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Biomedical subjects

M Billiard

Publications and source records attributed to M Billiard.

At least 19 recordsLinked to original sources

Sleep deprivation in narcoleptic subjects: effect on sleep stages and EEG power density.

Sleep of 8 narcoleptic and 8 control subjects was recorded under baseline (i.e., prior wakefulness 16 h) and after 24 h without sleep. During both baseline and recovery total sleep time and stage 2 non-REM sleep were significantly decreased in narcoleptic subjects. Slow wave activity (i.e., EEG power density in the range of 0.75-4.5 Hz) decayed exponentially during baseline and after sleep deprivation in both narcoleptic and control subjects. During both baseline and recovery EEG power density in delta and sigma frequencies in non-REM sleep was enhanced in narcoleptic subjects relative to controls. In REM sleep differences in the same direction were present in delta and beta frequencies. After sleep deprivation EEG power density in non-REM sleep was elevated in delta and some higher frequencies in both patients and controls, but the response to sleep deprivation was stronger in narcoleptic subjects. These data show that in narcoleptic subjects regulatory processes underlying non-REM sleep homeostasis are operative and indicate that the response to sleep deprivation is stronger than in control subjects.

Adolescent

Effects of zopiclone on subjective evaluation of sleep and daytime alertness and on psychomotor and physical performance tests in athletes.

1. In a double-blind cross-over study 8 athletes received during 2 sessions of 2 nights zopiclone (7.5 mg) or placebo. 2. Residual effects on subsequent daytime functions were evaluated both subjectively by visual analogue scales as well as objectively by a test battery measuring psychomotor and physical skills. 3. Zopiclone had some favourable effects on self-estimated sleep quality and daytime sleepiness. 4. Psychomotor and physical performance tests did not show any significant difference between zopiclone and placebo. 5. We conclude that zopiclone has useful hypnotic activity without significant adverse effects on athletic performance.

Adult

Epileptic electroencephalographic abnormalities and developmental dysphasias: a study of 32 patients.

The relationships between severe developmental dysphasias and epilepsy were analysed in 32 patients with congenital dysphasias. The mean age was 8 years 2 months; 19 of 32 had never had seizures; 9 had had occasional seizures; 4 were epileptic. Twenty-two of 32 had normal repeated standard EEGs, but 10 (2 of which never had seizures) showed epileptic interictal discharges. During prolonged EEG after sleep deprivation, epileptic abnormalities were observed in 13 of the 32 cases (4 of which never had seizures). The overall night sleep recordings showed epileptic abnormalities in 30 of the 32 cases (17 of which had never had seizures). The epileptic interictal abnormalities varied considerably in intensity and aspect in the same patient from one examination to another. Developmentally aphasic children show a higher incidence of abnormal EEG than expected, particularly during overall night recordings. In most cases, the physiopathology of the language disturbance might be identical to that in Landau-Kleffner syndrome.

Adolescent

Sleep in human narcolepsy revisited with special reference to prior wakefulness duration.

Sleep of 11 narcoleptic subjects was recorded on baseline and after 16 and 24 hours of prior wakefulness (16 and 24 hours sleep deprivation). Eleven sex- and age-matched control subjects were recorded for comparisons. All recordings in narcoleptic subjects were characterized by frequent sleep onset rapid eye movement (REM) episodes, increased amounts of wake time after sleep onset and low sleep efficiencies. Mean total sleep time (TST) was significantly decreased in narcoleptic subjects after sleep deprivation (SD). Recovery sleep after 24 hours SD showed reduced nonREM (NREM) sleep stage 2 percentage, whereas percentages of stage 4 and slow-wave sleep (SWS = stages 3 + 4) were significantly increased. The values of REM sleep percentage of TST were remarkably constant throughout and did not differ significantly as a function of experimental conditions, indicating a normal REM sleep pressure in narcolepsy. Sleep stage analysis per sleep cycles revealed significant differences between the two groups. Percentages of stage 4 and SWS were increased during the first cycle of recovery sleep in narcoleptic subjects. Stage 2 was decreased during the third cycle, and SWS decreased rapidly from cycle 1 to cycle 2 and slightly increased thereafter. These results indicate that sleep need is increased in narcolepsy, whereas its decrease over the first NREM-REM cycle is accelerated. We hypothesize that this could reflect an alteration of the homeostatic process of sleep regulation in narcolepsy.

Adolescent

DQB1-0602 (DQw1) is not present in most nonDR2 Caucasian narcoleptics.

