Evaluation de la douleur et de l'anxiété lors de soins dentaires chez les patients hospitalisés en psychiatrie.

OBJECTIF: La santé bucco-dentaire des patients en psychiatrie est problématique, puisque le recours au chirurgien-dentiste demeure inférieur de 25 % à la population générale. En partant de ce postulat, nous avons souhaité comprendre en quoi l'anxiété et la douleur du patient peuvent impacter la prise en charge bucco-dentaire et le bon déroulement des soins. MÉTHODE: Cette étude a été menée sur 100 patients hospitalisés en psychiatrie. Grâce à différentes échelles, nous avons évalué leur niveau d'anxiété et de douleur, mais aussi leur coopération aux soins. RÉSULTATS: L'anxiété ne constitue pas un frein à la prise en charge, et diminue significativement après les soins. Le comportement durant les soins bucco-dentaires des patients hospitalisés en psychiatrie semble similaire à celui de la population générale. CONCLUSION: Notre étude permet de mieux appréhender les soins dentaires en psychiatrie et devrait contribuer à placer les soins dentaires au centre de la prise en charge somatique en psychiatrie.

Brain connectivity and auditory hallucinations: In search of novel noninvasive brain stimulation therapeutic approaches for schizophrenia.

Auditory verbal hallucinations (AVH) are among the most characteristic symptoms of schizophrenia and have been linked to likely disturbances of structural and functional connectivity within frontal, temporal, parietal and subcortical networks involved in language and auditory functions. Resting-state functional magnetic resonance imaging (fMRI) has shown that alterations in the functional connectivity activity of the default-mode network (DMN) may also subtend hallucinations. Noninvasive neurostimulation techniques such as repetitive transcranial magnetic stimulation (rTMS) have the ability to modulate activity of targeted cortical sites and their associated networks, showing a high potential for modulating altered connectivity subtending schizophrenia. Notwithstanding, the clinical benefit of these approaches remains weak and variable. Further studies in the field should foster a better understanding concerning the status of networks subtending AVH and the neural impact of rTMS in relation with symptom improvement. Additionally, the identification and characterization of clinical biomarkers able to predict response to treatment would be a critical asset allowing better care for patients with schizophrenia.

[Pedophilia: contribution of neurology and neuroimaging techniques]. / Corrélats cérébraux de la pédophilie: apports de la neurologie et de la neuro-imagerie.

INTRODUCTION: Pedophilia is characterized by a persistent sexual interest of an adult for prepubescent children. The development of neuroimaging techniques such as functional Magnetic Resonance Imaging (fMRI) is starting to clarify the cerebral basis of disorders of sexual behavior such as pedophilia, which had been previously suggested by case studies. OBJECTIVE: To review structural and functional neuroimaging studies of pedophilia. METHOD: An exhaustive consultation of PubMed and Ovid databases was conducted. We obtained 19 articles presented in the present review of the literature. RESULTS: Case studies have demonstrated various changes of sexual behavior in relation to brain lesions, including the late appearance in adults of a sexual attraction to prepubescent children. In most cases of pedophilia associated with brain lesions, these lesions were located in frontal or in temporal regions. Structural neuroimaging studies have compared pedophiles with healthy subjects and tried to relate pedophilia to anatomical differences between these two groups. The location of structural changes is inconsistent across studies. Recent functional neuroimaging studies have also attempted to investigate the cerebral correlates of pedophilia. Results suggest that the activation pattern found in pedophiles in response to pictures of prepubescent nude girls or boys is similar to the pattern observed in healthy subjects in response to pictures of adult nude women or men. However, regions that become more activated in patients than in healthy controls in response to the presentation of pictures of children vary across studies. CONCLUSION: Studies that have begun to investigate the cerebral correlates of pedophilia demonstrate that it is possible to explore them through neuroimaging techniques. These initial results have to be confirmed by new studies backed with objective measurements of sexual arousal such as phallometry.

[The placebo effect: general information and specificities in psychiatry (depression and schizophrenia)]. / L'effet placebo : généralités et spécificités en psychiatrie (dépression et schizophrénie).

