RESUMEN
Forty-three depressed inpatients, referred for electroconvulsive therapy, and 30 manic patients were examined with clinical ratings and regional cerebral blood flow (rCBF) determinations. The depressed patients were mainly medication free, while most of the manic patients were medicated. Both patient groups showed a normal cerebral blood flow level and regional distribution compared with age- and sex-matched normal controls. In the depressed group and especially in the unipolar subgroup, a significant positive relationship was found between the mean rCBF and symptoms of depression and cognitive dysfunction. Eighteen of the depressed and 18 of the manic patients were reexamined in a euthymic state following treatment and recovery. Only minor and statistically nonsignificant flow changes were found in connection with the clinical improvement. In the manic patients, a significant negative relationship was found between neuroleptic dosage and rCBF.
Asunto(s)
Trastorno Bipolar/fisiopatología , Circulación Cerebrovascular , Trastorno Depresivo/fisiopatología , Adulto , Anciano , Antipsicóticos/uso terapéutico , Trastorno Bipolar/diagnóstico , Trastorno Bipolar/tratamiento farmacológico , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Radioisótopos de XenónRESUMEN
Serial bilateral measurements of regional cerebral blood flow (rCBF) by the xenon Xe 133 inhalation method were made during 13 withdrawal periods in 12 male alcoholics with pronounced physical dependence. A significant global reduction of rCBF was found during the first two days of withdrawal. The largest decreases were seen in cases with clouded sensorium and with an extended preceding drinking period. An rCBF distribution with relatively high temporal and low parietal flows during the first two days was coupled to aggravated symptoms. In two men who reported auditory and visual hallucinations during the measurements, elevated rCBF values were found in the temporal, Sylvian, and occipital regions.
Asunto(s)
Delirio por Abstinencia Alcohólica/sangre , Velocidad del Flujo Sanguíneo , Circulación Cerebrovascular , Psicosis Alcohólicas/sangre , Encéfalo/irrigación sanguínea , Humanos , MasculinoRESUMEN
The purpose of this study was to evaluate the use of electroencephalography (EEG) and magnetic resonance imaging (MRI) in the clinical evaluation of acute decompression sickness (DCS) in the central nervous system (CNS). Twenty-one patients treated because of acute DCS in the CNS during 1999-2001 were included, 15 patients with clinical cerebral DCS and five with clinical spinal cord DCS. Seven patients had abnormalities in their EEG, five with cerebral DCS and two with spinal cord DCS. MRI showed high intensity lesions in the spinal cord in four patients with clinical spinal cord DCS and in one with clinical cerebral DCS. Cerebral lesions were not identified by MRI in any patient. In conclusion, EEG showed unspecific abnormalities in only one third of the cases. Conventional MRI with a 1.5 T scanner may be of help in the diagnosis of DCS in the spinal cord, but not in the brain. EEG and MRI have low sensitivity in the diagnosis of acute DCS in the CNS. Recompression treatment of DCS should still be guided by clinical neurological examination and assessment of symptoms.
Asunto(s)
Encefalopatías/diagnóstico , Enfermedad de Descompresión/diagnóstico , Imagen por Resonancia Magnética , Enfermedades de la Médula Espinal/diagnóstico , Adolescente , Adulto , Encefalopatías/fisiopatología , Encefalopatías/terapia , Enfermedad de Descompresión/fisiopatología , Enfermedad de Descompresión/terapia , Electroencefalografía , Femenino , Humanos , Oxigenoterapia Hiperbárica , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Enfermedades de la Médula Espinal/fisiopatología , Enfermedades de la Médula Espinal/terapiaRESUMEN
Regional cerebral blood flow was measured by the 133-xenon inhalation method during resting in 38 healthy men and 38 healthy women matched pairwise for age in the range 18-72 years. The results showed 11% higher global flow level in the women in all ages. A similar and significant regression of flow by age was seen for both sexes. The regional flow distribution also showed some sex-related differences. Frontal regions showed an asymmetry in the men with higher values on the right side. The female flows were more symmetric. As a hypothesis, it is suggested that the higher flow level in women may be a systemic phenomenon. In fact, other authors have found a higher cardiac index in females. The sex differences in regional flow pattern might be due to differences in the functional organization of the cortex and/or to differences in the mental processes of the "resting" state.