Human narcolepsy is a genetically determined disorder of sleep strongly associated with the human leucocyte antigens (HLA) DR2 and DQw1. In black narcoleptic patients, susceptibility for narcolepsy is more closely related to a specific gene subtype of DQw1, DQB1-0602, than to DR2. About 30% of black narcoleptic patients are nonDR2, but all carry the HLA DQB1-0602 gene. In the present study, we have tested caucasian nonDR2 cataplectic patients (6 sporadic cases and 7 familial cases from 3 multiplex families) for the presence of the HLA DQB1-0602 and DQA1-0102 (DQw1) using a specific polymerase chain reaction (PCR)-oligotyping technique. None of the patients was DQB1-0602 or DQA1-0102 positive, thus proving that, in caucasians, DQB1-0602 and DQA1-0102 (DQw1) are not prerequisites for the diagnosis of narcolepsy. Further studies with more patients are warranted to exclude the possibility that a few caucasian patients carry rare haplotypes with DQB1-0602 independently of DR2.

Amino Acid Sequence

Surgical alternatives to uvulopalatopharyngoplasty in sleep apnea syndrome.

Uvulopalatopharyngoplasty (UPPP) is the surgery most often performed for sleep apnea syndrome (SAS). However, good results with UPPP, demonstrated by polysomnography, have been reported in only 50% of cases. Failure of UPPP may be caused by: 1) bad management of the SAS, which is better treated in some patients with nasal CPAP than with surgery; and 2) an airway obstruction located not only at the palatopharynx (PP) level. Other surgical procedures to enlarge other sites of obstruction are described. Retro-tongue-base-pharynx (RTBP) surgery is emphasized, including mandibular advancement, hyoid bone suspension, and tongue base reduction. Maxillomandibular advancement is the most efficient technique but also the most complicated.

Airway Obstruction

[Urination control during sleep].

The authors present their approach to the sleep factor in children with enuresis, based on a still on-going exploration of manometric changes in bladder activity. Twenty patients have already been examined by cystomanometry in day time and polygraphic sleep recording at night, combined with continuous measurement of bladder pressure. This method derives from the studies of Gastaut and Broughton, in 1963, but takes into account the concept of bladder immaturity. The patients studied fell into two homogeneous groups, depending on whether enuresis was obviously due to bladder immaturity (Group I) or was strictly isolated (Group II). No disorder of sleep organization has been found in none of these two groups, but both had apparently nonspecific irritant factors. The enuresis episode is described. It tends to occur frequently at the beginning of the night, is prepared by an increase in bladder pressure which is always very pronounced in Group I subjects, and is associated with insufficient awakening reaction due to an apparently exceedingly high awakening threshold. The physiopathological and therapeutic implications of these findings are discussed.

Adolescent

Why don't all heavy snorers have obstructive sleep apnea?

Patients with obstructive sleep apnea (OSA) and heavy snorers without apnea both show intrathoracic suction pressures during sleep that exceed their static upper airway closing pressures. Complete airway occlusion, however, occurs only in the former patient group. We hypothesized that the kinetic properties of the airflow would be different in these two types of patients because of differences in upper airway morphology. The pharyngeal computed tomography (CT) was used to measure the cross-sectional areas of the upper airways in 15 patients with OSA, 25 nonapneic heavy snorers, and 14 control subjects while they were awake. Nocturnal breathing was monitored with the static charge-sensitive bed (SCSB). The patients with OSA had a narrower airspace at the velopharyngeal (VP) level than the controls (p less than 0.01); the nonapneic snorers did not differ from the other groups. At the tongue base (TB) and the hyoid bone (HB) levels there was no difference between the OSA and the control groups, but the nonapneic snorers had narrower airways at both of these levels compared with control subjects (p less than 0.01) and at the hyoid bone level compared with the OSA group (p less than 0.05). The VP/HB ratio was the parameter that best distinguished the patients with OSA from the nonapneic snorers (lower in the OSA group, p less than 0.001). We suggest that airway collapse during sleep is favored by a narrow velopharynx associated with large hypopharynx. Some heavy snorers may not have an oropharyngeal collapse because the peak inspiratory suction pressure could already be damped down at the level of the relatively narrow hypopharyngeal airways.

Airway Resistance

Sleep organization and epilepsy.

Sleep is known to facilitate epileptic manifestations but can also protect the sleeper against the recurrence of seizures. This has been demonstrated in studies on sleep deprivation, and is particularly evident in alcoholic epilepsy and matutinal myoclonus epilepsy. Sleep organization in the epileptic patient is permanently altered by frequent awakenings and stage shifts. Nocturnal grand mal and repetitive partial seizures worsen the sleep disorder by reducing total sleep time and decreasing REM percentage by half. The cumulative effect of these sleep disorders may act on day-time vigilance in epileptics, and may even exert an influence on the recurrence of seizures.

Adult

CSF immune variables in patients with narcolepsy.

Cerebrospinal fluid (CSF) and serum from 15 patients with narcolepsy were examined regarding presence of oligoclonal bands on isoelectric focusing, IgG index elevation as indicator of intrathecal IgG production and CSF/serum albumin ratios. Two of 15 patients (13%) showed oligoclonal IgG bands in CSF, one of whom had increased IgG index. Slight disturbance of blood-brain-barrier function as reflected by elevated CSF/serum albumin ratios was present in 4 other patients. The frequency of oligoclonal IgG bands in CSF from patients with narcolepsy is within the range of what is found in other neurological, non-inflammatory diseases. These findings do not support the hypothesis of an immune-mediated pathogenesis of narcolepsy.

