Coloring complex shapes decreases patient anxiety in three care environments: a pilot study with color analysis

Introduction

This study was conducted to determine the effectiveness of coloring activity of circular symmetrical shape with complex patterns, so-called mandala, on anxiety associated with chronic illness in three different ambulatory medical situations (general consultation, psychiatric day hospital, and hemodialysis session).

Methods

Thirty patients were included in three groups and came from three different ambulatory medical situations: a hemodialysis group (n = 10), a psychiatric day hospital group (n = 10), and a nephrology consultation group (n = 10). We asked the patients to fill STAI-S and STAI-T questionnaires before to color complex circular shape with complex patterns, then to fill the STAI-S questionnaire again and a questionnaire on the experience of the activity.

Results

The results show that the STAI-S score was significantly lower after coloring for the hemodialysis (p = 0.02) and psychiatric groups (p = 0.005) but not for the general consultation group (p = 0.26). STAI-T scores did not differ between groups. The distribution of colors in the mandala was different in the three groups of patients. A positive subjective experience of the activity was found in all groups.

Discussion

These results show the effectiveness of a coloring activity of a circular shape with complex patterns on anxiety associated with chronic illness in care environment. The different distribution of the colors of the mandala in the three groups raises the question of the influence of the context on the mood of the patients and the deeper meaning of the choice of colors and their placement in the mandala. Our study reinforces the multiple applications of art activities in different medical disciplines and encourages their development within healthcare settings.

Iatrogenic encephalopathies are not so rare in psychiatry: A retrospective study about 5217 EEG examinations

OBJECTIVES

Encephalopathy is a severe pathological process induced by multiple factors, which is typically associated with electroencephalogram (EEG) abnormalities. Early diagnosis, management, and treatment improve the patient's prognosis. Psychotropic treatments are a risk for drug-induced encephalopathies. In this study, the prevalence of encephalopathies in a psychiatric hospital has been studied for 5 years (2012 to 2016) using 5217 EEG records.

METHODS

EEGs were performed i) systematically on patient admission, ii) in response to inexplicable modifications of consciousness or behavior, or when metabolic anomalies occurred, and iii) to perform therapeutic monitoring in outpatient consultations. When encephalopathy was suspected, the clinical data (age, sex and concomitant treatment) and biological data (plasma levels of medications) were collected.

RESULTS

Encephalopathy was suspected in 189 patients. Following EEG examination, and monitoring of clinical course, encephalopathy was subsequently determined to be highly probable for 52 patients, (giving a prevalence of 1% per year), and low suspicion of encephalopathy in the other 137 patients. The suspicion of encephalopathy was made on both clinical (n=28) and non-clinical (n=24) signs. Involved drugs were mainly valproic acid (n=14), lithium (n=11) and clozapine (n=11) in the highly probable encephalopathy group.

CONCLUSIONS

Our study demonstrates the importance of EEG in the diagnosis and monitoring of encephalopathies in a psychiatric hospital. Clinical symptoms of encephalopathies are polymorphic and sometimes atypical. This diagnosis is underestimated in a context where behavior or consciousness disorders are generally not attributed to psychotropic drugs used in psychiatry.

Psychosomatic states and their correlation with letting-go: two newly evaluated core factors for investigating the therapeutic effect of spa treatment

Spa therapy (aka crenobalneotherapy) has been the object of criticism due to insufficient evidence of its effectiveness. While further effectiveness studies are needed, others are also required to better evaluate the curative factors involved during spa therapy that may contribute to the effectiveness. The current study used specific scales to investigate two possible curative factors: the psychosomatic state and the letting-go of patients with mental disorders after 3 weeks of spa therapy. The Saujon Psychosomatic Questionnaire (SPQ) and the Quantified Assessment of Fluidity of Consciousness Questionnaire (QACF) evaluate psychosomatic state and letting-go, respectively. The Hospital Anxiety and Depression Scale (HAD) and the Insomnia Severity Index (ISI) evaluate depression and anxiety symptoms and insomnia symptoms, respectively. Sixty-five subjects (57 women (87.69%); 8 men), with a mean age of 56.9 (± 9.7) years, were included. SPQ and QAFC scores improved significantly before and after the 3 weeks of spa therapy. Improvement in HAD and ISI scores was significantly correlated with SPQ and QACF scores. These preliminary results suggest that the induced psychosomatic state and the letting-go induced by spa treatment with bubbling baths, jet showers, pool bathing and massage could help patients to become more available and more able to change their psychophysiological state.

