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1.
Science ; 221(4611): 673-5, 1983 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-6603020

RESUMO

The polyamine metabolism of transplanted N-nitrosomethylurea-derived rat glioma was determined with radiolabeled putrescine used as a marker for malignancy. The uptake of putrescine in vivo was complete within 5 minutes and was specific for tumor tissue. The conversion of putrescine to spermine and other metabolites by the tumor was rapid, in contrast to the case for adjacent normal brain. These results suggest that putrescine labeled with carbon-11 may be used as a positron-emission tomographic tracer for the selective metabolic imaging of brain tumor and may be used in an appropriate model as a marker for tumor growth rate.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Putrescina , Animais , Autorradiografia , Glioma/diagnóstico por imagem , Cinética , Transplante de Neoplasias , Putrescina/metabolismo , Ratos , Tomografia Computadorizada de Emissão
2.
Science ; 186(4161): 361-3, 1974 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-4412776

RESUMO

A technique has been developed to micromap deuterium by using the D(T,n)(4)He reaction and plastic track detectors. Labeling of cells with subpicogram quantities of deuterium was demonstrated. The technique was used to localize human lymphocytes transformed in vitro.


Assuntos
Deutério , Hélio , Marcação por Isótopo/métodos , Partículas alfa , Chlorella/efeitos da radiação , Cromatografia em Camada Fina , Eritrócitos/efeitos da radiação , Humanos , Lectinas/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/efeitos da radiação , Espectrometria de Massas , Física Nuclear , Fotomicrografia , Efeitos da Radiação , Radiometria , Espectrofotometria Ultravioleta , Timidina , Trítio
3.
Science ; 212(4492): 340-1, 1981 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-7209534

RESUMO

An investigation of the efficacy of astatine-211--tellurium colloid for the treatment of experimental malignant ascites in mice reveals that this alpha-emitting radiocolloid can be curative without causing undue toxicity to normal tissue. By comparison, negatron-emitting phosphorus-32 as colloidal chromic phosphate had no antineoplastic activity. The most compelling explanation for this striking difference is the dense ionization and short range of action associated with alpha-emission. These results have important implications for the development and use of alpha-emitters as radiocolloid therapy for the treatment of human tumors.


Assuntos
Ascite/radioterapia , Astato/uso terapêutico , Compostos de Cromo , Neoplasias Experimentais/radioterapia , Radioisótopos/uso terapêutico , Telúrio/uso terapêutico , Partículas alfa , Animais , Sobrevivência Celular/efeitos da radiação , Cromo/uso terapêutico , Coloides , Feminino , Camundongos , Transplante de Neoplasias , Neoplasias Ovarianas , Fosfatos/uso terapêutico , Radioisótopos de Fósforo/uso terapêutico , Transplante Homólogo
4.
Science ; 235(4787): 481-5, 1987 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-3099392

RESUMO

The regional distributions of monoamine oxidase (MAO) types A and B have been identified in human brain in vivo with intravenously injected 11C-labeled suicide enzyme inactivators, clorgyline and L-deprenyl, and positron emission tomography. The rapid brain uptake and retention of radioactivity for both 11C tracers indicated irreversible trapping. The anatomical distribution of 11C paralleled the distribution of MAO A and MAO B in human brain in autopsy material. The corpus striatum, thalamus, and brainstem contained high MAO activity. The magnitudes of uptake of both [11C]clorgyline and L-[11C]deprenyl were markedly reduced in one subject treated with the antidepressant MAO inhibitor phenelzine. A comparison of the brain uptake and retention of the 11C-labeled inactive (D-) and active (L-) enantiomers of deprenyl showed rapid clearance of the inactive enantiomer and retention of the active enantiomer within MAO B-rich brain structures, in agreement with the known stereoselectivity of MAO B for L-deprenyl. Prior treatment with unlabeled L-deprenyl prevented retention of L-[11C]deprenyl. Thus, suicide enzyme inactivators labeled with positron emitters can be used to quantitate the distribution and kinetic characteristics of MAO in human brain structures.


