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

Abstract

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.

Keywords: Veterans; balance; balance impairment; blast exposure; computerized posturography; impairment; mild traumatic brain injury; posttraumatic amnesia; posttraumatic stress disorder; servicemembers.