Biomedical subjects

F Lotstra

Publications and source records attributed to F Lotstra.

At least 19 recordsLinked to original sources

PubMed1999

Brain glucose metabolism in eating disorders assessed by positron emission tomography.

OBJECTIVE: As anorectic and bulimic patients present similar clinical and neurobiological symptoms, the purpose of this study was to compare brain glucose metabolism at rest in these patients. METHODS: Positron emission tomography with (18-F)-fluorodeoxyglucose was used to evaluate cerebral glucose metabolism (CMRglu) in 10 normal-weight bulimic women, in 10 underweight anorectic patients, and in 10 age- and sex-matched healthy volunteers. RESULTS: Absolute global cortical glucose activity was significantly lower in anorectic patients compared with bulimic and control subjects. Anorectic patients compared with normal control subjects also showed higher relative CMRglu in the inferior frontal cortex and in the basal ganglia, and putamen and caudate relative hypermetabolism when compared with bulimic patients. Thus, both eating disorder groups differed from control subjects in low relative parietal values of glucose. DISCUSSION: While absolute global metabolism seems to be related to weight loss, we can hypothesize either a common parietal cortex dysfunction in eating disorders or a particular sensitivity of this cortex to consequences of eating disturbances.

Adolescent↗

PubMed1997

Brain glucose metabolism in anorexia nervosa and affective disorders: influence of weight loss or depressive symptomatology.

Relationships between eating and affective disorders remain complex and unclear. Brain glucose metabolism of anorectic patients has been demonstrated to be reduced both globally and regionally, with a particular relative hypometabolism in the parietal cortex. To explore the possible influence of weight loss or depressive symptomatology on brain metabolism, we studied age- and sex-matched low-weight anorectic and depressed patients, normal-weight depressed patients, and healthy volunteers. Absolute global and regional glucose activity levels were reduced in low-weight patients, with the lowest values being found for anorectic patients. In relative values, anorectic patients showed a significant parietal hypometabolism in comparison to control subjects while they had higher metabolism in the caudate nuclei when compared with the other groups. Absolute hypometabolism of glucose seems to be a consequence of low weight as it was found in both low-weight anorectic and low-weight depressive patients. In addition, absolute glucose values were significantly correlated with body mass index in all subjects. Future positron emission tomographic studies in psychiatric patients should control for alimentary parameters.

Adolescent↗

PubMed1997

Brain hypometabolism of glucose in bulimia nervosa.

OBJECTIVE: A cerebral function lateralization has been described in bulimic patients in positron emission tomography (PET) studies realized during a specific cognitive task. The purpose of this study was to evaluate, at rest, brain glucose metabolism in patients with bulimia nervosa. METHOD: PET with (18-F)-fluorodeoxyglucose was used to evaluate cerebral glucose metabolism in 11 normal-weight bulimic girls compared to 11 age- and sex-matched healthy volunteers. Patients were diagnosed following DSM-IV and were off psychoactive medication. RESULTS: In comparison with control subjects, bulimic patients showed global and regional absolute hypometabolism of glucose. In relative values, only parietal cortex metabolism was significantly lower in bulimic patients. No correlation was found within groups for absolute or relative cerebral glucose metabolic rates (rCMRglu) and body mass index (BMI), anxiety scores, or Hamilton scores of depression. DISCUSSION: Since previous studies have demonstrated similar disturbances in anorectic patients, we hypothesized that these observations could be a consequence of neurobiological perturbations following nutritional deficiencies or a particular cerebral dysfunction in eating disorders.

Adolescent↗

PubMed1997

Brain hypometabolism of glucose in low-weight depressed patients and in anorectic patients: a consequence of starvation?

As low-weight anorectic patients presented a global as well as a regional absolute hypometabolism of glucose, we investigated a population of ten age- and sex-matched low-weight depressed patients without anorexia nervosa to evaluate the impact of weight loss on cerebral glucose metabolism evaluated by positron emission tomography and [18F]-fluorodeoxyglucose. Ten age- and sex-matched healthy volunteers were used as controls. Absolute global and regional glucose activity was significantly lower in anorectic and low weight depressed patients than in control subjects. Anorectic patients compared with normal control subjects also showed lower relative metabolism of glucose in the parietal cortex. Within patients, absolute hypometabolism of glucose seems to be a consequence of low-weight while there is a positive correlation between absolute metabolism of glucose and body mass index.

