scispace - formally typeset
Search or ask a question

Showing papers on "Non-rapid eye movement sleep published in 1987"


Journal ArticleDOI
TL;DR: Trazodone therapy has been shown to reduce the frequency of arousals, the severity of drowsiness, and the duration of REM sleep, and increase restorative slow wave sleep and stage III and IV NREM sleep.
Abstract: Manifestations of sleep disturbances can potentially serve as external criteria for the diagnosis of specific subtypes of major depressive disorder (MDD). Depressed patients generally experience disturbances of sleep continuity and rapid eye movement (REM) sleep. Disturbances in nonrapid eye movement (NREM) sleep (stages III and IV) also occur. Characteristic of primary sleep disturbance in many depressed patients are shortened REM latency periods and instabilities in NREM sleep identified by increases in the number of stage shifts, decreases in the duration of stage III and IV sleep, and a shift towards lighter sleep stages (sleep efficiency disturbances). Treatment modalities for these sleep disturbances include sleep deprivation therapy and antidepressant therapy. Sleep deprivation alone has been only moderately successful, while antidepressant therapy usually results in symptomatic improvement. To restore normative sleep, REM sleep periods and stage III and IV sleep must be returned to normal. Trazodone therapy has been shown to reduce the frequency of arousals, the severity of drowsiness, and the duration of REM sleep, and increase restorative slow wave sleep and stage III and IV NREM sleep.

312 citations


Journal ArticleDOI
03 Apr 1987-JAMA
TL;DR: The RBD was unrelated to psychopathologic conditions but in five cases was closely linked with major neuropathologic disorders: dementia, olivopontocerebellar degeneration, subarachnoid hemorrhage, and the Guillain-Barré syndrome.
Abstract: Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia defined by intermittent loss of electromyographic atonia during REM sleep with emergence of complex and vigorous behaviors. Punching, kicking, and leaping from bed during attempted dream enactment caused repeated injury in nine of our first ten adult patients. Mean age at onset was 62 years; nine of the patients were male. All patients underwent standard polysomnographic studies with videotaping of behaviors and extensive neurologic and psychiatric evaluations. The RBD was unrelated to psychopathologic conditions but in five cases was closely linked with major neuropathologic disorders: dementia (two), olivopontocerebellar degeneration, subarachnoid hemorrhage, and the Guillain-Barre syndrome. Other common polysomnographic abnormalities were high REM density, increased stage 3/4 (slow-wave) sleep, and both periodic and aperiodic limb twitching in non-REM sleep. Eight patients had dream changes involving motor overactivity and violent confrontations of dream characters. Clonazepam induced rapid and sustained improvement of dream and sleep behavior problems in seven patients, as did desipramine hydrochloride in one patient. ( JAMA 1987;257:1786-1789)

271 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the effectiveness of positive pressure ventilation through a nose mask in preventing nocturnal hypoxemia and compared it with negative pressure systems, and concluded that nasal positive pressure would provide stability for the upper airway.
Abstract: Severe nocturnal hypoxemia may occur in patients with respiratory muscle weakness caused by neuromuscular disorders. Negative pressure ventilators may be partially effective in these patients but can cause upper airway obstructive apneas. We examined the effectiveness of positive pressure ventilation through a nose mask in preventing nocturnal hypoxemia and compared it with negative pressure systems. We reasoned that nasal positive pressure would provide stability for the upper airway. Five patients with neuromuscular disorders underwent a series of all-night sleep studies under control conditions, negative pressure ventilation, and positive pressure ventilation through a comfortable nose mask. Sleep staging and respiratory variables were monitored during all studies. Daytime awake lung function, respiratory muscle strength, and arterial blood gases were also measured. The severe hypoxemia and hypercapnia that occurred under control conditions were prevented by positive pressure ventilation through a nose mask. Negative pressure ventilation improved NREM ventilation in all patients, but did not prevent severe oxyhemoglobin desaturation, which occurred during REM sleep. Negative pressure ventilation appears to contribute to upper airways obstruction during REM sleep as evidenced by cessation of air flow, reduced chest wall movements, falls in arterial oxyhemoglobin saturation, and hypercapnia. With treatment, daytime PaO2 improved from a mean of 70 to 83 mm Hg, and PaCO2 decreased from a mean of 61 to 46 mm Hg. We conclude that nasally applied positive pressure ventilation is a highly effective method of providing nocturnal assisted ventilation because it stabilizes the oropharyngeal airway.

