Biomedical subjects

R Cluydts

Publications and source records attributed to R Cluydts.

31 records · Page 2Linked to original sources

PubMed1996

Neuropsychological functioning and determinants of morning alertness in patients with obstructive sleep apnea syndrome.

Neuropsychological functioning is reported to be impaired in patients suffering from obstructive sleep apnea syndrome (OSAS). This syndrome is characterized by nocturnal respiratory disturbances, blood oxygen desaturations, sleep fragmentation, and excessive daytime sleepiness. Opinions are divided concerning the exact relationship between the observed cognitive deficits, nocturnal hypoxia, sleep disruption, and impaired daytime alertness. In the present study, morning neuropsychological function of 26 moderate to severe middle-aged sleep apneics is compared to that of 22 primary insomniacs. There were no performance differences on a range of neuropsychological tests among the two patient groups. In addition, the data suggest that morning alertness impairment, which is closely associated with a lack of slow wave sleep (SWS) and rapid eye movement (REM) sleep, is of major importance in inducing poorer cognitive performance in patients with moderate to severe sleep apnea.

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↗

PubMed1996

Comparison of 99m Tc HMPAO SPECT scan between chronic fatigue syndrome, major depression and healthy controls: an exploratory study of clinical correlates of regional cerebral blood flow.

An explorative analysis of the relationship between symptomatology and cerebral blood flow in the chronic fatigue syndrome (CFS) as assessed with 99mTc HMPAO SPECT scan reveals statistically significant positive correlations between frontal blood flow on the one hand and objectively and subjectively assessed cognitive impairment, self-rating of physical activity limitations and total score on Hamilton Depression Rating Scale on the other. A pathophysiological role of frontal blood flow in the cognitive impairment and physical activity limitations in CFS is hypothesized. A comparison of cerebral blood flow between CFS, major depression (MD) and healthy controls (HC) has been performed. A lower superofrontal perfusion index is demonstrated in MD as compared with both CFS and HC. There is neither a global nor a marked regional hypoperfusion in CFS compared with HC. Asymmetry (R > L) of tracer uptake at parietotemporal level is demonstrated in CFS as compared with MD.

Adult↗

PubMed1995

Antagonizing the effects of experimentally induced sleep disturbance in healthy volunteers by lormetazepam and zolpidem.

The effects on sleep of two well known hypnotics, lormetazepam and zolpidem, during experimentally induced environmental noise were compared with placebo. In a double-blind, crossover study, 12 normal volunteers were subjected to prerecorded traffic noise with a mean noise level of 52 dB(A) and peaks to 77 dB(A) continuously for 8 hours in bed. Both hypnotics increased total sleep time, predominantly stage 2 sleep. A significant decrease in the number of sleep stage transitions, arousals, and awakenings longer than 3 minutes was found only with lormetazepam. No significant effects on rapid eye movement (REM) and slow wave sleep were observed. Latencies to persistent sleep and REM sleep onset were not different for either active treatment compared with placebo. Only after lormetazepam was performance on the morning reaction time test significantly affected. However, no differences were found in the subjective sleep quality and alertness ratings. Changes in the distribution of sleep stages throughout the night were related to the elimination half-life characteristics of the hypnotics, but few trends were detected. Both the protective properties against environmental noise of the hypnotics studied and the validity of the model of induced sleep disturbance in evaluating hypnotic agents are discussed.

Adult↗

PubMed1994

Effects of bretazenil vs. zolpidem and placebo on experimentally induced sleep disturbance in healthy volunteers.

The effects of bretazenil 0.25 and 0.5 mg, a partial agonist at the benzodiazepine receptor, on sleep electroencephalogram (EEG), subjective sleep quality and morning psychomotor performance were compared to zolpidem 10 mg and placebo using noise as an experimental sleep disturbing factor in a single dose, double-blind, crossover study. Twelve healthy volunteers were subjected to prerecorded traffic noise with a mean sound level of 52 dB(A) during eight hours in bed. Significant effects of noise were found on sleep electroencephalogram (EEG) parameters (rapid eye movement [REM] sleep, stage 2 sleep and number of arousals), and subjective sleep quality assessments, but not on psychomotor performance (choice reaction time, digit span memory, and symbol digit substitution). Both drugs reduced the number of shifts between sleep stages and the number of arousals and increased REM sleep latency. Only after 0.5 mg bretazenil, stage 2 sleep increased and REM sleep decreased. Both doses of bretazenil significantly affected performance in the symbol digit substitution test. Sleep quality improved under drug treatments compared to placebo. The results suggest that experimental sleep disturbance can be a valuable tool in the investigation of potential sleep promoting compounds.

Adult↗

PubMed1993

MMPI assessment of the DSM-III-R histrionic personality disorder.

This study investigated the MMPI characteristics of a group of 25 Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev. [DSM-III-R]; American Psychiatric Association, 1987) histrionic personality disorder patients, contrasted with a mixed group of 57 other personality disorder patients. All patients were diagnosed by means of a semistructured interview (SCID-II; Spitzer, Williams, & Gibbon, 1987). Effects for diagnostic category were found for MMPI Scales 9 (Ma), 0 (Si) and for the HST scale, developed by Morey, Waugh, and Blashfield (1985) for the diagnosis of the histrionic personality disorder. Further analysis of the results revealed that these MMPI scales, and especially the HST scale, mainly assess a social introversion-extraversion dimension, on which histrionic inpatients can be differentiated from nonhistrionic inpatients. This study does not offer direct empirical support for the use of the HST scale as a measurement of the DSM-III-R histrionic personality disorder concept.

