Search PubMed⌕ Search

Biomedical subjects

G Franck

Publications and source records attributed to G Franck.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Non-invasive methods to study drug disposition: positron emission tomography. Detection and quantification of brain receptors in man.

Positron emission tomography (PET) has been used mostly for the study of brain blood flow and metabolism in normal controls and in a variety of neurological and psychiatric conditions. With the appropriate radiotracers, PET also allows non-invasive imaging and quantification of a growing list of neuroreceptors, the target of most psychotropic drugs. For example, 11C-carfentanil and 11C-diprenorphine, two potent opiate ligands, have been used to label opiate receptors in vivo in man. Methods have been developed to quantify receptor studies with PET in terms of receptor density and affinity. PET is a unique tool that now allows measurement of receptor occupancy in vivo and could be used by the pharmacologist to optimize drug treatment.

Brain↗
PubMedDate not supplied

The neural correlates of updating information in verbal working memory.

The aim of the present study was to re-examine cerebral areas subserving the updating function of the central executive with a running span task requiring subjects to watch strings of consonants of unknown length and then to recall serially a specific number of recent items. In order to dissociate more precisely the updating process from the storage function, a four-item instead of a six-item memory load was used, contrary to our previous study (Salmon et al., 1996). In addition, a serial recall procedure was preferred to a recognition procedure in order to suppress the use of visuospatial strategies. The most significant increase of rCBF occurred in the left frontopolar cortex (Brodmann's area 10), spreading to the left middle frontal (Brodmann's area 46). Results suggest that frontopolar activation underlies an updating process in working memory.

Adult↗
PubMedDate not supplied

Landau-Kleffner syndrome: a clinical and EEG study of five cases.

In five children with normal initial psychomotor development, a Landau-Kleffner syndrome appeared at age 3-7 years. No neuroanatomic lesions were noted. Aphasia and hyperkinesia were isolated in three patients and associated with global regression of higher cortical functions in one patient. Massive intellectual deterioration and psychotic behavior were associated with transient aphasia in one patient. The epilepsy (focal motor and generalized tonic-clonic seizures, subclinical EEG focal seizures during sleep, and atypical absences) always regressed spontaneously or with antiepileptic drug (AED) treatment. The EEG in waking patients showed focal and generalized spike-wave discharges on a normal background rhythm. Discharge topography and pattern changed frequently. During sleep, discharges always increased. At some time during syndrome development, all patients had bilateral spike-waves for greater than 85% of the sleep period, while at other times the discharges were discontinuous or continuous but focal or unilaterally hemispheric. Discharge topography and abundance changed from night to night. The abnormal EEG and the impaired higher functions developed and regressed together, but not with strict temporal correlation. Our own experience suggests that the Landau-Kleffner syndrome and epilepsy with continuous spike-wave activity in slow-wave sleep cannot be clearly differentiated. They may be different points on the spectrum of a single syndrome.

Aphasia↗
PubMedDate not supplied

Landau-Kleffner syndrome: a pharmacologic study of five cases.

Five children with Landau-Kleffner syndrome (epilepsy, acquired aphasia, and continuous spike-wave discharges during sleep), were treated with antiepileptic drugs (AEDs), sleep-modifying drugs, and corticosteroids. The pharmacologic profiles differed from those observed in focal epilepsies, resembling instead those of certain generalized epilepsies, such as West or Lennox-Gastaut syndromes. Phenobarbital (PB), carbamazepine (CBZ), and phenytoin (PHT) were ineffective or worsened the EEG and neuropsychological symptoms, whereas valproate (VPA), ethosuximide (ESM), and benzodiazepines were partially or transiently efficacious. Dextroamphetamine produced a dramatic but transient improvement in waking and sleep EEG in one of two children; aphasia did not change. Corticosteroid treatment resulted in improved speech, suppression of seizures, and normalization of the EEG in three of three children. Our own experience and data from the literature suggest that corticosteroids should be given in high doses as soon as the diagnosis is firmly established and should be continued in maintenance dose for several months or years to avoid escape. Early diagnosis, before mutism or global deterioration develops, appears to be essential for effective therapy with minimal neuropsychological sequelae.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Cerebral glucose utilization during sleep in Landau-Kleffner syndrome: a PET study.

