Neuropsychological outcomes in OEF/OIF veterans with self-report of blast exposure: Associations with mental health, but not MTBI.

Abstract

A history of mTBI with or without LOC during deployment does not contribute to objective cognitive impairment in the chronic phase post injury. In contrast, PTSD and depression symptoms are associated with cognitive performance decrements. This finding is thought to reflect at least in part the impact of psychiatric distress on neuropsychological performance.

Comparing the Neuropsychological Test Performance of Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans with and without Blast Exposure, Mild Traumatic Brain Injury, and Posttraumatic Stress Symptoms

“…Future research should further examine the impact of mechanism of injury, and investigators should consider conducting research on blast exposure regardless of MTBI diagnosis due to the potential for misclassification of MTBI status. When examining cognitive outcomes, many researchers adjust for the known confounders of age and education; however, this study and others support the need to include PTSD as a covariate (Verfaellie et al, 2014).…”

Self-Reported Sleep Disturbance Mediates the Relationship Between PTSD and Cognitive Outcome in Blast-Exposed OEF/OIF Veterans

“…This likely reflects overlap in symptoms between the 2 disorders but is also consistent with the proposal that PTSD and depression in the aftermath of trauma are best conceptualized as a single, general response to traumatic stress. 89 In our previous work, 38 we evaluated PTSD and depression in separate models as predictors of cognitive outcome and found that both were significant predictors, although the model fit was better with PTSD as the predictor, hence the focus on PTSD in this study. However, additional mental health variables such as substance use should also be considered in future work.…”

“…Previous studies examining associations of chronic mTBI and PTSD with neuropsychological outcomes have highlighted PTSD symptoms as a primary contributor to cognitive impairment. [35][36][37][38] Although there is some evidence that sleep duration may moderate the association between PTSD and cognitive function, 32 no study has directly assessed the overlap among PTSD, sleep disturbance, and cognitive outcomes, while taking into account mTBI-comorbidity. Here, we evaluate whether self-reported sleep disturbance mediates the relationship between PTSD and cognitive outcomes.…”

“…Results of neuropsychological assessment for a subset of the sample have been reported elsewhere. 38 Measures mTBI interview-Diagnosis of TBI was based on an extensive clinical interview that consisted of 4 parts: (1) determination of the most severe blast exposure based on the participant's description of the event and associated symptoms; (2) in-depth description of the index event, including description of events preceding the blast, the blast event itself, and events subsequent to the blast to determine presence and duration of alteration of consciousness (ie, disorientation, posttraumatic amnesia, LOC); (3) probing of the presence immediately following the blast of neurological symptoms consistent with TBI; and (4) query regarding medical examination or reports by a witness that could corroborate the presence of TBI. In all but 6 instances, presence and duration of LOC were based on information provided by a medic or combat peers who witnessed the event and often were the first to assess responsiveness.…”

“…38 Processing speed was measured using Wechsler Adult Intelligence Test -III (WAIS-III) Digit Symbol Coding, 45 requiring participants to write symbols corresponding to digits according to a key presented in front of them; the number sequencing, letter sequencing, and motor speed subtests of the D-KEFS Trail Making Test, 46 which require connecting in sequence letters, numbers, or circles following a dotted line; and the word and color naming subtests of the DKEFS Color-Word Interference Test. 46 Working memory was assessed using WAIS-III Digit Span Backwards, 45 which requires recall of digits in reverse; and Auditory Consonant Trigrams, 47 which requires recall of 3 consonants after variable delays of counting backward by 3 from a specified number.…”