.0) and stiffness subscale (mean difference, 10.8 points; 95% CI: 0.7, 21.3), the Knee injury and Osteoarthritis Outcome Score pain subscale (mean difference, 13.3 points; 95% CI: 3.4, 23.3), and the Knee Outcome Survey activities of daily living subscale (mean difference, 13.9 points; 95% CI: 2.0, 25.9) compared to controls. CONCLUSION Stationary group cycling may be an effective exercise option for individuals with mild-to-moderate knee OA and may reduce pain with walking. US trial registration NCT00917618. LEVEL OF EVIDENCE Therapy, level 1b-.

The Development and Validation of the Vestibular Activities and Participation Measure

OBJECTIVES To develop and validate a new self-report outcome measure named the Vestibular Activities and Participation (VAP) for people with vestibular disorders to examine their activities and participation according to the International Classification of Functioning Disability and Health. DESIGN Delphi iterative survey for the development of the VAP and validation study. SETTING Tertiary balance clinic. PARTICIPANTS A panel of worldwide experts (n=17) in vestibular dysfunction participated in the development of the VAP, and patients (N=58) with vestibular disorders were enrolled in the validation of the VAP. INTERVENTION Not applicable. MAIN OUTCOME MEASURES For the development of the VAP, an Internet-based survey of 55 activities and participation items was presented to the panel of experts and the percentage agreement per item was calculated. For the validation of the VAP, the VAP was completed twice to examine the test-retest reliability, the World Health Organization Disability Assessment Schedule II (WHODAS II) was used to examine the concurrent validity with the VAP, and the Dizziness Handicap Inventory (DHI) was used to examine the convergent validity of the VAP. RESULTS After 2 rounds of the Delphi technique, the VAP was developed. The VAP total score had excellent test-retest reliability (intraclass correlation coefficient=.95; confidence interval=.91-.97) and good to excellent agreement per item indicated by the unweighted kappa (.41-.80) and the weighted kappa (.58-.94). The minimum detectable change at 95% confidence level of the VAP score was .58. The VAP had strong correlation (ρ=.70; P<.05) with the WHODAS II and moderate to strong correlations (ρ=.54-.74) with the DHI subscale and total scores. After adjustment for age, we found sex and self-reported imbalance to be independent explanatory variables of the transformed VAP total score. CONCLUSIONS The VAP measure was developed to examine the disabling effect of vestibular disorders on peoples activities and participation based on a standardized framework (the International Classification of Functioning Disability and Health). The VAP demonstrated excellent reliability and was validated with external instruments in people with vestibular disorders.

Content Comparison of Self-Report Measures Used in Vestibular Rehabilitation Based on the International Classification of Functioning, Disability and Health

Background Physical therapists should understand the content included in self-report questionnaires in order to choose the appropriate questionnaire for examination and follow-up purposes. The International Classification of Functioning, Disability and Health (ICF) provides a universal and standard language for the description of health and health-related states and can be used for the content comparison of self-report questionnaires. Objective The purpose of this study was to describe and compare the contents covered by 8 self-report measures used in vestibular rehabilitation based on the linkage of their content to the ICF. Design This was a cross-sectional study. Method Eight vestibular questionnaires were identified and linked to the ICF by 2 health care professionals according to established linking rules. Based on the linking, the contents of the 8 questionnaires were compared and the interobserver agreement between 2 raters was estimated using kappa coefficients. Results A total of 312 meaningful concepts from the 164 items of the 8 vestibular questionnaires were identified and linked to the ICF. The meaningful concepts identified were linked to 51 different ICF components: 19 categories of the component “body functions,” 30 categories of the component “activities and participation,” and 2 categories of the component “environmental factors.” Forty-two concepts could not be linked to any of the ICF components. The estimated kappa coefficients for 2 raters at the component and first and second levels of the ICF ranged from 0.83 to 0.96. Limitations The method of identifying vestibular measures was not based on a systematic search; instead, the most widely used instruments in the field of vestibular rehabilitation were selected. Thus, the study results are limited to the examined vestibular instruments. Conclusion Using the ICF as a theoretical framework was found to be useful for comparing the content of health status questionnaires, as well as for exploring the focus of the measures currently in use in vestibular rehabilitation.

The influence of age and vestibular disorders on gaze stabilization: a pilot study.

Objective: The purpose of this study was to identify the sensitivity and specificity of a computerized gaze stabilization test (GST), to analyze if age affects vestibulo-ocular reflex function, and to assess differences of vestibulo-ocular reflex function between patients and control subjects. Study Design: Descriptive, cross sectional. Setting: Tertiary medical center. Patients: Fifty-seven subjects, including 20 young controls (20-40 yr), 21 elderly controls (60-80 yr), and 16 patients with vestibular disease (20-80 yr), were included. Main Outcome Measures: Sensitivity and specificity characteristics of the GST, which records visual acuity during active head movement. Results: Identification of subjects with vestibular disease was maximized at an average downward velocity of less than 61 degrees per second and a likelihood ratio of 4.4 (sensitivity, 44%; specificity, 90%). Patients demonstrated significantly slower GST downward speeds than the control-young subjects. There were no differences in GST head velocities in either the pitch or yaw planes between young and older control subjects. Conclusion: There were no differences in GST maximum velocities in healthy young and older adults. The GST maximum velocity differentiated between young control subjects and patients with vestibular disorders in the pitch plane.