Psychiatry research
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Psychiatry research · Feb 2010
Metabolic alterations associated with impaired clock drawing in Lewy body dementia.
The clock drawing test (CDT) is a widely used dementia screening instrument that assesses executive and visuospatial abilities; studies in patients with Alzheimer's disease (AD) suggest frontoposterior networks to be involved in clock drawing. Clock drawing errors are also often observed in dementia with Lewy bodies (DLB), but the functional neuroanatomical substrate of impaired clock drawing has not been firmly established in this disorder. The present study was designed to provide initial evidence for brain metabolic alterations associated with CDT performance in DLB. ⋯ There was a significant negative association between test scores and rCMRglc in a left-hemispheric posterofrontal network including the temporoparietal and dorsal pre-motor cortices and the precuneus. The present study provides evidence for a direct association between frontoparietal dysfunction and impaired CDT performance in DLB. These findings also suggest that the CDT is an appropriate screening instrument for this disorder and that metabolic dysfunction, and therefore disease severity, is mirrored by performance on the test.
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Psychiatry research · Feb 2010
Reduced interhemispheric structural connectivity between anterior cingulate cortices in borderline personality disorder.
Functional and structural alterations of the anterior cingulate cortex (ACC), a key region for emotional and cognitive processing, are associated with borderline personality disorder (BPD). However, the interhemispheric structural connectivity between the left and right ACC and between other prefrontal regions in this condition is unknown. ⋯ In the BPD group as compared with healthy controls, we found decreased interhemispheric structural connectivity between both ACCs in fiber tracts that pass through the anterior corpus callosum and connect dorsal areas of the ACCs. Decreased interhemispheric structural connectivity between both ACCs may be a structural correlate of BPD.
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Psychiatry research · Jan 2010
The characteristics of decision making, potential to take risks, and personality of college students with Internet addiction.
This study aimed to identify risk factors involved in Internet addiction. A total of 216 college students (132 males and 84 females) were given the following: (a) the diagnostic interview for Internet addiction, (b) the Iowa gambling test for decision-making deficits, (c) the Balloon Analog Risk Test (BART) to assess risk-taking tendencies, and (d) the Tridimensional Personality Questionnaire (TPQ) for personality characteristics. ⋯ Their higher performance on the Iowa gambling test differentiates the Internet addiction group from the substance use and pathologic gambling groups that have been shown to be deficient in decision making on the Iowa test. Thus, students that fit these characteristics should be closely monitored to prevent Internet addiction.
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Psychiatry research · Jan 2010
Loss of laterality in chronic cocaine users: an fMRI investigation of sensorimotor control.
Movement disturbances are often overlooked consequences of chronic cocaine abuse. The purpose of this study was to systematically investigate sensorimotor performance in chronic cocaine users and characterize changes in brain activity among movement-related regions of interest (ROIs) in these users. Functional magnetic resonance imaging data were collected from 14 chronic cocaine users and 15 age- and gender-matched controls. ⋯ Whereas the controls used a left-sided network of motor-related brain areas to perform the task, cocaine users activated a less lateralized pattern of brain activity. Users had significantly more activity in the ipsilateral (right) motor and premotor cortical areas, anterior cingulate cortex and the putamen than controls. These data demonstrate that, in addition to the cognitive and affective consequences of chronic cocaine abuse, there are also pronounced alterations in sensorimotor control in these individuals, which are associated with functional alterations throughout movement-related neural networks.
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Psychiatry research · Dec 2009
Lower glutamate levels in rostral anterior cingulate of chronic cocaine users - A (1)H-MRS study using TE-averaged PRESS at 3 T with an optimized quantification strategy.
Previous studies have shown significantly lower metabolism and functional activity in the anterior cingulate cortex (ACC) of human cocaine addicts. The present study examined whether this ACC hypoactivity is associated with altered glutamate (Glu), the primary excitatory neurotransmitter in the central nervous system (CNS), which has been recently implicated in drug addiction. Participants comprised 14 chronic cocaine addicts and 14 matched healthy volunteers who were examined using (1)H magnetic resonance spectroscopy at 3 T. ⋯ Glu/tCr was also positively correlated with NAA/tCr. NAA/tCr significantly decreased with age but was not significantly different between the two groups. These findings suggest a metabolic/neurotransmitter dysregulation associated with cocaine addiction and support a possible therapeutic intervention strategy aimed at normalizing the Glu transmission and function in the treatment of cocaine addiction.