Sensory Gating Capacity and Attentional Function in Adults With ADHD: A Preliminary Neurophysiological and Neuropsychological Study

Objective: The inability to filter sensory input correctly may impair higher cognitive function in ADHD. However, this relationship remains largely elusive. The objectives of the present study is to investigate the relationship between sensory input processing and cognitive function in adult patients with ADHD. Method: This study investigated the relationship between deficit in sensory gating capacity (P50 amplitude changes in a double-click conditioning-testing paradigm and perceptual abnormalities related to sensory gating deficit with the Sensory Gating Inventory [SGI]) and attentional and executive function (P300 amplitude in an oddball paradigm and attentional and executive performances with a neuropsychological test) in 24 adult patients with ADHD. Results: The lower the sensory gating capacity of the brain and the higher the distractibility related to sensory gating inability that the patients reported, the lower the P300 amplitude. Conclusion: The capacity of the brain to gate the response to irrelevant incoming sensory input may be a fundamental protective mechanism that prevents the flooding of higher brain structures with irrelevant information in adult patients with ADHD.

Electroencephalogram Modifications Associated With Atypical Strict Antipsychotic Monotherapies

BACKGROUND

Antipsychotics produce electroencephalogram (EEG) modifications and increase the risk of epileptic seizure. These modifications remain sparsely studied specifically for atypical antipsychotics. In this context, our study focuses on EEG modifications associated with atypical strict antipsychotic monotherapies.

METHODS

Electroencephalogram recordings of 84 psychiatric patients treated with atypical antipsychotics in strict monotherapy (clozapine, n = 22; aripiprazole, n = 22; olanzapine, n = 17; risperidone, n = 9; quetiapine, n = 8; risperidone long-acting injection, n = 4; and paliperidone long-acting injection, n = 2) were analyzed. The modifications were ranked according to both slowing and excitability scores.

RESULTS

Electroencephalogram modifications (in 51 subjects, 60.71%) were graded according to 4 stages combining general slowing and sharp slow waves and/or epileptiform activities. The presence of sharp or epileptiform activities was significantly greater for clozapine (90.9%) compared with other second-generation antipsychotics (aripiprazole, 50%; olanzapine, 58.8%; quetiapine, 37.5%; risperidone, 44.4%). Age, duration of disease progression, and diagnosis were not associated as risk factors. Electroencephalogram modifications were associated with lower doses for treatment with quetiapine but not for specific antipsychotics. Electroencephalogram modifications and severe excitability were associated with higher chlorpromazine equivalent doses.

CONCLUSIONS

Atypical antipsychotics (clozapine, aripiprazole, quetiapine, olanzapine, and risperidone) induce EEG modifications, and these are significantly greater for clozapine and appear dependent on chlorpromazine equivalent dose. No encephalopathy was observed in these antipsychotic monotherapies, whatever dose.

Sensory gating deficits and impaired quality of life in patients with schizophrenia: A preliminary study

BACKGROUND

New determinants of quality of life in schizophrenia need to be identified. As sensory gating deficit is core impairment in schizophrenia, the present study hypothesized that sensory gating deficit is a determinant of impaired quality of life in schizophrenia. This study therefore investigated the relationship between sensory gating deficit and quality of life in patients with schizophrenia after adjusting for key confounding factors.

SUBJECTS AND METHODS

Sensory gating was assessed with the auditory event-related potential method by measuring P50 amplitude changes in a double-click conditioning-testing procedure, perceptual impairments related to sensory gating deficit was assessed with the SGI questionnaire and quality of life was assessed with the SQoL 18 questionnaire in 39 patients with schizophrenia.

RESULTS

Patients with sensory gating deficit (n=14) had a lower subjective quality of life on the psychological well-being dimension evaluated with SQoL 18 questionnaire (p=0.008) compared to those without it (n=25). This result remained significant (B=-0.45, Wald=4.84, p=0.02) after taking into account 7 potential confounding factors (gender, age, level of education, duration of disorder, positive symptoms, depressive symptoms and anxiety symptoms). Poorer psychological well-being was related to a higher score on the SGI (rho=-0.40, p=0.01), in particular on the Distractibility dimension (rho=-0.47, p=0.001).

CONCLUSIONS

These findings suggest that sensory gating deficit may be a determinant of impaired quality of life in schizophrenia. Further studies are needed to address the causal relationship between sensory gating deficit, perceptual impairments, attentional deficit and impaired quality of life in schizophrenia in order to act more efficiently on the quality of life of patients with this disorder.

