Search PubMed⌕ Search

Biomedical subjects

J Montplaisir

Publications and source records attributed to J Montplaisir.

At least 55 records · Page 3Linked to original sources
PubMed1999

The influence of sex, age and sleep/wake state on characteristics of periodic leg movements in restless legs syndrome patients.

Restless legs syndrome (RLS) patients experience periodic stereotyped leg movements while awake and during sleep. The aim of the present study was to measure the effects of sex, age and the sleep/wake state on several characteristics (frequency, duration and periodicity) of these periodic leg movements (PLM). One hundred unrelated patients diagnosed with primary RLS were studied. During wakefulness, frequency of PLM increased and the mean inter-movement interval decreased with advancing age. The modal value of inter-movement interval distribution was also altered suggesting that aging influences rhythm-generation mechanisms. Sleep/wake states had a profound effect on leg movement characteristics. Movements of longer duration were seen during wakefulness, while REM sleep was characterized by the shorter duration and the lowest frequency of PLM, due most likely to the inhibition of spinal motoneurons that prevails in REM sleep. States of vigilance also modulated the periodicity of PLM. Intervals were shorter during wakefulness and increased progressively from stage 1 to stage 2 sleep, and to slow wave sleep (SWS). During REM, the duration of sleep intervals returned to values obtained in stage 1 sleep; these two stages sharing similar patterns of EEG activity. These results indicate that a single state dependent mechanism may be responsible for the periodicity of PLM noted both during sleep and wakefulness.

Adult↗
PubMed1999

Somnambulistic-like behaviour in patients attending a lithium clinic.

The prevalence of somnambulistic-like behaviour related to treatment with lithium alone or in combination with other psychotropic medications was evaluated in patients attending a lithium clinic. A written questionnaire on somnambulistic-like behaviour was completed by 389 patients. Information was provided on the time of occurrence, frequency and severity of the episodes, the presence of childhood somnambulism, and the temporal relationship between psychiatric treatment and somnambulistic-like behaviour. Twenty-seven (27) patients (6.9%) presented sleepwalking behaviour related to the onset of treatment with lithium alone or in combination with other psychotropic drugs. Forty-five patients (11.6%) reported childhood somnambulism and 12 of them (27%) had their childhood somnambulism reactivated by the medication. Most patients had a diagnosis of bipolar affective disorder but somnambulistic-like behaviour also occurred in patients with other axis 1 diagnosis. Sleep-related violence was seldomly reported. Therefore, lithium alone or in combination with other psychotropic drugs may induce somnambulistic-like behaviour. A history of childhood somnambulism may increase the risk of developing sleepwalking behaviour while under psychotropic drugs treatment.

Adult↗
PubMed1998

Comparative effects of nefazodone and fluoxetine on sleep in outpatients with major depressive disorder.

BACKGROUND: Sleep disturbances are common in major depressive disorder. In previous open-label trials, nefazodone improved sleep continuity and increased rapid eye movement (REM) sleep, while not affecting stage 3/4 sleep or REM latency: in contrast, fluoxetine suppressed REM sleep. This study compared the objective and subjective effects of nefazodone and fluoxetine on sleep. METHODS: This paper reports combined results of three identical, multisite, randomized, double-blind, 8-week, acute-phase trials comparing nefazodone (n = 64) with fluoxetine (n = 61) in outpatients with nonpsychotic major depressive disorder and insomnia. Sleep electroencephalographic (EEG) recordings were gathered at baseline and weeks 2, 4, and 8. Clinical ratings were obtained at weeks 1-4, 6, and 8. RESULTS: Nefazodone and fluoxetine were equally effective in reducing depressive symptoms; however, nefazodone differentially and progressively increased (while fluoxetine reduced) sleep efficiency and reduced (while fluoxetine increased) the number of awakenings in a linear fashion over the 8-week trial. Fluoxetine, but not nefazodone, prolonged REM latency and suppressed REM sleep. Nefazodone significantly increased total REM sleep time. Clinical evaluations of sleep quality were significantly improved with nefazodone compared with fluoxetine. CONCLUSIONS: Nefazodone and fluoxetine were equally effective antidepressants. Nefazodone was associated with normal objective, and clinician- and patient-rated assessments of sleep when compared with fluoxetine. These differential sleep EEG effects are consistent with the notion that nefazodone and fluoxetine may have somewhat different modes and spectra of action.

Adult↗
PubMed1998

Immobilization tests and periodic leg movements in sleep for the diagnosis of restless leg syndrome.

