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Biomedical subjects

R Cancro

Publications and source records attributed to R Cancro.

At least 19 recordsLinked to original sources

Low cerebellar metabolism in medicated patients with chronic schizophrenia.

Because of the frequent association of cerebellar structural defects with schizophrenia, the authors reanalyzed the metabolic brain images of patients with chronic schizophrenia to assess if they had abnormalities in cerebellar metabolism. They used carbon-11-2-deoxyglucose and positron emission tomography to study 18 medicated patients with chronic schizophrenia and 12 normal comparison subjects. Patients with schizophrenia showed significantly lower absolute and relative metabolism in the cerebellum than normal subjects.

Adult

Spatial low frequency pattern analysis in positron emission tomography: a study between normals and schizophrenics.

Using the two-dimensional Fourier transform and the brain's centroidal principal axis, a method is developed for the analysis of PET metabolic brain images without the use of predefined anatomic regions of interest. We applied the method to images from a group of 11 normal and 12 medicated schizophrenics tested under resting conditions and under a visual task. A cortical/subcortical spatial pattern was found to be significant in two directions; anterior/posterior and chiasmatic (left-anterior/right-posterior). The best individual clinical classification (Jackknife classification) occurred under visual task at two axial brain levels: at the basal ganglia with correct classification rates of 91% and 84%, while the cerebellum had rates of 82% and 92%. These high classification rates were obtained using only the four coefficients of the lowest spatial frequency. These results point to the generalized brain dysfunction of regional glucose metabolism in chronic medicated schizophrenics both at rest and at a visual image-tracking task.

Analysis of Variance

Neurobiology of schizophrenic syndromes.

The development of imaging technologies for investigating the living human brain has expanded knowledge about schizophrenia and is providing clues about biological factors associated with the disorder. Drawing on these and other developments in the last two decades, the authors review selected structural, functional, neurochemical, immunological, and infectious factors associated with the schizophrenic syndrome. Many of the biological alterations reported have also been found in other psychiatric, neurological, and medical conditions; therefore, the findings have little specificity for schizophrenia and in fact support the heterogeneity of the disorder.

Brain

Low frontal glucose utilization in chronic schizophrenia: a replication study.

Frontal/posterior ratios of cerebral glucose metabolism as determined by positron emission tomography were significantly lower in 13 chronic schizophrenic patients than in eight normal control subjects, as were absolute metabolic rates in both the frontal and posterior regions. The differences were not accounted for by cerebral atrophy.

Adult

Effects of amphetamine on local cerebral metabolism in normal and schizophrenic subjects as determined by positron emission tomography.

The effects of d-amphetamine (0.5 mg/kg PO) on regional cerebral glucose utilization were measured with Positron Emission Tomography (PET). Subjects included ten chronic schizophrenics and six controls who received amphetamine, and six chronic schizophrenics and nine controls who received placebo or no treatment. Amphetamine decreased glucose metabolism in all regions studied (frontal, temporal, and striatal) in normal and schizophrenic subjects. The metabolic effects of amphetamine were correlated with plasma level of the drug. Cortical atrophy was associated with a blunted metabolic response.

Adult

Phenomenological correlates of metabolic activity in 18 patients with chronic schizophrenia.

Using [11C]-deoxy-D-glucose and positron emission tomography (PET), the authors measured brain metabolism in 18 patients with chronic schizophrenia to assess which of the metabolic measures from two test conditions was more closely related to the patients' differing clinical characteristics. The two conditions were resting and activation, and an eye tracking task was used. Patients with more negative symptoms showed lower global metabolic rates and more severe hypofrontality than did the patients with fewer negative symptoms. Differences among the patients were distinguished by the task: sicker patients failed to show a metabolic activation response. These findings suggest that cerebral metabolic patterns reflect clinical characteristics of schizophrenic patients.

Adult

Brain organization in schizophrenia.

Brain metabolism was measured with positron emission tomography and [11C]deoxyglucose during baseline and during a visual task in 12 normal subjects and 18 schizophrenic patients. Global measures of metabolism for 11 brain regions were transformed into relative values by dividing them by the metabolic value for whole brain. Factor analysis was accomplished on the matrix of intercorrelations among the relative regional values for the normal and for the schizophrenic patients under baseline and under the task. Four factors that revealed independently varying metabolism in frontal, occipital, left-versus-right hemisphere, and subcortical structures were obtained. The frontal and subcortical factors discriminated between normal subjects and schizophrenic patients, whereas the occipital factor discriminated between baseline and task. Although activity in these individual regions varied significantly, it was the pattern of differences in regional metabolic activity that best discriminated between diagnostic groups and testing conditions.

Adult

Brain metabolism in patients with schizophrenia before and after acute neuroleptic administration.

Positron emission tomography (PET) with 11C-2-deoxyglucose (11DG) was used to compare regional brain metabolism in four patients with chronic schizophrenia who had no history of psychotropic medication and in 12 normal controls. Patients had a second PET scan after an injection of thiothixene to evaluate the effects of acute neuroleptics on glucose metabolism. The patients showed higher glucose metabolic values than the normals and did not show the metabolic hypofrontality reported in chronic medicated patients with schizophrenia. Administration of the neuroleptic did not have a significant effect in the metabolic pattern of the patients. These results give support to the hypothesis that prolonged medication may contribute to the metabolic hypofrontal pattern seen in patients with schizophrenia.

Adult

Persistence of cerebral metabolic abnormalities in chronic schizophrenia as determined by positron emission tomography.

Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before and after somatic treatment and in eight normal subjects. Before treatment, schizophrenic subjects had markedly lower absolute metabolic activity than did normal controls in both frontal and temporal regions and a trend toward relative hyperactivity in the basal ganglia area. After treatment, their metabolic rates approached those seen in normal subjects in nearly all regions except frontal. Persistence of diminished frontal metabolism was manifested as significant relative hypofrontality. These findings suggest specific loci of aberrant cerebral functioning in chronic schizophrenia and the utility of positron emission tomography in characterizing these abnormalities.

Adult

Medical and legal implications of side effects from neuroleptic drugs. A round-table discussion.

The side effects that may occur during treatment of schizophrenia with neuroleptic drugs are fully examined. Included are autonomic, extrapyramidal, other CNS, endocrine and metabolic, allergic, and skin and eye side effects. The differences between the side effect profiles of various antipsychotic drugs are noted. The restrictions imposed by laws designed to protect the patients's rights are evaluated with regard to the side effects of neuroleptic drugs. The meaning of informed consent is delineated.

Antipsychotic Agents

Genetic evidence for the existence of subgroups of the schizophrenic syndrome.

Evidence for the existence of a genetic factor in the etiology of a significant proportion of the people diagnosed as having a schizophrenic disorder is reviewed. It is suggested that whatever is transmitted genetically need not be inherently pathologic and/or pathogenic. It is argued that only people who have certain trait expressions or phenotypes are capable of a schizophrenic decompensation but that these phenotypes, while genetically loaded, are not necessarily pathogenic. An effort is made to show that even those cases in whom genetic factors operate are not homogeneous but represent separate subgroups which differ in their etiopathogenesis. This etiologic heterogeneity, in the development of a characteristic necessary but not sufficient for a schizophrenic decompensation, will almost certainly be associated with differences in the clinical course of the disorder.

Adaptation, Psychological