229 citations


Journal ArticleDOI
TL;DR: It is suggested that young, never-medicated schizophrenics do not show the characteristic constellation of abnormalities in the first NREM-REM cycle seen in patients with major depression, however, decreased slow-wave sleep should be investigated as a possible marker for negative symptoms in schizophrenia.
Abstract: • Electroencephalographic (EEG) sleep characteristics of young, never-medicated, nonschizoaffective schizophrenics were compared with the EEG sleep of patients with major depressive disorders (delusional and nondelusional) and with that of healthy controls. Schizophrenics had decreased sleep continuity comparable to delusional depressives. Slow-wave sleep percent was similar to that seen in healthy controls, as was the intranight temporal distribution of EEG delta activity. However, schizophrenics showed diminished delta counts per minute of non-rapid eye movement (NREM) sleep and a decreased total delta wave count. In contrast, depressives showed diminished slow-wave sleep percent compared with controls, greatly decreased delta activity (more so than did the schizophrenics), and an altered temporal distribution of delta activity, as evidenced by a shift of delta activity from the first to the second NREM period. Minutes of slow-wave sleep in the schizophrenics was inversely correlated with the severity of negative symptoms independent of the effects of age and the presence of depression. The schizophrenics showed normal REM latency and first REM period duration, in contrast to the depressives. These findings, reviewed in the historical context of sleep physiologic studies of schizophrenia over the past 30 years, suggest that young, never-medicated schizophrenics do not show the characteristic constellation of abnormalities in the first NREM-REM cycle seen in patients with major depression. However, decreased slow-wave sleep should be investigated as a possible marker for negative symptoms in schizophrenia.

189 citations


Journal ArticleDOI
TL;DR: The Multiple Sleep Latency Test (MSLT) reveals a daily biphasic organization of sleepiness that is affected in predictable ways by the length and continuity of nocturnal sleep on one or several nights, and by maturation, aging, sleep pathology, and drug ingestion.

167 citations


Journal ArticleDOI
01 Jan 1987-Sleep
TL;DR: It is proposed that LS, along with HS, is an NREM sleep stage that exhibited similarly quiescent spontaneous behavior, similar intermediate response thresholds, and similar low rates of PGO-type activity.
Abstract: NREM sleep in the rat has traditionally been defined by electroencephalographic (EEG) amplitudes above those of wakefulness (W) and paradoxical sleep (PS); we refer to this high-amplitude NREM sleep as "HS." We have found that approximately 5% of total time is occupied by episodes in which EEG amplitude is low, distinguishing it from HS; theta amplitude is low, distinguishing it from PS; and electromyographic (EMG) amplitude is low, distinguishing it from W. We have called these low-EEG, low-theta, low-EMG episodes "low-amplitude sleep" (LS). Three studies are done to elucidate additional characteristics of LS. Polygraphically scored 30-s epochs were matched with independent classifications of rat behavior as W, NREM, or PS; 87% of polygraphically scored LS epochs were matched with NREM sleep behavior. Response thresholds to noxious stimuli were lowest in W, intermediate and similar in LS and HS, and highest in PS. The incidence of PGO-type (ponto-geniculo-occipital) waves in W, HS, and LS were all very low in comparison with rates in PS. Thus, LS and HS exhibited similarly quiescent spontaneous behavior, similar intermediate response thresholds, and similar low rates of PGO-type activity. Accordingly, we have proposed that LS, along with HS, is an NREM sleep stage.

