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Biomedical subjects

M Billiard

Publications and source records attributed to M Billiard.

At least 55 records · Page 3Linked to original sources
PubMed1996

Ultradian aspects of sleep in narcolepsy.

Following a baseline night recording, 9 narcoleptic subjects and 9 sex and age-matched control subjects were maintained on 16 hours of diurnal sleep deprivation. Thereafter subjects were submitted to a 32 hour bed rest protocol in a sound-light attenuated room. The EEG was recorded and processed using a Fast Fourier Transform. Narcoleptic patients did not differ from control subjects in total sleep time over the whole time-span. An ultradian tendency to sleep seems to be predominant in narcoleptic patients and evidence of a strong basic rest activity cycle is shown. The coupling between the homeostatic process of sleep regulation and an ultradian drive to sleep would explain the peculiar 4 hour distribution pattern of SWA in narcoleptic patients.

Activity Cycles↗
PubMed1996

Use of modafinil in the treatment of narcolepsy: a long term follow-up study.

One hundred and forty patients (104 male and 36 female) aged 42.26 +/- 19.19 (range = 8 to 79.5 years) with narcolepsy-cataplexy were given modafinil (200 to 400 mg) at the Montpellier sleep disorders center from 1984 onwards. The follow-up focused on the reduction of excessive daytime somnolence (EDS), side effects and duration of treatment. In order to determine if any clinical aspect of narcolepsy could be involved in modafinil discontinuation, patients were divided into two groups according to continued or interrupted treatment. When modafinil effect on EDS was evaluated according to a scale varying from 0 (no effect) to 3 (excellent effect), 64.1% of the subjects, scored good or excellent. The mean duration of treatment was 22.05 months +/- 24.9, ranging from 1 to 114 months. Dependency signs were never observed.

Adolescent↗
PubMed1996

Idiopathic hypersomnia.

Idiopathic hypersomnia is not as well delineated as narcolepsy and its history is much more recent. There are at least two forms of the disorder: (1) a polysymptomatic form, characterized by excessive daytime sleepiness, nocturnal sleep of abnormally long duration, and signs of sleep drunkenness on awakening, and (2) a monosymptomatic form that manifests only by excessive daytime sleepiness. The most widely used laboratory procedures are nocturnal polysomnographic recording following by an MSLT demonstrating a mean sleep latency of less than 10 minutes. At least in the polysymptomatic form, however, continuous polysomnography on an ad lib protocol deserves to be performed to catch the abnormally long major sleep episode and the long unrefreshing naps. Idiopathic hypersomnia is probably one of the most overdiagnosed sleep disorders. Several other disorders must be excluded before the diagnosis can be considered conclusive. Treatment of idiopathic hypersomnia relies on stimulants, which are frequently less effective and less well tolerated than in narcolepsy.

Adult↗
PubMed1996

[Circadian rhythm in normal and pathological sleep].

Different challenges, constraints for quality of sleep and wakefulness, sleep in extreme conditions, search for a better identification of disorders of sleep and wakefulness, spur researches on the circadian rhythm of sleep and on its disorders. Any advance in that field rests on the understanding of different physiologic phenomena: the intrinsic period of our internal clock is not 24-hours but a little less than 25-hours and it must be reset daily by the Zeitgebers. A sudden phase shift provokes an external desynchronisation. In addition not all rhythms resynchronize together resulting in an internal desyncronization. There is a close relationship between quantities of total sleep and REM sleep and the time of sleep onset within the 24-hours. The propensity to sleep follows a circasemidian rhythm with a major peak during the night and a secondary peak in the midafternoon. Disorders of the circadian rhythm of sleep are of two types: related to the misalignment of the sleep-wake schedule and the synchronizer-controlled rest-activity rhythm (shift work sleep disorder and time zone change syndrome) or related to an abnormal escape of the individual rest-activity rhythm from synchronizer control (delayed sleep phase syndrome, advanced sleep phase syndrome and non 24-hour sleep-wake syndrome.

Biological Clocks↗
PubMed1995

Dynamics of slow wave activity in narcoleptic patients under bed rest conditions.

Following a baseline night recording, 9 narcoleptic subjects and 9 sex- and age-matched control subjects were maintained on 16 h of diurnal sleep deprivation. Thereafter subjects were submitted to a 32 h bed rest protocol in a sound- and light-attenuated room. The EEG was recorded and processed by a Fast Fourier Transform. Narcoleptics did not differ from controls in total sleep time over the whole 32 h, but spent more time sleeping during the daytime (DT). In both groups slow wave activity (SWA) showed an exponential decaying trend during the first night (N1); a similar exponential trend during the second night (N2) was evident only in controls. In controls SWA showed a circadian-circasemidian distribution that was hardly detectable in nacroleptics. Narcoleptics showed an ultradian distribution of SWA with periodic emergence every 4 h during DT and N2. Our data confirm that a homeostatic mechanism is evident in narcolpetics when stimulated by diurnal sleep deprivation, while circadian and circasemidian mechanisms are less evident during DT and N2. These findings suggest a different coupling between homeostatic sleep regulating and circadian drives to sleep in narcoleptics. Ultradian drives to sleep seem to be predominant in these patients, thus probably acting as a means for the avoidance of stressful attempts to counteract a weaker waking state maintenance mechanism.

