D2/D3 dopamine receptor binding with [F-18]fallypride correlates of executive function in medication-naïve patients with schizophrenia

Converging evidence indicates that the prefrontal cortex is critically involved in executive control and that executive dysfunction is implicated in schizophrenia. Reduced dopamine D2/D3 receptor binding potential has been reported in schizophrenia, and the correlations with neuropsychological test scores have been positive and negative for different tasks. The aim of this study was to examine the relation between dopamine D2/D3 receptor levels with frontal and temporal neurocognitive performance in schizophrenia. Resting-state 18F-fallypride positron emission tomography was performed on 20 medication-naïve and 5 previously medicated for brief earlier periods patients with schizophrenia and 19 age- and sex-matched healthy volunteers. Striatal and extra-striatal dopamine D2/D3 receptor levels were quantified as binding potential using fallypride imaging. Magnetic resonance images in standard Talairach position and segmented into gray and white matter were co-registered to the fallypride images, and the AFNI stereotaxic atlas was applied. Two neuropsychological tasks known to activate frontal and temporal lobe function were chosen, specifically the Wisconsin Card Sorting Test (WCST) and the California Verbal Learning Test (CVLT). Images of the correlation coefficient between fallypride binding and WCST and CVLT performance showed a negative correlation in contrast to positive correlations in healthy volunteers. The results of this study demonstrate that lower fallypride binding potential in patients with schizophrenia may be associated with better performance. Our findings are consistent with previous studies that failed to find cognitive improvements with typical dopamine-blocking medications

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ABSTRACT. Objective. While work disability is common in patients with systemic lupus erythematosus (SLE), it is not known which lupus disease characteristics predispose toward work disability. We examined demographic, clinical, serological, and neuropsychological factors in a group of disabled and nondisabled patients with SLE. Methods. Fifty patients meeting American College of Rheumatology criteria for SLE were assessed for work status, disease characteristics, fatigue, anxiety, depressive symptoms, and quality of life. All subjects underwent an abbreviated panel of neuropsychological tests. Subjects who had formal work disability (social security or longterm disability, n = 16) and subjects who self-reported work disability without formal recognition (n = 8) were compared to subjects denying work disability from lupus (n = 26). Results. Education level, African-American race, and SLICC Damage Index score were significantly associated with formal work disability relative to other subjects. Neurocognitive impairment (OR 14.44, 95% CI 3.01, 68.20; p = 0.001), nephritis (OR 3.75, 95% CI 1.01, 13.9; p = 0.048), and discoid lupus (OR 19.93, 95% CI 3.51, 113.3; p = 0.001) were all associated with formal disability. Formally disabled patients had higher fatigue and anxiety scores and more impaired quality of life in many domains relative to nondisabled subjects. Subjects with self-reported work disability also had neurocognitive dysfunction, high fatigue scores, and poor quality of life, but in other respects appeared to have milder disease than formally disabled subjects. Conclusion. Neurocognitive dysfunction and fatigue are 2 manifestations that may contribute materially to work disability in lupus. Other associated factors include low education levels, SLICC Damage Index scores, discoid lupus, nephritis, and possibly African-American race. (J Rheumatol 2006; 33:531-8)

D2/D3 Dopamine Receptor Binding with [F-18]fallypride Correlates of Executive Function in Medication-naïve Patients with Schizophrenia

Converging evidence indicates that the prefrontal cortex is critically involved in executive control and that executive dysfunction is implicated in schizophrenia. Reduced dopamine D2/D3 receptor binding potential has been reported in schizophrenia, and the correlations with neuropsychological test scores have been positive and negative for different tasks. The aim of this study was to examine the relation between dopamine D2/D3 receptor levels with frontal and temporal neurocognitive performance in schizophrenia. Resting-state 18F-fallypride positron emission tomography was performed on 20 medication-naïve and 5 previously medicated for brief earlier periods patients with schizophrenia and 19 age- and sex-matched healthy volunteers. Striatal and extra-striatal dopamine D2/D3 receptor levels were quantified as binding potential using fallypride imaging. Magnetic resonance images in standard Talairach position and segmented into gray and white matter were co-registered to the fallypride images, and the AFNI stereotaxic atlas was applied. Two neuropsychological tasks known to activate frontal and temporal lobe function were chosen, specifically the Wisconsin Card Sorting Test (WCST) and the California Verbal Learning Test (CVLT). Images of the correlation coefficient between fallypride binding and WCST and CVLT performance showed a negative correlation in contrast to positive correlations in healthy volunteers. The results of this study demonstrate that lower fallypride binding potential in patients with schizophrenia may be associated with better performance. Our findings are consistent with previous studies that failed to find cognitive improvements with typical dopamine-blocking medications

D2/D3 Dopamine Receptor Binding with [F-18]fallypride Correlates of Executive Function in Medication-naïve Patients with Schizophrenia

Converging evidence indicates that the prefrontal cortex is critically involved in executive control and that executive dysfunction is implicated in schizophrenia. Reduced dopamine D2/D3 receptor binding potential has been reported in schizophrenia, and the correlations with neuropsychological test scores have been positive and negative for different tasks. The aim of this study was to examine the relation between dopamine D2/D3 receptor levels with frontal and temporal neurocognitive performance in schizophrenia. Resting-state 18F-fallypride positron emission tomography was performed on 20 medication-naïve and 5 previously medicated for brief earlier periods patients with schizophrenia and 19 age- and sex-matched healthy volunteers. Striatal and extra-striatal dopamine D2/D3 receptor levels were quantified as binding potential using fallypride imaging. Magnetic resonance images in standard Talairach position and segmented into gray and white matter were co-registered to the fallypride images, and the AFNI stereotaxic atlas was applied. Two neuropsychological tasks known to activate frontal and temporal lobe function were chosen, specifically the Wisconsin Card Sorting Test (WCST) and the California Verbal Learning Test (CVLT). Images of the correlation coefficient between fallypride binding and WCST and CVLT performance showed a negative correlation in contrast to positive correlations in healthy volunteers. The results of this study demonstrate that lower fallypride binding potential in patients with schizophrenia may be associated with better performance. Our findings are consistent with previous studies that failed to find cognitive improvements with typical dopamine-blocking medications