Progression of posturographic findings after acquired brain injury

Test-retest reliability and minimal detectable change of the computerized dynamic posturography PROPRIO for adults with chronic traumatic brain injury

PURPOSE

Balance deficits after brain injury, including reactive recovery from unexpected perturbations, can persist well after rehabilitation is concluded. While traditional clinical assessments are practical, the anticipatory nature of the tasks may mask perceptible balance control. Computerized dynamic posturography can directly quantify capacity to respond to unexpected, external perturbations. This study examined the reliability of the computerized dynamic posturography assessment with the device PROPRIO^® 4000 in adults with traumatic brain injury and created the minimal detectable change for its standardized test.

METHODS

Ten adults (ages 21-55 years) with chronic (average 10 ± 6 years post-injury) severe (loss of consciousness 2-75 days) brain injury performed three trials of the Propriotest^® on two separate days. The average of three trials and the best scores were used separately for analysis. Test-retest reliability was verified using Intraclass Correlation Coefficients with 95% confidence interval and standard error of measurement in relation to the Intraclass Correlation Coefficients at 95%. The minimal detectable change was calculated at 95% confidence level (minimal detectable change₉₅) and Bland-Altman plots were created to express agreement between measurement days.

RESULTS

The results exhibited excellent reliability for both average (Intraclass Correlation Coefficient of 0.969, standard error of measurement 50.9 points) and best (Intraclass Correlation Coefficient of 0.985, standard error of measurement 31.3 points) scores, with average and best minimal detectable change₉₅ of 141.0 and 86.7 points, respectively.

CONCLUSIONS

Clinicians and rehabilitation researchers can use these findings to determine if a Propriotest^® change score represents a true post-treatment effect with adults with chronic brain injury.IMPLICATIONS FOR REHABILITATIONAfter brain injury, balance deficits are common and can persist well after completion of rehabilitation programs.Computerized dynamic posturography allows for objective quantification of one's capacity to respond to external perturbations.The device PROPRIO^® 4000 provides reliable quantification of balance deficits of community dwelling individuals who have experienced a severe traumatic brain injury.The minimal detectable change scores created can assist clinicians and rehabilitation researchers detect whether a change in balance score represents a true effect of an intervention at post-treatment.

Physical Performance and Fall Risk in Persons With Traumatic Brain Injury

Injuries sustained from traumatic brain injury (TBI) culminate in both cognitive and neuromuscular deficits. Patients often progress to higher functioning on the Rancho continuum even while mobility deficits persist. Although prior studies have examined physical performance among persons with chronic symptoms of TBI, less is known about the relatively acute phase of TBI as patients prepare for rehabilitation discharge. The aims of this cross-sectional study were to (a) compare balance and gait performance in 20 ambulant persons with moderate to severe TBI who were nearing rehabilitation discharge with their age-matched controls and (b) describe performance with thresholds for fall risk and community navigation. During a designed task circuit, 40 participants (20 persons with TBI and 20 controls) performed the Timed Up and Go (TUG), gait velocity, and Walking and Remembering tests. Balance testing included the Fullerton Advanced Balance Scale (FABS) and instrumented Modified Clinical Test for Sensory Interaction in Balance (MCTSIB). Statistical analyses included analysis of covariance for group comparisons and a multivariate analysis of covariance for MCTSIB sway velocities with anthropometric controls. The TBI group (mean [ M] age = 42, standard deviation [ SD] =19.5 years; 70% males) performed significantly more poorly on all mobility tests ( p < .05) and their scores reflected a potential fall risk. Gait velocity was significantly slower for the TBI versus control group ( M = .96, SD = 2.6 vs. M = 1.5, SD = 2.2 m/s; p < .001), including TUG times ( M = 13.5, SD = 4.9 vs. M = 7.7, SD = 1.4; p < .001). TBI participants also demonstrated significantly greater sway velocity on all MCTSIB conditions ( p < .01) and lower performance on the FABS ( p < .001). Performance indices indicate potential fall risk and community navigation compromise for individuals with moderate to severe TBI. Physical performance scores support the need for continued interventions to optimize functional mobility upon discharge.

Altered postural control and stability in cirrhotic patients with minimal hepatic encephalopathy correlate with cognitive deficits

BACKGROUND & AIMS

Cognitive dysfunction in cirrhotic patients with minimal hepatic encephalopathy (MHE) is associated with falls. Alterations in postural control and stability could contribute to increase falls risk in these patients. We aimed to assess whether postural control and direction-specific limits of stability are altered in cirrhotic patients with MHE compared to patients without MHE and controls. We also assessed if alterations in postural control correlate with neurological impairment and/or blood biomarkers.

