Showing papers on "Sleep disorder published in 1994"

Nonpharmacological interventions for insomnia: a meta-analysis of treatment efficacy.

Abstract: OBJECTIVE Because of the role of psychological factors in insomnia, the shortcomings of hypnotic medications, and patients' greater acceptance of nonpharmacological treatments for insomnia, the authors conducted a meta-analysis to examine the efficacy and durability of psychological treatments for the clinical management of chronic insomnia. METHOD A total of 59 treatment outcome studies, involving 2,102 patients, were selected for review on the basis of the following criteria: 1) the primary target problem was sleep-onset, maintenance, or mixed insomnia, 2) the treatment was nonpharmacological, 3) the study used a group design, and 4) the outcome measures included sleep-onset latency, time awake after sleep onset, number of nighttime awakenings, or total sleep time. RESULTS Psychological interventions, averaging 5.0 hours of therapy time, produced reliable changes in two of the four sleep measures examined. The average effect sizes (i.e., z scores) were 0.88 for sleep latency and 0.65 for time awake after sleep onset. These results indicate that patients with insomnia were better off after treatment than 81% and 74% of untreated control subjects in terms of sleep induction and sleep maintenance, respectively. Stimulus control and sleep restriction were the most effective single therapy procedures, whereas sleep hygiene education was not effective when used alone. Clinical improvements seen at treatment completion were well maintained at follow-ups averaging 6 months in duration. CONCLUSIONS The findings indicate that nonpharmacological interventions produce reliable and durable changes in the sleep patterns of patients with chronic insomnia.

The Sleep Disorders Questionnaire I: Creation and Multivariate Structure of SDQ

Abstract: The development of the Sleep Disorders Questionnaire (SDQ) from the Sleep Questionnaire and Assessment of Wakefulness (SQAW) of Stanford University is described in detail. The extraction of the best question items from the SQAW and their subsequent rewording in the SDQ to insure greater completion rates are described. Two item test-retest reliability studies are reported on 71 controls and on 130 sleep-disorder patients, which confirmed adequate reliability. To create multivariate scoring scales, SDQ was then given in a multicenter study to 519 persons, 435 of whom were sleep-disorder patients with full polysomnography. Canonical Discriminant Function Analysis was employed, which resulted in four clinical-diagnostic scales: SA for sleep apnea, NAR for narcolepsy, PSY for psychiatric sleep disorder and PLM for periodic limb movement disorder. Each was adjusted for male and female responses and transformed to a percentile using the observed distribution of raw scores. Using Receiver Operating Characteristics analysis, cutoff points were determined for each scale to maximize its sensitivity and specificity. Positive and negative predictive values were also calculated. The SA and NAR scales proved to be the most discriminating.

Sleep apnea and sleep disruption in obese patients.

Abstract: Objectives: To describe the frequency and severity of sleep apnea in obese patients without a primary sleep complaint and to assess the sleep patterns of obese patients without apnea and compare them with the sleep patterns of nonobese controls. Design and Setting: Prospective case series with historical controls in an obesity and sleep disorders clinic. Subjects: Two hundred obese women and 50 obese men (mean body mass index, 45.3) consecutively referred for treatment of their obesity and 128 controls matched for age and sex. Main Outcome Measures: Eight-hour sleep laboratory recording, including electroencephalogram, electro-oculogram, electromyogram, and respirations. Subjectively reported sleep-related symptoms and signs were also recorded. Results: Twenty men (40%) and six women (3%) demonstrated sleep apnea warranting therapeutic intervention. Another four men (8%) and 11 women (5.5%) showed sleep apneic activity that warranted recommendation for evaluation in the sleep laboratory. In contrast, none of the 128 controls demonstrated sleep apneic activity severe enough for therapeutic intervention. The best clinical predictors of sleep apnea in the obese population were severity of snoring, subjectively reported nocturnal breath cessation, and sleep attacks. Obese patients, both men and women, without any sleep-disordered breathing demonstrated a significant degree of sleep disturbance compared with nonobese controls. Wake time after sleep onset, number of awakenings, and percentage of stage 1 sleep were significantly higher in obese patients than in controls, while rapid eye movement sleep was significantly lower. Conclusion: Severely or morbidly obese men are at extremely high risk for sleep apnea and should be routinely evaluated in the sleep laboratory for this condition, while for severely or morbidly obese women the physician should include a thorough sleep history in the clinical assessment. (Arch Intern Med. 1994;154:1705-1711)

Sleep disorders and melatonin rhythms in elderly people.