Adolescent

Partial upper airway obstruction in sleep after uvulopalatopharyngoplasty.

Uvulopalatopharyngoplasty is the treatment of choice for selected patients with obstructive sleep apnea, although the response to surgery is variable. We measured, in addition to obstructive apnea, the frequency of sleep-related partial upper airway obstruction in 11 patients with the obstructive sleep apnea syndrome both before and after uvulopalatopharyngoplasty. Partial obstruction was detected indirectly by recording the secondary hemodynamic changes and respiratory stimulation with the static charge sensitive bed. The frequency of obstructive apnea episodes was reduced from 56.3% to 18.4% by the operation, while the episodes of increased respiratory resistance rose from 3.6% to 20.4%. The various breathing anomalies decreased significantly, although they were still present during 75.6% of the recording time. The results suggest that uvulopalatopharyngoplasty substantially reduces the frequency of obstructive apnea, some of which persists as partial obstruction. The persistent partial obstruction may be the key factor contributing to further pharyngeal narrowing and a recurrence of obstructive sleep apnea syndrome.

Airway Obstruction

[Effects of zopiclone on sleep, daytime somnolence and nocturnal and daytime performance in healthy volunteers].

Ten healthy volunteers, aged 20 to 39, underwent 2 adaptation nights and 3 sessions of 2 consecutive experimental nights and days at 1 week intervals. In the 3 sessions, subjects received under double blind conditions either Zopiclone 3.75 mg or 7.5 mg or placebo, according to a latin-square design. On nights 1 and 2 of each session, subjects were continuously polygraphically monitored, except for a 45 min provoked wake episode 135 min after sleep onset on night 2. Sleep continuity and architecture were evaluated during night 1, degree of daytime somnolence during day 1 and residual effects during night 2 (0 h 00) and day 2 (8 h 00 and 12 h 00). Sleep continuity was not modified, except for a reduction of the number of night awakenings. NREM sleep stage 1 was reduced and stage 2 was increased (in duration but not in percentage) with Zopiclone 3.75 and 7.5 mg. NREM sleep stages 3 and 4 were increased with Zopiclone 3.75 mg only. REM sleep was reduced (in percentage only) with Zopiclone 3.75 and 7.5 mg. Daytime somnolence varied according to the time but not with the 3 different conditions. One performance test only (choice reaction time test) showed a significant impairment at 0 h 00 with Zopiclone 7.5 mg. From a subjective point of view, sleep quality was improved and night time awakening was reduced with Zopiclone 7.5 mg.

Adult

[A world record in marathon tennis: sleep deprivation and performance].

We studied the effects of marked sleep deprivation on the EEG patterns and performance of a physically fit man (age 26) on the occasion of the world record continuous marathon tennis play (147 hours, 20 minutes). Before and immediately after the marathon, the sleep patterns of the player were recorded in our laboratory. After playing for 40 and 80 hours and within 24 hours, the performance changes were evaluated each hour. Amounts of the different sleep stages during the first recovery night compared with those of the baseline indicate an increase of 56% for total sleep time, 54% for stages 1 and 2, 154% for stages 3 and 4 and 20% for REM sleep. During the second recovery night, only REM sleep showed an increase. Activity index showed a marked decrease after 80 hours of sleep deprivation compared with that after 40 hours and was dramatically worsened during nighttime. The number of faults and pauses was also increased after 80 hours, suggesting a clear performance deterioration. Our results confirmed the effects of sleep deprivation on the recovery and performance deterioration.

Adult

[Recurrent hypersomnia].

Recurring hypersomnias are described according to 3 etiological groups: 1) idiopathic - the Kleine Levin syndrome and its clinical variants - 2) organic and 3) psychiatric. The typical form of the Kleine Levin syndrome is remarkable for the association of recurring episodes of sleep, overeating and temporary mental disturbances lasting from a few hours to several days. Its diagnosis is mainly based on clinical data Laboratory investigations have so far failed to document specific features. Emphasis is laid on circumstances at onset and pathological studies which could be in favour of a viral origin. Some clinical aspects and polysomnographic features are reminiscent of endogenous depression. The treatments of hypersomniac episodes based on stimulants are often disappointing. On the other hand, the prevention of the hypersomniac episodes of the Kleine Levin syndrome with lithium carbonate has been successful in several well-documented cases as well as the prevention of the hypersomniac episodes of the menstruation related hypersomnia with ovulatory inhibitors. Organic and psychiatric forms of recurring hypersomnias are not well known. Their clinical features are described and their various possible etiologies indicated.

Adolescent