Adult↗

PubMed1997

In vivo binding of [18F]altanserin to rat brain 5HT2 receptors: a film and electronic autoradiographic study.

To further validate its use in positron emission tomography (PET), we studied the binding of [18F]altanserin, a specific 5HT2 radioligand, in the rat brain using in vivo autoradiography. Distribution of [18F]altanserin binding was comparable to the in vitro mapping of 5HT2 receptors reported in the literature. Selective displacers were used to test the reversibility and the selectivity of this radioligand. Specific binding of [18F]altanserin in the rat frontal cortex was quantified by direct counting with an electronic imaging system and by quantification on digitalized autoradiograms. Close results of about 30 pmol/g were obtained with both methods. Our data confirmed that [18F]altanserin is a valid tracer for 5HT2 receptors binding studies.

Animals↗

PubMed1997

Serotonin 5-HT2 receptor imaging in major depression: focal changes in orbito-insular cortex.

BACKGROUND: Serotonin receptors may play an important role in the pathophysiology of affective disorders. We studied type-2 serotonin (5-HT2) receptors in the brain of patients with major depression. METHOD: Using positron emission tomography (PET) and the selective radioligand [18F]altanserin, we investigated 5-HT2 receptor distribution in eight drug-free unipolar depressed patients and 22 healthy subjects. Data were analysed using Statistical Parametric Mapping 95. RESULTS: In depressed patients, [18F]altanserin uptake was significantly reduced in a region of the right hemisphere including the posterolateral orbitofrontal cortex and the anterior insular cortex. A trend to similar changes was found in the left hemisphere. No correlation was found between the uptake and the Hamilton rating scale score. CONCLUSIONS: Pathophysiology of depression may involve changes in 5-HT2 receptor in brain regions selectively implicated in mood regulation.

Brain Diseases↗

PubMed1996

Brain hypometabolism of glucose in anorexia nervosa: normalization after weight gain.

Using positron emission tomography and (18-F)-fluorodeoxyglucose, we studied cerebral glucose metabolism in 10 anorectic girls within their underweight state and after weight gain. Ten age- and sex-matched healthy volunteers were used as controls. Both groups were scanned during rest, eyes closed and with low ambient noise. In absolute values, the underweight anorectic patients, when compared to control subjects, showed a global (p = 0.002) and regional (p < or = 0.001) hypometabolism of glucose which normalized with weight gain. In relative values, no global difference could be assessed between underweight anorectic patients and controls but a trend can, nevertheless, be observed toward parietal and superior frontal cortex hypometabolism associated with a relative hypermetabolism in the caudate nuclei and in the inferior frontal cortex. After weight gain, all regions normalized for absolute and relative values, although a trend appears toward relative parietal hypometabolism and inferior frontal cortex hypermetabolism in weight gain anorectic patients. Absolute brain glucose hypometabolism might result from neuroendocrinological or morphological aspects of anorexia nervosa or might be the expression of altered neurotransmission following deficient nutritional state. As some differences exists in relative values in underweight patients and tend to persist in weight gain states, this could support a potential abnormal cerebral functioning, a different reaction to starvation within several regions of the brain or different restoration rates according to the region.

Adolescent↗

PubMed1996

Sex difference in 5HT2 receptor in the living human brain.

Serotonergic mechanisms are involved in gender-related behaviors and psychiatric conditions like aggression, eating disorders, depression, impulsivity or suicide. We studied gender differences in the living human brain type-2 serotonin receptor (5HT2r). Twenty-two healthy age-matched men and women were investigated using positron emission tomography and the selective radiotracer, 18F-labeled altanserin. Binding was quantified using a non-linear least-squares minimization procedure. We found significantly higher 5HT2r binding capacity in men than in women, especially in the frontal and cingulate cortices. Distinct liability for men and women to suffer from some psychiatric disorders responding to serotonergic agents may be related to differences in brain serotonin receptors.

