Biomedical subjects
D Gourion
Publications and source records attributed to D Gourion.
[Chronic psychosis in an adult with antecedents of neonatal tuberculous meningitis].
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Maternal transmission disequilibrium of the glutamate receptor GRIK2 in schizophrenia.
Schizophrenia is characterized by thought disorders, hallucinations and delusions. Genetic studies have shown a high linkage at chromosome 6q16-21. Among the genes located in this region is the glutamate receptor ionotropic kainate 2 gene (GRIK2 or GLUR6), a functional candidate for susceptibility to schizophrenia. In this study, transmission of GRIK2 was evaluated in 356 schizophrenic patients from three different clinical centers. Whereas paternal transmission shows equilibrium, we observed maternal transmission disequilibrium of GRIK2 in the largest population (p=0.03), which was still significant when all populations were added (p=0.05). These results are similar to the maternal GRIK2 transmission disequilibrium previously reported for autism, and support the presence of a susceptibility gene for schizophrenia at 6q16.
Neurological and morphological anomalies and the genetic liability to schizophrenia: a composite phenotype.
BACKGROUND: Neurological soft signs (NSS) and minor physical anomalies (MPA) are frequent in patients with schizophrenia and their biological relatives. We examined whether the NSS and MPA are related to the genetic loading in schizophrenia. METHODS: Patients with schizophrenia (DSM-IV) (n=61), nonpsychotic parents of these patients (n=76) and healthy comparison subjects (n=44) took part in the study. Parents were further classified as "presumed carriers" of the genetic loading (n=26) if they had a second relative with schizophrenia in their ascendants and/or collaterals (first or second degree) or as "presumed noncarriers" (n=50). NSS and MPA were compared in these groups. RESULTS: A multivariate analysis indicated that total NSS and MPA scores, adjusted for age and gender, were significantly related to group status. Univariate tests showed higher scores in motor coordination and integration subscores (p=0.005 and 0.008, respectively) in presumed carriers than in presumed noncarriers. In addition, a discriminant function analysis based on total NSS and MPA scores correctly classified 71% of nonpsychotic parents in presumed carriers or presumed noncarriers. CONCLUSIONS: Neurological impairments and slight morphological anomalies seem to be associated with the genetic risk for schizophrenia, even when the disease itself is absent. Their presence might be a valuable composite intermediate phenotype for genetic studies.
5HTTLPR polymorphism in schizophrenic patients: further support for association with violent suicide attempts.
Previous studies testing the functional polymorphism in the promoter of the serotonin-transporter gene (5HTTLPR) in various psychiatric conditions have suggested that the association could be with an intermediate phenotype, impulsivity and/or violence rather than with a diagnosis. Schizophrenia is associated with a high risk of suicide, especially in patients with high impulsivity. We examined whether this polymorphism could be associated with violent suicide and/or impulsivity in schizophrenic patients. We genotyped the 5HTTLPR polymorphism in 185 unrelated schizophrenic patients from a French Caucasian population. The genotype frequencies significantly differed between patients who made violent suicide attempts and both, those who attempted suicide with a non-violent method (P = 0.013) and those who never attempted suicide (P = 0.026). The genotypes containing the low activity "short" allele was significantly more frequent in violent suicide attempters (P = 0.007) than in non-violent suicide attempters. No evidence was found for an association either with schizophrenia itself, when compared to gender and ethnically matched controls (n = 159) or with impulsivity, assessed using Barratt's Impulsivity Scale. Although replication studies are warranted, these results in schizophrenia further support the hypothesis that 5HTTLPR polymorphism is a risk factor for violent suicidal behavior.
Neonatal tuberculous meningitis in a patient with Asperger's syndrome.
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Familial factors influencing the consumption of anxiolytics and hypnotics by children and adolescents.
Many hypotheses have been made to explain the high rate of benzodiazepine consumption in France, including a general cultural and/or familial tendency to use certain types of psychotropic drugs. This study explored the association between lifetime medication use by parents and their children. Two hundred and twenty-one young patients (158 boys and 63 girls) consulting at a child and adolescent psychiatry department, six to 16 years of age (mean = 9.7 years), were screened for lifetime use of psychotropic drugs using a structured interview. Parents were asked about their own consumption, as well as their children's. Lifetime consumption rates (at least once) were 22.2% in boys and 20.6% in girls, and 19.6% in children less than 11 years old. Higher rates were found in patients with emotional disorders (anxiety disorders and depression). In parents, 45.1% of mothers and 24.1% of fathers reported using medications at least once. A significant association was found between child and parental medication use: 34.1% of children had positive lifetime consumption when their mothers also used medications at least once versus only 13.6% in other children (odds ratio = 3.31 [1.68-6.50]; P = 0.001). The most significant association was found between medication use by girls and their mothers (odds ratio = 12.1 [2.38-61.5]; P = 0.003). These data point to the existence of a family pattern of psychotropic drug consumption, especially in females.
