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At least 991 records · Page 55Linked to original sources
PubMed2004

Structural brain differences in patients with schizophrenia and schizotypal disorder demonstrated by voxel-based morphometry.

Brain abnormalities of schizophrenia probably consist of deviation related to the vulnerability and pathological changes in association with overt psychosis. We conducted a cross-sectional comparison in brain morphology between patients with overt schizophrenia and schizotypal disorder, a schizophrenia-spectrum disorder without florid psychotic episode. Voxelbased morphometry was applied to assess gray matter volume in 25 patients with schizophrenia, 25 patients with schizotypal disorder, and 50 healthy control subjects. In comparison with controls, schizophrenia patients showed gray matter reductions in the bilateral medial frontal, inferior frontal, medial temporal, and septal regions, and the left middle frontal, orbitofrontal, insula, and superior temporal regions, and an increased gray matter in the left basal ganglia. Schizotypal disorder patients showed reductions in the left inferior frontal, insula, superior temporal, and medial temporal regions. There was a significant reduction in the left orbitofrontal region of schizophrenia compared with schizotypal disorder. Gray matter reductions that are common to both patient groups such as those in the left medial temporal and inferior frontal regions may represent vulnerability to schizophrenia, and additional involvement of several frontal regions may be crucial to florid psychosis.

Adolescent↗
PubMed2006

Structural brain abnormalities in early onset first-episode psychosis.

BACKGROUND: Brain morphometry in children and adolescents with first-episode psychosis offer a unique opportunity for pathogenetic investigations. METHODS: We compared high-resolution 3D T1-weighted magnetic resonance images of the brain in 29 patients (schizophrenia, schizotypal disorder, delusional disorder or other non-organic psychosis), aged 10-18 to those of 29 matched controls, using optimized voxel-based morphometry. RESULTS: Psychotic patients had frontal white matter abnormalities, but expected (regional) gray matter reductions were not observed. Post hoc analyses revealed that schizophrenia patients (n = 15) had significantly larger lateral ventricles as compared to controls. Duration and dose of antipsychotics correlated negatively with global gray matter volume in minimally medicated patients (n = 18). CONCLUSION: Findings of white matter changes and enlarged lateral ventricles already at illness onset in young schizophrenia spectrum patients, suggests aberrant neurodevelopmental processes in the pathogenesis of these disorders. Gray matter volume changes, however, appear not to be a key feature in early onset first-episode psychosis.

Adolescent↗
PubMed1985

Self-stimulation of an 'aversive' brain structure: the mesencephalic central gray area.

Four experiments were performed in BALB/c mice implanted either in the lateral hypothalamus (LH) or in the dorsal part of the mesencephalic central gray area (CG) or both in LH and CG. In the first 3 experiments the animals were placed in a Y-maze where they could successively trigger and turn off continuous electrical stimulation. Expt. 1 showed that mice stimulated in CG (like animals stimulated in LH) are able to discriminate between the reinforced and the non-reinforced arm of the Y-maze in order to self-administer the stimulation. This behavior was observed whether the experimental situation was a simple spatial discrimination or a more complex light-dark discrimination. During the second experiment, the animals could choose between stimulation of low intensity (in one arm) or high intensity (in the other arm). We observed that, like LH animals, CG implanted mice chose the higher stimulation, despite its strong aversive component. On the other hand, Expt. 3 showed that when the animals could chose between CG stimulation, whose intensity was progressively increased, and LH stimulation whose intensity remained constant (low) they preferred the latter. When the mice were placed in a lever-press box where they could obtain 0.2 s of electrical stimulation (last experiment), LH animals showed vigorous self-stimulation behavior, whereas CG animals showed only a weak response rate. These results show that, in spite of its aversiveness, dorsal CG stimulation has an appetitive component whose magnitude may vary under different experimental conditions.

Animals↗
PubMed1989

Structural brain abnormalities in patients with bulimia nervosa.