Abstract: Biological aging is often associated with problems with sleep and daytime napping.1 There is considerable evidence linking melatonin, produced by the pineal gland, with the sleep-wake cycle. When administered orally to humans or animals it enhances sleep2 and has a synchronising effect on circadian rhythms. Circulating melatonin concentrations decrease in old age, and its time of secretion is delayed.3 We examined whether sleep disorders in old age were associated with changes in concentration of 6-sulphatoxymelatonin, the major urinary measure of melatonin. The study population comprised four groups: (a) eight independently living patients with insomnia (four men, four women, mean age 73.1 (SD 3.9)); (b) 15 patients with insomnia (five men, 10 women, mean age 82.1 (8.8)) who had lived a minimum of six months in a nursing home; (c) 25 elderly patients without sleep disorders (19 …

Assessment of the validity and utility of a sleep-symptom questionnaire.

Abstract: Although questionnaires have been developed to assess symptoms of obstructive sleep apnea (OSA), their overall reliability and utility have not been established. We have evaluated the ability of a questionnaire to identify increased apnea activity (IAA) in 465 participants in an epidemiologic study of OSA. Subjects and their roommates each completed a questionnaire and underwent in-home sleep studies. Responses to 56 questions about sleep habits, sleepiness, and daytime performance were analyzed with factor analysis, logistic regression, and receiver-operator curves (ROCs). Factor analysis demonstrated that 16 questions, grouped into five factors (functional impact of sleepiness, self-reported breathing disturbances, roommate-observed breathing disturbances, driving impairment, and insomnia) explained 67% of the variance in the questionnaire data. Symptom questions demonstrated internal consistency (Cronbach correlations: 0.91 to 0.98). Moderate levels of agreement were observed between self- and roommate...

Clinical diagnoses in 216 insomnia patients using the International Classification of Sleep Disorders (ICSD), DSM-IV and ICD-10 categories: A report from the APA/NIMH DSM-IV field trial

Abstract: Three diagnostic classifications for sleep disorders have been developed recently: the International Classification of Sleep Disorders (ICSD), the Diagnostic and Statistical Manual, 4th edition (DSM-IV), and the International Classification of Diseases, 10th edition (ICD-10). No data have yet been published regarding the frequency of specific diagnoses within these systems or how the diagnostic systems relate to each other. To address these issues, we examined clinical sleep disorder diagnoses (without polysomnography) in 257 patients (216 insomnia patients and 41 medical/psychiatric patients) evaluated at five sleep centers. A sleep specialist interviewed each patient and assigned clinical diagnoses using ICSD, DSM-IV and ICD-10 classifications. "Sleep disorder associated with mood disorder" was the most frequent ICSD primary diagnosis (32.3% of cases), followed by "Psychophysiological insomnia" (12.5% of cases). The most frequent DSM-IV primary diagnoses were "Insomnia related to another mental disorder" (44% of cases) and "Primary insomnia" (20.2% of cases), and the most frequent ICD-10 diagnoses were "Insomnia due to emotional causes" (61.9% of cases) and "Insomnia of organic origin" (8.9% of cases). When primary and secondary diagnoses were considered, insomnia related to psychiatric disorders was diagnosed in over 75% of patients. The more narrowly defined ICSD diagnoses nested logically within the broader DSM-IV and ICD-10 categories. We found substantial site-related differences in diagnostic patterns. These results confirm the importance of psychiatric and behavioral factors in clinicians' assessments of insomnia patients across all three diagnostic systems. ICSD and DSM-IV sleep disorder diagnoses have similar patterns of use by experienced clinicians.

Natural history of snoring and related behaviour problems between the ages of 4 and 7 years.

