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Matter Reduction (matter + reduction)

Distribution by Scientific Domains

Medical Sciences	66%

Selected Abstracts

Regional gray matter reduction and theory of mind deficit in the early phase of schizophrenia: a voxel-based morphometric study

ACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2009
R. Herold
Objective:, We tested the association between theory of mind (ToM) performance and structural changes in the brains of patients in the early course of schizophrenia. Method:, Voxel-based morphometry (VBM) data of 18 patients with schizophrenia were compared with those of 21 controls. ToM skills were assessed by computerized faux pas (FP) tasks. Results:, Patients with schizophrenia performed significantly worse in FP tasks than healthy subjects. VBM revealed significantly reduced gray matter density in certain frontal, temporal and subcortical regions in patients with schizophrenia. Poor FP performance of schizophrenics correlated with gray matter reduction in the left orbitofrontal cortex and right temporal pole. Conclusion:, Our data indicate an association between poor ToM performance and regional gray matter reduction in the left orbitofrontal cortex and right temporal pole shortly after the onset of schizophrenia. [source]

Structural abnormalities of ventrolateral and orbitofrontal cortex in patients with familial bipolar disorder

BIPOLAR DISORDERS, Issue 2 2009
Andrew C Stanfield
Objectives:, Abnormalities of ventral prefrontal function have been widely reported in bipolar disorder, but reports of structural abnormalities in the same region are less consistent. We examined the presence and location of ventral prefrontal abnormalities in a large sample of individuals with bipolar disorder and their relationship to gender, psychotic symptoms, and age. Methods:, Structural magnetic resonance imaging brain scans were carried out on 66 individuals with bipolar disorder, type I, and 66 controls. Voxel-based morphometry was used to examine differences in grey and white matter density between the groups and their relationship with a lifetime occurrence of psychotic symptoms and age. Results:, Reductions in grey matter density were seen in the left and right lateral orbital gyri and the right inferior frontal gyrus, while white matter density reductions were seen in the corona radiata and the left temporal stem. In contrast, hallucinations and positive symptoms were associated with grey matter reduction in the left middle temporal gyrus. Age was more strongly associated with the right inferior frontal gyrus grey matter reductions in the bipolar group than in the controls, but not with any other finding. Conclusion:, Abnormalities of the ventral prefrontal cortex are likely to be involved in the aetiopathology of bipolar disorder, while hallucinations appear to be more closely associated with temporal lobe abnormality, extending earlier work in schizophrenia. Further prospective studies are required to comprehensively address the trajectory of these findings. [source]

Voxel-based analysis of MRI detects abnormal visual cortex in children and adults with amblyopia

HUMAN BRAIN MAPPING, Issue 2 2005
Janine D. Mendola
Abstract Amblyopia, sometimes called "lazy eye," is a relatively common developmental visual disorder well characterized behaviorally; however, the neural substrates associated with amblyopia in humans remain unclear. We hypothesized that abnormalities in the cerebral cortex of subjects with amblyopia exist, possibly as a result of experience-dependent neuronal plasticity. Anatomic magnetic resonance imaging (MRI) and psychophysical vision testing was carried out on 74 subjects divided into two age ranges, 7,12 years and 18,35 years, and three diagnoses, strabismic amblyopia, anisometropic amblyopia, and normal vision. We report a behavioral impairment in contrast sensitivity for subjects with amblyopia, consistent with previous reports. When the high-resolution MRI brain images were analyzed quantitatively with optimized voxel-based morphometry, results indicated that adults and children with amblyopia have decreased gray matter volume in visual cortical regions, including the calcarine sulcus, known to contain primary visual cortex. This finding was confirmed with a separate region-of-interest analysis. For the children with amblyopia, additional gray matter reductions in parietal-occipital areas and ventral temporal cortex were detected, consistent with recent reports that amblyopia can result in spatial location and object processing deficits. These data are the first to provide possible neuroanatomic bases for the loss of binocularity and visual sensitivity in children and adults with amblyopia. Hum Brain Mapp 25:222,236, 2005. © 2005 Wiley-Liss, Inc. [source]

Structural brain abnormalities in adolescents with autism spectrum disorder and patients with attention deficit/hyperactivity disorder

THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 12 2007
Sarah Brieber
Background:, Although autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD) are two distinct neurodevelopmental diseases, they share behavioural, neuropsychological and neurobiological characteristics. For the identification of endophenotypes across diagnostic categories, further investigations of phenotypic overlap between ADHD and autism at the behavioural, neurocognitive, and brain levels are needed. Methods:, We examined regional grey matter differences and similarities in children and adolescents with ASD and ADHD in comparison to healthy controls using structural magnetic resonance imaging (MRI) and voxel-based morphometry. Results:, With regard to clinical criteria, the clinical groups did not differ with respect to ADHD symptoms; however, only patients with ASD showed deficits in social communication and interaction, according to parental rating. Structural abnormalities across both clinical groups compared to controls became evident as grey matter reductions in the left medial temporal lobe and as higher grey matter volumes in the left inferior parietal cortex. In addition, autism-specific brain abnormalities were found as increased grey matter volume in the right supramarginal gyrus. Conclusions:, While the shared structural deviations in the medial temporal lobe might be attributed to an unspecific delay in brain development and might be associated with memory deficits, the structural abnormalities in the inferior parietal lobe may correspond to attentional deficits observed in both ASD and ADHD. By contrast, the autism-specific grey matter abnormalities near the right temporo-parietal junction may be associated with impaired ,theory of mind' abilities. These findings shed some light on both similarities and differences in the neurocognitive profiles of ADHD and ASD patients. [source]