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Biomedical subjects

O Le Bon

Publications and source records attributed to O Le Bon.

29 records · Page 2Linked to original sources

Cerebral blood flow in just detoxified alcohol dependent patients. A 99 m Tc-HMPAO-SPECT study.

Chronic alcohol abuse is responsible for several organic brain disorders. However, even the most characteristic of them are largely underdiagnosed by routine procedures. Therefore, there is need for sensitive, noninvasive and low-cost diagnostic procedures. 99m-Tc-HMPAO-SPECT could be an interesting candidate in this indication, because it estimates the distribution of the cerebral blood flow and the metabolic activity of the brain with a good resolution. We used this technique in 17 healthy volunteers and in a sample of 50 patients dependent on alcohol, without other major physical or mental disorder. SPECT was performed during the attendance of these patients in an inpatient detoxification program. We observed abnormal SPECT in 34 patients, but only in 2 volunteers (p < 0.001). The main abnormality was heterogeneity of the distribution of the tracer. SPECT abnormalities appear to be due nor to withdrawal syndrome, nor to medication. On the contrary, they are correlated with stigmata of heavy alcoholism. Furthermore, a genetic vulnerability to alcohol was suspected because SPECT abnormalities are more frequent in patients with an history of drinking problems in their relatives.

Adult↗

[Fetal alcoholism syndrome: apropos of a case].

Fetal alcoholic syndrome (F.A.S.) is a well-recognized entity for over 20 years; it associates mental retardation, delayed growth and anomalies of the cranium in children born from alcoholic mothers. The syndrome has been described primarily in young children. By contrast, its evolution is not well known. We report the case of a 15-year old youngster, who exhibited the characteristic features of F.A.S. We also review the data related to the clinical and pathophysiologic aspects of the syndrome.

Adolescent↗

[Evaluation of typical psychopathic traits with juvenile offenders].