Abstract: In 1989-90 a survey was carried out of the prevalence of snoring and related symptoms in 782 4 to 5 year old children. Two years later, in 1992, the same group of children was studied to gather information on the natural history of snoring and the related behaviour problems. A total of 507/782 (64.8%) completed questionnaires were received. Comparison of the responses with the 1989-90 survey showed that those who did not reply to the questionnaire were no different from the respondents in terms of the prevalence of snoring, daytime sleepiness, hyperactivity, and restless sleep. The overall prevalence of habitual snoring did not change between the two surveys (12.1% in 1989-90 v 11.4% in 1992), though more than half of the children who snored habitually in the original survey no longer did so. There was little change in the prevalence of hyperactivity (24.2% in 1989-90 v 20.7% in 1992) or restless sleep (both 39%) among the 507 who responded to the present survey. The prevalence of daytime sleepiness, however, did decrease substantially (20.7% in 1989-90 v 10.2% in 1992). There was moderate agreement between the individual questionnaire responses for the 1989-90 and 1992 surveys for snoring (weighted kappa 0.52), but poor agreement for the other symptoms (daytime sleepiness 0.37, hyperactivity 0.35, and restless sleep 0.38). Trend analysis showed that the increasing prevalence of sleepiness, hyperactivity, and restless sleep across the snoring categories was highly significant. Daytime sleepiness, hyperactivity, and restless sleep were all significantly more common in the habitual snorers than in those who never snored. Relative risks (95% confidence interval) were as follows: daytime sleepiness 6.13 (2.5 to 14.9), hyperactivity 2.78 (1.6 to 4.7), and restless sleep 2.3 (1.6 to 3.2). Though habitual snoring and the associated behaviour problems resolved spontaneously over two years in about half of the children with these symptoms, there is still the same overall percentage with these problems due to the emergence of new cases.

Partial sleep deprivation reduces natural killer cell activity in humans.

Abstract: Sleep disturbance, measured by either subjective report or electroencephalographic (EEG) assessment of sleep, correlates with a reduction of natural killer (NK) cell activity in major depression. To test whether sleep loss independent of mood disturbance alters daytime values of cellular immune function, the effect of late-night partial sleep deprivation on NK cell activity was studied in 23 medically and psychiatrically healthy male volunteers. After a night of sleep deprivation between 3 and 7 AM, NK cell activity was reduced in 18 of the 23 subjects with average lytic activity reduced significantly (p < .01) to a level 72% of the mean of three separate baseline values. After a night of resumed nocturnal sleep, NK cell activity had returned to baseline levels. These data implicate sleep in the modulation of natural immunity and demonstrate that even modest disturbances of sleep produce a reduction of NK cell activity.

A multicenter, placebo-controlled study evaluating zolpidem in the treatment of chronic insomnia

Abstract: Background Zolpidem is a short-acting, nonbenzodiazepine hypnotic with rapid onset of action. Even though it is not a benzodiazepine, it binds to one of three types of central benzodiazepine receptors, showing selective binding to the type 1 benzodiazepine receptor subtype. Therapeutic hypnotic dosages do not disturb normal sleep patterns (sleep architecture). Method A randomized, double-blind, placebo-controlled, parallel group multicenter trial was conducted to determine the effectiveness of 10 mg and 15 mg of zolpidem in the long-term (35 nights) treatment of chronic insomnia in 75 patients. Sleep stage effects and motor and cognitive effects during the 35-night treatment period and the 3-night posttreatment period were also investigated. Results Within the first week of treatment, 10 mg of zolpidem had a significant effect on latency to persistent sleep and sleep efficiency. Efficacy was maintained throughout the 35 nights of drug administration. There was no evidence of residual effect with 10 mg of zolpidem. Stage 3-4 sleep was preserved at both the 10-mg and 15-mg zolpidem dosages. There was no evidence of tolerance at either dose and no significant treatment differences between the 10-mg zolpidem group and placebo in latency to persistent sleep or sleep efficiency during the posttreatment period. Also, the 10-mg zolpidem dosage was judged by the patients to have helped them fall asleep. Similar results were observed with the 15-mg zolpidem dosage. However, there were significant decreases in REM sleep at Weeks 3 and 4 with 15 mg of zolpidem compared with placebo. Overall, incidence rates of treatment-emergent adverse events in the zolpidem groups were similar to those in the placebo group. Conclusion This is the first sleep laboratory study using a parallel placebo group to demonstrate efficacy for longer than 4 weeks with a hypnotic agent. In this study 10 mg of zolpidem was found to be safe and effective for the long-term treatment of chronic insomnia, demonstrating hypnotic efficacy without affecting sleep stages or producing tolerance effects, rebound effects, or detrimental effects on psychomotor performance. The 15-mg zolpidem dosage provided no clinical advantage over the 10-mg zolpidem dosage.

