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Biomedical subjects

J Montplaisir

Publications and source records attributed to J Montplaisir.

At least 19 recordsLinked to original sources
PubMed1992

Spectral analysis of the rapid eye movement sleep electroencephalogram in right and left temporal regions: a biological marker of Alzheimer's disease.

Spectral analysis of electroencephalograms (EEGs) for both wakefulness and rapid eye movement (REM) sleep was performed over the temporal regions in 8 patients with mild to moderate Alzheimer's disease and in 8 age-matched control subjects. EEG slowing in Alzheimer patients was found to be much more prominent during REM sleep than during wakefulness. In addition, asymmetry on the awake EEG of Alzheimer patients was found to be even more prominent than on the REM sleep EEG. When EEG values of the most impaired hemisphere during REM sleep were examined, no overlap was found between the two groups either for the ratio of slow to fast frequencies or for percent power of each of the frequency bands. This was not the case for the awake EEG. These results suggest that diagnostically meaningful cutoff values for discriminating patients with mild to moderate Alzheimer's disease from age-matched control subjects can be derived from the REM sleep EEG of the temporal lobe.

Aged↗
PubMed1992

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↗
PubMed1992

Neurobehavioral manifestations in obstructive sleep apnea syndrome before and after treatment with continuous positive airway pressure.

Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent apneas during sleep, resulting in repetitive hypoxemic episodes and a constant interruption of the normal sleep pattern. Vigilance impairment and neuropsychological deficits are among the main symptoms seen in this condition. One of the major questions in this field concerns the reciprocal interactions between nocturnal hypoxemia, sleep disruption, excessive daytime sleepiness and cognitive deficits. Results of this study suggest that vigilance impairment is attributable mostly to nocturnal hypoxemia. However, in cognitive deficits, hypoxemia seems to play a major role in executive and psychomotor tasks, whereas attention and memory functions appear to be related to vigilance impairment. After treatment, hypoxemia-related deficits and some degree of sleepiness persist. These results raise the possibility of an irreversible anoxic central nervous system (CNS) damage in severe OSAS.

Adult↗
PubMed1992

Polysomnographic features of REM sleep behavior disorder: development of a scoring method.

REM sleep behavior disorder (RBD) is characterized by the intermittent absence of REM sleep EMG atonia and the appearance of elaborate motor activity associated with dream mentation. There are no specific diagnostic criteria for RBD based upon polysomnographic findings. We describe a new scoring method and show its sensitivity to treatment with clonazepam. An increased phasic submental EMG density occurs in RBD patients, but REM density is similar to that of controls. Clonazepam selectively decreases REM sleep phasic activity but exerts no effect on REM sleep atonia. Periodic limb movements in sleep (PLMS) occur equally in both REM and NREM sleep in RBD patients, suggesting that normal suppression of PLMS in REM sleep is due to motor inhibition.

Adult↗
PubMed1992

Sensory and motor components of the restless legs syndrome.

The restless legs syndrome (RLS) is characterized by two major manifestations: dysesthesias in the legs and irresistible leg movements. We developed a procedure to quantify these manifestations, and we studied their temporal interrelationships. We found that many dysesthesias may either closely precede or follow occurrences of EMG-defined leg activity, or both manifestations may occur independently. These results suggest that the sensory and motor components of RLS may represent two distinct manifestations of a common basic neurologic defect.

Adult↗
PubMed1992

The treatment of the restless leg syndrome with or without periodic leg movements in sleep.

There are presently three main treatments for restless leg syndrome-periodic leg movements in sleep (RLS-PLMS). The benzodiazepines (especially clonazepam) are considered by most clinicians to be the treatment of choice in mild cases, especially in young subjects. In our experience, however, L-dopa and bromocriptine are more effective treatments, although no controlled studies have ever been conducted to compare their therapeutic benefits and the side effects of benzodiazepines and dopaminergic drugs. The use of opioids should be restricted to patients who have severe symptoms and who fail to respond to benzodiazepines or L-dopa. Propoxyphene was found less effective than L-dopa in decreasing PLMS, but some patients resistant to L-dopa may exhibit a masked therapeutic response to opioids. However, there is currently no method to predict the response to any treatment modality.

Anti-Anxiety Agents↗
PubMed1991

Obstructive sleep apnea syndrome: pathogenesis of neuropsychological deficits.

Neuropsychological deficits have been documented in patients with obstructive sleep apnea syndrome (OSAS). Both nocturnal hypoxemia and impairement of daytime vigilance have been suggested as the pathogenesis of these deficits, yet it remains difficult to find good correlations between cognitive deficits and either of these physiological parameters. In the present study, 10 normal controls were compared to 10 moderately and 10 severely apneic patients, all recorded in a sleep laboratory for two consecutive nights, with a vigilance and neuropsychological assessment made during the intervening day. Relative to the controls, moderate and severe OSAS showed differences in many cognitive functions, although the severely affected showed the greater differences. Moreover, severe apneics were also worse than moderate apneics on tests that were found to be normal in the latter group. This suggests a discontinuity in the appearance of neuropsychological deficits as OSAS progresses. Further analyses revealed that reductions in general intellectual measures, as well as in executive and psychomotor tasks were all attributable to the severity of hypoxemia, while other attention and memory deficits were related to vigiance impairment. Therefore, both vigilance impairment and nocturnal hypoxemia may differentially contribute to the cognitive dysfunctions found in OSAS.