Association of metabolic syndrome with sensory gating deficits in patients with chronic schizophrenia

Metabolic syndrome is more prevalent in schizophrenia than in the general population and is associated with an increased rate of morbidity. It has been associated with cognitive impairments in schizophrenia, which are a core deficit in patients with chronic schizophrenia. Sensory gating deficit is also a core deficit in schizophrenia. The principal objective of this study was to investigate the relationship between sensory gating deficit and metabolic syndrome in patients with schizophrenia, after adjusting for key confounding factors. We hypothesized that patients with metabolic syndrome exhibit a higher rate of sensory gating deficit compared to those without metabolic syndrome. This study investigated sensory gating with the auditory event-related potential method by measuring P50 amplitude changes in a double click conditioning-testing procedure in 51 patients with schizophrenia. Patients with metabolic syndrome (n = 14) had a higher rate of sensory gating deficit (P50 suppression <50%) (p < 0.001) compared to those without metabolic syndrome (n = 37). This result remained significant (B = 2.94, Wald = 8.32, p = 0.004) after taking into account 5 potential confounding factors (age, gender, duration of disorder, Fagerström test, presence of clozapine or olanzapine). In patients without metabolic syndrome, sensory gating deficit was linked to a poorer attentional performance (rho = -0.371, p = 0.05). In patients with metabolic syndrome, sensory gating deficit was linked to poorer memory performance (rho = -0.635, p = 0.02). These findings suggest that metabolic syndrome may be linked to sensory gating deficit in patients with schizophrenia and that the relationship between neurocognitive function and sensory gating deficit could be affected by the metabolic status of the patients. Further studies are needed to address the causal relationship between sensory gating deficit related to schizophrenia, cognitive impairments and metabolic syndrome.

Elevated C-reactive protein is associated with sensory gating deficit in schizophrenia

Sensory and cognitive impairments and inflammatory processes are contributing factors to the pathogenesis of schizophrenia. A previous study found that an elevated CRP level (≥5mg/L) was associated with higher cognitive impairments in schizophrenia. We aimed to investigate the association between an elevated CRP level and sensory impairments defined by a sensory gating deficit (abnormal P50 suppression) in 55 outpatients. Fifteen patients (27.3%) had an elevated CRP level that was associated with higher rate of sensory gating deficit (60% vs. 12.5%, p<0.001). This is the first study suggesting a relationship between sensory gating deficit and inflammatory processes in schizophrenia.

On the correlation between perceptual inundation caused by realistic immersive environmental auditory scenes and the sensory gating inventory in schizophrenia

BACKGROUND

In schizophrenia, perceptual inundation related to sensory gating deficit can be evaluated "off-line" with the sensory gating inventory (SGI) and "on-line" during listening tests. However, no study investigated the relation between "off-line evaluation" and "on-line evaluation". The present study investigates this relationship.

METHODS

A sound corpus of 36 realistic environmental auditory scenes was obtained from a 3D immersive synthesizer. Twenty schizophrenic patients and twenty healthy subjects completed the SGI and evaluated the feeling of "inundation" from 1 ("null") to 5 ("maximum") for each auditory scene. Sensory gating deficit was evaluated in half of each population group with P50 suppression electrophysiological measure.

RESULTS

Evaluation of inundation during sound listening was significantly higher in schizophrenia (3.25) compared to the control group (2.40, P<.001). The evaluation of inundation during the listening test correlated significantly with the perceptual modulation (n=20, rho=.52, P=.029) and the over-inclusion dimensions (n=20, rho=.59, P=.01) of the SGI in schizophrenic patients and with the P50 suppression for the entire group of controls and patients who performed ERP recordings (n=20, rho=-.49, P=.027).

CONCLUSION

An evaluation of the external validity of the SGI was obtained through listening tests. The ability to control acoustic parameters of each of the realistic immersive environmental auditory scenes might in future research make it possible to identify acoustic triggers related to perceptual inundation in schizophrenia.

Skin conductance biofeedback training in adults with drug-resistant temporal lobe epilepsy and stress-triggered seizures: a proof-of-concept study

The present proof-of-concept study investigated the feasibility of skin conductance biofeedback training in reducing seizures in adults with drug-resistant temporal lobe epilepsy (TLE), whose seizures are triggered by stress. Skin conductance biofeedback aims to increase levels of peripheral sympathetic arousal in order to reduce cortical excitability. This might seem somewhat counterintuitive, since such autonomic arousal may also be associated with increased stress and anxiety. Thus, this sought to verify that patients with TLE and stress-triggered seizures are not worsened in terms of stress, anxiety, and negative emotional response to this nonpharmacological treatment. Eleven patients with drug-resistant TLE with seizures triggered by stress were treated with 12 sessions of biofeedback. Patients did not worsen on cognitive evaluation of attentional biases towards negative emotional stimuli (P>.05) or on psychometric evaluation with state anxiety inventory (P = .059); in addition, a significant improvement was found in the Negative Affect Schedule (P = .014) and in the Beck Depression Inventory (P = .009). Biofeedback training significantly reduced seizure frequency with a mean reduction of -48.61% (SD = 27.79) (P = .005). There was a correlation between the mean change in skin conductance activity over the biofeedback treatment and the reduction of seizure frequency (r(11) = .62, P = .042). Thus, the skin conductance biofeedback used in the present study, which teaches patients to achieve an increased level of peripheral sympathetic arousal, was a well-tolerated nonpharmacological treatment. Further, well-controlled studies are needed to confirm the therapeutic value of this nonpharmacological treatment in reducing seizures in adults with drug-resistant TLE with seizures triggered by stress.