Assessment of intervention for infant night waking : parental reports and activity-based home monitoring

Abstract: Sleep patterns of 50 infants (aged 9-24 months) with sleep disturbances were studied by using an activity monitor (actigraph) and parental reports during the baseline and intervention periods. Two behavioral intervention methods were used to treat the multiple or prolonged night-waking problems. Infant sleep significantly improved during the period of intervention as measured by both actigraphic and parental monitoring. The discrepancy between parental and actigraphic measures increased over time, as did the number of omitted items from the parental daily logs. The results highlight some of the advantages as well as some of the limitations of actigraphic and parental monitoring of infant sleep, and they suggest that the two methods may have complementary roles in assessing intervention efficacy in this field.

Trazodone for antidepressant-associated insomnia.

Abstract: Objective: The authors investigated trazodone as a hypnotic for depressed patients who had persistent, exacerbated, or new insomnia while taking either fluoxetine or bupropion. Method: Seventeen depressed patients who had insomnia while taking fluoxetine or bupropion were given either trazodone or placebo in a double-blind crossover trial. Sleep was assessed by self-report with the Pittsburgh Sleep Quality Index and the sleep items of the Yale-New Haven Hospital Depressive Symptom Inventory. Results: Improvement with trazodone, but not with placebo, was shown by the total Pittsburgh index scores and Yale-New Haven inventory total sleep scores and by the Pittsburgh index measures of sleep duration and Yale-New Haven inventory measures of early morning awakening, and there was a trend toward improvement in the Yale-New Haven inventory item regarding middle of the night awakenings. Subjective sleep quality and sleep latency also showed a trend toward improvement, but the Pittsburgh index measures of sleep efficiency and disturbances and the Yale-New Haven inventory item regarding difficulty falling asleep were unaffected by trazodone. One patient dropped out because of excessive daytime sedation with trazodone, and another dropped out because of nonresponse to placebo. Of the completers, 67% experienced overall improvement in sleep with trazodone according to a priori criteria, whereas only 13% experienced improvement with placebo. Conclusions: Trazodone is an effective hypnotic for patients with antidepressant-associated insomnia.

Epilepsy and sleep apnea syndrome

Abstract: We identified seven patients with refractory partial epilepsy and sleep apnea. Treatment of the sleep apnea with nasal continuous positive airway pressure (CPAP), protriptyline, trazodone, acetazolamide, or tracheostomy reduced seizure frequency and severity in six patients. Success with CPAP depended largely on compliance. Four of five patients had a clear reduction in seizure frequency with the use of CPAP. Sleep apnea may exacerbate epilepsy by causing sleep disruption and deprivation, hypoxemia, and decreased cerebral blood flow. In epilepsy patients with risk factors (eg, obesity) or markers (eg, habitual snoring, daytime somnolence) for sleep apnea, a careful sleep history should be elicited and a polysomnogram obtained when indicated. Treatment of the sleep disorder can improve seizure control.

Interaction of hyperventilation and arousal in the pathogenesis of idiopathic central sleep apnea

Abstract: Central apneas during sleep may arise as a result of reduction in PaCO2 below the apnea threshold. We therefore hypothesized that hyperventilation and arousals from sleep interact to cause hypocapnia and subsequent central apneas in patients with idiopathic central sleep apnea (ICSA). Accordingly, the relationships among preapneic ventilation, arousal from sleep, and the onset and duration of subsequent central apneas were examined during Stage 2 non-REM sleep in eight patients with ICSA (mean +/- SEM, 45.4 +/- 4.7 central apneas and hypopneas/h of sleep). During Stage 2 sleep, all episodes of periodic breathing with central apneas were triggered by hyperventilation. Minute ventilation (VI) was greater (6.3 +/- 0.7 versus 5.4 +/- 0.8 L/min, p < 0.05) and mean transcutaneous PCO2 (PtcCO2) was lower (37.8 +/- 1.3 versus 38.9 +/- 1.6 mm Hg, p < 0.05) during periodic breathing than during stable breathing. VI during the ventilatory phase of the periodic breathing cycle increased progressively with increasing ...

Sleep cycles and alpha-delta sleep in fibromyalgia syndrome.

