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Biomedical subjects

O Le Bon

Publications and source records attributed to O Le Bon.

At least 19 recordsLinked to original sources
PubMed2004

Personality profile and drug of choice; a multivariate analysis using Cloninger's TCI on heroin addicts, alcoholics, and a random population group.

As personality may predispose, precipitate or perpetuate substance abuse and/or dependence, and as it is considered to remain stable across the years in a given subject, potential links with the drug of choice may help screen future patients before drug consumption. The present study compared three groups: 42 patients with heroin dependence (mean age: 31.2; standard deviation (SD): 5.5; 10 females), 37 patients with alcohol dependence (mean age 44.2; SD: 9.1; 9 females) and 83 subjects from a random population sample (mean age: 38.8; SD: 6.9; 20 females). Personality was measured by Cloninger's Temperament and Character Inventory (TCI). Pillai's MANCOVA with age as a covariate and gender as a cofactor was highly significant. Univariate ANOVA analyses using TCI dimensions as dependent variable showed most variables to vary in parallel for the two patient groups in comparison with controls. Post-hoc tests showed heroin patients to score higher in Novelty-Seeking and Self-Directedness than alcohol patients. Sub-dimensions Exploratory Excitability, Fear of the Uncertain, Responsibility, Congruent Second Nature and Transpersonal Identification were also significantly different in the two patient samples. Logistic regression showed Exploratory Excitability to segregate up to 76% of heroin patients from alcohol patients. In conclusion, personality profiles were linked to some preferential choice of drug and personality screening might be tested in preventive strategies.

Adult↗
PubMed2003

[Effect of the first sleep night in polysomnography: classification by variable sensitivity and factorial analysis of differences between nights].

It has been known since the sixties that a habituation phenomenon is present in polysomnographic analyses of sleep, the first night including more awakenings and less Rapid Eye Movement sleep (REM) than consecutive ones. Results about Non-Rapid Eye Movement sleep (NREM) are less clear. The study presented here attempted to classify the variables in function of their sensitivity to this phenomenon by comparing inter-night and inter-subject effects in a series of ANCOVA analyses and on the other hand, to group the same variables in function of a factorial analysis on the differences between the two first nights. The study included 26 subjects with no somatic nor psychiatric disorder and was performed at their homes for four consecutive nights. The most sensitive variables were, in descending order: Ultra-Slow spectral power band, REM sleep, Sleep Efficiency Index, Delta spectral power band, number of awakenings, duration of awakenings, number of ultradian sleep cycles and Total Sleep Time. The factorial analysis showed 7 factors, grouping separately the two series of results from the spectral analysis (corresponding to visually-scored NREM and REM sleep), awakenings, sleep duration variables, variables linked to REM sleep, microarousals and deep sleep.

Adolescent↗
PubMed2002

Correlations using the NREM-REM sleep cycle frequency support distinct regulation mechanisms for REM and NREM sleep.

Polysomnograms of most homeothermic species distinguish two states, rapid eye movement (REM) and non-REM (NREM) sleep. These alternate several times during the night for reasons and following rules that remain poorly understood. It is unknown whether each state has its own function and regulation or whether they represent two facets of the same process. The present study compared the mean REM/NREM sleep ratio and the mean number of NREM-REM sleep cycles across 3 consecutive nights. The rationale was that, if REM and NREM sleep are tightly associated, their ratio should be comparable whatever the cycle frequency in the night. Twenty-six healthy subjects of both sexes were recorded at their home for 4 consecutive nights. The correlation between the REM/NREM sleep ratio and the number of cycles was highly significant. Of the two sleep components, REM sleep was associated to the number of cycles, whereas NREM sleep was not. This suggests that the relationship between REM sleep and NREM sleep is rather weak within cycles, does not support the concept of NREM-REM sleep cycles as miniature units of the sleep process, and favors the concept of distinct mechanisms of regulation for the two components.

Adolescent↗
PubMed2001

Shorter REM latency associated with more sleep cycles of a shorter duration in healthy humans.

A significant association between rapid eye movement (REM) sleep latency and the number of non-REM/REM sleep cycles was found 15 years ago in a large retrospective study. The present prospective study further explored this intra-sleep relationship and analyzed the links between these two variables and the mean cycle duration. It was based on a carefully selected group of healthy control subjects whose sleep was polysomnographically recorded at home for 4 sequential nights. The latency of REM sleep was inversely correlated with the number of cycles and positively correlated with the mean cycle duration, both in individual nights and on means of 4 nights. The present study demonstrated that variations in the number of cycles or the mean cycle duration between the nights are far less important than the substantial differences observed between subjects. Present outcomes support the study of sleep cycle periods and frequencies in those psychiatric disorders where REM sleep latencies have been found to be shorter, and they suggest that these variables be included in sleep studies in which cycles are compared with each other.