[Neurodevelopmental hypothesis in schizophrenia].
The hypothesis for a neurodevelopmental basis to the underlying physiopathological disorder leading to schizophrenia has been proposed by many investigators for more than two decades. This hypothesis is supported by -several lines of evidence. Pregnancy and delivery complications, particularly those with known or presumed impact on fetal neurologic development, result in increased risk for psychotic disorders. Other possible etiologic candidates include viral infections. Minor physical anomalies, manifesting as slight anatomical defects of the head, hair, eyes, mouth, hands and feet, as dematoglyphic fluctuating asymmetries, are due to some injury occurring during the first or second trimester of fetal life, and are more common among patients with schizophrenia and in their unaffected siblings than in the general population. But a major Issue in a such neurodevelopmental model theory is the delayed onset of the schizophrenic disorder. Although early signs and prodromal symptoms can be defined retrospectively in patients who have developed schizophrenia, they do have to be confirmed as early predictors in prospective and longitudinal studies. Abnormalities in brain development and maturation seem to begin prenatally, but may continue throughout childhood and the observed changes during these periods must have -consequences for the neuronal circuitry and connectivity. Advances in brain imaging have now led to the identification of a great number of brain abnormalities in schizophrenia. The most consistently replicated structural anomaly present in the brains of patients with chronic schizophrenia is ventricular enlargement. These findings also include medial temporal lobe structures (which include the amygdala, hippocampus, and parahippocampal gyrus), and neocortical temporal lobe regions (superior temporal gyrus). There is also some evidence for frontal lobe abnormalities, particularly prefrontal gray matter and orbitofrontal regions. Similarly, there are findings for parietal lobe abnormalities (particularly of the inferior parietal lobule which includes both supramarginal and angular gyri) and subcortical abnormalities (basal ganglia, corpus callosum, and thalamus) but more equivocal evidence for cerebellar abnormalities. However, it is possible that the brain structural abnormalities observed in schizophrenia are not only due to neurodevelopmental anomalies, but also to an alteration in cortical plasticity and maturation processes that occurs over the long course of the disease. The genetic predisposition for schizophrenia has been confirmed in many studies. It is utterly disappointing that molecular genetic approaches have so far not yielded conclusive evidence for vulnerability or protection genes in schizophrenia. Future studies will likely benefit from: 1) studying more homogeneous patient groups, 2) studying high risk populations such as biological relatives of patients with schizophrenia, 3) using longitudinal and prospective methodological design in order to confirm the predictive validity of neurodevelopmental clues found in patients with schizophrenia, 4) applying newer strategies such as composite phenotypes of developmental origin, in combination with new genetic methods.
[Fluoxetine: an update of its use in major depressive disorder in adults].