Adult↗
PubMed1991

Muscle pain, dyskinesia, and sleep.

Muscle pain and poor sleep commonly occur together. Whether pain induces poor sleep or vice versa is difficult to know. Muscle pain is also observed in the presence of some types of dyskinesia or movement disorders. The interaction between sleep, movement disorders, and some musculoskeletal pain appears to be complex and may be influenced by various concomitant psychological and (or) biological factors.

Fibromyalgia↗
PubMed1991

Restless legs syndrome and periodic leg movements in sleep: the primary role of dopaminergic mechanism.

We report here the possible effect of opiates on a patient exhibiting particularly severe restless legs syndrome (RLS) and periodic leg movements in sleep (PLMS). This patient was investigated in the sleep laboratory under three conditions, namely, unmedicated (baseline), medicated with codeine sulfate, and medicated with both codeine sulfate and pimozide. Codeine sulfate dramatically improved abnormal motor behavior in this patient. The addition of pimozide reversed the beneficial effect of codeine during the Forced Immobilization Test but not in spontaneous RLS or PLMS at night. These results are discussed in view of the possible involvement of the dopaminergic mechanism in RLS/PLMS syndrome.

Codeine↗
PubMed1991

The effects of L-dopa on excessive daytime sleepiness in narcolepsy.

We examined the effects of L-dopa on the excessive daytime sleepiness of six narcoleptic patients while using a double-blind design and objective measurements of vigilance. The two treatment periods, L-dopa or placebo, lasted for 2 weeks each, separated by a 1-week washout period. In addition to the standard Multiple Sleep Latency Test (MSLT), two different tests assessed the daytime vigilance: the Analogue Vigilance Scale (AVS) and the Four Choice Reaction Time Test (FCRTT). L-dopa improved vigilance and performance as evaluated by the AVS and the FCRTT, while the capacity to fall asleep rapidly remained unchanged as evaluated by the MSLT. Results of the present study suggest that L-dopa is effective in improving the vigilance level of narcoleptic patients and raises the hypothesis that dopamine may play a role in the physiopathology of excessive daytime sleepiness of this condition.

Adolescent↗
PubMed1991

Nocturnal hypoxemia as a determinant of vigilance impairment in sleep apnea syndrome.

In sleep apnea syndrome (SAS), vigilance impairment is typically associated with highly disrupted sleep, but recently, nocturnal hypoxemia has also been identified as a second pathogenetic factor in patients with a high degree of desaturation. However, although sleep disruption has been demonstrated to play a role in both the propensity to fall asleep and the capacity to stay awake, the role of nocturnal hypoxemia has been implicated only in the latter. In the present study, both sleep disruption and nocturnal hypoxemia were assessed in 20 moderately to severely apneic patients. During the day, vigilance was assessed both by the multiple sleep latency test (MSLT), as a measure of the propensity to fall asleep, and by the four-choice reaction time test (FCRTT), as a measure of the capacity to stay awake in a performance task. Severity of nocturnal hypoxemia was found to predict performance on the MSLT, as well as on the FCRTT, but sleep disruption was found to predict performance only on the FCRTT. These results suggest that in moderately to severely affected SAS patients, nocturnal hypoxemia may play a primary role in the pathogenesis of vigilance impairment.

Adult↗
PubMed1991

[The effect of continuous peri-thoracic negative pressure on nocturnal desaturation of chronic obstructive bronchopneumopathies].

The fall of functional residual capacity (FRC) in the genesis of nocturnal desaturation in chronic airflow obstruction (COPD) continues to be discussed. This hypothesis is being tested by applying a negative continuous thoracic pressure using a cuirass/poncho attached to a pump for one night (night II) after a control night with a cuirass/poncho at atmospheric pressure (night 1). Seven subjects with a mean age of 61 +/- 9, with a mean weight of 108 +/- 21% of their ideal weight, who were suffering from severe airflow obstruction with a mean forced expired volume (FEV1: 39 +/- 20% th., FEV1/FVC: 35 +/- 9%, PaO2: 60 +/- 3 mmHg, PaCO2: 42 +/- 4 mmHg). These seven subjects had two polysomnographies on the two successive nights. During night II, the FRC was increased by 0.33 +/- 0.6 L by applying a continuous negative thoracic pressure of 10 +/- 1 cm of water. A significant decrease in the sleep time was noted (248 +/- 86 min vs 316 +/- 74 min, p less than 0.02) also the efficacy of sleep (54 +/- 9% vs 71 +/- 15% vm p less than 0.02). There was no difference between the two nights as regards the distribution of the sleep stages. In 2 subjects, the hypopnoea-apnoea index passed from 0 to 11 and from 4 to 22 respectively. The principal result was the absence of any significant difference in mean nocturnal oxygen saturation between the two nights.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1990

Interhemispheric EEG coherence during sleep and wakefulness in left- and right-handed subjects.