Asunto(s)
Circulación Cerebrovascular , Caracteres Sexuales , Adolescente , Adulto , Anciano , Envejecimiento/fisiología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Visual regional CBF (rCBF) responses were measured in 10 healthy male subjects before and after an ethanol dose of 1 g/kg body weight. This dose induces well-established cerebral vasodilatation. However, significant bilateral occipital increases were found in both conditions. Apparently, the coupling between neuronal activity and rCBF is preserved following ethanol. The occipital and posterior parietal flow increases were, however, larger on the right than the left side in the sober state. During inebriation the asymmetry disappeared, possibly representing a more undifferentiated processing of visual information. We propose that ethanol causes a reduced inhibition of the left posterior cortex and a reduction of right-hemisphere information processing.
Asunto(s)
Circulación Cerebrovascular/efectos de los fármacos , Etanol/farmacología , Adulto , Análisis de Varianza , Etanol/sangre , Lateralidad Funcional , Humanos , Masculino , Lóbulo Occipital/irrigación sanguínea , Concentración Osmolar , Estimulación Luminosa , Valores de Referencia , Flujo Sanguíneo Regional/efectos de los fármacosRESUMEN
Regional cerebral blood flow (rCBF) was measured in 23 patients with organic dementia (17 patients with Alzheimer's disease and six with low-pressure hydrocephalus [LPH]). The flow of gray matter was significantly reduced, especially in occipito-parieto-temporal regions, as well as frontally in some patients. During activation with psychologic tests, reading, etc., the flow augmentation in the association areas in the demented patients was not as marked as in nondemented controls. Instead, in some patients, a flow diminution was recorded in the same regions (intellectual steal). Organic dementia appears to be accompanied by a low activity in the association cortex and a reduced ability to activate these regions during mental effort.
Asunto(s)
Corteza Cerebral/fisiopatología , Circulación Cerebrovascular , Demencia/fisiopatología , Procesos Mentales , Anciano , Enfermedad de Alzheimer/fisiopatología , Corteza Cerebral/irrigación sanguínea , Demencia/etiología , Dominancia Cerebral , Femenino , Humanos , Hidrocéfalo Normotenso/complicaciones , Hidrocéfalo Normotenso/fisiopatología , Masculino , Pruebas Psicológicas , PensamientoRESUMEN
Measurements of regional cerebral blood flow (rCBF) provide information about the metabolic and functional level of the cortex. Different techniques for measurement of rCBF are described and their potentials and limitations are outlined. Typical results from measurements in normals during performance of mental tasks are shown and as well as clinical measurements in patients with organic dementia. Future improvements of the techniques regarding spatial as well as temporal resolution are outlined. It is concluded that measurements of rCBF are likely to be of great value in the future exploration of brain-behaviour relationships.
Asunto(s)
Corteza Cerebral/irrigación sanguínea , Neuropsicología/métodos , Enfermedad de Alzheimer/fisiopatología , Mapeo Encefálico/métodos , Arterias Carótidas , Corteza Cerebral/diagnóstico por imagen , Humanos , Inyecciones Intraarteriales , Flujo Sanguíneo Regional , Tomografía Computarizada de Emisión , Radioisótopos de XenónRESUMEN
Difficulties with verbal fluency tasks (VFIT) have been shown mainly to be associated with left frontal lobe pathology in lesion studies. The design fluency test (DFT) is a non-verbal analogue of word fluency tasks and has, in patients with right frontal lobe pathology, been coupled to an inability to perform well. Regional cerebral blood flow measurements (rCBF) were made in normals to elucidate the involvement of frontal and frontotemporal brain regions during the performance of VFT and DFT. In addition, the subjects' reports were used for obtaining information about the cognitive strategy used when solving the tasks. The results confirm previous CBF findings showing a mainly left-sided frontal activation during the VFT. During the DFT significant flow augmentations were seen in both frontal lobes compared to baseline. Furthermore, the use of different strategies was reflected in different patterns of brain activation. Our results support the proposal that the left frontal cortical area is engaged in the generation of internally driven responses. Furthermore, we argue that the cortical areas engaged during the execution of these tasks may reflect differences in cognitive strategy.
