Need for systematic screening for IGD in adolescent psychiatric inpatients.

Psychiatric comorbidities are frequent in adolescents with internet gaming disorder (IGD). In contrast, the proportion of IGD among adolescents hospitalized for a psychiatric disorder has not been documented yet. In addition, parental ratings of IGD could be useful for diagnosis, but very few data exist on this issue. The objectives of this study were to: (1) assess the prevalence of IGD among adolescent psychiatric inpatients, using the Ten-Item Internet Gaming Disorder Test (IGDT-10), and (2) assess the parental version developed for this study (IGDT-10-P). A total of 102 patients, aged from 12 to 17 years old, were included from four psychiatric units of the French region Auvergne-Rhône-Alpes, during a 6-month inclusion period. Adolescents completed the IGDT-10 while one of their parents completed the IGDT-10-P. The inclusion rate among the eligible population was 57.95%. The prevalence of IGD in the sample, based on the IGDT-10 and IGDT-10-P, was 6.00% and 12.79%, respectively. Psychometric features of the IGDT-10-P indicated excellent internal consistency, a good model fit to the one factor model in confirmatory factor analysis, a strong correlation with gaming time, and a moderate correlation with the IGDT-10. Our results support the need for a systematic screening of IGD among adolescents hospitalized for a psychiatric disorder. Future studies should aim to confirm and explain the prevalence gap between self- and parent-reported criteria.

Imported malaria: 54 cases diagnosed at the Ibn Sina Hospital Center in Rabat, Morocco.

Morocco does not record any indigenous malaria case since 2004 and is certified by the World Health Organization as malaria-free since 2010. However, the country continues to record a significant number of imported malaria cases from endemic areas, especially from West Africa. The purpose of our work is to determine the epidemiological and diagnostic characteristics of malaria cases diagnosed at Ibn Sina Hospital Center in Rabat, Morocco. This work is a retrospective study of a series of malaria cases diagnosed between January 2012 and December 2016 at the Central Laboratory of Parasitology and Mycology of Ibn Sina Hospital Center. The methods used for the parasitological diagnosis are the search for the parasite at direct examination on thin blood film and thick drop and the search for parasite antigens by a rapid diagnostic immunochromatographic test (OptiMAL-IT® kit). Of 192 patients in whom malaria was sought, we recorded 54 positive cases (average of 10.8 cases per year). The prevalence was 28.12%. The age ranged from 4 to 76 years (average of 29.5 years). The sex ratio was 2.6. All cases had in their antecedents a notion of recent travel in an endemic area. The most common travel area was West Africa: Ivory Coast, with 31.43% of cases, followed by Guinea, with 14.29% of cases. The symptomatology was dominated by fever in 52 patients (96.3% of cases), followed by headache in 22 cases (40.74%). Anemia was present in 7 and thrombocytopenia in 12 patients. The most isolated species was Plasmodium falciparum (84.21% of cases), followed by P. vivax (10.53% of cases) and P. ovale (5.26% of cases). One case involved two species: P. falciparum and P. vivax. Parasitaemia was between less than 0.1 and 20%. Despite the local eradication of malaria, the persistence of imported cases, mainly due to the lack of chemoprophylaxis, should call for the strengthening of health education of travelers, especially in endemic areas.

Pramipexole-responsive acute restless arms syndrome after surgery under general anesthesia: Case report and literature review.

We reported a case of acute restless arms syndrome occurring after colorectal surgery under general anaesthesia. This case was also compared with other cases of restless legs/arms syndromes occurring in a perioperative context through a literature review. As the restless legs syndrome, the restless arms syndrome can be exacerbated by perioperative procedures and improved with pramipexole from the first day of treatment. This case reinforces the idea that the restless arms syndrome seems to be subsumed along with the restless legs syndrome, and is a further argument to use the diagnosis term "restless limb syndrome" for the restlessness of any limb with clinical features similar to the restless legs syndrome.

Predictors of response to repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder.