Adolescent↗
PubMed2001

Impaired emotional facial expression recognition in alcoholism compared with obsessive-compulsive disorder and normal controls.

Emotional facial expression (EFE) decoding skills have been shown to be impaired in recovering alcoholics (RA). The aim of the present study is to replicate these results and to explore whether these abnormalities are specific to alcoholism using two control groups: non-patient controls (NC) and patients with obsessive-compulsive disorder (OC). Twenty-two alcoholic patients at the end of their detoxification process (RA) were compared to 22 OC and 22 NC matched for age, sex and education level. They were presented with 12 photographs of facial expressions portraying different emotions: happiness; anger; and fear. Each emotion was displayed with mild (30%) and moderate (70%) intensity levels. Each EFE was judged on 8 scales labeled happiness, sadness, fear, anger, disgust, surprise, shame and contempt. For each scale, subjects rated the estimated intensity level. RA were less accurate in EFE decoding than OC and NC, particularly for anger and happiness expressions. RA overestimated the emotional intensity for mild intensity level expressions compared with both OC and NC while no significant differences emerged for moderate intensity level expressions. Deficits in EFE decoding skills seem to be specific to RA when compared with OC. Comparison with other psychopathological groups is still needed. Possible consequences of EFE decoding deficits in RA include distorted interpersonal relationships.

Adult↗
PubMed2001

Supervisory attentional system in nonamnesic alcoholic men.

BACKGROUND: Many studies have shown that recently detoxified alcoholic persons perform poorly on tasks thought to be sensitive to frontal lobe damage, supporting the hypothesis that the frontal lobes are highly vulnerable to chronic alcohol consumption. However, it appeared that most of the executive tasks used in these studies also involved nonexecutive components, and these tasks had been shown to be impaired as a result of nonfrontal lobe lesions. In this study, we examined further the "frontal lobe vulnerability" hypothesis using executive tasks, proved to be associated with frontal lobe functioning, that allowed us to distinguish the relative importance of executive and nonexecutive processes. METHOD: Thirty recently detoxified asymptomatic male alcoholic inpatients and 30 control subjects were tested for planning, inhibition, rule detection, and coordination of dual task, as well as the speed of processing and nonexecutive functions (such as short-term memory storage). RESULTS: Alcoholics performed worse than controls in almost all tasks assessing executive functions. However, they were not slower than the controls and showed normal results for nonexecutive functions. CONCLUSIONS: Chronic alcohol consumption seems to be associated with severe executive function deficits, which are still present after a protracted period of alcohol abstinence. These data support the idea that the cognitive deficits in recently detoxified sober alcoholic subjects are due, at least partly, to frontal lobe dysfunctioning.

Adult↗
PubMed2001

Deficits in recognition of emotional facial expression are still present in alcoholics after mid- to long-term abstinence.

OBJECTIVE: Emotional facial expression (EFE) decoding skills play a key role in interpersonal relationships. Decoding errors have been described in several pathological conditions, including alcoholism. The aim of this study was to investigate whether EFE decoding skill deficits persist after abstention from alcohol of at least 2 months. METHOD: Alcoholic patients abstinent for at least 2 months (n = 25) were compared with 25 recently detoxified patients and with 25 normal controls matched for age, gender and educational level. Subjects were presented with 40 photographs of facial expressions portraying happiness, anger, sadness, disgust and fear. Each emotion was displayed with neutral, mild, moderate and strong emotional intensity. Each facial expression was judged successively on eight scales labeled happiness, sadness, fear, anger, disgust, surprise, shame and contempt. For each scale, subjects rated the estimated intensity level. A complementary scale assessed the self-estimated difficulty in performing the task. RESULTS: Recently detoxified alcoholics were significantly less accurate than controls, making more EFE labeling errors and overestimating the intensity of the portrayed emotions. Deficits in decoding accuracy for anger and disgust were present in mid- to long-term abstinent patients; intensity overestimation was present in the former and absent in the latter. CONCLUSIONS: Deficits in decoding accuracy for anger and disgust, and to a lesser degree sadness, persist with an abstinence of 2 months and beyond. Right frontotemporal regions and cingulate could be implicated. These deficits may contribute to the social skills deficits frequently encountered in alcoholic patients.

Adult↗
PubMed2000

5-HT2a receptor polymorphism gene in bipolar disorder and harm avoidance personality trait.