UNLABELLED: The concept of psychopathy has received many definitions for the first days of psychiatry. Recently, the Hare's Psychopathy Check List Revised has been created. This scale has the advantage to investigate the classically characteristic traits of the syndrome (need of stimulation, lack of culpability, superficial activity, lack of empathy, impassivity) and to point out the early development of behavior disturbances. In the American classification (DSM IV), oppositional and aggressive behavior in child and adolescent is grouped under the Conduct Disorder diagnostic criteria. This trouble appears to be a strong predictive factor of psychopathy in adult. Identifying the high risk factors of evolution to psychopathic personality would allow an earlier intervention and prevention by multisystemic interventions for example. The present study aims to evaluate in what measure characteristic traits of psychopathy in adults are present in severe juvenile offenders and to point out, in a second time, the differences between adolescents meeting the DSM IV criteria for Conduct Disorder and a control population by a dimensional personality inventory. METHOD: The sample consists in 47 severe juvenile offenders referred for at least 3 months by a Youth Court to a Public Institution for Youth Protection (Belgium, Wauthier-Braine, 1999-2001), who have given an oral contentment and completely fulfilled the Temperament and Character Inventory-TCI. We have collected data about: schooling year by year, number of fails, changes of school; antecedents of oppositional defiant disorder with provocation (ODD, DSM IV criteria); antecedent of Conduct Disorder (CD, DSM IV criteria); penal antecedents (Youth Judge, works of general interest, placements); medico-psychological antecedents (consultation to a psychologist or a psychiatrist, hospitalization, illness, surgical intervention); psychoactive drug use or abuse. We used the TCI--Temperament and Character Inventory. This is a dimensional personality inventory. Based on biological, genetic and clinical hypothesis, it describes 2 types of variables defining personality: Variables of temperament (genetically transmitted and biologically controlled), and Variables of character (learned part of the personality reflecting the degree of adaptation and maturity, varying with environment through development). We have chosen this tool because of its dimensional aspect. Adolescence being a time of psychological and personality changes, such a tool is more useful than a categorical one. We also used this tool to verify the existence of the specific triad described by Cloninger and Svrakic. According to these authors, psychopathic personality in adult is characterized by a specific triad in which novelty seeking is high while harm avoidance and reward dependence are low. These observations are highly correlated to Hare's definition of psychopathy. We give the principal scores for the 7 personality dimensions expressed in global scores (total of the items for each dimension) and pondered ones (global scores divided by the number of items of the dimension x 100). RESULTS: Statistical analysis was performed with the Stateview 5.0 t-test program for data analysis. Statistical results show the absence of a statistically significant difference between the 2 groups for TCI 1, 4.5 and 7 but a statistically significant difference for TCI 2, 3 and 6 (p <.0001). DISCUSSION: The first limitation of our study is linked to the sample composed of young adolescents placed in an Institution for Youth Protection who doesn't reflect the whole population of offenders. A second limitation is correlated to the randomization system: randomization for age but not for sex, ethnical and cultural origin and socioeconomic status. Our results with adolescent offenders don't completely meet the Cloninger's psychopathy triad in adults. Moreover, in literature data, aggressive behavior is correlated to high novelty seeking and associated with low harm avoidance, reward dependence and persistence in children, these items are predictive of antisocial behavior in teenage and young adulthood. In our sample where antisocial behaviors are severe, we should be expecting a high novelty seeking but that is not the case. Our results should be explained by the fact that adolescence in itself is a more powerful factor of high novelty seeking than psychopathic trait. Harm avoidance and reward dependence seem to be a real problem in offending population and reflect aggressive behaviors in adolescents (lack of harm perception, sensitivity and empathy). Another interesting element is the cooperation factor that is significantly lower in the study group. This seems to comfort the hypothesis of a lower social maturity in institutionalized adolescents. CONCLUSION: Regarding to a control group subjects from 15 to 25 years old, adolescent offenders observed in an Institution for Youth Protection show a significantly different profile in the TCI for Harm Avoidance, Reward Dependence and Cooperation. Regarding to adult psychopaths, adolescent offenders partially meet the classical diagnostic triad of psychopathy, what should be indicating that such adolescents already show emotional perturbations: lower harm avoidance, reward dependence and cooperation than control population. This third factor is not characteristic of psychopathy but reflects relational difficulties, which are important in adolescent offenders. So, our study point out the complex psychopathology of adolescent offenders and the coexistence in such adolescents of attachment disorder and the difficulty to treat them because of their multiple lacks (cognitive, psychopathological, familial and scholar). We think important to discuss the necessity of approaches based on the development of personal creative abilities and involving all the professionals concerned in the young's universe. Future researches should compare adolescent offenders and controls randomized for age, sex, socioeconomic, ethnical and cultural status. They also should test specifically the diagnostic triad of psychopathology developed by Cloninger, especially the novelty seeking dimension. Moreover, it would be interesting to integrate these results in a wider protocol and to compare them with clinical, forensic and neurocognitive data, individually and within the familial context.

Adolescent↗

The first-night effect may last more than one night.

The first-night effect in sleep polysomnographic studies is usually considered to last for one night. However, a few observations have indicated that variables associated to rapid eye movement sleep take longer to stabilize. Notwithstanding, current opinion holds that second nights of recording can be used without restriction for research and clinical purposes. The goal of this study was to describe the dynamics of habituation to polysomnography in optimal conditions. Twenty-six young, carefully screened, healthy subjects were recorded in their home for four consecutive full polysomnographies. Repeated measures ANOVA were applied. Between the two first nights, while there were no differences in sleep duration in non-rapid eye movement sleep, marked modifications in corresponding spectral power were observed. The dynamics of adaptation of rapid eye movement sleep appeared to be a process extending up to the fourth night. Similar dynamics in NREMS and REMS homeostasis have been observed in sleep deprivation studies, and it appears that the same mechanisms may be responsible for the FNE. The longer habituation process of REMS in particular has important implications for sleep research in psychiatry.

Adolescent↗

Critical analysis of the theories advanced to explain short REM sleep latencies and other sleep anomalies in several psychiatric conditions.

One of the most consistent and most studied sleep modifications in several psychiatric conditions is the shortening of the rapid eye movement (REM) sleep latency. While its clinical usefulness is still to be proven and its meaning relatively obscure, the appearance of a short REM latency continues to be a daily fact in sleep laboratories. Many theories compete to explain what is observed, the most important being the circadian rhythm hypotheses, the homeostatic model and the reciprocal interaction model. These three are summarised and their pros and cons are exposed in a systematic manner. Points of conflict, possible convergences and limitations are discussed in the light of recent developments on the general theories of sleep regulation.