METHODS

Posturography analysis, attention Stroop test and bimanual and visuo-motor coordination tests were performed in 18 controls, 19 patients with cirrhosis without MHE and 17 with MHE, diagnosed by PHES. Posturography was assessed by NedSVE^® /IBV system under four sensory conditions. Limits of stability and rhythmic weight-shifting tests were also performed. Blood ammonia and serum interleukins were also measured. Falls were assessed after 12-24 months follow-up.

RESULTS

MHE patients show impaired balance, mainly on unstable surface with eyes open, with longer reaction and confinement times and lower success in Limits of Stability test compared to patients without MHE. Performance in attention and motor coordination tests correlated with most posturography parameters alterations. Logistic regression analysis shows that posturography parameters and bimanual coordination test are good predictors of falls.

CONCLUSION

Balance patterns and limits of stability in MHE patients are impaired compared to patients without MHE and controls. This seems to contribute to a higher falls risk. Attention and motor coordination deficits could contribute to balance impairment in patients with MHE.

Using Xbox kinect motion capture technology to improve clinical rehabilitation outcomes for balance and cardiovascular health in an individual with chronic TBI

BACKGROUND

Motion capture virtual reality-based rehabilitation has become more common. However, therapists face challenges to the implementation of virtual reality (VR) in clinical settings. Use of motion capture technology such as the Xbox Kinect may provide a useful rehabilitation tool for the treatment of postural instability and cardiovascular deconditioning in individuals with chronic severe traumatic brain injury (TBI). The primary purpose of this study was to evaluate the effects of a Kinect-based VR intervention using commercially available motion capture games on balance outcomes for an individual with chronic TBI. The secondary purpose was to assess the feasibility of this intervention for eliciting cardiovascular adaptations.

METHODS

A single system experimental design (n = 1) was utilized, which included baseline, intervention, and retention phases. Repeated measures were used to evaluate the effects of an 8-week supervised exercise intervention using two Xbox One Kinect games. Balance was characterized using the dynamic gait index (DGI), functional reach test (FRT), and Limits of Stability (LOS) test on the NeuroCom Balance Master. The LOS assesses end-point excursion (EPE), maximal excursion (MXE), and directional control (DCL) during weight-shifting tasks. Cardiovascular and activity measures were characterized by heart rate at the end of exercise (HRe), total gameplay time (TAT), and time spent in a therapeutic heart rate (TTR) during the Kinect intervention. Chi-square and ANOVA testing were used to analyze the data.

RESULTS

Dynamic balance, characterized by the DGI, increased during the intervention phase χ2 (1, N = 12) = 12, p = .001. Static balance, characterized by the FRT showed no significant changes. The EPE increased during the intervention phase in the backward direction χ2 (1, N = 12) = 5.6, p = .02, and notable improvements of DCL were demonstrated in all directions. HRe (F (2,174) = 29.65, p = < .001) and time in a TTR (F (2, 12) = 4.19, p = .04) decreased over the course of the intervention phase.

CONCLUSIONS

Use of a supervised Kinect-based program that incorporated commercial games improved dynamic balance for an individual post severe TBI. Additionally, moderate cardiovascular activity was achieved through motion capture gaming. Further studies appear warranted to determine the potential therapeutic utility of commercial VR games in this patient population.

TRIAL REGISTRATION

Clinicaltrial.gov ID - NCT02889289.

Posturography using the Wii Balance Board™: A feasibility study with healthy adults and adults post-stroke

BACKGROUND

Posturography systems that incorporate force platforms are considered to assess balance and postural control with greater sensitivity and objectivity than conventional clinical tests. The Wii Balance Board (WBB) system has been shown to have similar performance characteristics as other force platforms, but with lower cost and size.

OBJECTIVES

To determine the validity and reliability of a freely available WBB-based posturography system that combined the WBB with several traditional balance assessments, and to assess the performance of a cohort of stroke individuals with respect to healthy individuals.

METHODS

Healthy subjects and individuals with stroke were recruited. Both groups were assessed using the WBB-based posturography system. Individuals with stroke were also assessed using a laboratory grade posturography system and a battery of clinical tests to determine the concurrent validity of the system. A group of subjects were assessed twice with the WBB-based system to determine its reliability.

RESULTS

A total of 144 healthy individuals and 53 individuals with stroke participated in the study. Concurrent validity with another posturography system was moderate to high. Correlations with clinical scales were consistent with previous research. The reliability of the system was excellent in almost all measures. In addition, the system successfully characterized individuals with stroke with respect to the healthy population.

CONCLUSIONS

The WBB-based posturography system exhibited excellent psychometric properties and sensitivity for identifying balance performance of individuals with stroke in comparison with healthy subjects, which supports feasibility of the system as a clinical tool.