Abstract: Objective Fibromyalgia syndrome (FMS) is a musculoskeletal disorder characterized by generalized pain, localized tender points, chronic fatigue and nonrestorative sleep. Since sleep disturbances frequently occur in FMS and alpha intrusion in nonrapid eye movement (NREM) sleep probably associates with the nonrefreshing sleep, we prospectively studied the delta and alpha activity and alpha-delta ratio across sleep cycles, performing polysomnography in 10 patients with FMS and in 14 healthy control subjects. Methods Night long polysomnography recordings were performed in all subjects. Sleep scoring was done visually according to Rechtschaffen and Kales criteria. By means of spectral analysis the conventional electroencephalogram (EEG) frequency bands were automatically computed for the all night recordings. For alpha and delta power the integrated and normalized values were calculated for each sleep cycle, the evolution of these activities across successive sleep cycles was studied. Results Alpha-delta patterns occurred in almost all the patients who had also superficial and fragmented sleep with increased awakenings and reduced REM and slow wave sleep. Delta decay across sleep cycles was different in FMS and alpha activity was greater and declined, whereas the controls were persistently low throughout their sleep. Alpha-delta ratio increased progressively in successive sleep cycles; this was again different from controls. Conclusion Patients with FMS presented a high frequency of subjective sleep disturbances, an increased incidence of alpha EEG NREM sleep and clear abnormalities in sleep cycle organization.

Sleep Disruption in Parkinson's Disease Assessment by Continuous Activity Monitoring

Abstract: Objective: To assess differences in activity and immobility during sleep between patients with Parkinson's disease (PD) and healthy subjects and to evaluate the relations of clinical variables with the motor activity measures in patients with PD. Design: Survey, case series. Setting: University hospital outpatient neurology department and urban population in Leiden, the Netherlands. Motor activity was recorded during 6 successive nights at home with a wrist-worn activity monitor. Participants: Eighty-nine patients with PD and 83 age-matched healthy controls. Main Outcome Measures: For each subject, three mean measures reflecting activity or immobility during the nocturnal period were calculated. Results: Compared with the healthy elderly subjects, patients with PD have an elevated nocturnal activity level and an increased proportion of time with movement, indicating a more disturbed sleep. The mean duration of nocturnal immobility periods was similar for both groups. This measure, however, did reflect the self-reported disturbed sleep maintenance in both groups. The daily dose of levodopa or the use of dopamine agonists in patients not receiving levodopa, rather than disease severity, proved to be the best predictors of nocturnal activity. Conclusions: We hypothesize that in mildly to moderately affected patients with PD, levodopa or dopamine agonists cause sleep disruption by their effects on sleep regulation. In more severely affected patients, the beneficial effects of these drugs on nocturnal disabilities that cause sleep disruption in PD prevail.

Changes in Sleep and Sleep Electroencephalogram During Pregnancy

Abstract: The impairment of sleep quality is a common complaint during pregnancy. To investigate the changes in sleep in the course of pregnancy, the sleep electroencephalogram (EEG) was recorded and analyzed in nine healthy women on 2 consecutive nights during each trimester of pregnancy. Waking after sleep onset increased from the second (TR2) to the third (TR3) trimester, whereas rapid eye movement (REM) sleep decreased from the first trimester (TR1) to TR2. Spectral analysis of the EEG in nonrapid eye movement (NREM) sleep revealed a progressive reduction of power density in the course of pregnancy. In comparison to TR1, the values in TR2 were significantly lower in the 10.25-11.0-Hz and 14.25-17.0-Hz bands. In TR3, the significant reduction extended over the ranges of 1.25-12.0 Hz and 13.25-16.0 Hz. The largest decrease (30%) occurred in the 14.25-15.0-Hz band. In REM sleep, the spindle frequency range was not affected, and a minor reduction of power density in some frequency bins below 12 Hz was present only in TR3. The study documents major alterations of the sleep EEG that are not evident from the sleep scores and that may be associated with the characteristic hormonal changes occurring during pregnancy.

Sleep problems in toddlers: effects of treatment on their daytime behavior

Abstract: Objective This study investigated the effects of a treatment program for severely sleep-disturbed children on their daytime interaction with their mothers. Method Twenty-eight children with serious sleep problems and 30 matched controls, aged 12 to 36 months, were compared on behavior rating scales, on sleep patterns, and during play and feeding interactions with their mothers before and after an intervention program. Results After treatment the sleep-disturbed children improved in their behavior, in their sleep patterns, and during feeding interactions with their mothers. However, the behavior of the children but not that of their mothers improved. Conclusions The findings of this study indicate that a brief behavioral intervention program focused on helping families manage children with sleep disturbances can generalize to daytime mother-child interactions. This suggests that a compromised relationship in early life may be modified by rather simple interventions since changes of one behavioral system may modify the total relationship of young children with those caring for them.