Do schizophrenia patients with low P50-suppression report more perceptual anomalies with the sensory gating inventory?

BACKGROUND

P50 amplitude changes in dual click conditioning-testing procedure might be a neurophysiological marker of deficient sensory gating in schizophrenia. However, the relationship between abnormalities in the neurophysiological and phenomenological dimensions of sensory gating in schizophrenia remains unclear. The aim of the present study was to determine if patients with low P50-suppression (below 50%) report more perceptual anomalies.

METHODS

Three groups were compared: twenty-nine schizophrenia patients with high P50-suppression (above 50% amplitude suppression), twenty-three schizophrenia patients with low P50-suppression (below 50%) and twenty-six healthy subjects. The Sensory Gating Inventory (SGI), a four-factor self-report questionnaire, was used to measure perceptual anomalies related to sensory gating. A comparison of demographic and clinical data was also carried out.

RESULTS

Patients with low P50-suppression presented: i) significantly higher scores on the SGI (for the overall SGI score and for each of the 4 factors) and ii) significantly larger P50 amplitude at the second click, than both patients with high P50-suppression and healthy subjects. There were no group differences in the most of demographic and clinical data.

DISCUSSION

The finding offers support for conceptual models wherein abnormal neurophysiologic responses to repetitive stimuli give rise to clinically relevant perceptions of being inundated and overwhelmed by external sensory stimuli. Further studies are needed to explore the contributions of clinical symptoms, medication and neuropsychological functions to the relationship between P50-suppression and the SGI, and the role of sensory "gating in" versus "gating out".

The covariation of independent and dependant variables in neurofeedback: a proposal framework to identify cognitive processes and brain activity variables

This methodological article proposes a framework for analysing the relationship between cognitive processes and brain activity using variables measured by neurofeedback (NF) carried out by functional Magnetic Resonance Imagery (fMRI NF). Cognitive processes and brain activity variables can be analysed as either the dependant variable or the independent variable. Firstly, we propose two traditional approaches, defined in the article as the "neuropsychological" approach (NP) and the "psychophysiology" approach (PP), to extract dependent and independent variables in NF protocols. Secondly, we suggest that NF can be inspired by the style of inquiry used in neurophenomenology. fMRI NF allows participants to experiment with his or her own cognitive processes and their effects on brain region of interest (ROI) activations simultaneously. Thus, we suggest that fMRI NF could be improved by implementing "the elicitation interview method", which allows the investigator to gather relevant verbatim from participants' introspection on subjective experiences.

Natural speech comprehension in bipolar disorders: an event-related brain potential study among manic patients

BACKGROUND

Thought and language disturbances are crucial clinical features in Bipolar Disorders (BD), and constitute a fundamental basis for social cognition. In BD, clinical manifestations such as disorganization and formal thought disorders may play a role in communication disturbances. However, only few studies have explored language disturbances in BD at a neurophysiological level. Two main Event-Related brain Potentials (ERPs) have been used in language comprehension research: the N400 component, elicited by incongruous word with the preceding semantic context, and the Late Positive Component (LPC), associated with non-specifically semantic and more general cognitive processes. Previous studies provided contradictory results regarding N400 in mood disorders, showing either preserved N400 in depression or dysthymia, or altered N400 in BD during semantic priming paradigm. The aim of our study was to explore N400 and LPC among patients with BD in natural speech conditions.

METHODS

ERPs from 19 bipolar type I patients with manic or hypomanic symptomatology and 19 healthy controls were recorded. Participants were asked to listen to congruous and incongruous complete sentences and to judge the match between the final word and the sentence context. Behavioral results and ERPs data were analyzed.

RESULTS

At the behavioral level, patients with BD show worst performances than healthy participants. At the electrophysiological level, our results show preserved N400 component in BD. LPC elicited under natural speech conditions shows preserved amplitude but delayed latency in difference waves.

LIMITATIONS

Small size of samples, absence of schizophrenic group and medication status.

CONCLUSIONS

In contrast with the only previous N400 study in BD that uses written semantic priming, our results show a preserved N400 component in ecological and natural speech conditions among patients with BD. Possible implications in terms of clinical specificity are discussed.