Adolescent↗

PubMed1991

MMPI characteristics of the DSM-III-R avoidant personality disorder.

The clinical description provided by the MMPI Scale 0 (Social Introversion, Si) reflects an apparent and striking affinity with the DSM-III--R concept of the avoidant personality disorder which was here investigated by comparing the MMPI variables of 22 avoidant with 60 other, nonavoidant personality disordered inpatients. Both of the groups were diagnosed by use of a semistructured interview (SCID-II). The avoidant group obtained for mean MMPI profile a 2-6-7 (D-Pa-Pt) code. Significant differences were found between groups on MMPI Scales 2 (D), 7 (Pt), 9 (Ma), and 0 (Si). ROC analysis of the diagnostic performance showed the importance and utility of the evaluation of Scale 0 (Si) in the psychodiagnostic assessment of the avoidant personality disorder.

Adult↗

PubMed1991

Low MMPI diagnostic performance for the DSM-III--R obsessive-compulsive personality disorder.

This study investigated the diagnostic performance of the MMPI validity and clinical scales, and especially of Scale 7 (Pt), for the DSM-IIII--R obsessive-compulsive personality disorder by comparing the MMPI variables for 24 obsessive-compulsive with those for 58 nonobsessive-compulsive inpatients. Both groups were diagnosed by semistructured interview (SCID-II). The obsessive-compulsive group obtained for the mean MMPI profile a 2-(6-1) (D-Pa-Hs) code, with a tendency for a lowered Scale 4 (Pd) score, compared to the nonobsessive-compulsive group. Neither the ROC analysis of the individual MMPI scales, including Scale 7 (Pt), nor the analyses of frequency of two-point codes and elevated (T greater than 69) scales showed any clear indications of good diagnostic performance for the DSM-III--R obsessive-compulsive personality disorder.

Adolescent↗

PubMed1989

Explorative single-blind study on the sedative and hypnotic effects of buspirone in anxiety patients.

In this single-blind study the sedative and hypnotic properties of buspirone, a nonbenzodiazepine anxiolytic, were investigated in 8 anxious outpatients. Polysomnographic recordings were gathered during baseline, at the start of active medication, after 3 weeks of treatment and one night after discontinuing treatment. Daytime alertness was measured using the Multiple Sleep Latency Test and performance tests. The effects of buspirone on sleep structure were minimal and of no clinical consequence. Subjectively, the patients reported improved sleep quality. There were no effects on daytime alertness at the beginning, after 3 weeks or at sudden discontinuation of the medication. It is concluded that buspirone does not have a sedative or hypnotic effect in anxiety patients.

Adult↗

PubMedDate not supplied

Comparison of continuous versus intermittent administration of zolpidem in chronic insomniacs: a double-blind, randomized pilot study.

The subjective efficacy and safety of intermittent administration of a hypnotic for insomnia was assessed, since such a regime may provide a potential means of reducing the risk of habituation and dependence. A total of 160 adult patients (mean 45 years) with chronic insomnia were treated for 2 weeks with zolpidem, 10 mg, either continuously or intermittently (five nights zolpidem, two consecutive nights placebo per week) in this multicentre, out-patient, pilot study. At the end of the 2-week treatment, patients subjectively estimated their nightly total sleep time as 6.96 +/- 1.19 h (from 6.07 +/- 1.25 h at baseline) and 6.94 +/- 1.30 h (from 5.72 +/- 1.46 h) after the continuous and intermittent treatments, respectively. Patients' reports did not indicate any differences between the two groups in global evaluation of impairment, sleep quality, or the incidence of adverse events. These results suggest that the efficacy and safety of zolpidem, 10 mg, are comparable whether the drug is administered every night or intermittently. Further studies with a broader well-defined patient base, are needed to confirm these data.

Adult↗

PubMedDate not supplied

Insomnia. From a single entity to a complex concept.

This paper presents a summary of 106 patients monitored at the Sleep/Wake Disorders Center of the University Hospital in Antwerp. Diagnostic assessment is based upon information from history, physical and psychiatric examination, sleep logs, psychological tests and polysomnographic workups, including at least 2 consecutive nights. A major conclusion is that complete understanding of sleep problems needs a multifactorial approach. This not only leads to a more accurate description of the disorder, but also to rational, specific and individualized treatment strategies.

Diagnosis, Differential↗

PubMedDate not supplied

Mood and Sleep. I. Effects of the menstrual cycle.

Four female subjects were studied during eight nights each at corresponding days of the menstrual cycle. No clear cycle effects could be discerned in the sleep variables of the subjects as a group. In one subject, however, a U-shaped course of negative mood was found during the menstrual cycle, together with an enhanced percentage of stage 2 sleep and a lowered percentage of slow wave sleep at the time of the menses. In the three other subjects' cycles no such cyclic variations in the mood or sleep variables were found.

Adult↗

PubMedDate not supplied

Mood and sleep. II. Effects of aversive pre-sleep stimulation.

To study the effect of an aversive film on subsequent sleep, 10 subjects slept in the sleep laboratory for two nights: one control night and one night after showing a color surgical movie. Only those subjects with higher tension scores on a self rating mood scale had a lowered number of sleep stage shifts, a higher percentage of stage 2 sleep and a higher number of waking periods and less sleep in the first 180 minutes after falling asleep.

Adult↗