Adult↗

PubMed1996

Interregional correlation of cerebral glucose metabolism in unmedicated schizophrenia.

To investigate metabolic relationships between different brain regions in schizophrenia, we measured regional brain metabolism using positron emission tomography (PET) and [18F]fluorodeoxyglucose (FDG) in 15 unmedicated schizophrenic patients and 15 healthy subjects. We analyzed correlations between glucose metabolism data of multiple brain regions using factorial analysis and correlation coefficient comparisons. Absolute regional intercorrelations in schizophrenic brains were found to be significantly stronger than in controls, in relationship to the greater variability of metabolic rates in schizophrenic patients. Variability of normalized metabolic rates and regional intercorrelations were not significantly different between schizophrenic patients and control subjects. We conclude that a global metabolic factor accounts for the variability of metabolic data in untreated schizophrenia.

Adult↗

PubMed1995

Altered frontostriatal relationship in unmedicated schizophrenic patients.

Positron emission tomography with [18F]-fluoro-2-deoxy-D-glucose as tracer was used to investigate frontal glucose metabolism in 15 unmedicated schizophrenic patients and 15 healthy subjects under resting conditions. Although no difference in absolute frontal cerebral metabolic rates of glucose (CMRglu) were found between schizophrenic patients and control subjects, relative measures significantly differentiated the two groups. Whole frontal metabolism and frontocaudate ratio were significantly decreased in both hemispheres in the patients. The results confirm the existence of hypofrontality in unmedicated schizophrenia and indicate disturbances in metabolic relationships between the frontal cortex and the striatum in this disorder.

Adult↗

PubMed1995

Brain hypometabolism of glucose in anorexia nervosa: a PET scan study.

Cerebral glucose metabolism was studied in 20 underweight anorectic girls and in 10 age- and sex-matched healthy volunteers using positron emission tomography with (18-F)-fluorodeoxy-glucose. Both groups were scanned during rest, with eye closed and with low ambient noise. Compared to controls, the underweight anorectic group showed a global hypometabolism (p = .002) and an absolute (p < .001) as well as relative (p < .01) hypometabolism of glucose in cortical regions, with the most significant differences found in the frontal and the parietal cortices. Within the underweight anorectic and the control groups, no correlations were found between absolute or relative rCMRGlu and BMI, anxiety scores, or Hamilton scores of depression. Different factors might explain this reduction of glucose metabolism in anorexia nervosa. It might be the consequence of neurophysiological or morphological aspects of anorexia nervosa and/or the result of some associated symptoms such as anxiety or depressed feelings. Supported by cognitive studies, we can also hypothesize a primary corticocerebral dysfunctioning in anorexia nervosa.

Adolescent↗

PubMed1995

Basal ganglia and frontal lobe glucose metabolism. A reproducibility positron emission tomography study.

Positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (FDG) is frequently used to study the metabolic correlates of movement and mental disorders. These studies generally focus on changes in the frontal cortex and the basal ganglia. The reproducibility of glucose metabolism estimates in these structures was tested in 13 normal subjects studied at rest using a standard and simple protocol. A reproducible dorsoventral metabolic gradient was demonstrated in the frontal cortex. Such a gradient was not present in the basal ganglia when the upper region of interest in the caudate nucleus, where the lower metabolic rate of glucose was probably attributable to partial volume effects, was not considered. Absolute values of glucose metabolic rates varied by 6.4 to 12.5% in the frontal cortex and by 6.8 to 14.7% in the basal ganglia. Variations in normalized values in the basal ganglia ranged from 4.0 to 8.6%. The number of subjects required to detect statistical differences in group comparison or in test-retest studies was calculated for different anticipated levels of change. With the variability detected in this experiment, less than 10 subjects were expected to be sufficient to detect a 15% change in most regions and in both types of studies.

Adult↗

PubMed1995

Changes in metabolism of cerebral glucose after stereotactic leukotomy for refractory obsessive-compulsive disorder: a case report.

