Affiliations: [a] Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, CA, USA | [b] Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California at Los Angeles, CA, USA | [c] Sections of Neurology, V.A. Greater Los Angeles Healthcare Center, Los Angeles, CA, USA | [d] Nuclear Medicine, V.A. Greater Los Angeles Healthcare Center, Los Angeles, CA, USA | [e] Physical Medicine and Rehabilitation, V.A. Greater Los Angeles Healthcare Center, Los Angeles, CA, USA | [f] Division of General Internal Medicine and Health Services Research, David Geffen School of Medicine, University of California at Los Angeles, CA, USA
Correspondence:
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Address for correspondence: M.F. Mendez, Neurobehavior Unit (691/116AF), V.A. Greater Los Angeles Healthcare Center, 11301 Wilshire Blvd., Los Angeles, CA. 90073. USA. Tel.: +1 310 478 3711x42696; Fax: +1 310 268 4181; E-mail: mmendez@UCLA.edu
Abstract: Introduction:Primary blast forces may cause dysfunction from mild traumatic brain injury (mTBI). Objective:To investigate the effects of primary blast forces, independent of associated blunt trauma and post-traumatic stress disorder, on sensitive post-concussive measures. Methods:This study investigated post-concussive symptoms, functional health and well-being, cognition, and positron emission tomography (PET) neuroimaging among 12 Iraq or Afghanistan war veterans who sustained pure blast-force mTBI, compared to 12 who sustained pure blunt-force mTBI. Results:Both groups had significantly lower scores than published norms on the Rivermead Post-Concussion Questionnaire (RPQ) and the SF36-V Health Survey. Compared to the Blunt Group, the Blast Group had poorer scores on the Paced Auditory Serial Addition Test (PASAT) and greater PET hypometabolism in the right superior parietal region. Only the Blast Group had significant correlations of their RPQ, SF36-V Mental Composite Score, and PASAT scores with specific regional metabolic changes. Conclusion:This pilot study suggests that pure blast force mTBI may have greater post-concussive sequelae including deficits in attentional control and regional brain metabolism, compared to blunt mTBI. A disturbance of a right parietal-frontal attentional network is one potential explanation for these findings.