Patients with restless leg syndrome (RLS) complain of motor restlessness, usually occurring while they rest in the evening. Two immobilization tests have been described to assess leg restlessness in these patients. In the first test, the patient sits in bed with his or her legs outstretched while electromyograms are recorded from right and left anterior tibialis muscles for an hour (Suggested Immobilization Test [SIT]); in the second test, the legs are immobilized in a stretcher (Forced Immobilization Test [FIT]). In the current study, the SIT and the FIT were compared in patients with RLS and normal control subjects matched for age and sex. More leg movements were seen in patients than in controls during immobilization tests, especially the SIT. These movements were periodic, occurring at a frequency of approximately one every 12 seconds. The SIT (index > 40) was found to discriminate between RLS and control subjects better than the FIT (index > 25). Patients were also recorded during two consecutive nights to measure periodic leg movements in sleep (PLMS). A SIT index greater than 40 and a PLMS index greater than 11 (highest PLMS index of 2 consecutive nights) were found to discriminate patients with RLS from control subjects with similar power. With each of these two measures, the clinical diagnosis was correctly predicted in 81% of patients and 81% of the control subjects. The SIT has several advantages over the measure of the PLMS index; it does not require an all-night polygraphic recording and can be administered several times a day to measure circadian fluctuation of motor restlessness.

Adult↗
PubMed1998

Is excessive daytime sleepiness with periodic leg movements during sleep a specific diagnostic category?

Thirty-four patients who presented with excessive daytime sleepiness (EDS) and who showed an elevated number of periodic leg movements during sleep (PLMS) were studied. None of these patients reported other symptoms or presented sleep laboratory manifestations of narcolepsy or of breathing disorders during sleep. A diagnosis of restless leg syndrome, head trauma or a past history of psychopathology or infectious diseases known to cause EDS were also ruled out. In addition, none of the patients reported a history of drug or alcohol abuse, chronic sleep deprivation or irregular sleep-wake schedule and none were taking medications known to influence sleep at the time of the study. Results of the present study showed no correlation between PLMS index and poor sleep efficiency or daytime sleepiness as measured by the multiple sleep latency test (MSLT). However, a significant negative correlation was found between sleep efficiency at night and the mean sleep latency on the MSLT. These results suggest not only that PLMS and nocturnal sleep disruption are not the primary cause of EDS, but that these sleepy patients have a high propensity to sleep both at night and during the daytime. Therefore, the presence of PLMS during nocturnal sleep recording should not preclude the diagnosis of idiopathic hypersomnia.

Adult↗
PubMed1998

Spectral analysis of wakefulness and REM sleep EEG in patients with sleep apnoea syndrome.

Neuropsychological investigations of patients with obstructive sleep apnoea syndrome (OSAS) have shown impairments in such basic functions as memory, attention and executive control. Since executive functions are known to be dependent on the integrity of the frontal lobe, it was hypothesized that OSAS may be associated with hypoxaemic frontal lobe dysfunction. To test this hypothesis, 21 apnoeic patients and 10 normal controls were studied with quantitative electroencephalographic (EEG) methods during rapid eye movement (REM) sleep, when most apnoeic events occur and during wakefulness. In apnoeic patients, EEG slowing in REM sleep was observed over frontal, central and parietal regions, while EEG slowing during wakefulness was observed over all cortical regions examined. A positive correlation was found between EEG slowing during wakefulness and oxygen desaturation during the night. Contrary to the hypothesis, these electroencephalographic changes were not localized only to the frontal region. This result may explain the wide range of neuropsychological deficits noted in patients with obstructive sleep apnoea syndrome, in addition to their poor performance in tasks of executive functioning.

Adult↗
PubMed1998

Sleep disturbances and eeg slowing in alzheimer's disease.

Changes in sleep structure, and especially REM sleep, and in EEG activation were studied in relation to the cholinergic deficit found in Alzheimer's Disease (AD). With respect to sleep architecture, only REM sleep percent was reduced in AD patients compared to controls as a result of a decrease in mean REM episode duration. Different results were obtained in patients with progressive supranuclear palsy (PSP). These results are discussed with respect to the role of brainstem and forebrain cholinergic populations in REM sleep generation in humans. More importantly, it was shown by means of spectral analyses that EEG slowing is much more prominent in REM sleep than in wakefulness in AD. Furthermore, there is a distinct topographical pattern of REM sleep EEG slowing in AD patients which is in agreement with findings from neuroradiological and neuropathological studies. Using the ratio of slow over fast frequencies from the temporal regions, a correct classification of 90.4% of subjects was obtained for the REM sleep EEG. This discrimination rate is the best marker of AD so far using a single measure. Quantitative REM sleep EEG was also used to evaluate patients' biological response to cholinergic treatments. Finally, we present here preliminary data on the progression of EEG slowing in wakefulness and in REM sleep. After six months on a placebo, there was only a decrease in alpha activity in wakefulness over all regions studied. No changes were observed for REM sleep.