Brain glucose metabolism was investigated with PET and [18F]fluorodeoxyglucose, before and after a bifrontal stereotactic leukotomy in a 37 year old woman with refractory obsessive-compulsive disorder. A bilateral decrease in glucose metabolism was found in the orbital frontal cortex after psychosurgery. Glucose metabolism was decreased to a lesser degree in Brodmann's area 25, in the thalamus, and in the caudate nucleus. Clinical improvement in obsessive-compulsive disorder after stereotactic tractotomy seems to be associated with metabolic changes in the brain, in particular, in the orbital part of the frontal lobe.

Adult↗

PubMed1994

Frontal and parietal metabolic disturbances in unipolar depression.

The authors investigated brain glucose utilization using positron emission tomography (PET) in 12 normal volunteers and 12 unipolar unmedicated depressed patients (six endogenous; six nonendogenous) following injection of [18F]fluoro-deoxyglucose (FDG). Compared by analyses of variance, absolute and relative regional glucose metabolic rates appeared different in depressed patients and control subjects, especially in parietal and frontal lobes. In patients with unipolar depression, metabolic rates were increased in the orbital part of the frontal lobe and decreased in a frontal dorsolateral area. The metabolic supero-basal gradient calculated in the frontal cortex was significantly lower in depressed patients than in normal subjects. Decreased glucose metabolism was also observed in the parietal cortex of depressed patients. No differences in glucose metabolic rates have been detected between endogenous and nonendogenous patients. No correlation has been found between the metabolic data and the Hamilton Rating Scale.

Adult↗

PubMed1994

Multicompartmental study of fluorine-18 altanserin binding to brain 5HT2 receptors in humans using positron emission tomography.

Serotoninergic type 2 (5HT2) receptors have been implicated in the regulation of many brain functions in humans and may play a role in several neurological and psychiatric diseases. Fluorine-18 altanserin has been proposed as a new radiotracer for the study of 5HT2 receptors by PET because of its high affinity for 5HT2 receptors (Ki: 0.13 nM) and its good specificity in in vitro studies. Dynamic PET studies were carried out in 12 healthy volunteers after intravenous injection of 0.1 mCi/kg [18F]altanserin. Ninety minutes after injection, we observed mainly cortical binding. Basal ganglia and cerebellum showed very low uptake and the frontal cortex to cerebellum ratio was about 3. To evaluate the quantitative distribution of this ligand in the brain, we used two different methods of data analysis: a four-compartment model was used to achieve quantitative evaluation of rate constants (K1 and k2 through k6) by non-linear regression, and a multiple-time graphical analysis technique for reversible binding was employed for the measurement of k1/k2 and k3/k4 ratios. Using both methods, we found significant differences in binding capacity (estimated by k3/k4 = Bmax/Kd) between regions, the values increasing as follows: occipital, limbic, parietal, frontal and temporal cortex. After correction of values obtained by the graphical method for the existence of non-specific binding, results generated by the two methods were consistent.

Adult↗

PubMed1994

A trial of carbamazepine in borderline personality disorder.

Borderline personality disorder does not have a first choice pharmacological treatment. We studied 20 borderline inpatients in a double-blind parallel placebo-controlled trial with carbamazepine for a mean of 30.9 days. No significant positive effects of the drug were found.

Adult↗

PubMed1994

Temporal glucose metabolism in borderline personality disorder.

The pathophysiology of borderline personality disorder (BPD) is obscure. Underlying organic factors such as epilepsy are suspected because clinical characteristics of the syndrome are similar to some manifestations of patients with complex partial seizures (CPS). Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) reveals hypometabolism in the area surrounding epileptic foci. To test the epilepsy hypothesis in BPD, we have explored 10 patients with BPD and compared them with 15 control subjects using PET with FDG. We conclude that PET provides no metabolic indication of temporal lobe epilepsy in BPD.

Adult↗

PubMed1992

Factitious hemiplegia and Munchausen's syndrome.

We report a case of a thirty-year-old woman suffering from chronic factitious disorder with hemiplegia. Such a pathomimia is very uncommon in Munchausen's syndrome. Indeed, most often, the clinical picture is characterised by acute abdominal pain, fainting, haemoptysis, precordialgia, hematemesis or dermatological lesions.

Adult↗