Repetitive transcranial magnetic stimulation (rTMS), based on the principle of electromagnetic induction, consists of applying series of magnetic impulses to the cerebral cortex so as to modulate neurone activity in a target zone. This technique, still experimental, could prove promising in the field of psychiatry, in particular for the treatment of major depressive disorder. It is important for the clinician to be able to assess the response potential of a given patient to rTMS, and this among other things requires relevant predictive factors to be available. This review of the literature aims to determine and analyse reported predictive factors for therapeutic response to rTMS treatment in major depressive disorder. Different parameters are studied, in particular age, the severity of the depressive episode, psychological dimensions, genetic factors, cerebral blood flows via cerebral imagery, and neuronavigation. The factors found to be associated with better therapeutic response were young age, low level of severity of the depressive episode, motor threshold intensity over 100%, more than 1000 stimulations per session, more than 10 days treatment, L/L genotype on the 5-HTTLPR transporter gene, C/C homozygosity on the promotor regions of the 5-HT1A receptor gene, Val/Val homozygosity on the BDNF gene, cordance analyses by EEG, and finally the accurate localisation provided by neuronavigation. The authors conclude that investigations in larger patient samples are required in the future, and that the work already achieved should provide lines of approach for the coming experimental studies.

[RÉALITÉ LT, a pharmacoepidemiological study of semiology and therapeutic strategy of patients with schizophrenia treated by antipsychotic loxapine in routine clinical practice]. / RÉALITÉ LT : Recherche Épidémiologique sur l'Activité de la Loxapine et ses Indications en Thérapeutique quotidiennE lors d'une utilisation à Long Terme. Étude pharmacoépidémiologique : sémiologie et stratégie thérapeutique d'une population de patients présentant des troubles schizophréniques traités par loxapine.

INTRODUCTION: Data concerning the clinical and therapeutic characteristics of patients with schizophrenia treated by antipsychotic in naturalistic conditions are useful. Two national pharmacoepidemiological studies were conducted in France, a retrospective survey RÉALITÉ and a prospective study RÉALITÉ LT, to examine the use of loxapine, first in acute and chronic psychotic states and second in long-term treatment prescribed for patients with schizophrenia. AIM OF STUDY: The aim of RÉALITÉ LT is to specify the clinical characteristics of schizophrenic patients treated by loxapine for at least 4 months and the description of the methods of use of this antipsychotic medication during a 6-month follow-up in "real life" conditions. DESIGN OF STUDY: RÉALITÉ LT is an epidemiologic, observational, longitudinal, prospective (during a half-year period), multicenter and national study of the prescription of loxapine in routine clinical practice. For this study, 645 patients with schizophrenia treated by loxapine were recruited, assessed by PANSS, CGI, GAF, MeDra-SOC-PT for side effects and Girerd questionnaire for compliance; statistical analysis used SAS 9.2. RESULTS: Six hundred and forty-five adult patients were included and assessed at inclusion, month 3 and 6. These patients were mostly male (69%), with an average age of 41, inactive (68%), lonely with no child (79%), under psychiatric care for more than 5 years (81%), less than one third were inpatients. The subtypes of schizophrenia were paranoid (59%), disorganised (21%), undifferentiated or residual (10%), the outcome of psychotic illness was episodic (50%) or continuous (33%). The daily mean dosage of loxapine was 168,4 mg/d, in antipsychotic loxapine monotherapy (27%) or in combination with other antipsychotics (63%); it was often associated with psychotropic medications (anxiolytic [72%], antidepressant [21%], normothymic [19%]). The stability of the dosage of loxapine during the 6 months follow-up (60%) was associated with strict loxapine monotherapy or antipsychotic monotherapy (loxapine associated with other psychotropic medication). Safety, side effects and compliance were compared with previous studies. DISCUSSION AND CONCLUSION: These results are discussed, comparing the two pharmacoepidemiological studies RÉALITÉ and RÉALITÉ LT, loxapine is used in compliance with the two indications (smpc) and French guidelines (HAS, Haute Autorité de santé).

Treatment of shizophrenic patients and rTMS.