Adult↗
PubMed1995

Changing heat and moisture exchangers every 48 hours rather than 24 hours does not affect their efficacy and the incidence of nosocomial pneumonia.

Heat and moisture exchangers (HME) (Dar-Hygrobac II, Peters) can safely be used every 24 h for long-term mechanical ventilation and provide a cost-saving alternative to heated humidifiers. We have prospectively determined whether changing HMEs every 48 h only affects their clinical and bacteriological efficiency in a series of consecutive nonselected ICU patients requiring long-term mechanical ventilation. Two consecutive periods were compared. During period 1, HMEs were replaced every day; during period 2, they were changed every 48 h. Patients from the two periods were similar in terms of age and indication for and overall duration of MV (10 +/- 8.6 versus 10 +/- 9 d, p = 0.9). Minute ventilation and maximum values for peak airway pressure were identical during the two periods. These values were also identical after 1 and 2 d of HME use during period 2, indicating that HME resistance was not increased by prolonged use. Obstruction of the tracheal tube occurred only once in a period 1 patient. The results of quantitative cultures indicate that the maximum and mean levels of bacterial colonization during the two periods were similar for the pharynx, trachea, Y-connector, patient, and ventilator side of the HME. More importantly, the incidence of nosocomial pneumonia was similar during the two periods (6/61 versus 8/68, p = 0.7). Thus, prolonged HME use is safe and provides a substantial reduction in the cost of mechanical ventilation.

Adult↗
PubMed1995

Effects of zolpidem on the architecture and cyclical structure of sleep in poor sleepers.

Effects of zolpidem, a short acting non benzodiazepine hypnotic, have been studied in eight female poor sleepers, aged 25 to 54 years, documented during two consecutive adaptation nights. Subjects were recorded according to a 22 day single blind study. Placebo was given orally at bedtime on nights 2-4, zolpidem on nights 5-20 and finally placebo on nights 21-22. Polygraphic recordings (conventional analysis) were performed on nights 1-6; 12, 13; 19-22. Parameters of sleep continuity, sleep architecture and cyclical structure of sleep were studied. Zolpidem 10 mg showed a hypnotic effect on poor sleepers. It reduced sleep latency, increased total sleep time and decreased the number of awakenings during all recorded nights. During the first post-drug night a rebound insomnia was observed in two subjects only. Zolpidem did not increase specifically stage 2 to the detriment of stages 3 and 4 but it restored them during the first nights of administration. Study of the rapid eye movements-non rapid eye movements (REM-NREM) sleep cycles structure showed that the increase of stages 3 and 4 occurred only during the first part of the night. Finally, zolpidem had no effect on REM sleep temporal distribution.

Adult↗
PubMed1994

Objective and subjective sleep disturbances in patients with rheumatoid arthritis. A reappraisal.

OBJECTIVE: To assess objective and subjective evidence of sleep disturbances in patients with rheumatoid arthritis (RA) and to examine correlations between parameters of inflammatory activity and sleep pathology. METHODS: Nineteen RA patients and 19 age-matched healthy control subjects underwent all-night polysomnography on 2 consecutive nights. RA patients were also evaluated for daytime sleepiness by mean sleep latency test and responded to a self-report questionnaire on their first night. RESULTS: Whereas normal sleep architecture is conserved in RA, we confirmed former findings of severe sleep fragmentation and an enhanced presence of primary sleep disorders. No correlation exists between RA activity and the sleep disorders. Subjective assessment was not consistent with the objective evidence of sleep disruption, unlike the findings in patients with fibrositis. CONCLUSION: Sleep is severely disturbed in patients with RA, regardless of the inflammatory disease activity. The specificity of the sleep disorders assessed needs confirmation, as does specific sleep therapy for these patients.

Adult↗
PubMed1994

Hypersomnia associated with mood disorders: a new perspective.

Thirty-six subjects affected with hypersomnia associated with mood disorders, 31 with a diagnosis of dysthymia, 4 with a diagnosis of bipolar disorder and one with a diagnosis of major recurrent depression underwent standardized polysomnographic procedures including night 1, MSLT and night 2 (uninterrupted). 36.1% of these subjects had a reduced or intermediate mean sleep latency on the MSLT and 13.8% slept over 9 hr at night. In addition 17 of these subjects underwent prolonged polysomnography during day 2. In comparison with eight subjects affected with idiopathic hypersomnia, mean sleep latency on the MSLT was significantly longer and total sleep time during night 2 and during night 2 plus day 2 was significantly lower in subjects affected with hypersomnia associated with mood disorders. It is concluded that a positive diagnosis of hypersomnia associated with a mood disorder requires both behavioral observation and polysomnography. Among these subjects there may be subjects with well-documented hypersomnia and subjects with anergia facilitating or mimicking sleep.