Body Temperature↗

Alcoholism and emotional reactivity: more heterogeneous film-induced emotional response in newly detoxified alcoholics compared to controls--a preliminary study.

Alcoholics are thought to be characterized by irregular emotional responses, having trouble reaching an optimal level of emotional arousal. They therefore may use alcohol to restore emotional homeostasis. This study investigated whether recently detoxified alcoholics show different emotional responses as compared to controls. Film excerpts were used to induce emotions in 14 newly detoxified alcoholics (9 men, 5 women) and matched controls in a standardized laboratory setting. Subjective emotional (questionnaires) and physiological measures were employed. Depression and cognitive deterioration were controlled. Based on subjective ratings, alcoholics displayed greater variability of emotion; they displayed also fewer or no physiological arousal changes. Subjective emotional responses were exceedingly high or low. These differences were not accounted for by depression or cognitive deterioration. We hypothesize that alcohol could be used to restore an optimal level of emotional arousal. This homeostatic function of alcohol is yet to be clearly assessed.

Adult↗

Is REM latency a dying concept?

Twenty years have passed since the discovery that a shorter REM latency was one of the most significant biological correlates of depression. Its diagnostic and clinical discriminant power have been challenged both in terms of sensitivity and specificity. The present paper is a review of the relevant literature of these years until the present time and has focused on (a) technical problems concerning the REM latency, (b) its diagnostic value, (c) the state or trait meaning, (d) the use of the cholinergic and aminergic challenge, (e) the effects of treatments. A summary of (f) the effects of age and (g) REM sleep propensity as a cycle phenomenon have been added. The conclusions tend toward considering REM sleep disorders as an expression of a multiple circadian cycle abnormality, globally seen as a trait, itself highly correlated with psychiatric pathology and especially with affective disorders.

Circadian Rhythm↗

[Pharmacological approach to the treatment of drinking problems].

Many pharmacological agents have been proposed for the treatment of drinking problems. However, there are many pitfalls in the assessment of the clinical interest of those drugs. In this paper, we propose a new classification of drugs of interest for treating alcohol abuse and related problems. We also review the major clinical studies about those pharmacological agents and discuss some peculiar aspects of those trials think to be important to develop better strategies for the evaluation of pharmacotherapy of alcoholism.

Alcohol Deterrents↗

[Tridimensional Personality Questionnaire (TPQ): validation in a French-speaking control population].

Among the dimensional scales that measure personality, Cloninger's TPQ (Tridimensional Personality Questionnaire) holds a place apart in the literature, because the hypotheses it relies on are partially biological. The questionnaire (100 forced binary items) includes three axes: "Novelty Seeking", "Harm Avoidance" and "Reward Dependence", each theoretically bound to a preferential neuromediator, respectively dopamine, serotonin and norepinephrine. Each axis includes four minor subscales. The study presented here is the analysis of 104 control volunteers from both genders (59 males). This database is the first to be published with a French-speaking population. The comparison with Cloninger's normative database shows many similarities: the mean values for the 3 axes are relatively close. The population studied here is younger and this factor could play a role in the somewhat higher mean novelty seeking scores found here. The three axes show a normal distribution. Skewness and kurtosis are between -1 and +1 for all the subscales, except here for NS2. Factorial structure is quite similar to Cloninger's results. The three first axes correspond to the variables isolated in the first studies and the fourth one includes the same subscales as in the large American database. Inverse correlation between age and novelty seeking, positive correlation between female gender and harm avoidance and reward dependence were also found. However, no correlation was found between novelty seeking and male gender. A correlation was found between level of instruction and NS1 only, not with the whole NS axis. Eighty-seven % of volunteers presented with at least one standard deviation on at least one axis and 68% on at least two. This does not seem to have been described previously. It can be a sign of the difficulty of human beings to show a balanced personality. In conclusion, the database presented here shows many similarities with Cloninger's normative database. This underscores its value for comparisons in clinical trials in the future.

Adult↗