INTRODUCTION: schizophrenia (SCH) is a heterogeneous syndrome characterized by positive and negative symptoms. Despite appropriate medication, about 1/4 of patients suffer for refractory positive and/or negative symptoms, which are associated with functional handicap, increase of duration and of the number of hospitalizations. Numerous studies have suggested that the pathophysiology of auditory hallucinations (AH) is related to a hyper activity of the left temporoparietal cortex (TPC). On the other hand, negative symptoms are associated with a prefrontal hypoactivity and the efficiency of pharmacological treatments is frequently partial. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation tool with excellent tolerability and safety. Given its hypothesized mechanisms of action and the clinical beneficial effects obtained in several types of pathology (Aleman et al. 2007), the efficacy of rTMS has been investigated for drug-resistant SCH symptoms. OBJECTIVE: our objective is to expose the knowledge concerning the rTMS use in the treatment of these symptoms and to purpose a critical analysis of these data. METHOD: a systematic review of the literature has been conducted using NIH Pubmed. The following search terms were used: TMS - rTMS - Schizophrenia - negative symptoms - hallucinations. RESULTS: concerning the treatment of AH, 16 publications and 4 meta analyses were selected. For the negative symptoms, we retained 16 studies and 3 meta analyses. The most extensively investigated application for rTMS in SCH is the use of low-frequency stimulation to the left TPC with the aim to improve AH symptomatology. When compared to sham, this type of acute course of rTMS has been proven to induce a substantial and significant reduction in AH. But this effect does not seem long-lasting and maintenance protocols must be developed. Concerning negative symptoms, the results are less solid but we find some works which demonstrate an improvement of these symptoms while various stimulation parameters were used. Recently, new parameters of stimulation in particular the theta burst stimulation have permitted us to obtain larger effects with longer duration. The interest of these new parameters will be discussed here. CONCLUSION: overall, rTMS studies have demonstrated some promise in the treatment of SCH. However, more research is required to enhance rTMS efficacy and increase its beneficial effect duration and to test new therapeutic strategies in this topic.

[Validation of the French translation of the impulsive nonconformity scale]. / Traduction et validation de la version française de l'échelle d'impulsivité non conformité de Chapman.

INTRODUCTION: Impulsive traits are key characteristics in a lot of psychiatric disorders and are part of the "normal" behaviour spectrum. Although impulsivity is a controversial concept, some questionnaires have focused on its "dysfunctional" aspect. The Barratt Impulsive Scale (BIS-10) is the scale the most used to explore impulsiveness, but it does not explore antisocial or nonconform behaviour. The Chapman Impulsive and Nonconformity Scale (INCS) is a questionnaire of 51 items that measures the impulsivity and nonconformism. The INCS reflects "failure to internalize societal norms, lack of empathy for the pain of others, and an unrestrained yielding to impulse and self-gratification" and was originally designed to assess psychosis proneness. It has been validated in the USA, but has not yet been validated in France. Interestingly, although it was not predictive of psychosis, high scorers on INCS exceeded controls on depression, and on rates of substance abuse. Furthermore, participants scoring high on hypomanic personality scale and INCS were found to have an especially heightened risk for bipolar disorders. OBJECTIVE: To translate and determine reliability and validity of the French version of the Chapman Impulsive and Nonconformity Scale in young adults by comparison with the BIS. METHOD: Chapman Impulsive and Nonconformity Scale has been back-translated into French, and filled out by 237 students (males: 104; females: 133; mean age: 20.4 [range 19-25]). BIS-10 was used for convergent validity. Each participant completed the two scales. Reliability and validity of the French form of INCS were assessed with the internal consistency (coefficient alpha of Cronbach and the split half reliability) and the convergent validity. RESULTS: In the French version of the INCS, the 51 items have high internal reliability (Cronbach's alpha=0.81 and split half reliability=0.80). Concerning the BIS, internal reliability is good (Cronbach's alpha=0.72 and split half reliability=0.66). Moreover, Pearson's r of the INCS/BIS is statistically significant (0.65) and underlines the concomitant validity of the INCS with the BIS. CONCLUSION: The psychometric properties of the French version of the INCS are very similar to those of the English version. Hence, the INCS could provide a way to explore the two related dimensions: impulsivity and nonconformism.

The stop null mice model for schizophrenia displays [corrected] cognitive and social deficits partly alleviated by neuroleptics.