Aspects visuels et descriptifs de l’électroencéphalographie pendant les séances d’électroconvulsivothérapie

La surveillance électroencéphalographique (EEG) des séances d’électroconvulsivothérapie (ECT) est indispensable mais nécessite une connaissance minimale de la neurophysiologie et de la lecture de l’EléctroEncéphaloGramme (EEG) par le psychiatre. La lecture de l’EEG pendant les ECT nécessite un œil formé à la reconnaissance sur le tracé EEG de certaine forme spécifique, associée à l’utilisation d’un vocabulaire de description rigoureux. Ce poster a pour objectif de fournir une méthode illustrée de lecture de l’EEG pendant les ECT. Premièrement, les artefacts du signal EEG doivent être reconnus pour ne pas les confondre avec des activités épileptiformes. Deuxièmement, le déroulement de la crise doit être reconnu et décrit en phase : pré-critique, critiques (précritique, recrutante, tonique et clonique) et post-critique. Troisièmement, la qualification de la crise doit être posée par l’utilisation des termes de crise épileptique adéquate, optimale et prolongée. Cette démarche de lecture EEG pendant la séance ECT permet de détecter une crise épileptique prolongée afin de diminuer le risque à court terme d’état de mal épileptique post-ECT et à moyen terme le risque de mauvaise tolérance cognitive de la cure ECT. Elle permet également d’adapter de manière optimale les paramètres de stimulation à la prochaine séance d’ECT afin de maximiser l’efficacité des ECT. La lecture de l’EEG pendant les ECT ne résume pas l’entièreté de la conduite des cures ECT en psychiatrie. Cependant elle reste une démarche indispensable à l’aide à la prise de décision et souligne la place centrale que peut prendre la neurophysiologie clinique dans une stratégie thérapeutique psychiatrique.

[Neuroenhancement in healthy subject? A French case study]

Neuroenhancement is an anglo-saxon concept concerning the use of stimulating psychotropic drugs by healthy subjects, outside any established medical indication or festive setting, to achieve an improvement of their mental functioning. In 2009, because of increasing requests for neuroenhancement in USA, the American Association of Neurology has published practical recommendations stating that "it is ethically permissible to prescribe medications for neuroenhancement" if a number of conditions is met. We present these ethical and psychopharmacological conditions ("the inverted U-Shape principle" in which cognitive performance is related to catecholamine levels and "the trade-off principle" to cognitive enhancement) through a clinical case of methylphenidate prescription in a healthy 24 years old medical student, preparing for the "examen classant national" (the French national ranking before postgraduate education). We then discuss anglo-saxon ethical context in which these recommendations have been proposed.

Parieto-temporal alpha EEG band power at baseline as a predictor of antidepressant treatment response with repetitive Transcranial Magnetic Stimulation: a preliminary study

BACKGROUND

The aim of this preliminary study was to determine the predictive value of absolute alpha band power measured during the rest EEG eyes closed task for responses to 20 sessions of high frequency repetitive transcranial stimulation (rTMS) in the left dorsolateral prefrontal cortex in patients with pharmacoresistant major depressive episode.

METHODS

13 major depressive disorders (8 males) and 8 bipolar disorders (6 males) were included (mean age 58years). Spearman correlations between pretreatment alpha band power in height regions of analysis and absolute improvement in Beck Depression Inventory Short Form (ΔBDI-SF) were analyzed. The predictive value of alpha band power for classifying patients as responders and non-responders to rTMS was determined using Receiver Operating Characteristic (ROC) curve.

RESULTS

Spearman correlation analysis revealed that ΔBDI-SF correlated significantly and negatively with alpha band power on the right (r=-.673, p=.001) and left parieto-temporal regions (r=-.638, p=.002). The area under the ROC curve for the right parieto-temporal was .815, p=.0037. The cut-off point that maximized both sensitivity and specificity was 1.49μV. Sensitivity, specificity, positive and negative predictive values were 100, 66, 80, 100% respectively.

LIMITATIONS

The population was small and lacked homogeneity concerning affective disorders (unipolar and bipolar disorder). The use of a self-rating subjective scale (BDI-SF) to measure the severity of depression could be criticized.

CONCLUSIONS

Pretreatment alpha band power on parieto-temporal regions could be a predictor for response to rTMS in patients with homogenous demographic/clinical features. The association between electrical activity and the perfusion under each electrode need to be examined.

[Towards a new approach of neurophysiology in clinical psychiatry: functional magnetic resonance imaging neurofeedback applied to emotional dysfunctions]

Emotions color in a singular way our everyday life and constitute important determinants of human cognition and behavior. Emotional regulation is an essential process involved in neuropathophysiology and therapeutic efficacy in many psychiatric disorders. Yet, traditional psychiatric therapeutic has focused on symptomatic rather than neurophysiological criteria. Therefore, it was proposed to teach patients to modify their own brain activity directly, in order to obtain a therapeutic effect. These techniques, which are named neurofeedback, were originally developed using electroencephalography. Recent technical advances in fMRI enable real-time acquisition, and open opportunities to its utilization in neurofeedback. This seems particularly interesting in emotion regulation, which, at a neurofunctional level, lies on cortico-limbic pathways that, in great parts, were previously identified by traditional fMRI paradigms. This emotion regulation plays a central role in the etiopathogeny psychiatric, especially depressive and anxious, disorders. It is possible to devise new therapeutic strategies and research approach for addressing directly the neurophysiological processes of emotion regulation by integrating the neurofunctional activities of a subject. These prospects seem to be in line with the neurophenomenology project, which proposes to establish a link between subjective experiences and objective neurophysiological measures.

