The views expressed in this article do not necessarily reflect the official position of the Department of Defense or any of the institutions with which the authors are affiliated.
Article first published online: 11 OCT 2012
Copyright © 2012 American Neurological Association
Annals of Neurology
Volume 72, Issue 5, pages 673–681, November 2012
How to Cite
Xydakis, M. S., Ling, G. S. F., Mulligan, L. P., Olsen, C. H. and Dorlac, W. C. (2012), Epidemiologic aspects of traumatic brain injury in acute combat casualties at a major military medical center: A cohort study. Ann Neurol., 72: 673–681. doi: 10.1002/ana.23757
This protocol was approved by the Department of Clinical Investigations and was conducted in compliance with all applicable federal regulations governing the protection of human subjects in research.
Injury Severity Scores were provided under a memorandum of understanding between Uniformed Services University of the Health Sciences and the US Army Institute of Surgical Research, Fort Sam Houston, Texas.
- Issue published online: 27 DEC 2012
- Article first published online: 11 OCT 2012
- Manuscript Accepted: 3 AUG 2012
- Manuscript Revised: 12 JUL 2012
- Manuscript Received: 2 MAY 2012
From the ongoing military conflicts in Iraq and Afghanistan, an understanding of the neuroepidemiology of traumatic brain injury (TBI) has emerged as requisite for further advancements in neurocombat casualty care. This study reports population-specific incidence data and investigates TBI identification and grading criteria with emphasis on the role of loss of consciousness (LOC) in the diagnostic rubric.
This is a cohort study of all consecutive troops acutely injured during combat operations—sustaining body-wide injuries sufficient to require immediate stateside evacuation—and admitted sequentially to our medical center during a 2-year period. A prospective exploration of the TBI identification and grading system was performed in a homogeneous population of blast-injured polytrauma inpatients.
TBI incidence was 54.3%. Structural neuroimaging abnormalities were identified in 14.0%. Higher Injury Severity Score (ISS) was associated with abnormal neuroimaging, longer length of stay (LOS), and elevated TBI status—primarily based on autobiographical LOC. Mild TBI patients had normal neuroimaging, higher ISS, and comparable LOS to TBI-negative patients. Patients who reported LOC had a lower incidence of abnormal neuroimaging.
This study demonstrates that the methodology used to assign the diagnosis of a mild TBI in troops with complex combat-related injuries is crucial to an accurate accounting. The detection of incipient mild TBI, based on an identification system that utilizes LOC as the principal diagnostic criterion to discern among patients with outcomes of interest, misclassifies patients whose LOC may not reflect actual brain injury. Attempts to identify high-risk battlefield casualties within the current point-of-injury mild TBI case definition, which favors high sensitivity, will be at the expense of specificity. ANN NEUROL 2012;72:673–681