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Biomedical subjects

M Billiard

Publications and source records attributed to M Billiard.

At least 91 records · Page 5Linked to original sources

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↗

The validity of the static charge sensitive bed in detecting obstructive sleep apnoeas.

The demand for polysomnographic recordings associated with respiratory control exceeds the capacity of the few existing sleep disorder centres and therefore a simple and inexpensive method is needed for screening and diagnosing sleep-related breathing disorders. The static charge sensitive bed (SCSB) permits long-term recordings of body movements, respiratory movements and the ballistocardiogram (BCG) without electrodes or cables being attached to the subject. The aim of the present study was to test the validity of this particular method in detecting obstructive sleep apnoeas without airflow measurements. Simultaneous SCSB and spirometer recordings were compared in fourteen sleep apnoea patients and six controls. The mean sensitivity of the SCSB method to detect the obstructive apnoeas was 0.92-0.98. The specificity to detect 2 min apnoea epochs was 0.61-0.68 in the apnoea group, while in the control group it was 0.99-1.00. According to this study, the SCSB detects the obstructive events without always distinguishing between severe periodic hypopnoeas and obstructive apnoeas. The sensitivity of the SCSB makes it valuable for screening subjects suspected of having obstructive sleep apnoeas. Further studies will concentrate on a more detailed analysis of the various respiratory, BCG and body movement patterns, which may lead to additional information on the severity of the upper airway obstruction.

Aged↗

Lithium carbonate: effects on sleep patterns of normal and depressed subjects and its use in sleep-wake pathology.

The effects of lithium carbonate on sleep patterns have been investigated both acutely in normal and depressed subjects and chronically in depressed subjects. In normal subjects receiving lithium for two weeks total sleep time did not vary, REM sleep decreased and REM sleep latency increased. In depressed subjects, either on short therm therapy or on long term therapy stages 3 and 4 increased, REM sleep decreased, REM latency increased and REM activity/time spent asleep (an index of REM intensity per minute of sleep) decreased. Plasma lithium levels were negatively correlated with REM sleep percentage and positively correlated with REM sleep latency. Besides, it has been shown in one paper that short term therapy with lithium caused small but significant delays in the sleep-wake circadian rhythm. These effects are of interest in view of polygraphic sleep abnormalities found in affective disorders and possible circadian disturbances accounting for these abnormalities. Indeed lithium might act in correcting spezial sleep abnormalities and/or circadian disturbances. In addition to its predominant use for the prophylaxis of recurrent mania and depression, lithium carbonate has been proposed and tried in the prophylactic treatment of abnormally prolonged sleep episodes featuring the Kleine-Levin syndrome.

Circadian Rhythm↗

Excessive daytime somnolence in young men: prevalence and contributing factors.

To investigate the prevalence of excessive daytime somnolence and contributing factors, 58,162 draftees between 17 and 22 years of age, registered in two selection centers of the French army, were screened by means of a 17-item questionnaire. In response, 8,201 subjects (14.1%) reported occasional daytime sleep episodes, 2,210 (3.8%) one or two daily episodes, and 640 (1.1%) more than two daily episodes. Of the total sample, five percent or 2,933 considered these sleep episodes to affect their lives. Different possible factors of daytime sleep episodes were investigated, including hours of nocturnal sleep, sleep-wake schedule, sleep difficulties, use of hypnotics, snoring, and occurrence of cataplexy. A strong association was found between these factors and excessive daytime somnolence. A stepwise multivariate analysis was performed on five of these factors: hours of nocturnal sleep, sleep-wake schedule, sleep difficulties, use of hypnotics, and snoring. All five factors were shown to be independently related to excessive daytime somnolence and were ranked in the following descending order: use of hypnotics, sleep difficulties, irregular sleep-wake schedule, snoring, and hours of sleep.

Adolescent↗

Dose-response effects of zopiclone on night sleep and on nighttime and daytime functioning.

