Objective: To determine the factor structure of persistent postconcussive syndrome symptoms in a blast-exposed military sample and validate factors against objective and symptom measures.
Setting: Veterans Affairs medical center and military bases.
Participants: One hundred eighty-one service members and veterans with at least 1 significant exposure to blast during deployment within the 2 years prior to study enrollment.
Design: Confirmatory and exploratory factor analyses of the Rivermead Postconcussion Questionnaire.
Main Measures: Rivermead Postconcussion Questionnaire, PTSD (posttraumatic stress disorder) Symptom Checklist–Civilian, Center for Epidemiological Studies Depression scale, Sensory Organization Test, Paced Auditory Serial Addition Test, California Verbal Learning Test, and Delis-Kaplan Executive Function System subtests.
Results: The 3-factor structure of persistent postconcussive syndrome was not confirmed. A 4-factor structure was extracted, and factors were interpreted as reflecting emotional, cognitive, visual, and vestibular functions. All factors were associated with scores on psychological symptom inventories; visual and vestibular factors were also associated with balance performance. There was no significant association between the cognitive factor and neuropsychological performance or between a history of mild traumatic brain injury and factor scores.
Conclusion: Persistent postconcussive symptoms observed months after blast exposure seem to be related to 4 distinct forms of distress, but not to mild traumatic brain injury per se, with vestibular and visual factors possibly related to injury of sensory organs by blast.
Defense and Veterans Brain Injury Center, Richmond, Virginia (Drs Franke and Walker); Departments of Physical Medicine and Rehabilitation (Drs Franke and Walker) and Biostatistics (Ms Czarnota and Dr Ketchum), School of Medicine, Virginia Commonwealth University, Richmond, Virginia; and The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc, Bethesda, Maryland (Drs Franke and Walker).
Corresponding Author: Laura M. Franke, PhD, Defense and Veterans Brain Injury Center, 1201 Broad Rock Blvd (151), Richmond, VA 23249 (Laura.Manning3@va.gov).
This work was funded by the Congressionally Directed Medical Research Projects (CDMRP) Award # W91ZSQ8118N620 and in part by the Defense and Veterans Brain Injury Center (DVBIC) through contract # W91YTZ-12-C-0132 to the Henry M. Jackson Foundation.
The project was supported by National Institutes of Health T32ES007334. Jenna Czarnota is supported by NIEHS, T32 Training Grant: Integration of Mixtures, Toxicology, Toxicogenomics and Statistics (T32ES007334).
The views, opinions, and/or findings contained in this report are those of the authors and should not be construed as an official Department of Defense or Veterans Affairs position, policy, or decision unless so designated by other documentation. In the conduct of research where humans are the subjects, the investigators adhered to the policies regarding the protection of human subjects as prescribed by Code of Federal Regulations (CFR) Title 45, Volume 1, Part 46; Title 32, Chapter 1, Part 219; and Title 21, Chapter 1, Part 50 (Protection of Human Subjects).
The authors declare no conflicts of interest.