Asunto(s)
Encéfalo/irrigación sanguínea , Cognición/fisiología , Lateralidad Funcional/fisiología , Pruebas Neuropsicológicas , Conducta Verbal/fisiología , Adulto , Encéfalo/fisiología , Femenino , Humanos , Masculino , Flujo Sanguíneo Regional/fisiología , Lóbulo Temporal/fisiología , Radioisótopos de XenónRESUMEN
The aim was to investigate the relationship between creativity and hemispheric asymmetry, as measured by regional cerebral blood flow (rCBF). Two groups, each consisting of 12 healthy male subjects, who got either very high or low scores on a creativity test, were pre-selected for the rCBF investigation. rCBF was measured during rest and three verbal tasks: automatic speech (Auto), word fluency (FAS) and uses of objects (Brick). State and trait anxiety inventories were answered after the rCBF measurements. Intelligence tests were also administered. It was predicted that highly creative subjects would show a bilateral frontal activation on the divergent thinking task (Brick), while low creative subjects were expected to have a unilateral increase. Calculations were made of differences in blood flow levels between the FAS and the Brick measurements in the anterior prefrontal, frontotemporal and superior frontal regions. In accordance with our prediction, repeated measure-ANOVAs showed that the creativity groups differed significantly in all three regions. The highly creative group had increases, or unchanged activity, while the low creative group had mainly decreases. The highly creative group had higher trait anxiety than the low creative group. On the intelligence tests the low creative group was superior both on logical-inductive ability and on perceptual speed, while the groups were equal on verbal and spatial tests. The results are discussed in terms of complementary functions of the hemispheres.
Asunto(s)
Circulación Cerebrovascular/fisiología , Creatividad , Lóbulo Frontal/fisiopatología , Adulto , Lateralidad Funcional/fisiología , Humanos , Masculino , Percepción Espacial/fisiología , Pensamiento/fisiología , Conducta Verbal/fisiologíaRESUMEN
The regional cerebral blood flow (133Xe-inhalation method) was measured during acute amphetamine intoxication in a male 25 years old addict. During the study the patient displayed symptoms of paranoia and slight euphoria and tension. The flow level was found to be elevated by about 30% compared to a study in non-intoxicated state. The augmentation was most marked in the left hemisphere and in frontal regions (local increases up to 100%). The results confirm earlier findings in animal models and indicate the central role of frontal cortical structures in the production of psychotic symptoms.
Asunto(s)
Anfetamina/envenenamiento , Circulación Cerebrovascular/efectos de los fármacos , Adulto , Humanos , Masculino , Síndrome de Abstinencia a Sustancias/fisiopatologíaRESUMEN
The effects of vincamine and bromvincamine (BV 26-723) on mental functions and regional cerebral blood flow (rCBF) measured by the 133Xe inhalation method, were investigated in ten patients with mild to severe symptoms of multi-infarct dementia. The double blind cross over design included three treatment periods, each of 2 weeks' duration. The patients were drug free at the time of the first investigation in each treatment period. Then placebo, vincamine or bromvincamine was given orally (4 X 20 mg/day). Psychiatric evaluation, psychometric assessment and measurement of rCBF were done at start of medication and after 1 and 2 weeks during medication. There were 2 drug-free weeks between the first and second, and second and third treatment periods. Results from treatment with vincamine showed a significant increase in the global CBF level and reduction of initial right-left asymmetry of hemispheric means. No effects were seen in regional flow patterns. Performance score on a verbal memory test increased significantly. No significant effect on the global rCBF level was indicated for bromvincamine. However, the number of ischemic regions decreased significantly during treatment. Performance on two memory tests improved significantly. No significant changes in overall psychiatric ratings were observed for any of the treatment periods.
Asunto(s)
Infarto Cerebral/fisiopatología , Circulación Cerebrovascular/efectos de los fármacos , Demencia/fisiopatología , Procesos Mentales/efectos de los fármacos , Alcaloides de la Vinca/farmacología , Vincamina/farmacología , Anciano , Infarto Cerebral/complicaciones , Infarto Cerebral/psicología , Ensayos Clínicos como Asunto , Demencia/complicaciones , Demencia/psicología , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Desempeño Psicomotor/efectos de los fármacos , Distribución Aleatoria , Vincamina/análogos & derivadosRESUMEN
The effects of piracetam (Nootropil, UCB6215) on mental functions and on regional cerebral blood flow (rCBF) were investigated in eight patients in the presenile age who displayed symptoms of moderate dementia. The double-blind crossover design included nine measurement occasions, each involving rCBF measurement by the 133-Xe inhalation method, ratings of symptoms of dementia, personality changes, and side effects, and a psychometric investigation. Three investigations were included in each of three treatment periods. The first investigation in a period was made without medication. Then either placebo or piracetam 4.8 g/day or 9.6 g/day was given during four weeks with measurements after 2 weekks and 4 weeks. There were intervals of 4 weeks without medication between the treatment periods. Piracetam had no significant effect on either mental functions or rCBF.