Toward an exploration of feeling of strangeness in schizophrenia: perspectives on acousmatic and everyday listening

The aim of this study was to investigate abnormal perceptual experiences in schizophrenia, in particular the feeling of strangeness, which is commonly found in patients' self-reports. The experimental design included auditory complex stimuli within 2 theoretical frameworks based on "sensory gating deficit" and "aberrant salience," inspired from conventional perceptual scales. A specific sound corpus was designed with environmental (meaningful) and abstract (meaningless) sounds. The authors compared sound evaluations on 3 perceptual dimensions (bizarre, familiar, and invasive) and 2 emotional dimensions (frightening and reassuring) between 20 patients with schizophrenia (SCZ) and 20 control participants (CTL). The perceptual judgment was rated on independent linear scales for each sound. In addition, the conditioning-testing P50 paradigm was conducted on 10 SCZ and 10 CTL. Both behavioral and electrophysiological data confirmed the authors' expectations according to the 2 previous theoretical frameworks and showed that abnormal perceptual experiences in SCZ consisted of perceiving meaningful sounds in a distorted manner and as flooding/inundating but also in perceiving meaningless sounds as things that become meaningful by assigning them some significance. In addition, the use of independent scales to each perceptual dimension highlighted an unexpected ambivalence on familiarity and bizarreness in SCZ compatible with the explanation of semantic process impairment. The authors further suggested that this ambivalence might be due to a conflicting coactivation of 2 types of listening, that is, every day and musical (or acousmatic) listening.

[The measurement of electrodermal activity]

INTRODUCTION

Electrodermal activity (EDA) is an early physiological index and the subject of constant interest, in spite of the bad reputation attached to "lie detectors". This interest is expected to increase in the future, following the development of research related to the neurobiological aspect of emotions of which it is an index. Recent data provided by functional cerebral imaging has added to the significance of this index and should result in further interest.

AIM

The authors thus re-examined the various notions related to measuring EDA, and its practical aspect as well as its mechanisms. EDA should be useful both for authors wishing to use this variable and for readers wishing to form their own critical point of view.

LITERATURE FINDINGS

The article first defines the various terms used to qualify EDA. Then, it analyses the mechanisms occurring at the sweat glands' level, showing that a distinct innervation of the sweat glands causes sweat to be released in the excretory channels, thereby allowing the recording of a negative surface potential in parallel to the lowering of skin conductance. Arguments are then pointed out to illustrate that the potential's positive phase following this first answer occurs in the case of high intensity stimulations. The study of the central command of sudation demonstrates that, several areas are involved and that different functions such as thermal regulation and motricity may interfere with emotive reactions. Difficulties regarding the mode of measurement of these answers as to their number and amplitude are also brought to light.

DISCUSSION

A particular interest of measuring EDA is its ability to highlight individual characteristic and unconscious emotional reactivity. Subjects who constitutionally present many spontaneous and therefore habitual EDA can indeed be opposed to subjects whose EDA reflexes are very few and hardly habitual. A theory suggests that for the first category, whose subjects are named labiles, emotional control may be at the origin of EDA. This characteristic brings to mind the case of antisocial subjects whose rate of EDA is also reduced, although for the latter a primitive drop in behavioral inhibition is involved. The production of EDA in response to non-conscious emotive stimulations can be objectified in the rare cases of prosopagnosia. These subjects who are unable to recognize familiar faces can produce EDA when presented faces with an emotional load. These cases contrast with the delusional denial of the Capgras syndrome where subjects do not present EDA, suggesting that the dysfunction of visual analysis occurs at a different level. There are other rare cases represented by cortical blindness where EDA shows that an unconscious emotional analysis is preserved. These subjects are known however to be capable of unconscious visual discriminations, which are possibly accompanied by EDA. This possibility of a "blind vision" is experimentally studied via subliminal vision testing (backward masking tests). These demonstrate that a rudimentary visual analysis is carried out in the subcortical circuits while taking into account the affective aspect of stimulations.

CONCLUSION

Present or future data should allow a greater comprehension of electrodermal signals, making it possible to overcome the difficulties related to their interpretation and facilitate their applications.

Categorization and timbre perception of environmental sounds in schizophrenia

Perception of environmental sounds from impacted materials (Wood, Metal and Glass) was examined by conducting a categorization experiment. Stimuli consisted of sound continua evoking progressive transitions between material categories. Results highlighted shallower response curves in subjects with schizophrenia than healthy participants, and are discussed in the framework of Signal Detection Theory and in terms of impaired perception of specific timbre features in schizophrenia.