Assuntos
Encéfalo/enzimologia , Monoaminoxidase/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Tronco Encefálico/enzimologia , Córtex Cerebral/enzimologia , Clorgilina , Corpo Estriado/enzimologia , Humanos , Selegilina , Tálamo/enzimologia , Tomografia Computadorizada de Emissão
5.
Arch Gen Psychiatry ; 41(3): 293-300, 1984 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6608333

RESUMO

Thirteen diagnosed schizophrenics and 11 normal controls were studied with a method using the PETT III positron emission tomograph (PET) and fluorodeoxyglucose labeled with fluorine 18. Each subject also had a computed tomographic (CT) scan. For each subject, two brain levels, one through the basal ganglia and one through the semioval center, were analyzed for the mean regional metabolic glucose rate. Specifically, relationships between frontal and posterior regions were evaluated. The CT scans of matching levels were superimposed on the functional PET images to provide anatomic criteria for region of interest selection. While no whole-slice metabolic differences were apparent between groups, schizophrenics had significantly lower activity in the frontal lobes, relative to posterior regions. The medicated and drug-free groups did not differ from one another in these regards. Trait v state dependency of the phenomenon was analyzed, and several technological limitations were considered.


Assuntos
Encéfalo/metabolismo , Glucose/metabolismo , Esquizofrenia/metabolismo , Adulto , Gânglios da Base/diagnóstico por imagem , Gânglios da Base/metabolismo , Encéfalo/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/metabolismo , Desoxiglucose/análogos & derivados , Desoxiglucose/metabolismo , Flúor , Fluordesoxiglucose F18 , Lobo Frontal/diagnóstico por imagem , Lobo Frontal/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Radioisótopos , Esquizofrenia/diagnóstico , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X
6.
Arch Gen Psychiatry ; 49(12): 959-65, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1360200

RESUMO

Frontal lobe dysfunction is widely suspected to underlie negative symptoms of schizophrenia. This hypothesis is based largely on long-standing observations of the similarities between the effects of frontal lobe lesions and negative symptoms. However, there is little direct evidence specifically for such an association in schizophrenic patients. We measured the relationship between decreased relative prefrontal cortex glucose metabolism (hypofrontality) using positron emission tomography and evaluated the severity of negative symptoms in 20 chronic schizophrenics who underwent scanning while not receiving neuroleptic drugs. We found a close relationship between negative symptoms and prefrontal hypometabolism, particularly in the right dorsolateral convexity. This association was regionally specific. Furthermore, there was no evidence that this relationship was an artifact of age, cerebral atrophy, or severity of positive symptoms.


Assuntos
Lobo Frontal/metabolismo , Glucose/metabolismo , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Adulto , Antipsicóticos/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Doença Crônica , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Esquizofrenia/metabolismo , Índice de Gravidade de Doença , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X
7.
Biol Psychiatry ; 19(10): 1365-75, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6083807

RESUMO

An experimental strategy for external detection of specific neuroleptic receptors in living brain using positron emission transaxial tomography (PETT) and [11C]spiroperidol was applied to the mapping of brain neuroleptic receptors in the live baboon. A double injection of [11C]spiroperidol with an intervening time interval for carbon-11 decay and an intervening dose of (+)-butaclamol to block specific neuroleptic receptors produced two sets of PETT scans which were subtracted to produce a three-dimensional map of relative regional binding of neuroleptic receptors in the baboon brain. Sixty-five percent of the total radioactivity in the striatum was bound to neuroleptic receptors at 65 min after injection.


Assuntos
Encéfalo/metabolismo , Papio/metabolismo , Receptores Dopaminérgicos/metabolismo , Animais , Butaclamol/farmacologia , Feminino , Espiperona/metabolismo , Tomografia Computadorizada de Emissão
8.
Biol Psychiatry ; 36(5): 317-25, 1994 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-7993958

RESUMO

The effects of d-amphetamine (0.5 mg/kg orally) on regional cerebral glucose utilization were measured with positron emission tomography (PET) in 17 schizophrenics (along with a placebo-control group of an additional six schizophrenic patients). The acute d-amphetamine challenge tended to decrease glucose utilization throughout much of the brain, with a regional effect that was statistically significant in the left temporal cortex. There was no apparent relationship between the effects of amphetamine-induced changes in regional cerebral metabolism and psychotic symptom exacerbation. An exploratory analysis suggested that features characteristic of Crow's type II syndrome were significant predictors of cerebral hyporesponsivity to stimulant challenge, however.