INTRODUCTION: Placebos, consequences of their use, the placebo effect and the associated negative effects, the nocebo effect, have been widely studied. However, the lack of any consensus definition makes the interpretation and analysis of such findings difficult. LITERATURE FINDINGS: In this article, we will review existing definitions and factors affecting the placebo effect in medicine. We will then consider the possible mechanisms of action of the placebo effect, with a view to improving understanding of this issue. Finally, we will analyse data relating to placebos used in psychiatry and, more specifically, for schizophrenic patients. In an extensive review of the literature, we identified the various factors playing a role in the appearance of placebo effects in general medicine. As well as purely factual elements, such as the disorder, the sex of the subject and the treatment given, the placebo effect is strongly correlated with the quality of the relationship between the doctor and patient and with the capacity of the patient to communicate and establish a link. The attitude of the doctor, the temperament of the subject and the expectations and beliefs of each also contribute to the appearance and extent of a placebo effect. We then investigated placebo effects in psychiatry, particularly in depressed patients (the most widely studied condition) where studies have shown particular efficacy. We also addressed the use of placebos in schizophrenia: the placebo effect in patients with this disorder is essentially used as a tool for assessing new molecules to be released onto the market but the phenomenon itself has been little studied, if at all. Thus, it is of particular interest to consider in detail the use of placebos in schizophrenia, to try to gain a deeper understanding of the factors involved. This will allow potential specific effects associated with placebo use in this disorder to be established, improving the integration of placebos into therapy and to optimize the efficacy of treatment prescribed, taking into account mental state; indeed, the placebo effect is present in all treatments, whether involving a placebo or an active compound.

[Pain and schizophrenia: myth and reality]. / Douleur et schizophrénie: mythe et réalité.

INTRODUCTION: The International Association for the Study of Pain (IAPS), in 1986, defined pain as "an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage". Thus, the few studies on this phenomenon conducted on schizophrenic patients did not result in a firm consensus; certain studies showed that such patients seemed to have a higher threshold against pain (hypoalgesia) than healthy subjects, whilst other studies showed that the threshold is the same, but the absence of expressing the pain would be due to the pathology itself (non-expression of the pain, denial). Insensitivity to pain would be the consequence of a complex reaction between a biological sensorial abnormality and the psychopathology of schizophrenia itself (including the affective processes). Hence, various hypotheses referring to biological, psychological and sociological mechanisms have been proposed. BIOLOGICAL THEORIES: Various other hypotheses based on biological factors have been suggested. One of the interesting biologically-based hypotheses postulates that the insensitivity is due to a dysregulation of N-methyl-d-aspartate (NMDA). The biological factors are still not fully explored and would only explain in part the phenomenon of the apparent insensitivity to pain of individuals with schizophrenia. PSYCHOLOGICAL THEORIES: The thresholds of pain and a higher level of tolerance could be explained by an indifference to external stimuli and by inappropriate mental functions for these tests. The deficit is situated, therefore, both in the sensory discrimination of the stimulus (biological function) but also in the interpretation (cognitive and emotional functions). These different hypotheses (biological and psychological) might explain the insensitivity to pain of schizophrenic patients. PAIN AND SCHIZOPHRENIA: THE REALITY: Schizophrenic patients have a sensitivity to pain which is identical to that of healthy subjects. The apparent analgesia would be the result of a denial "attitude", a different manner of expressing pain in relation with the non-verbal communication difficulties, and not an alteration in the brain functions nor a biological anomaly. Diverse methodological biases arise from the studies of pain in patients with schizophrenia.

Activation of mirror-neuron system by erotic video clips predicts degree of induced erection: an fMRI study.

Although visually-induced erection is a common occurrence in human male behaviour, the cerebral underpinnings of this response are not well-known. We hypothesized that the magnitude of induced erection would be linearly correlated with the activation of the mirror-neuron system in response to sexually explicit films. When presented with sexual video clips, eight out of ten healthy subjects had an erectile response demonstrated through volumetric penile plethysmography. The level of activation of the left frontal operculum and of the inferior parietal lobules, areas which contain mirror neurons, predicted the magnitude of the erectile response. These results suggest that the response of the mirror-neuron system may not only code for the motor correlates of observed actions, but also for autonomic correlates of these actions.

