Neuroimaging of reaction time task activation using oxygen-15 positron emission tomography

Normal subjects were used to investigate potential experimental utility of positron emission tomography (PET) neuroimaging during performance of the Shakow reaction time (RT) paradigm preliminary to application in schizophrenia research. It was hypothesized that different conditions of the Shakow crossover RT task, consisting of regular and irregular series of preparatory intervals (PI), would result in differential activation of contributory cerebral systems as indicated by regional cerebral blood flow (rCBF). Task-activated regional rCBF data were obtained from eleven normal volunteers by intravenous infusion of \sp{15}O radiolabeled water and PET. During PET scans, subjects performed one of three task conditions: a baseline motor task, RT with regular PIs, or RT with irregular PIs. Differences found between RT conditions in frontal, anterior cingulate, and parietal rCBF are congruent with currently prominent neurocognitive theories of executive function and support the potential utility of this paradigm in schizophrenia research

Comparison of MMPI-2 Profiles of Gulf War Veterans with Epileptic and Nonepileptic Seizure Patients

As part of a larger study of illnesses related to service in the Gulf War, MMPI-2 profiles of epileptic seizure (ES) patients; nonepileptic seizure (NES) patients; Gulf War veterans with unexplained cognitive, psychological, musculoskeletal, fatigue, or dermatologic symptoms; and asymptomatic Gulf War veterans (Controls) were analyzed. There were 70 people in each group. Seizure diagnosis was based upon intensive EEG monitoring. Gulf War cases were mildly abnormal on MMPI-2 Scales Hs and D and significantly higher than controls on 8 of 10 MMPI-2 clinical scales, but they were significantly lower than NES patients on several scales including Hs and Hy

Objective Cognitive Impairment and Subjective Cognitive Problems in Veterans Initiating Psychotherapy for Posttraumatic Stress Disorder: An Exploratory Study

The prevalence of cognitive impairment in Veterans initiating an evidence-based psychotherapy (EBP) for posttraumatic stress disorder (PTSD) is not yet established and has implications for service delivery. Our objectives were to (1) describe the type, severity, and prevalence of objective cognitive impairment and subjective cognitive problems experienced by Veterans at the time they began an EBP for PTSD and (2) determine whether assessments of objective cognitive impairment and subjective cognitive problems agree. We conducted objective and subjective (self-report) cognitive assessments in a sample of 38 Veterans initiating EBP for PTSD at one Veterans Affairs Medical Center. Thirty Veterans produced valid assessments. Almost half (14/30) of the participants demonstrated objective impairment in one or more cognitive domains, primarily in the areas of learning, memory, and processing speed. Almost all (29/30) participants endorsed moderate or greater cognitive problems on at least one self-report measure. After adjustment for multiple comparisons, there were no significant correlations between objective and subjective assessments. Objective cognitive impairment and subjective cognitive problems are common in Veterans beginning an EBP for PTSD. Longitudinal research on a larger sample is warranted to better understand relationships among subjective cognitive problems, objective cognitive impairment, and PTSD treatment participation and outcomes