Assuntos
Glicemia/metabolismo , Córtex Cerebral/efeitos dos fármacos , Dextroanfetamina , Esquizofrenia/diagnóstico por imagem , Psicologia do Esquizofrênico , Tomografia Computadorizada de Emissão , Nível de Alerta/efeitos dos fármacos , Nível de Alerta/fisiologia , Córtex Cerebral/diagnóstico por imagem , Dominância Cerebral/efeitos dos fármacos , Dominância Cerebral/fisiologia , Método Duplo-Cego , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Esquizofrenia/induzido quimicamente , Esquizofrenia/diagnóstico , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/efeitos dos fármacos
9.
Biol Psychiatry ; 23(7): 653-63, 1988 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-2967093

RESUMO

An indirect approach to the relationship among drug dose, plasma level, and the competition between a labeled neuroleptic drug [18F]N-methylspiroperidol (18F-NMS) for binding sites in striatal tissue in normal and schizophrenic subjects is described. The slope of the line plotting the ratio of activity in the striatum (As) to activity in the cerebellum (Ac) versus time up to 5 hr postinjection of 18F-NMS is taken as a marker of site occupancy. An inverse relation between labeled competitor uptake and drug plasma level has been demonstrated for the classes of antipsychotic drug studied. Striatal uptake studies showed a progressive increase in all subjects following drug withdrawal up to 156 hr postwithdrawal. Uptake and clearance of 18F-NMS in cerebellar tissue was not appreciably affected by antipsychotic medication or drug withdrawal.


Assuntos
Clorpromazina/uso terapêutico , Corpo Estriado/efeitos dos fármacos , Haloperidol/uso terapêutico , Receptores Dopaminérgicos/efeitos dos fármacos , Esquizofrenia/tratamento farmacológico , Espiperona/análogos & derivados , Tomografia Computadorizada de Emissão , Adulto , Ligação Competitiva , Clorpromazina/farmacocinética , Corpo Estriado/metabolismo , Haloperidol/farmacocinética , Humanos , Masculino , Pessoa de Meia-Idade , Receptores Dopaminérgicos/metabolismo , Receptores de Dopamina D2 , Espiperona/metabolismo
10.
J Cereb Blood Flow Metab ; 8(4): 502-12, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3260593

RESUMO

Positron emission tomography with 11C-2-deoxyglucose was used to determine the test-retest variability of regional cerebral glucose metabolism in 22 young normal right-handed men scanned twice in a 24-h period under baseline (resting) conditions. To assess the effects of scan order and time of day on variability, 12 subjects were scanned in the morning and afternoon of the same day (a.m.-p.m.) and 10 in the reverse order (p.m.-a.m.) with a night in between. The effect of anxiety on metabolism was also assessed. Seventy-three percent of the total subject group showed changes in whole brain metabolism from the first to the second measurement of 10% or less, with comparable changes in various cortical and subcortical regions. When a scaling factor was used to equate the whole brain metabolism in the two scans for each individual, the resulting average regional changes for each group were no more than 1%. This suggests that the proportion of the whole brain metabolism utilized regionally is stable in a group of subjects over time. Both groups of subjects had lower morning than afternoon metabolism, but the differences were slight in the p.m.-a.m. group. One measure of anxiety (pulse at run 1) was correlated with run 1 metabolism and with the percentage of change from run 1 to run 2. No significant run 2 correlations were observed. This is the first study to measure test-retest variability in cerebral glucose metabolism in a large sample of young normal subjects. It demonstrates that the deoxyglucose method yields low intrasubject variability and high stability over a 24-h period.


