Showing papers by "Nora D. Volkow published in 1986"
01 Jan 1986
TL;DR: In this paper, the authors used PET with 11C-2-deoxyglucose (11DG) to compare regional brain metabolism in four patients with chronic schizophrenia who had no history of psychotropic medication and in 12 normal controls.
Abstract: 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.
123 citations
TL;DR: Results give support to the hypothesis that prolonged medication may contribute to the metabolic hypofrontal pattern seen in patients with schizophrenia.
Abstract: 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.
120 citations
TL;DR: 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.
Abstract: 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.
95 citations
TL;DR: The metabolism of putrescine in brain tumors was related to tumor type and appeared to correlate with the degree of malignancy, and the significance of these findings with regard to positron emission tomographic scanning and therapy of patients with malignant gliomas is discussed.
Abstract: The metabolism of the polyamines, putrescine, spermidine and spermine, was studied in human brain and brain tumors. Samples of brain and tumors were incubated with3H-putrescine and the amounts of labeled polyamines were measured. The amount of putrescine conversion was found to be greater in tumors that in normal brain samples. Furthermore, the metabolism of putrescine in brain tumors was related to tumor type and appeared to correlate with the degree of malignancy. The significance of these findings with regard to positron emission tomographic scanning and therapy of patients with malignant gliomas is discussed.
11 citations
9 citations
TL;DR: The basic principles of PET, its relationship to other existing imaging devices, and the issues to be considered when making a technological assessment of positron emission tomography are discussed.
Abstract: Positron emission tomography (PET) is a new nuclear medicine technique that has recently entered the clinical realm of medicine. Although it is a technique that can be utilized for assessment of biochemical and physiological parameters of any organ in the body, it has particular utility in the investigation of the brain. PET poses unique advantages over previous imaging devices. For the first time, it is feasible to investigate directly various biological parameters of the brain in a noninvasive way. PET allows for investigating the functional, biochemical, physiological, and pharmacological characteristics of various areas within the brains of normal and psychiatric or neurological patients. Although it has already started to give promising results, it is too new a technique to obtain an accurate appraisal of its true potentials. This is a problem that seems always to surface when one tries to evaluate the utility of a new technique in a new area of research. The problem is accentuated in the case of PET where there is no other technique available with which to compare results. This paper will discuss the basic principles of PET, its relationship to other existing imaging devices, and the issues to be considered when making a technological assessment of positron emission tomography.
8 citations