Neurocircuitry of Prospective Memory in Veterans with Mild Traumatic Brain Injury

NIH RePORTER · VA · IK2 · · view on reporter.nih.gov ↗

Abstract

Rates of mild traumatic brain injury (mTBI) are high among combat veterans, with reports suggesting 10-20% of Iraq and Afghanistan Veterans meet diagnostic criteria for mTBI, the vast majority of which being related to explosive blasts. There is on-going debate as to whether blast-related mTBI may result in long-term neuropsychological impairment, given the paucity of positive findings, despite on-going complaints of cognitive difficulties within this cohort. One possible explanation for this discrepancy is that traditional neuropsychological test procedures may lack sensitivity in capturing subtle deficits in everyday functioning in blast-related mTBI. Prospective memory (PM) is the ability to remember to execute an action at a certain point in the future, or is the fulfillment of delayed intentions. PM may be more sensitive to the functional difficulties described by some Veterans with mTBI (e.g., forgetting appointments) than those domains typically assessed (e.g., executive functions, attention and retrospective memory). Results of functional neuroimaging studies suggest that PM is dependent on a frontally-guided cortical network comprised of the anterior prefrontal cortex, dorsolateral prefrontal cortex, the anterior cingulate and parietal cortex. Neurostructural damage to the white matter pathways that integrate this network presents a possible underlying mechanism for PM disruption in mTBI. To date, few studies have investigated the effect of mTBI on PM, and no published studies have investigated the neurocircuitry of PM in OEF/OIF Veterans with a history of blast-related mTBI. The proposed study aims to utilize neuropsychological assessment and an integrated multi-modal neuroimaging analysis to study prospective memory (PM) functioning in Veterans with histories of blast-related mTBI. Eighty participants will be recruited from within an existing VA-funded TBI research study and will include Veterans with a history of blast-related mTBI (n = 40) or deployed Veterans without a history of mTBI (n = 40). Participants will complete a broad neurocognitive assessment which includes PM questionnaires and objective measures of PM. Veterans will also undergo an MRI scan which includes diffusion tensor imaging (DTI) and completion of a PM fMRI task. The study aims are to investigate PM performance in Veterans with histories of blast-related mTBI, investigate the neural network associated with PM functions via integration of fMRI and DTI modalities and determine whether this network is disrupted for Veterans with mTBI. The candidate is a current VA postdoctoral fellow studying mTBI and neuroimaging research, has trained in the neuropsychological assessment of mTBI, has demonstrated a capacity to learn neuroimaging research methods across multiple imaging modalities and has collaborated with the proposed mentorship team on several prior grant applications and manuscripts related to neuroimaging and cognitive functions following TBI. Successful complet...

Key facts

NIH application ID
9814108
Project number
5IK2CX001508-04
Recipient
VA SAN DIEGO HEALTHCARE SYSTEM
Principal Investigator
Scott Francis Sorg
Activity code
IK2
Funding institute
VA
Fiscal year
2020
Award amount
Award type
5
Project period
2016-10-01 → 2021-09-30