Assuntos
Encéfalo/metabolismo , Glucose/metabolismo , Adolescente , Adulto , Ansiedade/fisiologia , Encéfalo/diagnóstico por imagem , Ritmo Circadiano , Humanos , Masculino , Valores de Referência , Descanso , Tomografia Computadorizada de Emissão
11.
J Cereb Blood Flow Metab ; 11(2): A103-13, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1997478

RESUMO

We introduce the concept of the metabolic centroid spectrum as the feature space to characterize the distribution of metabolic activity in three-dimensional brains. The method computes the metabolic centroid of a brain subvolume for each increment of metabolic activity occurring in the whole brain. The result is the metabolic spectral signature, a continuous three-dimensional curve whose shape reflects the distribution of metabolic rates in the brain. The method's sensitivity to metabolic distribution asymmetries is greatly increased over that of the metabolic centroid method, while retaining its advantages; it is almost invariant to head size, head positioning, photon scatter, and the positron emission tomography (PET) camera's full width at half-maximum. It does not require magnetic resonance, computed tomography, or x-ray images. To test the method we analyzed the metabolic PET images of 40 normal subjects and 20 schizophrenics. The results show a unification of several metabolic characteristics of schizophrenic brains, such as laterality, hypofrontality, cortical/subcortical abnormalities, and overall brain hypometabolism, which were identified by different laboratories in separate studies using differing methodologies. Here they are presented by a single automatic objective method.


Assuntos
Encéfalo/metabolismo , Esquizofrenia/metabolismo , Tomografia Computadorizada de Emissão/métodos , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Córtex Cerebral/metabolismo , Lateralidade Funcional , Glucose/metabolismo , Humanos , Cinética , Matemática , Pessoa de Meia-Idade , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/patologia
12.
J Cereb Blood Flow Metab ; 8(3): 433-5, 1988 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3259243

RESUMO

Young normal, elderly, and clinically diagnosed Alzheimer disease subjects who had undergone positron emission tomography (PET) and computed tomography (CT) examinations were studied to determine the effect of periventricular white matter lesions on cerebellar glucose metabolic rates. PET-determined cerebellar metabolic rates were elevated in subjects with periventricular white matter lesions. These results suggest the cautious use of cortical-to-cerebellar ratios in future PET or single-photon-emission CT (SPECT) studies.


Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/metabolismo , Cerebelo/metabolismo , Glucose/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Análise de Variância , Cerebelo/diagnóstico por imagem , Ventrículos Cerebrais/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Tomografia Computadorizada de Emissão
13.
J Cereb Blood Flow Metab ; 6(4): 441-6, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3488322

RESUMO

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.


Assuntos
Encéfalo/metabolismo , Esquizofrenia/metabolismo , Adulto , Encéfalo/diagnóstico por imagem , Desoxiglucose/metabolismo , Análise Fatorial , Feminino , Humanos , Masculino , Tomografia Computadorizada de Emissão
14.
J Cereb Blood Flow Metab ; 3(3): 391-4, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6603463

RESUMO

Young normal subjects, old normal subjects, and patients with senile dementia of the Alzheimer's type (SDAT) were studied with both computed tomography (CT) and positron emission transaxial tomography (PETT). Increases in ventricular size with both aging and disease were measured. Regional glucose metabolic rate was not affected by age, but was markedly reduced in SDAT patients. These data indicate that in normal aging, structural brain changes may be more salient than biochemical changes. Although both structural and biochemical changes occur in SDAT, the biochemical changes are more marked. The results suggest that PETT is potentially more useful than CT in the in vivo diagnosis of SDAT.


Assuntos
Envelhecimento , Doença de Alzheimer/diagnóstico por imagem , Demência/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Tomografia Computadorizada por Raios X , Adulto , Idoso , Doença de Alzheimer/psicologia , Cognição , Humanos
15.
J Cereb Blood Flow Metab ; 9(3): 388-97, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2565910