124 citations


Journal ArticleDOI
TL;DR: The occurrence of disorganized breathing and compensatory hyperpnea during wakefulness with regular, continuous breathing during sleep is characteristic of Rett's syndrome and suggests an altered or impaired voluntary/behavioral respiratory control system.
Abstract: Rett's syndrome is a progressive disorder that occurs in females and is characterized by autistic behavior, dementia, ataxia, loss of purposeful use of the hands, and seizures. Patients with Rett's syndrome have been observed to have stereotyped hand movements (hand-washing) and to exhibit intermittent hyperventilation. To characterize more precisely the sleep and respiratory patterns associated with this disorder, polygraphic studies were made during sleep and wakefulness in 11 patients with this syndrome. These studies showed abnormal respiratory patterns during wakefulness, and abnormal sleep and electroencephalographic characteristics. The patients had decreased percentages of rapid-eye-movement sleep, and during wakefulness, a pattern of disorganized breathing was observed in all 11 patients and consisted of hypoxia followed by a period of increased respiratory rate and effort. The occurrence of disorganized breathing and compensatory hyperpnea during wakefulness with regular, continuous breathing during sleep is characteristic of Rett's syndrome and suggests an altered or impaired voluntary/behavioral respiratory control system.

123 citations


Journal ArticleDOI
TL;DR: It appears that the classic REM sleep findings associated with the adult depressive syndrome are not present among depressive adolescents, indicating a later ontogeny for these abnormalities.
Abstract: • Forty-nine, mostly outpatient (86%), nonbipolar adolescents, aged Tanner stage III to 18 years, with a current diagnosis of major depressive disorder and 40 adolescents without current presence or history of psychiatric disorder were studied polysomnographically for three consecutive nights. Sleep latency was significantly longer in the depressive groups. The nonendogenous depressive patients exhibited significantly more awake time and lower sleep efficiency during the sleep period. No significant group differences were found for first rapid eye movement (REM) period latency, REM density, or any other REM sleep measures. Age correlated significantly with REM latency and delta sleep time, especially among depressive patients. No significant correlations between sleep measures and severity of illness were found. It appears that the classic REM sleep findings associated with the adult depressive syndrome are not present among depressive adolescents, indicating a later ontogeny for these abnormalities.

118 citations


Patent
08 Jul 1987
TL;DR: In this article, an electronic filter is applied to analog signals representing eye movement and head movement, obtained from detectors attached to a simple headgear, to provide satisfactory information for automatically reporting an individual's sleep state.
Abstract: Electronic filters are applied to analog signals representative of eye movement and head movement, obtained from detectors attached to a simple headgear, to provide satisfactory information for automatically reporting an individual's sleep state. The filters determine whether there has been substantial eye and head movement in a given period. Each filter then generates binary output signals representing movement (or the absence of it). Noise filters and a comparison filter are then applied to the binary output signals to predict sleep state; REM sleep; NREM sleep; or wakefulness.

108 citations


Journal ArticleDOI
TL;DR: The most predictable electroencephalographic sleep changes of major depression are a shortened first NREM sleep period, a prolonged first REM period (with increased density of rapid eye movements), sleep continuity disturbance, and diminished slow wave sleep.

99 citations


Journal ArticleDOI
TL;DR: It was concluded that performance recovery following sleep loss was no slower in older subjects than in younger subjects despite very different recovery sleep stage parameters, implying that aging effects on sleep are developmental rather than degenerative.

Journal ArticleDOI
TL;DR: The effect of prolonged SD on vigilance states and EEG spectra was similar by both methods and strikingly small compared to similar results in rats.
Abstract: Sleep was studied by continuous 24-h recordings in adult male Syrian hamsters, chronically implanted with EEG and EMG electrodes. Three vigilance states were determined using visual scoring and EEG power spectra (0.25–25 Hz) computed for 4-s episodes.

Journal ArticleDOI
TL;DR: Several lines of evidence suggest that a constellation of electroencephalogram (EEG) monitored sleep abnormalities exists in the vast majority of depressed patients, and that changes in REM or NREM sleep are most pronounced during the first 100-120 min following sleep onset.

Journal ArticleDOI
TL;DR: In REM sleep and dreaming CBF values greatly increased, particularly in right temporo-parietal regions in subjects experiencing both visual and auditory dreaming.