Recently evidence has accumulated that schizophrenia can arise from primary synaptic defects involving structural proteins particularly, microtubule associated proteins. Previous experiments have demonstrated that a STOP (stable tubule only peptide) gene deletion in mice leads to a phenotype mimicking some aspects of positive symptoms classically observed in schizophrenic patients. In the current study, we determined if STOP null mice demonstrate behavioral abnormalities related to the social and cognitive impairments of schizophrenia. Compared with wild-type mice, STOP null mice exhibited deficits in the non-aggressive component of social recognition, short term working memory and social and spatial learning. As described in humans, learning deficits in STOP null mice were poorly sensitive to long term treatment with typical neuroleptics. Since social and cognitive dysfunction have consistently been considered as central features of schizophrenia, we propose that STOP null mice may provide a useful model to understand the neurobiological correlates of social and cognitive defects in schizophrenia and to develop treatments that better target these symptoms.

Comorbidity between temporal lobe epilepsy and depression: a [18F]MPPF PET study.

Brain and brainstem changes of serotoninergic 5-hydroxytryptophan (5-HT)(1A) receptor density have been reported in patients with major depressive disorder as well as in patients with temporal lobe epilepsy (TLE), using PET and the selective antagonist radiotracers [(11)C]WAY-100635 or [(18)F]FC-WAY. We used a distinct 5-HT(1A) antagonist, [(18)F]MPPF, whose binding potential depends on both receptor density and extracellular serotonin concentration, in 24 patients with drug-resistant TLE and MRI evidence of hippocampal sclerosis but without prior antidepressant exposure. Their Beck Depression Inventory (BDI-2) score ranged from 0 to 34, with nine patients having a score >11. We used a simplified reference tissue model, statistical parametric mapping and anatomical regions of interest (ROIs) to correlate parametric images of [(18)F]MPPF BP with the total BDI score and its four subclasses. The total BDI score, as well as symptoms of psychomotor anhedonia and negative cognition, correlated positively with [(18)F]MPPF BP in the raphe nuclei and in the insula contralateral to seizure onset, whereas somatic symptoms correlated positively with [(18)F]MPPF binding potential in the hippocampal/parahippocampal region ipsilateral to seizure onset, the left mid-cingulate gyrus and the inferior dorsolateral frontal cortex, bilaterally. We confirm an association of depressive symptoms in TLE patients with changes of the central serotoninergic pathways, in particular within the raphe nuclei, insula, cingulate gyrus and epileptogenic hippocampus. These changes are likely to reflect lower extracellular serotonin concentration in more depressed patients, with an upregulation of receptors a less likely alternative.

[Efficacy of repetitive transcranial magnetic stimulation (rTMS) in major depression: a review]. / Efficacité de la stimulation magnétique transcrânienne (rTMS) dans le traitement de la dépression: revue de la littérature.

INTRODUCTION: In 1985, Barker et al. showed that it was possible to stimulate both nerves and brain using external magnetic stimulation without significant pain. During the past 10 years, therapeutic effects of repeated Transcranial Magnetic Stimulation (rTMS) have been widely studied in psychiatry and its efficacy has been demonstrated in the treatment of major depressive disorders, particularly as an alternative to electroconvulsivotherapy (ECT). Facing the large range of studies, we found necessary to propose an up-to-date review in French of the methodological and therapeutic variations among them. METHOD: Based on an exhaustive consultation of Medline data and the Avery-George-Holtzheimer Database of rTMS Depression-Studies, supplemented by a manual research, only works evaluating the therapeutic efficacy of rTMS on depressive symptoms were retained, excluding all studies exclusively investigating the stimulation parameters or the tolerance as well as case reports. RESULTS: Out the 66 available reports we retained 30 studies. After a description of the main results of these 30 studies, several elements of the 66 will be discussed. Open studies demonstrated that short courses rTMS (5 to 10 sessions) produced a decrease in the mean Hamilton Depression Ratting Scale (HDRS) scores, although significant remission of depression in individuals was rare. Most authors had used high frequency rTMS applied to the left Dorso Lateral Prefrontal Cortex (left DLPFC). However, low frequency rTMS applied to the right DLPFC was also followed by significant reduction of HDRS scores. Parallel arm, double blind versus placebo studies are designed to clarify the therapeutic efficacy of rTMS therapy but conclude in contradicting results. Literature data globally confirms a greater efficacy of rTMS compared to placebo (37% responders in the active group vs 20% in the sham). This efficacy could in fact be even greater because the sham procedure is disputable in most studies. Indeed, positioning rTMS coil at 45 or 90 from the scalp may not represent an accurate sham procedure and the use of real sham coil is to be recommended. Only one study has suggested that associating rTMS and ECT could decrease the number of general anesthesia required. Therapeutic efficacy has been shown by either inhibiting the right DLPFC or by stimulating the left DLPFC, although some patients exhibit paradoxical responses. High frequency rTMS (>5 Hz) increases cortical excitability and metabolism, while low-frequency rTMS stimulation ( 1 Hz) has the opposite effect. Other parameters are: relevant: intensity (from 80 to 110% of motor threshold), total number of stimulations (from 120 to 2 000) and total number of rTMS sessions (from 5 to 20). As suggested in most recent studies, higher-intensity pulses, higher number of stimulation or longer treatment courses may be more effective. Greater responsiveness to rTMS may be predicted by several patients' factors, including the absence of psychosis, younger age and previous response to rTMS therapy. DISCUSSION: Conclusions on these factors and others, such as the importance of anatomically accurate coil placement and the distance from the coil to the brain, await further investigation. Despite heterogeneity of these reports according to methodology and treatment parameters, the antidepressive properties of rTMS now appear obvious, opening interesting prospects, in particular in the treatment of pharmacoresistant major depressive patients and, we hope, administered as adjuvant therapy in non-resistant depression. CONCLUSION: Thus, many questions remain unanswered concerning the optimal stimulation parameters, privileged indications and maintenance sessions. This justifies the development of structured evaluation trials on larger samples.