RESUMO

The method of centroids is an approach to the analysis of three-dimensional whole-brain positron emission tomography (PET) metabolic images. It utilizes the brain's geometric centroid and metabolic centroid so as to objectively characterize the central tendency of the distribution of metabolic activity in the brain. The method characterizes the three-dimensional PET metabolic image in terms of four parameters: the coordinates of the metabolic centroid and the mean metabolic rate of the whole brain. These parameters are not sensitive to spatially uniform random noise or to the position of the subject's head within a uniform PET camera field of view. The method has been applied to 40 normal subjects, 22 schizophrenics who were treated with neuroleptics, and 20 schizophrenics who were neuroleptic-free. The mean metabolic centroid of the normal subjects was found to be superior to the mean geometric centroid of the brain. The mean metabolic centroid of chronic schizophrenics is lower and more posterior to the mean geometric centroid than is that of normals. This difference is greater in medicated than in unmedicated schizophrenics. The posterior and downward displacement of the mean metabolic centroid is consistent with the concepts of hypofrontality, hyperactivity of subcortical structures, and neuroleptic effect in schizophrenics.


Assuntos
Encéfalo/diagnóstico por imagem , Tomografia Computadorizada de Emissão/métodos , Adulto , Antipsicóticos/uso terapêutico , Encéfalo/metabolismo , Glucose/metabolismo , Humanos , Cinética , Masculino , Matemática , Pessoa de Meia-Idade , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Software
16.
J Cereb Blood Flow Metab ; 7(2): 248-51, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3494029

RESUMO

Elderly controls and probable Alzheimer's disease patients underwent serial positron emission tomography (PET) studies during a baseline condition and while performing a verbal memory task. For the temporal lobes, all 7 Alzheimer patients demonstrated a relative shift in glucose metabolic rates to the right hemisphere during the memory condition relative to baseline, and 5 of 7 controls showed a shift to the left hemisphere. Baseline absolute regional metabolic rates replicate previous findings and were somewhat less useful than the memory challenge in differentiating patients from controls. These results indicate that a temporal lobe abnormality in Alzheimer's disease is related to memory performance.


Assuntos
Doença de Alzheimer/fisiopatologia , Lobo Temporal/fisiopatologia , Tomografia Computadorizada de Emissão , Idoso , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Análise de Variância , Radioisótopos de Carbono , Cognição , Desoxiglucose , Glucose/metabolismo , Humanos , Memória , Pessoa de Meia-Idade
17.
J Cereb Blood Flow Metab ; 10(5): 740-7, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2384545

RESUMO

A graphical method of analysis applicable to ligands that bind reversibly to receptors or enzymes requiring the simultaneous measurement of plasma and tissue radioactivities for multiple times after the injection of a radiolabeled tracer is presented. It is shown that there is a time t after which a plot of integral of t0ROI(t')dt'/ROI(t) versus integral of t0Cp(t')dt'/ROI(t) (where ROI and Cp are functions of time describing the variation of tissue radioactivity and plasma radioactivity, respectively) is linear with a slope that corresponds to the steady-state space of the ligand plus the plasma volume,.Vp. For a two-compartment model, the slope is given by lambda + Vp, where lambda is the partition coefficient and the intercept is -1/[kappa 2(1 + Vp/lambda)]. For a three-compartment model, the slope is lambda(1 + Bmax/Kd) + Vp and the intercept is -[1 + Bmax/Kd)/k2 + [koff(1 + Kd/Bmax)]-1) [1 + Vp/lambda(1 + Bmax/Kd)]-1 (where Bmax represents the concentration of ligand binding sites and Kd the equilibrium dissociation constant of the ligand-binding site complex, koff (k4) the ligand-binding site dissociation constant, and k2 is the transfer constant from tissue to plasma). This graphical method provides the ratio Bmax/Kd from the slope for comparison with in vitro measures of the same parameter. It also provides an easy, rapid method for comparison of the reproducibility of repeated measures in a single subject, for longitudinal or drug intervention protocols, or for comparing experimental results between subjects. Although the linearity of this plot holds when ROI/Cp is constant, it can be shown that, for many systems, linearity is effectively reached some time before this. This analysis has been applied to data from [N-methyl-11C]-(-)-cocaine ([11C]cocaine) studies in normal human volunteers and the results are compared to the standard nonlinear least-squares analysis. The calculated value of Bmax/Kd for the high-affinity binding site for cocaine is 0.62 +/- 0.20, in agreement with literature values.