Journal ArticleDOI
TL;DR: The data suggest that the airways may be triggered to open by a protective reflex originating in the larynx or the inspiratory muscles upon reaching a certain degree of contraction.
Abstract: This report discusses mechanisms causing the airways to open during obstructive sleep apnea (OSAS). In 4 male patients with OSAS, 92 nonrapid eye movement (NERM) sleep apnea episodes and 37 rapid eye movement (REM) sleep apnea episodes were analyzed breath by breath during a one-night study. We calculated the pressure time index of the diaphragm (the product of inspiratory time/cycle duration (Tl/Ttot) and mean transdiaphragmatic pressure swing), evaluated the sleep stages via EEG, and performed frequency spectrum analysis of the EMG of the diaphragm. It was found that with each occluded inspiratory effort the tension time index of the diaphragm (TTdi) increased progressively to reach or slightly exceed the fatigue threshold, 0.15 to 0.18 (during NREM sleep the TTdi of the last occluded breath was 0.195 +/- 0.045 and during REM sleep the TTdi of the last occluded breath was 0.153 +/- 0.037); that a close time relationship was observed as well between the onset of arousal and the opening of the airways. Our data suggest that the airways may be triggered to open by a protective reflex originating in the larynx or the inspiratory muscles upon reaching a certain degree of contraction.

Journal ArticleDOI
TL;DR: Compared with demented patients, depressed elderly had greater severity of sleep continuity disturbance both before and after sleep deprivation, a more protracted course of recovery sleep, and increased slow-wave density in the second non-REM sleep period (during recovery).
Abstract: • Decreased slow-wave sleep (SWS) and sleep continuity are major effects of healthy aging and of associated psychopathological states. Using sleep deprivation, we studied the extent to which age- and psychopathology-related sleep "decay" is reversible in aged normal, depressed, and demented subjects. Depression or probable Alzheimer's dementia compromised the augmentation of sleep continuity and SWS seen in healthy elderly following sleep deprivation. Rapid eye movement (REM) latency decreased during recovery sleep in the controls but increased in both patient groups. Compared with demented patients, depressed elderly had greater severity of sleep continuity disturbance both before and after sleep deprivation, a more protracted course of recovery sleep, and increased slow-wave density in the second non-REM (NREM) sleep period (during recovery). The REM sleep time was diminished in dementia compared with depression both at baseline and during recovery sleep. These differential effects of age, health, and neuropsychiatric disease on recovery from sleep loss are relevant to recovery or reversal theories of sleep and have implications for daytime well-being in the elderly.

Journal ArticleDOI
TL;DR: The inability of forced activity to disrupt the faithful relationships between DRN discharge, PGO waves, and sleep cycle phase thus provides a new form of correlative evidence consistent with the hypothesis that the DRN is involved in sleep cycle regulation.
Abstract: Brain stem transection studies suggest that pontine neurons play a key role in regulating the mammalian sleep cycle. The serotonin (5-HT) hypothesis originally postulated that pontine 5-HT containing neurons directly initiated and maintained synchronized or NREM sleep and "primed" rapid eye movement (REM) sleep. Contrary to the predictions of this hypothesis, single unit recordings from the serotonergic dorsal raphe nucleus (DRN) have uniformly shown that DRN discharge rate is positively correlated with behavioral arousal but negatively correlated with both the NREM and REM phases of sleep. These findings required revision of the original 5-HT hypothesis and suggested instead that DRN discharge may influence the maintenance of behavioral arousal and, by ceasing to discharge, may contribute to the generation of NREM and REM sleep. The purpose of this paper was to quantitatively assess the strength of the correlation between DRN discharge, REM sleep, and PGO waves following the experimental perturbations of the sleep cycle. Since forced locomotor activity is known to powerfully alter the timing of sleep and wakefulness, the present experiments used forced activity in an attempt to dissociate DRN discharge from the sleep cycle. It was hypothesized that such dissociations would suggest DRN discharge is not involved in sleep cycle regulation. Contrastingly, preserved correlations would support the hypothesis of a possible causal relationship between DRN discharge, PGO waves activity, and the timing of sleep and wakefulness. Extracellular recordings were obtained from single cells in the DRN of intact, undrugged cats across greater than 300 sleep cycles with durations ranging from about 8 to 80 mins. Forced activity significantly reduced the amount of time spent in wakefulness and increased the number but not the duration of REM sleep epochs. The results revealed that DRN discharge rate was altered as a function of sleep cycle duration. In no case, however, was forced activity able to completely dissociate the characteristic DRN discharge rates from PGO waves or the ultradian sleep cycle. The inability of forced activity to disrupt the faithful relationships between DRN discharge, PGO waves, and sleep cycle phase thus provides a new form of correlative evidence consistent with the hypothesis that the DRN is involved in sleep cycle regulation.