Aged↗
PubMed1997

Clinical, polysomnographic, and genetic characteristics of restless legs syndrome: a study of 133 patients diagnosed with new standard criteria.

One hundred thirty-three cases of restless legs syndrome (RLS), diagnosed with criteria recently formulated by an international study group, were studied by questionnaire and with all-night polysomnographic recordings. Results show that RLS starts at a mean age of 27.2 years and before age 20 in 38.3% of patients. Symptoms often appear in one leg only and also involve upper limbs in about half of all cases. Most patients (94%) report sleep-onset insomnia or numerous nocturnal awakenings due to RLS symptoms. A strong relationship was found between these complaints and polysomnographic findings; increasing sleep latency and number of awakenings and decreasing sleep efficiency were associated with worsening symptoms. Periodic leg movements in sleep (index > 5 movements/h sleep) were found in 80.2% of patients. This study shows that this percentage is increased when 2 recording nights are considered (most severe score). Eighty patients of 127 (63%) reported the presence of RLS in at least one of their first-degree relatives. In these families, 221 of 568 first-degree relatives (39%) were reported by the patients to be affected with RLS.

Adult↗
PubMed1997

Alexithymia and impoverished dream recall in asthmatic patients: evidence from self-report measures.

Early clinical impressions that alexithymia is associated with diminished dream recall have been supported by more recent research. The present study was designed to examine this association using self-report measures and a carefully screened clinical population. Thirty-three male and 43 female asthmatics from an outpatient clinic were administered the Toronto Alexithymia Scale, the Eysenck Personality Questionnaire, and a questionnaire concerning retrospective recall of dreams and nightmares. Multiple regression analyses revealed that, among men, dream recall was negatively related to alexithymia, especially to the TAS analytical mode of thinking subscale, independent of age and neuroticism. Among women, dream and nightmare recall were positively correlated with neuroticism. These results are consistent with early clinical observations of pensée opératoire, with some research findings, and with the notion that dream recall may be differentially associated with components of alexithymia in men and women patients.

Adolescent↗
PubMed1997

REM sleep dream mentation in right hemispherectomized patients.

Investigations of dream mentation in brain damaged patients have shed some light on the controversial issue of cerebral lateralization of dreaming. To examine further the relationships between brain function and dreaming, we studied REM sleep dream recall and content in four patients having undergone right functional or anatomical hemispherectomy and eight matched control subjects. Patients were found to have the capacity to report dreams to much the same extent as control subjects. Further, the patients' dream content was overall similar to that of the control subjects. The results provide strong evidence that dreaming is not a right-hemisphere function, and that the left hemisphere may be more critical for the generation of dreams. In addition, some characteristics of hemispherectomized patients' dream content (characters, smells) are consistent with the possibility that a history of epilepsy may influence REM sleep imagery over the long term.

Adolescent↗
PubMed1997

Topographical distribution of spindles and K-complexes in normal subjects.

To assess the topographical distribution of sleep spindles and K-complexes, four 15-minute samples of stage 2 sleep in a group of eight healthy young adults were analyzed. Results show that a majority of spindles generated are detected over central regions, and that K-complexes are markedly predominant over prefrontal and frontal regions. These findings are consistent with the single-spindle generator hypothesis and raise questions concerning the Rechtschaffen and Kales rules for scoring K-complexes.

Adolescent↗
PubMed1997

Quantitative EEG and statistical mapping of wakefulness and REM sleep in the evaluation of mild to moderate Alzheimer's disease.

Statistical probability mapping was used to quantify and localize EEG differences between 27 patients with Alzheimer's disease (AD) and 25 age- and gener-matched controls. Differences in mean activity in four EEG frequency bands (delta, theta, alpha, beta) for wakefulness and for REM sleep were examined, t-statistic maps clearly highlighted common pattern anomalies in AD patients in the two states. More specifically, Alzheimer patients were more affected than control subjects in parieto-temporal and frontal regions. These differences were more prominent in REM sleep and consisted primarily in an increase in absolute delta and theta activities, and a decrease in absolute alpha and beta activities. Discriminant analysis, using a ratio of slow over fast frequencies, yielded a classification rate of 90.4% (sensitivity 81.5%, specificity 100%) for REM sleep. For wakefulness, the same measure allowed correct classification of 80.8% of the subjects (sensitivity 66.7%, specificity 96%).

