Lux et Lex: Volume 2, Number 2

This issue of Lux et Lex, a publication of the Chester Fritz Library at the University of North Dakota, was published in April 1992

Balance in chronic traumatic brain injury: correlations between clinical measures and a self-report measure

Objective: To assess associations among commonly used self-report and clinical measures of balance in chronic TBI. Design: Cross-sectional analysis of balance in a convenience sample of individuals at least one year post TBI. Main Outcome Measures: Activities-Specific Balance Confidence Scale (ABC) (self-reported balance impairment), Community Balance and Mobility Scale (CB&M) (clinical measure validated in TBI), and Balance Evaluation Systems Test (BESTest) (clinical measure not validated in TBI). Methods: Fifty-nine individuals (64% male, mean age 48.2 years) ambulating independently within the home participated in testing. Pearson correlation coefficients were used to quantify the direction and magnitude of the relationships among the three balance impairment measures. Results: A significant positive correlation was noted between the ABC and CB&M (r = 0.42, p = 0.0008), between the ABC and BESTest (r = 0.46, p = 0.0002), and between the CB&M and BESTest (r = 0.86, p \u3c 0.0001). Conclusions: This is the first study we are aware of in the chronic moderate to severe TBI population directly comparing patient’s self-reported balance impairment with clinical measures. Positive correlations were found between the self-report measure and both clinical measures. Overall, individuals with chronic TBI tend to self-report less impaired balance than clinical measures indicate. These results provide preliminary evidence to support the need for validation of the BESTest in this population. Abbreviations: ABC: Activities-specific balance confidence scale; BESTest: balance evaluation systems test; BOS: base of support; COM: center of mass; CB&M: community balance and mobility scale; CI: confidence interval; IQR: interquartile range; PTs: physical therapists; SD: standard deviation; SE: standard error; TBI: traumatic brain injury

Results From a Randomized Controlled Trial to Address Balance Deficits After Traumatic Brain Injury

Objective: To evaluate the efficacy of an in-home 12-week physical therapy (PT) intervention that utilized a virtual reality (VR) gaming system to improve balance in individuals with traumatic brain injury (TBI). Setting: Home-based exercise program (HEP). Participants: Individuals (N=63; traditional HEP n=32; VR n=31) at least 1 year post-TBI, ambulating independently within the home, not currently receiving PT services. Main Outcome Measures: Primary: Community Balance and Mobility Scale (CB&M); Secondary: Balance Evaluation Systems Test (BESTest), Activities-Specific Balance Confidence Scale (ABC), Participation Assessment with Recombined Tools-Objective (PART-O). Results: No significant between-group differences were observed in the CB&M over the study duration (P=.9983) for individuals who received VR compared to those who received a HEP to address balance deficits after chronic TBI nor in any of the secondary outcomes: BESTest (P=.8822); ABC (P=.4343) and PART-O (P=.8822). However, both groups demonstrated significant improvements in CB&M and BESTest from baseline to 6, 12, and at 12 weeks follow-up (all P\u27s \u3c.001). Regardless of treatment group, 52% of participants met or exceeded the minimal detectable change of 8 points on the CB&M at 24 weeks and 38% met or exceeded the minimal detectable change of 7.81 points on the BESTest. Conclusion: This study did not find that VR training was more beneficial than a traditional HEP for improving balance. However, individuals with chronic TBI in both treatment groups demonstrated improvements in balance in response to these interventions which were completed independently in the home environment

Axial MRI biomarkers of spinal cord damage to predict future walking and motor function: a retrospective study

Study design: Retrospective. Objectives: Primary: to assess if axial damage ratios are predictors of future walking after spinal cord injury (SCI), and if they add any predictive value if initial neurological impairment grades are available. Secondary: to determine if lateral spinal cord regions are predictors of future lower extremity motor scores (LEMS). Setting: University/hospital. Methods: Axial T2-weighted MRIs were used. Axial damage ratios and non-damaged lateral cord volumes were calculated. Each participant answered at 1 year after SCI, “Are you able to walk for 150 feet? (45.72 meters)” For the secondary aim, right and left LEMS were used. Results: In total, 145 participants were selected. Individuals that could walk had smaller ratios than those that were unable. Walking and axial damage ratios were negatively correlated. A 0.374 ratio cut-off showed optimal sensitivity/specificity. When initial neurological grades were used, axial damage ratios did not add predictive value. Forty-two participants had LEMS available and were included for the secondary aim. Right cord regions and right LEMS were positively correlated and left regions and left LEMS, but these variables were also correlated with each other. Conclusions: Axial damage ratios were significant predictors of walking ability 1 year after SCI. However, this measure did not add predictive value over initial neurological grades. Lateral cord regions correlated with same-side LEMS, but the opposite was also found, calling this biomarker’s specificity into question. Axial damage ratios may be useful in predicting walking after SCI if initial neurological grades are unavailable. Sponsorship: This research was funded by a National Institutes of Health award, National Institute of Child Health and Development—NIH R03HD094577

The influence of conventional T2 MRI indices in predicting who will walk outside one year after spinal cord injury

Context/Objective: Magnetic resonance imaging (MRI) indices of spinal cord damage are predictive of future motor function after spinal cord injury (SCI): hyperintensity length, midsagittal tissue bridges, and Brain and Spinal Injury Center (BASIC) scores. Whether these indices are predictive of outdoor walking after SCI is unknown. The primary purpose was to see if these MRI indices predict the ability to walk outdoors one-year after SCI. The secondary purpose was to determine if MRI indices provide additional predictive value if initial lower extremity motor scores are available. Design: Retrospective. Clinical T2-weighted MRIs were used to quantify spinal cord damage. Three MRI indices were calculated: midsagittal ventral tissue bridges, hyperintensity length, BASIC scores. Setting: Academic hospital. Participants: 129 participants with cervical SCI. Interventions: Inpatient rehabilitation. Outcomes Measures: One year after SCI, participants self-reported their outdoor walking ability. Results: Midsagittal ventral tissue bridges, hyperintensity length, and BASIC scores significantly correlated with outdoor walking ability (R = 0.34, P \u3c 0.001; R = −0.25, P \u3c 0.01; Rs = −0.35, P \u3c 001, respectively). Using midsagittal ventral tissue bridges and hyperintensity length, the final adjusted R 2 for model 1 = 0.19. For model 2, the adjusted R 2 using motor scores alone = 0.81 and MRI variables were non-significant. All five participants with observable intramedullary hemorrhage reported they were unable to walk one block outdoors. Conclusions: The MRI indices were significant predictors of outdoor walking ability, but when motor scores were available, this was the strongest predictor and neither midsagittal tissue bridges nor hyperintensity length contributed additional value. MRI indices may be a quick and convenient supplement to physical examination when motor testing is unavailable