Journal ArticleDOI
TL;DR: There is disproportionate inhibition of the genioglossus relative to the diaphragm at low CO2 tensions and at any PCO2 during phasic REM sleep, which may predispose the upper airway to inspiratory occlusion during sleep.
Abstract: Oropharyngeal patency during sleep is dependent on the dilating force of the genioglossus, the main tongue protrusor muscle. We measured the ventilatory (Vl), diaphragmatic (EMGdi), and genioglossal (EMGgg) electromyographic responses to CO2 in awake and sleeping goats; delta Vl/delta PETCO2 decreased from awake (0.85 +/- 0.087 L/min/mm Hg) to NREM sleep (0.69 +/- 0.069) to REM sleep (0.57 +/- 0.078, p less than 0.005 versus awake). There were minimal decreases in delta EMGdi/delta PETCO2 and EMGdi at a PETCO2 of 55 mm Hg from awake to NREM, but a significant decrease in EMGdi at a PETCO2 of 55 mm Hg during REM sleep (p less than 0.025 versus NREM). Inspiratory EMGgg was only present above a PCO2 threshold, which was similar for each state (49.3 +/- 2.3 mm Hg PETCO2 awake, 48.8 +/- 2.4 during NREM, 49.5 +/- 2.5 during REM), and delta EMGgg/delta PETCO2 tended to be less during both sleep states compared with that while awake (p = 0.10). At any PCO2, inspiratory EMGgg was markedly inhibited during REM sleep when rapid eye movements were present (phasic REM). We conclude that there is disproportionate inhibition of the genioglossus relative to the diaphragm at low CO2 tensions and at any PCO2 during phasic REM sleep. This imbalance may predispose the upper airway to inspiratory occlusion during sleep.

Journal ArticleDOI
TL;DR: It is suggested that the slow wave sleep deficiency so commonly associated with chronic, primary insomnia is the result of a failure in the thermoregulatory system to show a regulated, rapid decrease in body temperature with sleep onset which persists for the first 1–2 hrs into the sleep period.
Abstract: The following review article attempts to develop the argument that a regulated, rapid drop in rectal, core-body temperature following sleep onset is a necessary prerequisite to the presence of sustained slow wave sleep (NREM Stage 4). Based upon this premise, a theory1 is presented to suggest that the slow wave sleep deficiency so commonly associated with chronic, primary insomnia (Gaillard, 1976, 1978) is the result of a failure in the thermoregulatory system to show a regulated, rapid decrease in body temperature with sleep onset which persists for the first 1–2 hrs into the sleep period.

Journal ArticleDOI
TL;DR: The REM periods of the patients contained 3 times as many waking epochs as those of the controls, which suggests that in narcolepsy the transition REM/waking is selectively facilitated.