Asunto(s)
Circulación Cerebrovascular/efectos de los fármacos , Demencia/fisiopatología , Procesos Mentales/efectos de los fármacos , Piracetam/farmacología , Pirrolidinonas/farmacología , Anciano , Ensayos Clínicos como Asunto , Demencia/psicología , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración PsiquiátricaRESUMEN
Ten patients with Alzheimer's disease were treated with intravenous infusion of physostigmine for 2 h. The acute effects on cognitive function, regional cerebral blood flow, and EEG were compared to placebo (isotonic glucose) using a double-blind cross-over design. Physostigmine causes a limited improvement of psychomotor performance and EEG and an increase of blood flow in the most severely affected cortical areas, predominantly in an early phase of Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Encéfalo/irrigación sanguínea , Electroencefalografía , Pruebas Neuropsicológicas , Fisostigmina/uso terapéutico , Anciano , Ensayos Clínicos como Asunto , Método Doble Ciego , Potenciales Evocados/efectos de los fármacos , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Psicometría , Flujo Sanguíneo Regional/efectos de los fármacosRESUMEN
A group of 26 patients with the diagnosis of Senile Dementia of Alzheimer type (SDAT) was included by random assignment in a double-blind, cross-over trial of pyritinol versus placebo. The patients had a mild to moderate degree of dementia. Psychiatric and neurological examination, psychometric testing, and measurement of the regional cerebral blood flow (rCBF) at rest and during mental activation were used to assess treatment effects. The results of the study showed that pyritinol was associated with a significant improvement in cognitive performance. RCBF data showed that treatment with pyritinol normalized the pattern of blood flow increase during activation and improved the score on the test used for activation.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Circulación Cerebrovascular/efectos de los fármacos , Pruebas Neuropsicológicas , Piridinas/uso terapéutico , Piritioxina/uso terapéutico , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/psicología , Nivel de Alerta/efectos de los fármacos , Corteza Cerebral/irrigación sanguínea , Método Doble Ciego , Femenino , Humanos , Masculino , Procesos Mentales/efectos de los fármacos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Regional cerebral blood flow was measured during alcoholic blackout in a 61-year-old man with a blood-alcohol level of 0.38%. The mean flow level was found to be elevated by about 30-60% compared to repeated studies during long-term abstinence. The regional pattern did not change greatly. Increases of mean regional cerebral blood flow have previously been reported during social drinking and in Wernicke-Korsakoff's syndrome. A common disturbance of subcortical activation systems is hypothesized.
Asunto(s)
Trastorno Amnésico Alcohólico/fisiopatología , Alcoholismo/fisiopatología , Circulación Cerebrovascular , Corteza Cerebral/irrigación sanguínea , Circulación Cerebrovascular/efectos de los fármacos , Etanol/farmacocinética , Humanos , Masculino , Persona de Mediana Edad , Flujo Sanguíneo Regional/efectos de los fármacos , Radioisótopos de XenónRESUMEN
Regional cerebral blood flow (rCBF) was measured by the 133Xenon inhalation method in nine male chronic cannabis users. The rCBF level in cannabis users was significantly (11%) lower than that of age- and sex-matched healthy controls. Four of the subjects were reexamined after 9-60 days of detoxification and showed a significant (12%) increase of the CBF level at followup. No significant regional flow abnormalities were noted. The global CBF reduction seen in the early phase of detoxification is most likely the consequence of the dysfunction of the central nervous system accompanying chronic cannabis use.
Asunto(s)
Circulación Cerebrovascular , Abuso de Marihuana/fisiopatología , Adolescente , Adulto , Humanos , Masculino , Abuso de Marihuana/terapia , Factores de Tiempo , Radioisótopos de XenónRESUMEN
Regional cerebral blood flow (rCBF) measurements and clinical ratings were performed on 17 schizophrenic patients and a subgroup of 10 medication-free patients before and after treatment. While clinically exacerbated patients had normal blood flow, patients in remission showed a redistribution of flow with lower values in frontal areas. Anteroposterior ratios correlated with the degree of behavioral disturbances, suggesting that the level of frontal lobe activity in schizophrenia may be a function of the patient's clinical state at the time of study.