[Electrophysiology and schizophrenic vulnerability: the P300 component as endophenotype candidate?]

INTRODUCTION

Studies on early stages of schizophrenia imply the observation of stable markers of vulnerability. Among other research fields, these early and objective markers, or potential endophenotypes, can be described in event-related potential (ERP) paradigms.

LITERATURE FINDINGS

The P300 component, elicited during the allocation of attentional resources, is the most studied ERP among people with schizophrenia. In this review, we first develop the notion of endophenotypes in schizophrenia, notably in terms of stability, heritability and specificity. We also give a short account of the P300 component, its typical description, the classical paradigms which elicit it, and several interpretations of its significance.

DISCUSSION

After reviewing the main features of the schizophrenic alterations of P300 (their topography, amplitude and latency), we discuss the relevance of P300 when described as a potential schizophrenic endophenotype. In spite of an important number of studies, results remain controversial and incomplete. First, P300 in schizophrenia shows complex patterns of temporal evolution, and thus can be described as either a stable trait or a state marker. Second, its heritability is still discussed among high-risk participants with genetic, schizotypal or clinical vulnerability. Third, the issue of its specificity is the less studied criteria. In line with the debate of its specificity, only little is known about specific alterations of P300 among unipolar or bipolar disorders. In the discussion, we describe a few possible origins of such controversial results in both empirical and conceptual perspectives, and we provide several experimental propositions in order to develop a more systematic exploration of P300 alterations.

Valeurs contrôles obtenues avec une séquence press 135 ms en neurospectroscopie monovoxel du proton

The clinical value of MR spectroscopy is now well established and this technique has been added to the current French classification of medical acts (CCAM). This paper presents a set of normal control values for 3 metabolite ratios obtained using a PRESS sequence with a TE of 135 ms at 1.5T: NAA/Cho, NAA/Cr and Cho/CR. Spectroscopy data acquisition were obtained from the following 12 anatomical regions: parieto-occipital white matter, centrum semiovale, frontal white matter, thalamus, basal ganglia, cerebellum (hemisphere, including dentate nucleus), brain stem (including pons, medulla and midbrain), anterior and posterior temporal lobe, parietal, occipital and pre-frontal cortices. The presented data allow radiologists equipped with a similar MR system to implement a clinical spectroscopy program without undergoing research protocols in order to obtain control values.

Proton magnetic resonance neurospectroscopy and EEG cartography in corticobasal degeneration: correlations with neuropsychological signs

OBJECTIVE

To document the asymmetrical functional brain lesions in corticobasal degeneration (CBD) using proton magnetic resonance neurospectroscopy (MRS) and EEG cartography (EEGq).

METHODS

Eight patients with probable CBD were included in the study after full neurological examination and extensive neuropsychological testing, single photon emission computed tomography, anatomical x ray tomodensitometry (TDM), magnetic resonance imaging, and MRS examination.

RESULTS

MR spectra were abnormal in all seven patients in whom the examination could be completed. The EEG was also always modified in the CBD patients, and the abnormalities were enhanced by activation procedures. There was a good correlation between MRS anomalies and clinical presentation, between EEG modifications and neuropsychological patterns, and between metabolic (MRS) impairment and electrophysiological (EEG) slowing.

CONCLUSIONS

These results confirm the asymmetrical features of CBD. Combined EEGq/MRS examinations at disease onset and during its subsequent course could provide strong diagnostic evidence of CBD.

Magnetic resonance imaging of the neuroprotective effect of xaliproden in rats

RATIONALE AND OBJECTIVES

The neurotrophic effect of Xaliproden has been followed using sequential cerebral magnetic resonance imaging (MRI) in rats with vincristine-induced brain lesion as a model of Alzheimer disease.

METHODS

Nineteen rats received an intraseptal injection of vincristine on day 0, followed by a daily gavage with either the vehicle (Tween-20 1%) (n = 10) or Xaliproden (10 mg/kg) (n = 9). Eight sham-operated controls received a daily gavage with either the vehicle (n = 4) or Xaliproden (n = 4). Brain MR imaging was performed at 4.7 T on a Biospec 47/30 MR system before surgery then 3, 7, 10, and 14 days after surgery.

RESULTS

At day 3 following vincristine injection, an increase in MR signal intensity in the septum was observed on T2-weighted images. This increase was maximal at day 10, and remained stable until day 14. Daily treatment with Xaliproden delayed the appearance of hypersignals until day 7 and reduced by Ca. 50% the magnitude of the increase in signal intensity from day 10. No changes were observed in the hippocampus.

CONCLUSION

Quantitative MRI objectifies noninvasively the neuroprotective effect of Xaliproden on rat brain anatomy.

