Change in Learning and Memory Partially Mediates Effects of Compensatory Cognitive Training on Self-Reported Cognitive Symptoms.

OBJECTIVE: To examine associations among compensatory cognitive training (CCT), objective cognitive functioning, and self-reported cognitive symptoms. We examined whether change in objective cognitive functioning associated with participation in CCT at 10-week follow-up mediates change in self-reported cognitive symptoms associated with CCT at 15-week follow-up. SETTING: Three VA outpatient mental health clinics. PARTICIPANTS: Veterans with a history of mild traumatic brain injury who reported cognitive deficits. DESIGN: Randomized controlled trial post hoc causal mediation analysis. MAIN MEASURES: Self-reported cognitive symptoms were measured by the Prospective-Retrospective Memory Questionnaire and the Multiple Sclerosis Neuropsychological Screening Questionnaire. Objective cognitive functioning was measured using a battery of neuropsychological tests. RESULTS: Improvement on the Hopkins Verbal Learning Test-Revised (HVLT-R) Delayed Recall test mediated the association between participation in CCT and decrease in the Prospective-Retrospective Memory Questionnaire total score. Improvement on the HVLT-R Total Recall and HVLT-R Delayed Recall tests both meditated the association between participation in CCT and decrease in the Multiple Sclerosis Neuropsychological Screening Questionnaire total score. No other measures of objective cognitive functioning were significant mediators. CONCLUSION: Patients' perceptions of cognitive symptom improvement due to CCT are partially mediated by learning and memory, though these subjective improvements occur regardless of other changes in objective cognitive functioning associated with CCT.

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.

To compare neuropsychological test performance of Veterans with and without mild traumatic brain injury (MTBI), blast exposure, and posttraumatic stress disorder (PTSD) symptoms. We compared the neuropsychological test performance of 49 Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) Veterans diagnosed with MTBI resulting from combat blast-exposure to that of 20 blast-exposed OEF/OIF Veterans without history of MTBI, 23 OEF/OIF Veterans with no blast exposure or MTBI history, and 40 matched civilian controls. Comparison of neuropsychological test performance across all four participant groups showed a complex pattern of mixed significant and mostly nonsignificant results, with omnibus tests significant for measures of attention, spatial abilities, and executive function. The most consistent pattern was the absence of significant differences between blast-exposed Veterans with MTBI history and blast-exposed Veterans without MTBI history. When blast-exposed Veteran groups with and without MTBI history were aggregated and compared to non-blast-exposed Veterans, there were significant differences for some measures of learning and memory, spatial abilities, and executive function. However, covariation for severity of PTSD symptoms eliminated all significant omnibus neuropsychological differences between Veteran groups. Our results suggest that, although some mild neurocognitive effects were associated with blast exposure, these neurocognitive effects might be better explained by PTSD symptom severity rather than blast exposure or MTBI history alone.

Postconcussion symptoms reported by Operation Enduring Freedom/Operation Iraqi Freedom veterans with and without blast exposure, mild traumatic brain injury, and posttraumatic stress disorder.

OBJECTIVE: This study examined symptom reporting related to the 10th Edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) criteria for postconcussional syndrome (PCS) in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Veterans. Our aims were to: (a) examine relationships among PCS symptoms by identifying potential subscales of the British Columbia Postconcussion Symptom Inventory (BC-PSI); and (b) examine group differences in BC-PSI items and subscales in Veterans with and without blast exposure, mild traumatic brain injury (mTBI), and posttraumatic stress disorder (PTSD). METHOD: Our sample included Veterans with blast-related mTBI history (n = 47), with blast exposure but no mTBI history (n = 20), and without blast exposure (n = 23). Overall, 37 Veterans had PTSD, and 53 did not. We conducted an exploratory factor analysis (EFA) of the BC-PSI followed by multivariate analysis of variance to examine differences in BC-PSI subscale scores by blast exposure, mTBI history, and PTSD. RESULTS: BC-PSI factors were interpreted as cognitive, vestibular, affective, anger, and somatic. Items and factor scores were highest for Veterans with blast exposure plus mTBI, and lowest for controls. Vestibular, affective, and somatic factors were significantly higher for Veterans with blast exposure plus mTBI than for controls, but not significantly different for those with blast exposure but no mTBI. These results remained significant when PTSD symptom severity was included as a covariate. Cognitive, anger, and somatic subscales were significantly higher for Veterans with PTSD, though there was no interaction effect of PTSD and mTBI or blast history. CONCLUSIONS: EFA-derived subscales of the BC-PSI differentiated Veterans based on blast exposure, mTBI history, and PTSD.