The selective serotonin reuptake inhibitors (SSRIs) have emerged as a major therapeutic advance in psychiatry. They have emphasized the pathophysiological role of serotonin (5-HT) in affective disorders. Indeed, SSRIs were developed for inhibition of the neuronal uptake for serotonin (5-HT), a property shared with the TCAs (tricyclic anti-depressants), but without affecting the other various central neuroreceptors (ie, histamine, acetylcholine and adrenergic receptors) that are responsible for many of the safety and tolerability problems with TCAs. In this way, fluoxetine and other SSRIs represent a major advance over tricyclics, because of their lower toxicity. While the position of fluoxetine relative to other selective serotoninergic antidepressants requires further investigation, fluoxetine has a more favorable tolerability profile for a similar efficacy in comparison to tricyclic antidepressants. The pharmacokinetic and pharmacodynamic properties of fluoxetine are well described. After oral administration, fluoxetine is almost completely absorbed. Due to hepatic first-pass metabolism, the oral bioavailability is < 90%. Fluoxetine has a half-life of 2-7 days, whereas the half-life of norfluoxetine ranges between 4 and 15 days. This long half-life of fluoxetine may be advantageous when the patient omits a dose since drug concentrations decrease slightly. On the other hand, in the case of fluoxetine non-response, long washout periods are necessary before switching the patient to a TCA or a MAO inhibitor to avoid drug interactions or the development of a 5-HT syndrome. As a class, SSRIs are considerably more selective in comparison to TCAs in terms of their central nervous system mechanisms, but differ in other clinically relevant aspects. This action affects several specific 5-HT receptors, which, in turn, effects a multitude of neural systems and signalization pathways. However, despite the facilitating serotoninergic neurotransmission, the direct mechanism by which a SSRI exerts its anti-depressant activity remains uncertain. The therapeutic response in major depression for SSRIs (ie 15-20 days) maybe due to a progressive desensitization of somatodendritic 5-HT autoreceptors in the midbrain raphe nucleus. On the other hand, it has also been postulated that 5-HT is a modulator of several neurophysiological pathways, including dopamine, noradrenaline, but also neurotrophic factors, intra-cytoplasmic phosphorylations and nuclear genes expression. Therapeutic activity of SSRIs may finally results in a complex modulation and homeostasis between monoaminergic neurotransmisson and neuronal plasticity. In term of health-care, the introduction of fluoxetine and other SSRIs in the 1980s has radically changed the treatment of depressive disorder worldwide and they have emerged as the first line of treatment for depressive disorders. The efficacy of fluoxetine is now well established in the treatment of major depressive disorder. Indeed, this efficacy has been assessed in numerous clinical controlled trials involving patients with major depressive disorders. Meta-analysis were carried out and confirmed that fluoxetine was as effective as the tricyclic antidepressants, and appeared more effective than placebo in improving the symptoms of depression. However, there is no scientific evidence to suggest that any one SSRI is more effective than another, but not all patients respond to the same agent. Looking to the future, we need further comparative studies of the SSRIs with the next generation of antidepressants such as 5-HT noradrenaline reuptake inhibitors (SNRIs, Venlafaxine). Actually, it is interesting to note that, whereas the emphasis with the SSRIs has been on their selectivity, recent developments have tended to move towards less selective agents, and now to other neurobiological pathways (ie neurotrophic factors). Finally, fluoxetine, in common with other SSRIs, remains today a first-line treatment option for major depressive disorder.
[French validation of a Minor Morphologic Anomalies Scale in schizophrenic patients and their parents].
UNLABELLED: Minor Physical Anomalies represent valuable indices of disturbance in early neurodevelopment. They are frequently observed in individuals with various brain disorders, including mental retardation, autism, epilepsy, hyperactivity, foetal alcohol syndrome and schizophrenia. The high prevalence of Minor Physical Anomalies in schizophrenia provides considerable support for a neurodevelopmental model in this disorder. However, studies in large sample using standardised scale are lacking. Such studies are needed in order to confirm their actual frequency and study the clinical correlates or morphological anomalies. OBJECTIVE: The aim of this study was to revise and validate a French version of a scale designed for the evaluation of Minor Physical Anomalies in adult psychiatric patients and notably in patients with schizophrenia. METHODOLOGY: The scale was revised from the Waldrop scale. The choice of items was done on the basis of frequency, reliability in the adult, reliability of rating. Some new items, related to know syndroms with comportmental symptoms were added. Both raters had previously had a short initiation to the rating of the scale. Interrater reliability between two examiners, blind with regards to the diagnosis was evaluated. RESULTS: The interrater reliability was good, with an intraclass correlation coefficient at 0.97. Patients had significantly more minor physical anomalies than comparison subjects, and also more Minor Physical Anomalies than their parents. Fathers and mothers of these schizophrenic patients had significantly more Minor Physical Anomalies than normal comparison subjects. CONCLUSION: Although the evaluation of physical anomalies relies on subjective appreciation of normal vs abnormal, the revised version of minor physical anomalies scale (French version) was found to be a reliable tool, provided that a short initiation to the rating is performed. The scale differentiated schizophrenic patients from their parents, and the latter from the normal controls. A lot of questions remains unanswered concerning the neurodevelopmental hypothesis of schizophrenia. This scale appeared as a useful complementary tool to help in the determination of the developmental phenotypic status of the patients enrolled in pathophysiological studies aiming the identification of developmental factors in schizophrenia.