Impaired fronto-temporal processing of emotion in schizophrenia.

AIMS: Abnormal emotion processing in schizophrenia affects social and functional outcome. Spatiotemporal brain mechanisms underlying this deficit are unclear. MATERIALS AND METHODS: Event-related potential (ERP) responses to emotional and neutral face processing during an implicit (gender detection) and an explicit (expression detection) task were compared between a group of healthy volunteers (n=10) and a group of patients with schizophrenia (n=10). RESULTS: Whereas patients had normal primary visual cortex responses, the early modulation of occipital, temporal, and frontal responses by emotional expression observed in controls was absent in patients. The occipito-temporal N170 amplitude was reduced in patients relative to controls during expression detection, but not during gender detection. Frontal activity within 180-250ms was reduced in patients compared to controls. As opposed to controls, no significant difference was seen in patients at the right temporal electrode (T6) between amplitudes of long-latency ERPs elicited by distinct emotions during the expression detection task. CONCLUSION: In patients with schizophrenia, abnormal early extraction of expression-related information in the occipito-temporal cortex (before 170ms) impairs structural encoding of facial expressions (N170) and may disrupt motivation- and task-dependent context processing (180-250ms time window) of expression-related facial features. Moreover, top-down neuromodulation from frontal and limbic structures to visual occipito-temporal cortex may not be sufficient to optimize the extraction of expression-specific face features.

[Impact of a new cognitive remediation strategy on interpersonal problem solving skills and social autonomy in schizophrenia]. / Impact de la remédiation cognitive dans la schizophrénie sur les stratégies de résolution de problèmes et l'autonomie sociale: utilisation du logiciel REHACOM.

INTRODUCTION: Despite recent developments, the impact of pharmacotherapy on social autonomy and interpersonal problem solving skills in patients with schizophrenia remains limited, with consequences in terms of socio-professional functioning. Indeed, independently of the positive, negative and/or disorganization symptoms, functional deficits in patients with schizophrenia rely mainly on various cognitive impairments. OBJECTIVES: To determine the impact of a new Cognitive Remediation Strategy on interpersonal problem solving skills, social autonomy and symptoms in patients with schizophrenia. METHODS: Thirty patients with schizophrenia were enrolled in a program consisting of 14 training sessions of 4 cognitive functions (attention/concentration, topological memory, logical reasoning, executive functions) using the REHACOM software. Measurements of attention (Continuous Performance Test, CPT), memory (Rivermead Behavioural Memory Test, RBMT) and executive functions (Wisconsin Card Sorting Test, WCST) as well as interpersonal problem solving skills (Assessment of Interpersonal Problem-Solving Skills, AIPSS) and social autonomy (Social Autonomy Scale, EAS) and finally schizophrenia symptoms (Positive And Negative Syndrom Scale, PANSS) were undertaken at the beginning and the end of the 14 remediation meetings. RESULTS: Cognitive functions, interpersonal problems solving skills, social autonomy and symptoms were significantly improved by the Cognitive Remediation Strategy. CONCLUSION: Our results confirm the therapeutic impact of a Cognitive Remediation Strategy among 30 schizophrenic patients stabilised on clinical, therapeutic and functional levels. The question of the long-term maintenance of such improvements still requires further investigation.

