Sensory functions and their relation to balance metrics: a secondary analysis of the LIMBIC-CENC multicenter cohort.

Introduction: Among patients with traumatic brain injury (TBI), balance problems often persist alongside hearing and vision impairments that lead to poorer outcomes of functional independence. As such, the ability to regain premorbid independent gait may be dictated by the level of sensory acuity or processing decrements that are shown following TBI assessment. This study explores the relationships between standardized sensory acuity and processing outcomes to postural balance and gait speed. Methods: Secondary analysis was performed on the Long-Term Impact of Military- Relevant Brain Injury Consortium Chronic Effects of Neurotrauma Consortium LIMBIC (CENC) data set. Separate regression analyses were carried out for each of the balance assessments (via Computerized Dynamic Posturography, CDP) and walking speed. Discussion: TBI frequency was significantly related to the majority of single CDP outcomes (i.e., Conditions 2-6), while various sensory processing outcomes had task-specific influences. Hearing impairments and auditory processing decrements presented with lower CDP scores (CDP Conditions 3,5,6, and 1-3 respectively), whereas greater visual processing scores were associated with better CDP scores for Conditions 2,5, and 6. In sum, patients with TBI had similar scores on static balance tests compared to non-TBI, but when the balance task got more difficult patients with TBI scored worse on the balance tests. Additionally, stronger associations with sensory processing than sensory acuity measures may indicate that patients with TBI have increased fall risk.

Is balance performance reduced after mild traumatic brain injury?: Interim analysis from chronic effects of neurotrauma consortium (CENC) multi-centre study.

OBJECTIVES: Determine if mild traumatic brain injury (mTBI) history is associated with balance disturbances. SETTING: Chronic Effects of Neurotrauma Consortium (CENC) centres. PARTICIPANTS: The CENC multi-centre study enrols post-9/11 era Service Members and Veterans with combat exposure. This sample (n = 322) consisted of enrolees completing initial evaluation by September 2016 at the three sites conducting computerized dynamic post-urography (CDP) testing. DESIGN: Observational study with cross-sectional analyses using structural equation modelling. MAIN MEASURES: Comprehensive structured interviews were used to diagnose all lifetime mild traumatic brain injuries (mTBIs). The outcome, Sensory Organization Test (SOT), was measured on CDP dual-plate force platform. Other studied variables were measured by structured interviews, record review and questionnaires. RESULTS: The overall positive/negative mTBI classification did not have a significant effect on the composite equilibrium score. However, the repetitive mTBI classification showed lower scores for participants with ≥ 3 mTBI versus 1-2 lifetime mTBIs. For repetitive mTBI, pain interference acted as a mediator for the indirect effect, and a direct effect was evident on some sensory condition equilibrium scores. CONCLUSION: These findings show that repeated mTBI, partially mediated by pain, may lead to later balance disturbances among military combatants. Further study of CDP outcomes within this accruing cohort is warranted.

Characterizing effects of mild traumatic brain injury and posttraumatic stress disorder on balance impairments in blast-exposed servicemembers and Veterans using computerized posturography.

The high rate of blast exposures experienced by U.S. servicemembers (SMs) during the recent conflicts in Iraq and Afghanistan has resulted in frequent combat-related mild traumatic brain injuries (mTBIs). Dizziness and postural instability can persist after mTBI as a component of postconcussion syndrome, but also occur among the somatic complaints of posttraumatic stress disorder (PTSD). The goals of this study were to examine the use of computerized posturography (CPT) to objectively characterize chronic balance deficits after mTBI and to explore the utility of CPT in distinguishing between combat and blast-exposed participants with and without mTBI and PTSD. Data were analyzed from a subject pool of 166 combat-exposed SMs and Veterans who had a blast experience within the past 2 yr while deployed. Using nonparametric tests and measures of impairment, we found that balance was deficient in participants diagnosed with mTBI with posttraumatic amnesia (PTA) or PTSD versus those with neither and that deficits were amplified for participants with both diagnoses. In addition, unique deficiencies were found using CPT for individuals having isolated mTBI with PTA and isolated PTSD. Computerized balance assessment offers an objective technique to examine the physiologic effects and provide differentiation between participants with combat-associated mTBI and PTSD.

Diagnostic accuracy of Posttraumatic Stress Disorder Checklist in blast-exposed military personnel.