Aged↗
PubMed1997

Sleep and quantitative EEG in patients with progressive supranuclear palsy.

Sleep architecture and quantitative EEG from wakefulness and REM sleep were studied in six patients (mean age, 70.5 years) with progressive supranuclear palsy (PSP) and compared with that of six control subjects (mean age, 69.8 years). Particular attention was given to quantifying REM sleep variables because of the known PSP-associated degeneration of the pedunculopontine tegmentum (PPT)--a critical structure in REM sleep generation. Patients with PSP had a shorter total sleep time, a lower sleep efficiency, a drastic reduction in sleep spindles, an atonic slow-wave sleep, and a lower percentage of REM sleep. The lower percentage of REM sleep was the result of both a reduction in the number of REM periods and a reduction in mean period of duration. REM density was also reduced while REM efficiency, atonia, and phasic EMG were similar to control values. REM sleep findings are consistent with the known role of the PPT in REM sleep induction. A slowing of the awake EEG was found for the six frontal leads and for C4, P4, and T4 in PSP patients. The frontal EEG slowing found in wakefulness is in accord with imaging and neuropsychological studies showing impairment of the frontal lobes in these patients. REM sleep EEG was not significantly slower in any regions. Because all previous studies on PSP have relied on visual inspection of the EEG tracings, the present finding of EEG slowing in the frontal lobes (rather than in the temporal regions or diffusely) suggests that our quantitative EEG approach may be more useful in determining specific regions of impaired cortical activity.

Aged↗
PubMed1997

Cigarette smoking as a risk factor or an exacerbating factor for restless legs syndrome and sleep bruxism.

Cigarette smoking has been associated with sleep disturbances. However, little is known about how smoking affects restless legs syndrome (RLS) and sleep bruxism, two movement disorders associated with sleep. From a nationwide survey of 2,019 Canadian adults, we estimated the prevalence of smoking to be 36%. Although there was no difference between smokers and nonsmokers for RLS prevalence, almost twice as many smokers (12%) as nonsmokers (7%) were aware of experiencing sleep bruxism. The estimated risk of a smoker suffering from RLS was nonsignificant. On the other hand, the risk of a smoker grinding his or her teeth was moderate (odds ratio = 1.9). Analysis of sleep laboratory findings revealed no differences in motor RLS and periodic leg movements in sleep (PLMS) indices between smoking and nonsmoking patients; after adjustment for age, there were no differences in sleep efficiency, latency, number of awakenings, or the arousal index for the RLS/PLMS patients. Among those suffering from bruxism, smokers had more tooth-grinding episodes than did nonsmokers (35.0 vs. 7.0; p = 0.056); none of the sleep variables differentiated sleep bruxism smokers from nonsmokers. It appears that cigarette smoking does not influence RLS/PLMS, whereas the risk that smoking and tooth grinding are concomitant is moderate. Smoking was not significantly associated with more motor activity in RLS/PLMS, but more grinding was noted in sleep bruxism.

Adult↗
PubMed1997

Sleep Quality of Former Night-shift Workers.

This study explored the relationship between past night-shift work and present quality of sleep, first by a survey and second with standard laboratory recordings. Nurses (n = 479) working on a day or evening schedule answered a questionnaire about past night-shift work and present quality of sleep. An insomnia index, derived from the questionnaire, was elevated for nurses who had worked more than five nights per month for four to ten years. The index was low for the 13 nurses who had worked more than ten years on night shifts. The sleep of 15 day nurses was recorded in the laboratory. Results showed that a high insomnia index was associated with a high number of awakenings, and that former night-shift workers had a significant reduction in slow-wave sleep, whether or not they had subjective sleep complaints. These results suggest that working at night may have persistent deleterious effects on sleep quality when the experience is long and includes a substantial number of night shifts.

Journal Article↗
PubMed1996

Persistence of repetitive EEG arousals (K-alpha complexes) in RLS patients treated with L-DOPA.

Compared to normal control subjects, patients with primary restless legs syndrome (RLS) have an increased number of K-complexes, followed by bursts of electroencephalographic (EEG) alpha activity-together these are referred to as K-alpha complexes. In the present study, a large proportion of K-alpha complexes was found to be temporally associated with periodic leg movements in sleep. Because many K-alpha complexes precede the onset of movements, they cannot be considered secondary to the movements themselves. The persistence of K-alpha complexes after suppression of leg movements by means of L-DOPA further supports the hypothesis that these EEG events are a primary phenomenon. The results may have clinical implications because a large proportion of RLS patients complain of non-restorative sleep even after treatment with L-DOPA.

Adult↗