Olfactory Dysfunction with Traumatic Brain Injury and Posttraumatic-Stress Symptoms in Post-Deployed Military Personnel

Robert Shura^1,2,3*Treven Pickett^1,4,5Jacob Powell⁵Ruth Yoash-Gantz^1,2Scott D McDonald^1,4,6William Walker⁴Jared A. Rowland^1,2,7Larry A Tupler^1,8,9

• ¹Neurocognition Laboratory, Department of Veterans Affairs Mid-Atlantic Mental Illness Research, Education, and Clinical Center (MA-MIRECC), Durham, NC, United States
• ²Salisbury Veterans Affairs Health Care System (SVAHCS), Salisbury, NC, United States
• ³Department of Neurology, School of Medicine, Wake Forest University, Winston-Salem, North Carolina, United States
• ⁴Department of Physical Medicine and Rehabilitation, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States
• ⁵National Intrepid Center of Excellence (NICoE), Bethesda, Maryland, United States
• ⁶Department of Psychology, Virginia Commonwealth University, Richmond, VA, United States
• ⁷Department of Translational Neuroscience, Wake Forest University, Winston-Salem, NC, United States
• ⁸Biodemography of Aging Research Unit, Center for Population Health and Aging, Duke University, Durham, NC, United States
• ⁹Richmond Veterans Affairs Medical Center, Central Virginia VA Health Care System, Richmond, VA, United States

Introduction: Prior research suggests that olfactory dysfunction may occur following a traumatic brain injury (TBI) due to structural injury to the olfactory peripheral or central networks. Olfaction may also be affected in posttraumatic stress disorder (PTSD) due to traumatic re-experiencing. Given the relevance of both TBI and PTSD to the military and veteran populations, the purpose of this study was to evaluate whether the University of Pennsylvania Smell Identification Test (UPSIT) would be useful in differentiating TBI from significant PTSD symptom burden in a sample of post-deployed active-duty military and veterans. Methods: A sample of 276 participants with UPSIT data and passing scores on validity measures completed a larger study on neurocognition of predominantly post-deployed veterans of the wars in Afghanistan and Iraq. TBI history was ascertained by medical records or a self-report questionnaire; PTSD symptoms were measured using the PTSD Checklist-Military version (PCL-M) and the Traumatic Stress scale (ARD-T) of the Personality Assessment Inventory. Those with a history of TBI (+TBI) were compared with those without (–TBI) on total UPSIT score; severity of injury and number of injuries were also evaluated. Furthermore, those with and without significant PTSD symptoms (+PTSD and –PTSD) were compared on UPSIT total scores. Finally, group comparisons were conducted to assess whether PTSD demonstrated a significant effect above and beyond TBI. Results: History of TBI was associated with lower UPSIT scores (no TBI M = 34.02, TBI M = 32.76, z = -2.38, p = .017, r = .14); however, the effect size was small and driven by the difference between moderate/severe TBI and –TBI (moderate/severe M = 31.78). Number of mild TBIs was not associated with UPSIT scores:. The presence of PTSD symptoms and