The purpose [corrected] of this study was to investigate the relationship between bipolar disorder and the harm avoidance personality trait (HA), and the genetic contribution of the polymorphic DNA variation T102C in exon 1 of 5-HTR2a (chromosome 13q14-21) in bipolar disorder and HA personality trait. Forty bipolar patients and 89 normal subjects completed the TPQ questionnaire and were genotyped for 5-HT2a. Bipolar patients scored higher than normal subjects on the HA dimension. However, no contribution of the 5-HTR2a polymorphism on the bipolar disorder or on the HA personality trait emerged. Despite the limited sample size, these results exclude a major effect of the 5-HTR2a polymorphism on bipolar disorder and HA personality trait but not a minor effect.

Adult↗
PubMed2000

Mild to moderate sleep respiratory events: one negative night may not be enough.

STUDY OBJECTIVES: Reports on the reproducibility of apnea-hypopnea indexes (AHIs) across sequential polysomnography (PSG) sessions are conflicting, leading to a lack of clear recommendations on the optimal use of this technique: is one night of monitoring sufficient or is a second night required in order to safely reject the diagnosis? DESIGN: Retrospective comparison of two consecutive nights. SETTING: Sleep unit of a tertiary-care facility. PATIENTS: Two hundred forty-three subjects with suspected sleep apneas. INTERVENTIONS: Two sequential PSG sessions in a sleep unit. MEASUREMENTS AND RESULTS: Using analysis of covariance for repeated measures, with age and body mass index as covariates and gender as a cofactor, a classic first-night effect was found for sleep variables. In addition, a night effect was demonstrated for sleep respiratory variables. Moreover, the high variability of AHIs showed that many patients had their condition diagnosed on only one of the two nights, and more often on the second night than on the first. The gain in detection by adding a second night when the results of testing on the first were negative was between 15% and 25%, according to the AHI obtained on night 1. CONCLUSIONS: Considering the disability associated with sleep apnea/hypopnea syndrome, as well as its global cost for society, the present study shows that it is worth performing two consecutive PSG sessions or at least a second one when the result of the first one is negative in all patients admitted for apnea detection.

Body Mass Index↗
PubMed2000

How significant are primary sleep disorders and sleepiness in the chronic fatigue syndrome?

In order to study both the prevalence of Primary Sleep Disorders (PSD) and sleepiness, and their association to the Chronic Fatigue Syndrome (CFS), 46 unselected outpatients (34 women, mean age 36.5) were examined clinically and underwent two nights of all-night polysomnography and multiple sleep latency tests (MSLT). Forty-six percent presented with a Sleep Apnea/Hypopnea Syndrome Index (AHI>=5), 5% with a Periodic Limb Movements syndrome. No subject received a diagnosis of Narcolepsy or Idiopathic Hypersomnia. Thirty percent showed the presence of objective sleepiness as measured by MSLT<10 minutes. Objective and subjective measures of sleepiness were not associated with CFS, nor with the double diagnosis of CFS and a PSD. The presence of PSD or sleepiness was not associated with any of the clinical scales that were used to measure anxiety, depression, somatisation, physical or mental fatigue, or functional status impairment. Fifty-four percent of CFS patients had no PSD, and 69% no sleepiness. These patients could not be distinguished clinically from patients having a PSD or from those with sleepiness. Therefore, it is unlikely that CFS is simply a somatic expression of any PSD observed in our sample or of sleepiness per se.

Adult↗
PubMed1999

Alcoholics' deficits in the decoding of emotional facial expression.

The present study investigated emotional facial expression decoding in alcoholics. Twenty-five alcoholic patients at the end of the detoxification process were compared with 25 volunteers matched for age, sex, and education. They were presented with facial expressions of neutral, mild, moderate, or strong emotional intensity. Results indicate that alcoholics overestimate the intensity of emotional expressions and make more errors in their decoding with a special bias for anger and contempt. Moreover, this decoding deficit is not perceived by the alcoholic patients. A general model is proposed that links visuospatial deficits, abnormal processing of social information, interpersonal stress, and alcohol abuse.

Adult↗
PubMed1998

Association between novelty-seeking and the dopamine D3 receptor gene in bipolar patients: a preliminary report.

Recent studies in healthy controls suggest an association between novelty-seeking (NS) and the dopamine D4 receptor (DRD4) gene. In this study, we further investigated the relationship between genes implicated in dopamine as well as serotonin neurotransmission and personality traits in bipolar (BP) disorder. Scores on the Tridimensional Personality Questionnaire were examined in 37 recovered Research Diagnostic Criteria-diagnosed BP patients genotyped for DRD3, DRD4, and serotonin 2A receptor (5HTR2a) polymorphisms. Carriers of DRD3 allele 1 showed significantly lower NS values compared to patients without this allele. Scores on NS and on harm-avoidance were not related to DRD4 or 5HTR2a polymorphisms. These preliminary results suggest a role for D3 receptor in NS expression in BP patients.