Adult↗
PubMed1994

Modafinil: a double-blind multicentric study.

Modafinil is a central putative alpha-1 postsynaptic agonist with vigilance-promoting properties. Fifty narcoleptics (33 male and 17 female) participated in a multicentric study aimed at assessing the effects of the compound on night sleep, feeling on awakening, excessive daytime sleepiness and cataplexy. Modafinil was administered in a double-blind cross-over design at a daily dosage of 300 mg versus placebo. The duration of the study was 12 weeks, including a 2-week "run in" period with placebo, a first 4-week treatment period with either modafinil or placebo, a 2-week wash-out period with placebo and a second 4-week treatment period with either placebo or modafinil. Daily evaluation was based on a sleep log, visual analog scales, a sleep questionnaire and a clinical global index. Sleep laboratory evaluation took place on nights 1, 28, 42 and 70. It included 1 night of polysomnography preceded by a questionnaire on therapeutic and side effects, and a maintenance of wakefulness test (MWT). Sleep logs did not show any modification of night sleep, but a reduction of daytime sleepiness and sleep. Feeling on awakening was not modified. An overall benefit was noted by physicians as well as by patients. MWT disclosed a positive effect of modafinil on excessive daytime sleepiness. Cataplexy was not modified.

Adult↗
PubMed1994

Life events in the year preceding the onset of narcolepsy.

A multifactorial etiology for narcolepsy has been postulated, stressing the importance of environmental factors in the clinical onset of the condition. Our study evaluated the occurrence of stressful life events in the year preceding the onset of narcolepsy. Fifty narcoleptic and 50 control subjects completed a life event questionnaire (the Schedule of Recent Experiences). The proportion of narcoleptic subjects reporting the presence of life events in the year preceding the onset of narcolepsy was significantly greater than the proportion of control subjects reporting life events in the corresponding year. Moreover the weight of life events was increased in narcoleptic subjects in comparison with controls. In conclusion life events seem to be increased in narcoleptic subjects in the year preceding the onset of their condition. However a number of other factors could not be taken into consideration, which limits the full significance of these data.

Adolescent↗
PubMed1994

Family studies in narcolepsy.

Out of a population of 188 unrelated narcoleptic probands, we identified 14 probands (7.44%) with a family history of narcolepsy, 23 (12.23%) with a family history of isolated repeated episodes of naps and/or lapses into sleep and 151 (80.31%) without a family history of either condition. Clinical, polysomnographic or zygotic differences could not be evidenced in the three groups. Empirical risk for narcolepsy was 40.7 times greater among first-degree relatives of narcoleptics than in the general population. Narcolepsy and the condition characterized by isolated repeated episodes of naps and/or lapses into sleep have a common genetic component. This finding has important implications. Indeed, when the latter condition is included in the spectrum of narcolepsy, the empirical risk figure is relatively close to that expected in cases of simple mode of inheritance. A trend in favor of a more frequent transmission through mothers than fathers is emphasized.

Age of Onset↗
PubMed1994

Homeostasis and narcolepsy.

Narcolepsy is characterized by irresistible daytime sleep episodes and cataplectic attacks. Because of the finding of an ultradian rhythmicity of slow-wave sleep in narcolepsy, an alteration of nonrapid eye movement sleep homeostatic regulation has been hypothesized to explain the impairment of the sleep-wakefulness cycle. This hypothesis was tested by two different methods: 1) a sleep-deprivation method (16 or 24 hours) increasing the prior sleep wakefulness and 2) a bed-rest method shortening the prior sleep wakefulness. In both studies normal subjects, sex- and age-matched to narcoleptic subjects, served as controls. Although some differences could be evidenced between the two groups, it was clearly shown that the homeostatic process was functional in narcolepsy and that narcoleptics seemed to be more sensitive to homeostatic regulation of sleep than normal subjects.

Adolescent↗
PubMed1994

[Somatosensory evoked potentials in amyotrophic lateral sclerosis and primary lateral sclerosis].

Somatosensory evoked potentials (SEPs) were studied in 21 cases of amyotrophic lateral sclerosis (ALS) and 7 cases of primary lateral sclerosis (PLS). Despite the lack of clinical sensory abnormalities, SEPs showed abnormalities in both diseases: lack or delay of some components. In ALS these abnormalities indicate widespread sensory disturbance. In PLS only, the Brodmann area 4 seems to be affected.

Adult↗