Researchers often extrapolate posttraumatic stress disorder (PTSD) status from PTSD Checklist (PCL) data. When doing so, cut points should be based on samples with similar characteristics. This study assessed PCL diagnostic accuracy and postconcussive symptom levels within 106 Iraq/Afghanistan war Veterans and servicemembers with recent blast exposure. Two definitions of PTSD were applied: (1) "strict" Diagnostic and Statistical Manual of Mental Health Disorders (DSM), 4th edition (DSM-IV) criteria and (2) "relaxed" DSM-IV criteria dropping the A2 criterion as per the DSM, 5th edition (DSM-V). Using a structured interview for PTSD, we found moderate agreement with the PCL. Under strict criteria, PTSD prevalence was 16%, PCL cut point was 66 at peak kappa, and mean Rivermead Postconcussion Questionnaire (RPQ) score trended higher for those with PTSD than for those without PTSD (35.5 +/- 11.2 vs 30.5 +/- 10.7, respectively; p = 0.080). Under relaxed criteria, PTSD prevalence was 26.4%, PCL cut point was 58 at peak kappa, and those with PTSD had higher RPQ scores than those without PTSD (36.4 +/- 11.2 vs 29.5 +/- 10.2, respectively; p = 0.003). Participants diagnosed with blast-related mild traumatic brain injury (n = 90) did not differ from those without mild traumatic brain injury (n = 16) in symptom scores. In conclusion, persons with combat-related blast exposure need higher than conventional PCL cut points and those with PTSD have more severe postconcussive-type symptoms than those without PTSD.

Hyperbaric oxygen for blast-related postconcussion syndrome: three-month outcomes.

OBJECTIVE: Mild traumatic brain injury (mTBI) and postconcussion syndrome (PCS) are common among military combatants. Hyperbaric oxygen (HBO2 ) is a proposed treatment for these conditions, but it has not been rigorously studied. The objective of this study was to determine the effects of HBO2 by 3 months post compression at 2 commonly employed dosing levels to treat PCS; whether specific subgroups may have benefited; and if no overall effect was found, whether benefit is masked by other conditions. METHODS: This randomized, double-blind, sham-controlled study was conducted at the Naval Air Station in Pensacola, Florida on 61 male Marines with a history of mTBI and PCS. Intervention consisted of 40 once daily 60-minute hyperbaric chamber compressions at 2.0 atmospheres absolute (ATA) at 1 of 3 randomly preassigned oxygen fractions, resulting in respective blinded groups with an oxygen-breathing exposure equivalent to (1) surface air (sham), (2) 100% oxygen at 1.5ATA, or (3) 100% oxygen at 2.0ATA. The main outcome measure was the Rivermead Post-Concussion Questionnaire-16 (RPQ-16) collected before compressions and at 2 later points. RESULTS: The interaction of time by intervention group was not significant for improvement on the RPQ-16. Nor was there evidence of efficacy on the RPQ-16 for any subgroup. No significant time by intervention interaction was found for any functional, cognitive, or psychomotor secondary outcome measure at an unadjusted 0.05 significance level. INTERPRETATION: Using a randomized control trial design and analysis including a sham, results showed no evidence of efficacy by 3 months post-compression to treat the symptomatic, cognitive, or behavioral sequelae of PCS after combat-related mTBI.

Randomized, Sham-Controlled, Feasibility Trial of Hyperbaric Oxygen for Service Members With Postconcussion Syndrome: Cognitive and Psychomotor Outcomes 1 Week Postintervention.

Background Mild traumatic brain injury (mTBI) and residual postconcussion syndrome (PCS) are common among combatants of the recent military conflicts in Iraq and Afghanistan. Hyperbaric oxygen (HBO2) is a proposed treatment but has not been rigorously studied for this condition. Objectives In a secondary analysis, examine for possible effects on psychomotor (balance and fine motor) and cognitive performance 1 week after an HBO2 intervention in service members with PCS after mTBI. Methods A randomized, double-blind, sham control, feasibility trial comparing pretreatment and posttreatment was conducted in 60 male active-duty marines with combat-related mTBI and PCS persisting for 3 to 36 months. Participants were randomized to 1 of 3 preassigned oxygen fractions (10.5%, 75%, or 100%) at 2.0 atmospheres absolute (ATA), resulting in respective groups with an oxygen exposure equivalent to (1) breathing surface air (Sham Air), (2) 100% oxygen at 1.5 ATA (1.5 ATAO2), and (3) 100% oxygen at 2.0 ATA (2.0 ATAO2). Over a 10-week period, participants received 40 hyperbaric chamber sessions of 60 minutes each. Outcome measures, including computerized posturography (balance), grooved pegboard (fine motor speed/dexterity), and multiple neuropsychological tests of cognitive performance, were collected preintervention and 1-week postintervention. Results Despite the multiple sensitive cognitive and psychomotor measures analyzed at an unadjusted 5% significance level, this study demonstrated no immediate postintervention beneficial effect of exposure to either 1.5 ATAO2 or 2.0 ATAO2 compared with the Sham Air intervention. Conclusions These results do not support the use of HBO2 to treat cognitive, balance, or fine motor deficits associated with mTBI and PCS.