Six normal volunteers, aged 20 to 39 years, underwent 2 adaptation nights and three sessions of 2 consecutive experimental nights and days at 1-week intervals, according to a latin-square design. In the three sessions, subjects received either zopiclone, 3.75 mg or 7.5 mg, or placebo at 2215 h in a double-blind protocol. On nights 1 and 2 of each session, subjects were continuously monitored polygraphically, except for a 45-min provoked wake episode 135 min after sleep onset on night 2. Degree of daytime somnolence was assessed during day 1 by means of a multiple sleep latency test (MSLT) and performance evaluation was carried out during night 2 (0000 h) and day 2 (800 h and 1200 h) by means of a battery of four tests. NREM sleep stages 3 and 4 increased significantly after 3.75 mg and 7.5 mg zopiclone (p less than 0.05). No significant differences between placebo and 3.75 mg and 7.5 mg zopiclone were found at any time in the MSLT. Two performance tests (eye-hand coordination test and choice reaction time test) showed a highly significant impairment (p less than 0.01) at 0000 h with 7.5 mg zopiclone; one test (eye-hand coordination test) showed a significant impairment (p less than 0.05) at 0800 h also with 7.5 mg zopiclone and none at 1200 h. From a subjective point of view, depth and quality of sleep were improved, whereas number of awakenings and feeling on awakening were not modified. Side effects (bitter taste, jitteriness, difficulty to concentrate) were reported only with 7.5 mg zopiclone.

Adult↗

[Organization of sleep in recent temporal lobe epilepsy before and after treatment with carbamazepine].

Sleep in epileptic patients with complex partial seizures has been considered as being less well organized than in normal subjects. This study attempted to precise whether this disorganization could be related to the length of the disease and could be improved by carbamazepine treatment. The study was performed in 15 patients with recently diagnosed (less than 3 months) and untreated temporal lobe epilepsy. Neurologic examination and CT scan were normal. Patients did not present a generalized seizure in the preceding 48 hours and during the study. Nocturnal sleep polygraphic recordings were performed: 2 recordings before treatment and 2 others after one month of carbamazepine administration (800 mg/day). Before treatment sleep was characterized by a marked instability (increase in awakenings, shifts in sleep stages, waking after sleep onset, stage 1 duration) when compared to normal subjects. Carbamazepine treatment improved sleep stability. Our data support the hypothesis of another possible mechanism than the occurrence of seizures to explain the disorganization of sleep in temporal lobe epilepsy. On the other hand sleep instability could not be related to the length of the disease since it existed soon after its onset. Carbamazepine treatment improved sleep stability and this improvement could play a role in the therapeutic effect of the drug.

Adolescent↗

[EEG abnormalities of late-onset epilepsy].

Interictal EEG abnormalities were evaluated in 111 epileptic patients in which the first seizure occurred after the age of 18 years. Standard day-time EEG tracings performed prior to and after antiepileptic treatment, and all-night recordings were investigated. Before treatment, waking EEG was normal in 54% of patients. The percentage of normal sleep EEG recordings was only 28.6%. Focal EEG abnormalities were found in 39% of day-time recordings and in 48.6% of sleep recordings, while the percentage of generalized epileptic discharges observed was respectively 7 and 22.8. When considering the category of epilepsy and the etiology, it appears that the primary and secondary generalization of epileptic discharges is reduced with age.

Adolescent↗

HLA-DR2 and narcolepsy.

A positive association between HLA-DR2, DQw1, and narcolepsy was documented in 23 French caucasoid narcoleptic patients, 18 who were heterozygous for DR2 and 5 who were possibly homozygous. An autoimmune mechanism of narcolepsy is proposed with three successive stages, as well as relevant methodology for further investigation. A dominant mode of inheritance of narcolepsy, with an incomplete penetrance, is suggested although not yet evidenced.

Adolescent↗

Are REM cycles in narcoleptic patients governed by an ultradian rhythm?

Twelve narcoleptic subjects experiencing at least five daytime REM sleep episodes were monitored for 34 consecutive hours in the laboratory starting at 2200 h one evening and ending at 0800 h a day and a half later. There was no significant difference between the length of the daytime and nighttime REM cycles. To test the hypothesis that an underlying rhythm governs REM episodes, a grid was constructed on the basis of the mean and the SD of the daytime cycles (starting at 0800 h the first morning) was projected on the following nighttime and its correspondence with actual night cycles was evaluated. Overall, it was observed that the number of night cycles falling within the projected grid was significantly higher than chance (p less than 0.01), indicating that nighttime REM episodes tended to fall within the same periodicity as their preceding daytime episodes. This observation supports the hypothesis that an underlying basic rest-activity cycle governs REM sleep episodes in narcoleptic subjects.

Activity Cycles↗