Surgical treatment of obstructive sleep apnea by maxillomandibular advancement.

Abstract: In recent years obstructive sleep apnea syndrome has gained increasing interest. Treatment of choice is nasal continuous positive airway pressure ventilation during sleep for upper airway patency, which does not cure sleep apnea and has to be applied throughout a patient's lifetime. In respect to various underlying pathomechanisms, in certain cases with craniofacial disorders, causal therapy by craniofacial osteotomies seems possible. A series of 21 consecutive patients with maxillary and mandibular deficiency were treated primarily with a 10-mm maxillomandibular advancement by retromolar sagittal split osteotomy and Le Fort-I osteotomy, respectively. Obstructive sleep apnea syndrome was considerably improved in all patients. In 20 of 21 patients, the postoperative respiratory disturbance index (RDI) was reduced clearly to under 10, oxygen saturation rose and sleep quality improved. This was achieved by a maxillomandibular advancement of 10 mm without secondary refinements. In one patient the RDI could only be reduced to 20, probably due to insufficient maxillary advancement; oxygen desaturations still existed despite secondary corrections. These results indicate that successful surgical treatment is possible in a high percentage of selected patients with certain craniofacial characteristics. In addition to cardiorespiratory polysomnography there should be routine cephalometric evaluation of all patients. Maxillomandibular advancement should be offered as an alternative therapy to all patients with maxillary and/or mandibular deficiency or dolichofacial type in combination with narrow posterior airway space.

Pediatricians and Sleep Disorders: Training and Practice

Abstract: Objective. A series of studies were conducted to investigate pediatricians9 training, knowledge, and practices regarding sleep and sleep disorders in children and adolescents. Method and results. Study 1, a national survey of 156 pediatric residency programs, found that pediatricians receive a mean of 4.8 hours of instruction on sleep and sleep disorders, although the mode and median hours of instruction is 0 hours. In Study 2, 88 pediatricians completing a questionnaire concerning general knowledge about sleep disorders in children and adolescents received a mean score of 71.8% (range, 40% to 93%). Pediatricians appear to know the most about developmental issues and sleep hygiene and the least about specific disorders such as narcolepsy and parasomnias. In the third study, 183 pediatricians were surveyed about their actual beliefs and practices regarding young children9s sleep problems. Together, those surveyed reported that approximately 25% of their patients experience some type of sleep problem. Most pediatricians recommend behavioral interventions, although 14.8% of pediatricians report prescribing pharmacological treatments, and 48.9% inform parents that their child is likely to outgrow the problem. Conclusions. The results of these studies support the need for more education in sleep and sleep disorders in children and adolescents within medical schools, pediatric residency programs, and the practicing pediatric community.

Narcolepsy and its treatment with stimulants. ASDA standards of practice.

Abstract: This review is part of the standards of practice recommendations. It has been commended and reviewed by the Board of the ASDA. It reflects recommendations of the Board for the practice of sleep medicine in North America. The subcommittee is responsible for the presented write-up.

Motor dysfunction during sleep in posttraumatic stress disorder.

Abstract: A subjective disturbance of sleep, including the occurrence of repetitive, stereotypical anxiety dreams, is characteristic of posttraumatic stress disorder (PTSD). The phenomenology of the PTSD anxiety dream has seemed most consistent with an underlying rapid eye movement (REM) sleep dysfunction. However, motor behavior reportedly can accompany PTSD dreams, and normal REM sleep typically involves a nearly total paralysis of the body musculature. As a means of understanding this discrepancy, anterior tibialis muscle activity during sleep was studied in a group of Vietnam combat veterans with current PTSD and in an age-matched normal control group. The PTSD subjects had a higher percentage of REM sleep epochs with at least one prolonged twitch burst; they also were more likely to have periodic limb movements in sleep, during nonrapid eye movement sleep. Both these forms of muscle activation also have been observed in REM behavior disorder (RBD), a parasomnia characterized by the actual enactment of dream sequences during REM sleep. The identification of RBD-like signs in PTSD adds to the evidence for a fundamental disturbance of REM sleep phasic mechanisms in PTSD.