Repetitive transcranial magnetic stimulation does not potentiate antidepressant treatment.

In a double blind controlled study, rTMS results in a similar antidepressant effect to sham in combination with paroxetine. Both groups had the same delay in scale's scores improvement. rTMS seems not to be efficient as an add-on treatment to pharmacological medication in non-resistant major depression.

Neoechinorhynchus qatarensis sp. n. (Acanthocephala: Neoechinorhynchidae) from the blue-barred flame parrot fish, Scarus ghobban Forsskål, 1775, in Qatari waters of the Arabian Gulf.

Neoechinorhynchus qatarensis sp. n. (Acanthocephala: Neoechinorhynchidae) is described from the marine blue-barred flame parrot fish Scarus ghobban Forsskål, 1775 in the Arabian Gulf waters off the coast of Qatar. The new species is distinguished from all other species of the genus Neoechinorhynchus by its unique reproductive system and a glandular structure associated with the proboscis receptacle in both males and females. Other uncommon features of N. qatarensis are also discussed.

[Glutaminergic hypothesis of schizophrenia: clinical research studies with ketamine]. / Hypothèse glutamatergique de la schizophrénie: apports des recherches cliniques sur la kétamine.

Several lines of evidence suggest that the glutamatergic N-methyl-D-aspartate (NMDA) receptor is involved in schizophrenia pathophysiology. Post-mortem studies have revealed a lower density of glutamatergic receptors in patients with schizophrenia. Other studies of cerebrospinal fluid reported lower levels of glutamate in patients with schizophrenia in healthy comparison subjects. The most compelling evidence is provided by the psychomimetic effects of the NMDA antagonists phencyclidine and ketamine. Recently, much interest has been given to the study related to the role of NMDA receptor in pathophysiology of schizophrenia by administration of sub-anesthetic doses of ketamine. A phencyclidine hydrochloride derivate, ketamine, is a dissociative anesthetic and a non competitive antagonist of the NMDA receptor. In healthy subjects, ketamine produces: 1) positive symptoms of psychosis, such as illusions, thought disorder and delusions; 2) negative symptoms similar to those associated with schizophrenia including blunted emotional responses, emotional detachment, and psychomotor retardation; 3) cognitive impairments, in particular impairments on tests of frontal cortical function including increased distractibility, reduced verbal fluency and poorer performance on the Wisconsin Card Sorting Test. During smooth pursuit eye tracking, ketamine induces nystagmus as well as abnormalities which are among the characteristics of schizophrenia. In patients with schizophrenia, the administration of ketamine produces an activation of their psychotic symptoms, which have striking similarities to symptoms of their usual psychotic episodes. Ketamine effects on memory and other cognitive functions in schizophrenic patients are controversial. The psychomimetic effects of ketamine are transitional, reversible and influenced by time, dose and administration conditions. Susceptibility to the psychotomimetic effects of ketamine is minimal or absent in children and becomes maximal in early adulthood. The similarity between ketamine effects and endogenous psychoses created interest in the capacity of antipsychotic medications to block ketamine effects. Haloperidol failed to block this ketamine-induced psychomimetic effects in healthy subjects and in schizophrenic patients. However, clozapine, the prototype of atypical antipsychotic agents significantly reduced the ketamine-induced increase in positive symptoms in schizophrenic patients. Recently, lamotrigine significantly decreased ketamine-induced positive and negative symptoms in healthy subjects. Brain regions responsible for NMDA-mediated psychosis have not been established. Using positron emission tomography and [18F] fluorodeoxyglucose, the sub-anesthetic ketamine administration produces bilateral increases in metabolic activity in the prefrontal cortex. In a [15O] H2O positron emission tomography study, ketamine selectively increases cerebral blood flow in the anterior cingulate cortex and reduces cerebral blood flow in the hippocampus and primary visual cortex. The mechanism of neuropsychiatric effects of sub-anesthetic ketamine is not clear. A dysfunction in glutamate-dopaminergic interactions has been suggested as a mechanism for these effects of ketamine. Ketamine has been reported to primarily block NMDA receptor complex giving support to a glutamate deficiency hypothesis in schizophrenia. In addition, ketamine caused increases in cortical and striatal synaptic dopamine concentrations. The effects of NMDA receptor antagonist administration are argued to support a neurobiological hypothesis of schizophrenia, which includes pathophysiology within several neurotransmitter systems, manifested in behavioral pathology. Pharmacological modulation of the effects of NMDA receptor antagonists, such as ketamine, may lead to development of novel therapeutic agents for psychiatric illnesses such as schizophrenia.