In vivo brain proton MR spectroscopy in a case of molybdenum cofactor deficiency

A 20-day-old infant with molybdenum cofactor deficiency, a rare encephalopathy, was investigated using cerebral MRI and proton MR spectroscopy. Images demonstrated extensive white-matter destruction with large cavities. The short-echo-time MR spectrum acquired in the parieto-occipital area was characterised by global loss of signal and accumulation of lactate. No additional signal in relation to the pathophysiology of the disease was detected. The brain metabolic abnormalities observed in this patient may reflect destruction of white matter and the presence of large cavities.

[Proton magnetic resonance spectrometry for the non-invasive exploration of human brain metabolism: current and future clinical applications]

Magnetic resonance spectrometry (MRS) is now a routine investigation method in neurology. In some situations, its diagnostic sensitivity is better than MRI. In this review, we propose a critical analysis of the large body of literature on brain MRS concerning a wide range of pathologies and many different protocols. The diagnostic value of MRS is not fully determined in all neurological diseases, but the specific properties of MRS (detection of neuron-specific and glial-specific metabolites, quantitative data, reversibility of metabolic lesions) make it a high-performance tool for quantifying neuron, glial and membrane abnormalities. After reviewing the methodological advances in MRS and discussing restrictions on interpretation of spectral data, we describe variations in metabolic patterns detected by MRS in different groups of diseases. The currently reasonable indications for MRS exploration are presented as well as new avenues for research. Based on MRS data, we propose a metabolic definition of encephalopathy which could be useful in better understanding the role of MRS in modern neurology.

Brain metabolic impairment in non-cerebral and cerebral forms of X-linked adrenoleukodystrophy by proton MRS: identification of metabolic patterns by discriminant analysis

Cerebral metabolism in six children with X-linked adrenoleukodystrophy (X-ALD) was studied using 1H magnetic resonance spectroscopy (MRS), and the status of the patients was monitored for evaluating disease progression. Spectra were abnormal even in patients with no cerebral impairment. Four different metabolic patterns were identified, and a metabolic classification of the disease was proposed, from grade 0 to grade III. The evolution of the disease toward grade II appears to be systematic, but many patients did not evolve from this grade to grade III, which is the metabolic mark of severe progressive forms. Metabolic data of X-ALD were processed using discriminant analysis, which provides a classification accuracy of 95.2%. Proton cerebral MRS together with discriminant analysis may be useful during the follow-up in X-ALD for monitoring the evolution of the disease and the effects of therapy.

Magnetic resonance spectroscopy of serum and acute-phase proteins revisited: a multiparametric statistical analysis of metabolite variations in inflammatory, infectious and miscellaneous diseases

Proton MR spectra and biochemical assays have been recorded on the sera of 40 patients and ten controls in order to document the correlation between spectroscopic and biochemical variations in selected pathologies (cancer, inflammatory and infectious diseases, diabetes). N-acetyl proton resonances are essentially generated by the N-acetyl residues of the glucidic moieties borne by the most abundant acute-phase proteins (alpha1-acid glycoprotein, alpha1-antitrypsin and haptoglobin). These resonances are not correlated to immunoglobulins A, G and M levels. Principal component analysis shows that variations in spectroscopic and biochemical data are independent markers of the inflammatory status of patients but no additional sensitivity or specificity is obtained when the two sets of data are combined.

Localized proton magnetic resonance spectroscopy of the brain in children infected with human immunodeficiency virus with and without encephalopathy

Twenty children older than 2 y infected with human immunodeficiency virus (HIV) were examined by in vivo proton magnetic resonance spectroscopy (1H MRS) to study their cerebral metabolism and to identify metabolic profiles in relation with different stages of the disease. Patients were rated regarding their clinical and immunologic status according to the Centers for Disease Control classification and were divided into two groups: without encephalopathy (E-, n = 15) and with progressive encephalopathy (E+, n = 5). The acquisition was performed in the centrum semiovale using the short echo stimulated echo acquisition mode 20-ms sequence. The MRS profile was abnormal in all HIV-infected children compared with healthy age-matched controls (n = 7), even when magnetic resonance images were normal. A significant increase of the proportion of the lipid signals (ANOVA, p < 0.05) was found in all HIV-infected children. In addition, a significant decrease of the proportion of the N-acetylaspartate signal and a significant increase of the proportion of the myo-inositol signal (ANOVA, p < 0.05) characterized the E+ group. The principal component analysis performed on eight variables on 30 spectra confirms that the spectra of HIV-infected children differ from control spectra. The E+ group and the E- group are clearly separated on the map of subjects on the principal plane. The E- group lies in an intermediate position between the E+ group and the control group. The evolution of metabolic alterations in the brain of HIV-infected children can clearly be monitored by 1H MRS and associated with the occurrence of an encephalopathy.