Journal of the International Neuropsychological Society

Research Articles

Altered Brain Activation in Military Personnel with One or More Traumatic Brain Injuries Following Blast

Randall S. Scheibela1a2 c1, Mary R. Newsomea1a2, Maya Troyanskayaa1a2, Xiaodi Lina1a2, Joel L. Steinberga3, Majdi Radaideha1a4 and Harvey S. Levina1a2

a1 Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas

a2 Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Texas

a3 Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, Texas

a4 Department of Radiology, Baylor College of Medicine, Houston, Texas

Abstract

Explosive blast is a frequent cause of traumatic brain injury (TBI) among personnel deployed to Afghanistan and Iraq. Functional magnetic resonance imaging (fMRI) with an event-related stimulus-response compatibility task was used to compare 15 subjects with mild, chronic blast-related TBI with 15 subjects who had not experienced a TBI or blast exposure during deployment. Six TBI subjects reported multiple injuries. Relative to the control group, TBI subjects had slightly slower responses during fMRI and increased somatic complaints and symptoms of post-traumatic stress disorder (PTSD) and depression. A between-group analysis indicated greater activation during stimulus-response incompatibility in TBI subjects within the anterior cingulate gyrus, medial frontal cortex, and posterior cerebral areas involved in visual and visual-spatial functions. This activation pattern was more extensive after statistically controlling for reaction time and symptoms of PTSD and depression. There was also a negative relationship between symptoms of PTSD and activation within posterior brain regions. These results provide evidence for increased task-related activation following mild, blast-related TBI and additional changes associated with emotional symptoms. Limitations of this study include no matching for combat exposure and different recruitment strategies so that the control group was largely a community-based sample, while many TBI subjects were seeking services. (JINS, 2012, 18, 89–100)

(Received June 23 2010)

(Revised September 20 2011)

(Accepted September 20 2011)

Correspondence:

c1 Correspondence and reprint requests to: Randall S. Scheibel, Cognitive Neuroscience Laboratory, Baylor College of Medicine, 1709 Dryden Road, Suite 1200, Houston, TX 77030. E-mail: scheibel@bcm.tmc.edu