Factors That Impact the Long-Term Outcome of Postconcussive Dizziness Among Post-9/11 Veterans

Purpose: The primary aim of this study was to examine the factors associated with long-term outcomes of postconcussive disruptive dizziness in Veterans of the post-9/11 wars. Method: For this observational cohort study, the Neurobehavioral Symptom Inventory-Vestibular subscale (NSI-V) score was used as an outcome measure for dizziness in 987 post-9/11 Veterans who indicated disruptive dizziness at an initial Veterans Health Administration Comprehensive Traumatic Brain Injury Evaluation (CTBIE). An NSI-V change score was calculated as the difference in the scores obtained at the initial CTBIE and on a subsequent survey. Differences in the NSI-V change scores were examined for demographics, injury characteristics, comorbidities, and vestibular and balance function variables, and multiple linear regression analyses were used to explore associations among the variables and the NSI-V change score. Results: The majority of Veterans (61%) demonstrated a decrease in the NSI-V score, suggesting less dizziness on the survey compared with the CTBIE; 16% showed no change; and 22% had a higher score. Significant differences in the NSI-V change score were observed for traumatic brain injury (TBI) status, diagnoses of post-traumatic stress disorder (PTSD), headache and insomnia, and vestibular function. Multivariate regressions revealed significant associations between the NSI-V change score and the initial CTBIE NSI-V score, education level, race/ ethnicity, TBI status, diagnoses of PTSD or hearing loss, and vestibular function. Conclusions: Postconcussive dizziness can continue for years following an injury. Factors associated with poor prognosis include TBI, diagnoses of PTSD or hearing loss, abnormal vestibular function, increased age, identification as a Black Veteran, and high school education level.