Dizziness Severity and Its Relationship with Comorbid Headache and Psychological Disorders among U.S. Military Personnel with a History of Traumatic Brain Injury.

INTRODUCTION: Prolonged and disruptive dizziness is a post-concussive symptom that is particularly challenging to manage because of the overlapping symptoms of comorbid physical and psychological disorders frequently associated with traumatic brain injury (TBI), including depression, post-traumatic stress disorder (PTSD), and headache. The purpose of this retrospective data analysis was to determine if service members with a history of TBI demonstrate differences in levels of depression, PTSD, and headache burden when categorically grouped based on self-reported dizziness severity and if depression, PTSD, and headache burden influence the severity of self-reported dizziness handicap. MATERIALS AND METHODS: Data were obtained from a sample of U.S. military service members who received care at an Intrepid Network TBI clinic between 2010 and 2022. The Dizziness Handicap Inventory (DHI) was the variable of interest, with the Patient Health Questionnaire-9 (PHQ-9), Post-Traumatic Stress Disorder Checklist-Military (PCL-M), and Headache Impact Test-6 (HIT-6) as secondary variables. RESULTS: A total of 1,185 U.S. service members with a history of TBI were categorized by dizziness severity: none (n = 277), mild (n = 663), moderate (n = 191), and severe (n = 54). There was a significant difference between dizziness severity groups based on a composite of the PHQ-9, PCL-M, and HIT-6, Pillai's trace = 0.335, F(9, 3,543) = 49.41, P < .001, η2p = 0.112. The final ordinal regression model was significantly associated with DHI severity category, χ2(3) = 347.55, P < .001. Scores on the PHQ-9, PCL-M, and HIT-6 each demonstrated significant associations with self-reported dizziness severity (χ2(1) = 26.28, P < .001; χ2(1) = 14.39, P < .001; χ2(1) = 62.59, P < .001). Increases in PHQ-9, PCL-M, and HIT-6 scores were each associated with higher odds of reporting more severe dizziness. CONCLUSIONS: Severity of dizziness was associated with higher levels of depression and PTSD as well as greater headache burden in service members. Physicians who treat service members and Veterans with chronic complaints of dizziness after TBI must be aware of the symptom overlap of depression, PTSD, and headache; otherwise, they risk missing an integral part of their patient's presentation. Findings from this study highlight the importance of incorporating integrated multidisciplinary care and screenings for patients with chronic dizziness after TBI in the military.