Poor performance in smooth pursuit and antisaccadic eye-movement tasks in healthy siblings of patients with schizophrenia.

This study examines the area of eye movement dysfunctions as an indicator of vulnerability to schizophrenia. Eye movement performance was investigated with three different paradigms: Smooth Pursuit Eye Movements (SPEM); Visually Guided Saccades (VGS); and Antisaccades (AS) in 21 clinically stable patients with schizophrenia, 21 of their healthy, biological full siblings and 21 healthy control subjects. The three groups did not differ on VGS performance, whereas both patients and their siblings showed lower SPEM gain, an increased catch-up Saccades (CUS) rate, reduced AS accuracy and an increased number of AS errors in comparison to control subjects. In addition, patients with schizophrenia exhibited increased AS latency. Among the patients with schizophrenia, eye movement abnormalities did not correlate with age, gender, clinical state or duration of illness. These data suggest that abnormalities of SPEM and AS may represent neurobiological markers of the vulnerability to schizophrenia in individuals at high genetic risk for the disease.

[Pharmacological modulation of the effects induced by ketamine at subanesthetic doses]. / Modulation pharmacologique des effects induits par la kétamine à des doses subanesthésiques.

The similarity between ketamine effects and endogenous psychoses has created interest in the capacity of antipsychotic medications to block ketamine effects. In healthy subjects, a sub-anaesthetic single dose of lorazepam, typical neuroleptics, such as haloperidol, and atypical neuroleptics, such as clozapine and olanzapine, failed to block ketamine-induced positive and negative symptoms resembling schizophrenia. However, haloperidol is able to decrease ketamine-induced impairment in executive cognitive functions. Recently, lamotrigine reduced ketamine-induced psychotic symptoms, perceptual alterations, and cognitive impairments. In schizophrenic subjects, single doses of olanzapine do not decrease the effects of ketamine. However, long term treatment with clozapine has been reported to decrease ketamine-induced positive symptoms. Pharmacological modulation of the effects of NMDA receptor antagonists, such as ketamine, may lead to development of novel therapeutic agents for psychiatric illnesses such as schizophrenia.

[Validation of French versions of magical ideation and perceptual aberrations questionnaires]. / Validations des versions françaises des questionnaires d'idéation magique (MIS) et d'aberrations perceptives (PAS).

Chapman and colleagues have developed symptom-oriented scales based on Meehl's manual of schizotypy, such as the Social Anhedonia (SA) and Physical Anhedonia (PhA) Scales, the Magical Ideation Scale (MIS), and the Perceptual Aberration Scale (PAS). Whereas Chapman's scales of psychosis proneness are the most internationally used instruments for the assessment of schizotypy, some of them, such as MIS and PAS, were still not available in French. We reported here the validation study of the MIS and the PAS French versions that we had published previously. This study was conducted in a sample of 233 students (males: n = 108; females: n = 125; mean age: 21.17 +/- 1.47; mean educational level: 13.36 +/- 1.06). The French versions of the MIS and the PAS have high internal reliability (MIS: Cronbach's alpha = 0.85; PAS: Cronbach's alpha = 0.88). French norms are given for each of these scales. They are respectively 19/30 for the MIS and 17/35 for the PAS high cutoff scores without any difference when gender was considered. These results are very closed to those found by Chapman and colleagues for University of Wisconsin undergraduate students.