[Pharmacogenetics and treatment response in schizophrenia]. / Approche pharmacogénétique de la réponse aux antipsychotiques chez les schizophrènes. Revue de la littérature.

UNLABELLED: The pharmacogenetic strategy uses the genetic association approach with the aim of identifying genes that influence clinical response to drug treatment. Association studies have focused mainly on neuroleptics (in particular clozapine) and variants in candidate genes of dopamine and serotonin systems in schizophrenic patients. Concerning the serotonin 5-HT(2A) receptor gene, the frequency of allele tyrosine (versus histidine) at 452 was greater among nonresponders, and homozygosity for the cytosine allele at 102 was more frequent among nonresponders. In the serotonin 5-HT(2C) receptor gene, a cysteine to serine substitution at 23 was considered as a predictor of good response to clozapine. Concerning the dopamine D2 receptor gene, the patients with one or two A1 alleles showed greater improvement than those with no A1 allele (Taq1A genotype). In addition, compared with patients who exhibited a Del allele at 141, patients with no Del allele showed better clinical response. Regarding the dopamine D3 receptor gene, the homozygous genotype serine/serine at 9 was found to be more frequent among the nonresponders. Finally, there was a possible relationship between the 48 bp variant number tandem repeat polymorphism in dopamine D4 receptor gene and response to neuroleptics. DISCUSSION: However, some results conflict with other data in the literature. The frequent difficulties in replication of pharmacogenetic findings can be explained by, among others: (i) the lack of a consistent definition of drug response; (ii) the use of different scales to evaluate response to treatment and the use of several cut-offs for the same scale; (iii) the sample heterogeneity and the small sample size; and (iv) the multigenic interactions. In order for research to progress, methodological consistency must be achieved, not only to form the basis of comparison among studies and to confirm or invalidate previous results, but also to allow for meta-analysis between the various studies. Nevertheless Kane et al. [Arch Gen Psychiatry 45 (1988) 789-796] have defined precise criteria of clinical response, but they are restrictive and quite difficult to set up in practice. Pharmacogenetic research has the following advantages: (i) it is based on the individual patient's genotype, invariable data in normal conditions, and can therefore be measured at any time during treatment; (ii) it uses reliable molecular biological techniques; and (iii) it is in constant progress because of the increasing amount of genomic information available. CONCLUSION: In future, a combination of several polymorphisms showing a strong association with a specific neuroleptic response could constitute a clinical test to predict the individual response to such treatment, and therefore participate in the prescription process. A research team has already proposed a combination of six polymorphisms implicating 5-HT(2A) receptor, 5-HT(2C) receptor, 5-HTTLPR, and H2 receptor genes [Lancet 355 (2000) 1615-1616], but this result has to be replicated. Until now, pharmacogenetics has focused on the global clinical response, but in the years to come, it could focus on the genes implied in the effects of treatments on specific symptoms and on physiological mechanisms that would explain how gene polymorphism can influence therapeutic response. This review aims to summarise recent advances and to present future clinical applications for pharmacogenetics.

Neuroanatomical correlates of penile erection evoked by photographic stimuli in human males.

The objective of this study was to identify the cerebral correlates of the early phase, and of low to moderate levels, of penile tumescence using for the first time a volumetric measure of the penile response. We hypothesized that (i) regions whose response had been found correlated with circumferential penile responses in previous studies would be identified with volumetric plethysmography and (ii) that other brain regions, including the amygdalae, would be found using the more sensitive volumetric measurement. In ten healthy males, functional magnetic resonance imaging (fMRI) was used to study brain responses to sexually stimulating photographs and to various categories of control photographs. Both ratings of perceived erection and penile plethysmography demonstrated an erectile response to the presentation of sexually stimulating photographs. Regions where the BOLD signal was correlated with penile volumetric responses included the right medial prefrontal cortex, the right and left orbitofrontal cortices, the insulae, the paracentral lobules, the right ventral lateral thalamic nucleus, the right anterior cingulate cortex and regions involved in motor imagery and motor preparation (supplementary motor areas, left ventral premotor area). This study suggests that the development of low levels of penile tumescence in response to static sexual stimuli is controlled by a network of frontal, parietal, insular and cingulate cortical areas and that penile tumescence reciprocally induces activation in somatosensory regions of the brain.