Computed tomographic (CT) brain scans were performed in 50 inpatients with bulimia nervosa, 50 anorectic inpatients, and 50 age-matched control subjects. A number of patients with bulimia nervosa had enlarged ventricles and/or sulcal widening, but the degree and frequency of ventricular dilatation and sulcal widening were not so pronounced as in patients with anorexia nervosa. As the bulimic patients were of normal body weight, the CT abnormalities cannot be attributed to emaciation, which has often been suggested as the cause of abnormalities found in anorectic patients. Since many bulimic patients repeatedly attempt to lose weight by going on restrictive diets, the morphological brain alterations may reflect the endocrine and metabolic reactions to starvation--regardless of whether starvation has led to emaciation, as in the case of anorexia nervosa, or only counterbalanced the binges of high-caloric food. This assumption is supported by the finding that in both bulimic and anorectic patients ventricular size is inversely correlated with the plasma levels of triiodothyronine, a low concentration of which is an indicator for starvation.

3-Hydroxybutyric Acid↗
PubMed2005

Identifying lesions on structural brain images--validation of the method and application to neuropsychological patients.

The study of neuropsychological disorders has been greatly facilitated by the localization of brain lesions on MRI scans. Current popular approaches for the assessment of MRI brain scans mostly depend on the successful segmentation of the brain into grey and white matter. These methods cannot be used effectively with large lesions because lesions usually impair segmentation. We propose a novel, fully automated approach for the delineation of brain lesions on MR scans. This method involves comparing a skull stripped, smoothed, unsegmented T1 images to a control group using the general linear model. We tested this method by using images with simulated lesions of different sizes and images containing real lesions from patients with language deficits. We also tested how varying the size of the Gaussian smoothing kernel affects detection. The simulation was informed by findings of a lesion morphological study also presented here. The proposed method detected simulated lesions effectively in the range of 30--90%<normal signal. Smoothing kernels in the range of 8--12 mm resulted in the most accurate lesion detection. Both artificial and real lesions were optimally detected when the results were uncorrected for multiple comparisons at p<.001. This proposed method produced highly satisfactory results and can be used to generate reproducible detection of lesions.

Adult↗
PubMed2004

Structural brain variation and general intelligence.

Total brain volume accounts for about 16% of the variance in general intelligence scores (IQ), but how volumes of specific regions-of-interest (ROIs) relate to IQ is not known. We used voxel-based morphometry (VBM) in two independent samples to identify substantial gray matter (GM) correlates of IQ. Based on statistical conjunction of both samples (N = 47; P < 0.05 corrected for multiple comparisons), more gray matter is associated with higher IQ in discrete Brodmann areas (BA) including frontal (BA 10, 46, 9), temporal (BA 21, 37, 22, 42), parietal (BA 43 and 3), and occipital (BA 19) lobes and near BA 39 for white matter (WM). These results underscore the distributed neural basis of intelligence and suggest a developmental course for volume--IQ relationships in adulthood.

Adult↗
PubMed2006

Correlations between clinical symptoms, working memory functions and structural brain abnormalities in men with schizophrenia.

Thirteen male patients with schizophrenia and thirteen male normal control subjects were compared by magnetic resonance imaging (MRI) on volumes of the straight gyrus (SG), anterior cingulate gyrus, middle frontal gyrus, hippocampus, third ventricle, cavum septi pellucidi, total brain volume and intracranial volume. In addition, neuropsychological tasks were used to measure working memory and executive functions. Healthy volunteers and schizophrenic patients showed no significant differences in mean values for volumes of regions of interests. In the case of the SG, we found a significant difference in laterality: the tendency toward left dominance in healthy volunteers changed to significant right dominance in patients. The schizophrenic patients showed lower performance in working memory tasks, and strongly significant group differences were observed in measures of neurological signs assessed by the Neurological Evaluation Scale (NES). Negative symptoms correlated with the level of spatial working memory and executive functions. Negative symptoms also correlated with the volume of the right hippocampus, while the rate of anhedonia negatively correlated with the relative volume of the left SG.

Adult↗
PubMed2005

Is craniofacial dysmorpholgy correlated with structural brain anomalies in schizophrenia?

This study aimed to examine the relationship between craniofacial dysmorphology and anomalies of brain morphology in schizophrenia. Assessments of craniofacial dysmorphology and magnetic resonance imaging of brain were performed independently of each other and blind to each other in 24 males with schizophrenia and 16 male controls. Ventricular cerebrospinal fluid volume was negatively correlated with total dysmorphology score in males with schizophrenia (i.e., the larger the ventricular cerebrospinal fluid volume, the lower the total dysmorphology score) but not in male controls. These findings suggest that craniofacial dysmorphology and anomalies of brain morphology may be associated with independent processes in the etiology of schizophrenia.

Adult↗