Assuntos
Encéfalo/metabolismo , Cocaína , Modelos Neurológicos , Radioisótopos de Carbono , Cocaína/farmacocinética , Humanos , Ligantes , Modelos Lineares , Receptores Dopaminérgicos/metabolismo , Tomografia Computadorizada de Emissão/métodos
18.
Neurobiol Aging ; 1(2): 127-31, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-24279935

RESUMO

(18)F-2-deoxy-2-fluoro-D-glucose ((18)FDG) is a positron emitting tracer for rate of glucose utilization in brain. When used in conjunction with positron emission tomography (PET), the PET-FDG technique permits in vivo quantitation of regional brain metabolism in man. We have applied this technique to the study of regional brain function in normal aging and senile dementia. Preliminary results for 7 patients with senile dementia of the Alzheimer's type (SDAT) and 3 elderly normal subjects indicated a large, statistically significant (p < 0.01) diminution in rate of glucose utilization in SDAT. Furthermore, the degree of diminution in metabolic activity in SDAT was highly correlated with objective measures of degree of cognitive impairment. These results demonstrate the feasibility and potential utility of the PET-FDG technique for studying regional brain function in normal aging and dementia.

19.
Am J Psychiatry ; 142(5): 564-71, 1985 May.
Artigo em Inglês | MEDLINE | ID: mdl-3872603

RESUMO

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.


Assuntos
Encéfalo/metabolismo , Esquizofrenia/metabolismo , Adulto , Gânglios da Base/metabolismo , Doença Crônica , Desoxiglucose/análogos & derivados , Desoxiglucose/metabolismo , Flúor , Fluordesoxiglucose F18 , Lobo Frontal/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Radioisótopos , Esquizofrenia/diagnóstico , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Lobo Temporal/metabolismo , Tiotixeno/uso terapêutico , Tomografia Computadorizada de Emissão
20.
Am J Psychiatry ; 148(5): 621-6, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2018164

RESUMO

OBJECTIVE: The authors investigated changes in brain function associated with cocaine dependence and withdrawal to provide clues regarding the processes that lead to the uncontrollable self-administration of cocaine. METHOD: They measured regional brain metabolism with [18F]-fluorodeoxyglucose (FDG) and positron emission tomography in 15 outpatients with the diagnosis of cocaine abuse and 17 normal comparison subjects. Ten of the patients were studied less than 1 week after they had last had cocaine, and five were studied 2-4 weeks after withdrawal. RESULTS: Patients studied within 1 week of cocaine withdrawal but not those studied within 2-4 weeks of cocaine withdrawal had higher levels of global brain metabolism as well as higher levels of regional brain metabolism in the basal ganglia and orbitofrontal cortex than did normal subjects, probably as a consequence of less brain dopamine activity. There was also a significant relationship between the number of days since cocaine withdrawal and regional brain glucose metabolism in the orbitofrontal cortex and in the basal ganglia, and the correlations between cocaine craving and metabolic activity were significant in the prefrontal cortex and the orbitofrontal cortex. CONCLUSIONS: Although the time-dependent fall in metabolic activity suggests that the higher metabolic activity observed less than a week after cocaine withdrawal may represent a nonspecific expression of drug withdrawal, the selectivity of changes in glucose metabolism for the basal ganglia and for the orbitofrontal cortex suggests that the regional metabolic changes seen in cocaine abusers during detoxification are related to changes in brain dopamine activity.


Assuntos
Encéfalo/metabolismo , Cocaína/efeitos adversos , Glucose/metabolismo , Síndrome de Abstinência a Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Adolescente , Adulto , Assistência Ambulatorial , Gânglios da Base/metabolismo , Desoxiglucose/análogos & derivados , Desoxiglucose/metabolismo , Dopamina/metabolismo , Fluordesoxiglucose F18 , Lobo Frontal/metabolismo , Humanos , Masculino , Lobo Occipital/metabolismo , Análise de Regressão , Síndrome de Abstinência a Substâncias/etiologia , Síndrome de Abstinência a Substâncias/metabolismo , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Fatores de Tempo , Tomografia Computadorizada de Emissão
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