Asunto(s)
Encéfalo/irrigación sanguínea , Esquizofrenia/diagnóstico por imagen , Psicología del Esquizofrénico , Adulto , Antipsicóticos/uso terapéutico , Dominancia Cerebral/fisiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Cintigrafía , Flujo Sanguíneo Regional/efectos de los fármacos , Flujo Sanguíneo Regional/fisiología , Esquizofrenia/tratamiento farmacológico , Esquizofrenia Paranoide/diagnóstico por imagen , Radioisótopos de XenónRESUMEN
Regional cerebral blood flow (rCBF) measurements and psychiatric ratings were performed on seven schizophrenic patients (mean age = 41.4 years) who had been examined 18 years previously in a study that used similar psychiatric ratings and a comparable rCBF technique. Neither the clinical symptomatology nor the rCBF level and distribution had changed appreciably between 1972 and 1990. The findings indicate that cerebral functional activity in chronic schizophrenia remains constant in spite of continuous neuroleptic medication.
Asunto(s)
Corteza Cerebral/irrigación sanguínea , Esquizofrenia/diagnóstico por imagen , Psicología del Esquizofrénico , Adulto , Anciano , Nivel de Alerta/fisiología , Mapeo Encefálico , Corteza Cerebral/diagnóstico por imagen , Enfermedad Crónica , Dominancia Cerebral/fisiología , Femenino , Lóbulo Frontal/irrigación sanguínea , Lóbulo Frontal/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Cintigrafía , Flujo Sanguíneo Regional/fisiología , Esquizofrenia/diagnóstico , Radioisótopos de XenónRESUMEN
Measurements of regional cerebral blood flow (rCBF) were performed in 16 women suffering from spider phobia. The non-invasive 133Xe inhalation method, giving information about the blood flow of superficial areas, was used. The subjects were studied under three conditions: during resting, when exposed to a videotape showing nature scenery, and finally when watching a video with living spiders. During the rCBF measurements the subjects' behaviour was registered systematically and respiration, blood pressure, Pco2, and heart rate were monitored. Eight subjects who showed and reported severe panic during the spider exposure had marked rCBF decreases in frontal areas, especially in the right hemisphere. The remaining eight subjects displayed a more efficient control of their emotions and became frightened, but not panic-stricken, during the spider exposure. These showed a consistent rCBF increase in the right frontal area compared to neutral stimulation. Thus, results revealed significant functional changes in the frontal cortex in subjects with spider phobia during phobogenic exposure. It seems likely that these frontal changes are related to the experience and control of phobic anxiety.
Asunto(s)
Corteza Cerebral/irrigación sanguínea , Trastornos Fóbicos/fisiopatología , Arañas , Adulto , Animales , Nivel de Alerta/fisiología , Corteza Cerebral/diagnóstico por imagen , Dominancia Cerebral/fisiología , Femenino , Lóbulo Frontal/diagnóstico por imagen , Lóbulo Frontal/fisiopatología , Humanos , Persona de Mediana Edad , Pánico/fisiología , Trastornos Fóbicos/diagnóstico por imagen , Cintigrafía , Valores de Referencia , Flujo Sanguíneo Regional/fisiología , Radioisótopos de XenónRESUMEN
Regional cerebral blood flow was measured in patients with the diagnosis of chronic toxic encephalopathy induced by exposure to organic solvents. Measurements were made at the time of diagnosis and 24-84 months after the cessation of exposure. During the follow-up the patients were carefully examined for other possible causes of brain dysfunction. Comparisons were made to unexposed and solvent-exposed referents. At the first examination the patients had a 7% lower mean flow level than the unexposed referents and a 5% lower level than the exposed workers. The largest flow differences were seen in the frontotemporal areas. At the follow-up, the difference in the mean flow level between the patients and referents was no longer significant. Regionally, the flow had increased, especially in areas which initially showed the most pronounced decreases. There was a significant negative correlation between the initial cerebral blood flow level and the degree of normalization of the flow level at follow-up.