Three right-handed male children (aged 5, 6, and 11 years) with signs, symptoms and/or history of the syndrome of acquired aphasia-epilepsy (Landau-Kleffner syndrome) were studied during drug-induced, electroencephalographically (EEG)-monitored sleep by positron-emission tomography (PET) and the [18F]fluorodeoxyglucose (FDG) method. Our data demonstrate that in Landau-Kleffner syndrome, cerebral glucose utilization is not normal during sleep. The metabolic pattern varied between the children but the metabolic disturbances always predominated over the temporal lobes. They were right-sided, left-sided, or bilateral. In the two first patients, EEG recordings showed continuous spike-and-wave discharges during sleep and a right-greater-than-left asymmetry was observed in temporal areas. In patient 1, the asymmetry was associated with a relative increase of glucose utilization of the right posterior temporal region. In patient 2, the glucose utilization was relatively decreased in the left anterotemporal and left perisylvian regions. In patient 3, the sleep EEG showed no discharge and no significant asymmetry was observed; however, glucose utilization of both temporal lobes was decreased. Lower metabolic rates in subcortical structures than in cortex were also noted in the three children. This metabolic pattern may be related to the maturation of the central nervous system (CNS).

Aphasia↗
PubMedDate not supplied

Controlled comparison of buspirone and oxazepam in generalized anxiety.

The anxiolytic activity, the tolerance, and the withdrawal symptoms of buspirone and oxazepam were compared in two groups of 14 and 12 outpatients, respectively, suffering from generalized anxiety in a double-blind study with random allocation of patients. The 6-week active period was preceded and followed by 1 and 2 weeks on placebo, respectively. Clinical assessments were performed before and after the predrug placebo period and every 2 weeks thereafter and included Hamilton anxiety and depression scales and AMDP anxiety subscale. The initial daily dose was 15 mg buspirone or 45 mg oxazepam in 3 intakes and the mean final daily doses were 22.2 and 55.8 mg, respectively. Results showed a slower anxiolytic activity of buspirone compared to oxazepam with less improvement after 2 weeks of treatment. The rebound anxiety following abrupt discontinuation of the drug and the level of side effects did not significantly differ between the two compounds.

Adult↗
PubMedDate not supplied

[Electroconvulsive therapy and its mechanism of action].

Electroconvulsive therapy (ECT) is known as an effective treatment for some depressive disorders. Nevertheless ECT continues to be a subject of controversy. The absence of a unifying theory for its mechanisms of action explains the mistrust about ECT. The aim of this article is to review the literature about ECT and to propose a synthesis concerning its mechanisms of action. At the present time, the most reliable hypothesis suggests selective activations of central serotonergic and dopaminergic systems on the one hand, and a direct stimulation of the neuroendocrine neurons on the other hand.

Animals↗
PubMedDate not supplied

Positron emission tomography in degenerative dementias.

Positron emission tomography demonstrates different abnormalities of cerebral metabolism or characteristic disturbances of neurotransmission systems in "cortical" and "subcortical" dementias. Those patterns may reflect the underlying anatomopathology, but may also give clues to the pathophysiology of a disease and its symptoms.

Alzheimer Disease↗
PubMedDate not supplied

[The Newcastle Index for the diagnosis of endogenous depression. Comparison with the Research Diagnostic Criteria for major depression].

The Newcastle index comprises 10 items (with a positive or negative score) the sum of which enables us to separate endogenous and neurotic depressive patients. We applied this index to a sample of 41 depressive inpatients who met Research Diagnostic Criteria (RDC) for major depression. According to Newcastle index, 20 patients were considered to be endogenous and 21 to be neurotic. There was no significant difference between the two groups with regard to sex distribution and mean age. The distribution of scores suggested a trend toward bimodality. Endogenous depressives exhibited higher severity level than neurotic depressives, as shown by the total score on the Hamilton depression scale as well as the scores on various items related to depressive mood, guilt, decreased activity, psychomotor disturbances, genital symptoms, helplessness, hopelessness, and worthlessness. This higher severity level was confirmed by the higher frequency of two symptomatic criteria of major depression among endogenous depressives as compared to neurotic depressives: psychomotor and memory disturbances. Moreover, endogenous depressives defined by Newcastle index were more frequently of primary, endogenous, agitated and simple RDC subtypes whereas neurotic depressives were more frequently of secondary and situational RDC subtypes. Therefore, the results of this preliminary study suggest that the Newcastle index may enable us to define two subtypes of depressive patients characterized by different symptomatic severity levels.

Adult↗
PubMedDate not supplied

[EEG in non-traumatic subdural hematoma].

Clinical and EEG data in 44 adult cases of non-traumatic subdural hematoma are reported. Tracings are analysed with reference to consciousness, revealing some very suggestive electrographic aspects. A normal EEG does not rule out the diagnosis. Correct lateralization was established by the EEG in 84% of the cases and there was no incorrect lateralization. Heterolateral suffering reported in the literature must correspond to associated traumatic lesions. Two alpha-type coma tracings, of which one was distinctly asymmetrical, and two tracings comprising generalized paroxysms of triphasic waves are reported.

Adolescent↗