REM sleep is associated with the production of complex imagery sequences. Yet research is divided as to whether different brain regions are more or less coordinated in their functioning at this time. Some research suggests that there may occur a functional disconnection of the left and right cerebral hemispheres during REM sleep which is similar to the disconnection syndrome seen after corpus callosotomy. Other research suggests that an increase in interhemispheric coordination occurs. On the assumption that hemispheric coordination is reflected in the EEG coherence measure, we explored differences in interhemispheric coherence recorded in six left- and six right-handed normal subjects during periods of wakefulness, stage REM, stage 2, and stage 3/4 sleep. Strong evidence was found that mean EEG coherence values are larger during sleep than during waking and that they are approximately equal for the different stages of sleep. Frontal electrode placements demonstrated a slightly different pattern of coherence than central, parietal, or occipital placements. Furthermore, coherence values were larger for left-handed subjects over the occipital region during wakefulness, stage 2, and stage REM sleep, but not during stage 3/4 sleep. Coherence was not different for male and female subjects. These findings oppose the interpretation that a functional disconnection of hemispheres occurs during REM sleep and favor the interpretation that sleep in general is a state of heightened cortical coordination. Moreover, greater interhemispheric coherence over occipital brain regions in left-handed subjects suggests possible differences in the cognitive processes of these subjects during waking and dreaming states.

Brain Mapping↗
PubMed1990

The effect of gamma-hydroxybutyrate on nocturnal and diurnal sleep of normal subjects: further considerations on REM sleep-triggering mechanisms.

Gamma-hydroxybutyrate (GHB) is a drug currently used to treat narcolepsy. The present study documents its effect on sleep organization in healthy subjects. GHB and a placebo were given at bedtime and before a morning nap in a double-blind fashion. GHB administered before nocturnal or diurnal sleep increases stages 3 and 4 and decreases stage 1 non-rapid eye movement (NREM) sleep. In addition, GHB improves REM efficiency at night and reduces wake time after sleep onset when administered before a morning nap recording. GHB also slightly decreases REM latency when administered in the morning, and this effect is correlated with age. Hypotheses regarding mechanisms of action GHB and the involvement of hypothalamic structures in the regulation of REM sleep are discussed.

Administration, Oral↗
PubMed1990

Interhemispheric EEG coherence before and after partial callosotomy.

Measures of interhemispheric EEG coherence during REM and NREM sleep reflect the functional connectivity of the right and left hemispheres mediated by the corpus callosum. Surface recordings of interhemispheric coherence in two patients reflected fairly accurately the degree of anatomical section produced by partial callosotomy. With further development, EEG coherence may prove useful as a noninvasive method for assessing interhemispheric integration under different physiological and experimental conditions.

Adult↗
PubMed1989

Sleep disorder symptoms among nurses and nursing aides.

Nurses and nursing aides (n = 418) currently working on a regular evening or day schedule were compared in terms of sleep disorder symptoms. The relationship between past nightwork and sleep disorder symptoms was also assessed. The prevalence of individual symptoms varied from 6 to 53%. Evening workers showed a pattern of sleep disorder compatible with sleep deprivation, whereas the pattern for day workers was more compatible with insomnia. Past nightwork was significantly associated with symptoms of day tiredness and the quantity of sleep obtained was influenced by past nightwork. The prevalence of a combination of four insomnia symptoms (initial, intermittent, and terminal insomnia and fatigue during the day) was 5.4% among current day workers but no cases were identified among evening workers. Among day workers, the trend for insomnia across levels of duration of past nightwork fell slightly short of conventional statistical significance (P = 0.09). The relationship between a combination of four symptoms was neither modified nor confounded by variables such as age, chronotype, intensity of past nightwork, and latency. In conclusion, although some sleep symptoms were associated with nightwork, a clear residual effect on a combination of symptoms could not be shown.

Adult↗
PubMed1989

The effects of L-dopa on periodic leg movements and sleep organization in narcolepsy.

A large proportion of narcoleptic patients have periodic leg movements (PMS) in sleep. The contribution of these movements to the nocturnal sleep disturbance observed in narcoleptics remains a controversial issue. The aim of the present study was to look at the sleep organization of narcoleptic patients before and after suppression of periodic leg movements with L-dopa. L-dopa and a placebo were administered in a double-blind fashion to six narcoleptic patients. Each treatment period lasted 2 weeks and the treatment order was reversed for one-half of the subjects. The effects of L-dopa and placebo were evaluated by polysomnography. A significant reduction of PMS was seen after treatment with L-dopa, but this treatment did not improve sleep organization. On the contrary, L-dopa increased wake time after sleep onset. This result supports the hypothesis that PMS does not play a major role in the nocturnal sleep disruption observed in narcolepsy. It also supports the hypothesis that dopaminergic mechanisms play a role in the physiopathology of PMS.

Adolescent↗