Adult↗
PubMed1997

Sleep anomalies in the chronic fatigue syndrome. A comorbidity study.

Polysomnographic findings were compared between a group of patients with the chronic fatigue syndrome (CFS; n = 49) and a matched healthy control (HC) group (n = 20). Sleep initiation and sleep maintenance disturbances were observed in the CFS group. The percentage of stage 4 was significantly lower in the CFS group. A discriminant analysis allowed a high level of correct classification of CFS subjects and HC. Sleep-onset latency and the number of stage shifts/hour contributed significantly to the discriminant function. The presence of these anomalies as well as the decrease in stage 4 sleep were not limited to the patients also diagnosed with fibromyalgia or with a psychiatric disorder. No association was found between sleep disorders and the degree of functional status impairment. The mean REM latency and the percentage of subjects with a shortened REM latency were similar in CFS and HC.

Adult↗
PubMed1997

Efficacy and safety of acamprosate in the treatment of detoxified alcohol-dependent patients. A 90-day placebo-controlled dose-finding study.

BACKGROUND: Acamprosate is a newly registered drug that appears to reduce alcohol-drinking in both animal models and clinical conditions. METHOD: In order to assess the efficacy and safety of the drug in the treatment of detoxified alcoholics, we performed a 90-day double-blind trial comparing two dosages of acamprosate (1332 mg/day and 1998 mg/day). RESULTS: For all efficacy parameters, acamprosate appeared to be significantly superior to placebo, with a trend towards a better effect at the higher dosage. Furthermore, acamprosate appeared to be extremely safe. CONCLUSION: This study confirms that acamprosate could be an interesting adjuvant for maintaining abstinence in detoxified alcoholics.

Acamprosate↗
PubMed1997

Sleep in detoxified alcoholics: impairment of most standard sleep parameters and increased risk for sleep apnea, but not for myoclonias--a controlled study.

OBJECTIVE: To assess recently alcohol-abstinent chronic alcoholic patients for selected parameters indicative of sleep quality. METHOD: Patients (n = 24, 14 male), abstinent 3-6 weeks, and healthy controls (n = 20) were admitted to a clinical sleep unit. Measurements included sleep respiratory events and periodic limb movements, using strict methodology. RESULTS: Clear signs of sleep deterioration and a high prevalence of apneic/hypopneic episodes were observed. Apneas were found at the same frequency for men and women; this has not been described before. No periodic limb movement was found. CONCLUSIONS: Considering the high degree of morbidity and mortality observed in sleep apneic syndrome, systematic screening for sleep apneas is recommended for alcoholics seeking help.

Adult↗
PubMed1997

[Sleep apnea and nocturnal ventilatory assistance (nCPAP): 5-year experience in the conventional system].

The reimbursement of nasal continuous positive airway pressure (nCPAP) by the Belgian social security, via a conventional system, has made since 1991 this treatment available to an increasing number of patients having moderate to severe sleep apnoea hypopnoea syndrome (SAHS). We have reviewed our experience in prescribing domiciliary nCPAP from 1991 to 1995. Three hundred twenty-five subjects with SAHS, predominantly male (89%) and/or obese (77%) subjects, have benefited. Mean use of nCPAP machine, assessed by reading the time counter, amounted 4.7 h per 24 h, with only 23% of non-compliant patients (use < 3 h per 24 h). In 205 patients nCPAP was effective in controlling SAHS-related symptoms. Cure, with successful weaning from nCPAP, was obtained in 16 patients, as a result of marked weight loss in 13 of them. Forty-six non-compliant subjects were not allowed by the physician to go on, and 40 subjects left nCPAP because of intolerance. Finally, 10 patients abandoned nCPAP because of inefficacy, ascribed to some associated condition, being predominant, and 8 patients died. Our results suggest that domiciliary nCPAP is an effective treatment for SAHS in a majority of subjects, but that this kind of treatment is prescribed lifelong, unless there is a marked weight loss. The Belgian conventional system, as it requires a regular follow-up, contributes to keep non-compliance within acceptable limits.

Adult↗
PubMed1996

Cognitive functioning in patients with chronic fatigue syndrome.

A comprehensive battery of neuropsychological tests was administered to 35 outpatients suffering from Chronic Fatigue Syndrome (CFS). They were compared to 33 normal controls matched for age, gender, intelligence, and education. The patients displayed psychomotor slowing and impaired attention. The learning rate of verbal and visual material for patients with CFS was slower, and delayed recall of verbal and visual information was impaired. Because there was a high variability in cognitive impairment within the CFS group, it would be inappropriate to generalize results to the entire CFS population. Two neuropsychological variables indicating aspects of psychomotor performance and verbal memory were found to discriminate best between patients and controls.

Adult↗