Journal ArticleDOI
01 Jan 1987-Sleep
TL;DR: From a subjective point of view, depth and quality of sleep were improved, whereas number of awakenings and feeling on awakening were not modified, and side effects (bitter taste, jitteriness, difficulty to concentrate) were reported only with 7.5 mg zopiclone.
Abstract: 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. Language: en

Journal ArticleDOI
TL;DR: Significantly more epileptic activity was shown in patients who had their first seizure before the age of 20, and in young subjects, in patients with a family history of seizures, with pathological neurological findings, mental retardation and delayed psychomotoric development in early childhood, were not statistically significant.
Abstract: A sleep EEG of 190 patients without sleep deprivation was recorded, followed by a sleep EEG after 24 h of sleep deprivation on the next day. The patients suffered from various types of epilepsy, in th

Journal ArticleDOI
TL;DR: The data support the notion that 5-HT neurons in the brain, when active, can suppress REM sleep, and in a dose-related manner.

Journal ArticleDOI
TL;DR: Findings do not support the contention that eating disorders are variants of affective disorders, and Contrary to reports of shortened REM latency and increased REM density in depressed patients, it did not find significant REM differences between eating disorder patients without endogenous depression and healthy control subjects.
Abstract: Several recent investigations have suggested that neurobiological similarities may exist between patients with eating disorders and those with depression. We performed polysomnograms for two consecutive nights on nine bulimic and six anorectic patients who had no concomitant diagnosis of endogenous depression. The rapid eye movement (REM) latency, REM density, and delta sleep of these subjects on night 2 were compared to those of 10 healthy controls of similar ages. Contrary to reports of shortened REM latency and increased REM density in depressed patients, we did not find significant REM differences between eating disorder patients without endogenous depression and healthy control subjects. Low weight anorectics did appear to have less delta sleep than did controls. These findings do not support the contention that eating disorders are variants of affective disorders.

Journal ArticleDOI
TL;DR: Transcranial cortical stimulation with magnetic pulses was used to investigate motor excitability during sleep in man and responded to stimuli identical to those used in wakefulness.

Journal ArticleDOI
TL;DR: Whereas the modes of dreaming were quite different within post-stress nights, mood was unproved the next morning in all subjects, and the patterns of subsequent sleep remained unchanged.
Abstract: Previous research has demonstrated that in healthy subjects sit uat ional strain may provoke not only sleep disturbances characteristic of depression (e.g., shortened REM latencies), but also alterations in dream content. Nevertheless, there are some controversial results. The aim or our study was to clarify these inconsistencies by developing a design which might avoid some methodological problems which were present in some of these previous studies. Eleven male subjects slept in the laboratory for 7 consecutive nights. During 1 evenings they saw a stressful and a neutral movie in randomized order. The subsequent nights included REM sleep awakenings for the purpose of dream collections. Whereas the subjects were demonstrably affected by the disturbing films, the patterns of subsequent sleep remained unchanged. In contrast manifest content of the initial dreams were clearly altered. Whereas the modes of dreaming were quite different within post-stress nights, mood was unproved the next morning in all subjects. The results are discussed within the framework of several prevailing concepts about sleep, dreams, and psychological strain.

Journal Article
01 Dec 1987-Sleep
TL;DR: Examination of delta and REM activity during sleep as a function of age, gender, and time of night in 85 healthy, 6- to 16-year-old children confirmed that, in children as in adults, delta activity decreases andREM activity increases across the night.
Abstract: Using earlier developed computer-based measurement methods, delta and REM activity were examined during sleep as a function of age, gender, and time of night in 85 healthy, 6- to 16-year-old children. Chronological age was found to account most strongly for differences in automated delta and REM count measures in this age range. Increasing age was shown to be associated with a significant decline in both automated measures, but the effect was much greater for the delta count measure. The age-related decline in delta wave activity was reflected primarily in a linear decline in 2.0-3.0 Hz delta activity, that is, in the faster end of the delta frequency band. Examination of these measurements in successive NREM and REM sleep periods confirmed that, in children as in adults, delta activity decreases and REM activity increases across the night. Findings are discussed relative to those obtained in the same children using standard measurement methods.

Journal ArticleDOI
01 Jan 1987-Sleep
TL;DR: The results suggest that in the absence of sleep-wake circadian rhythms, sleep time is subject to short-term homeostatic regulation, with significant positive correlations with both prior and subsequent wake episode lengths.
Abstract: The lengths of sleep and wake episodes during 2 consecutive days of recording were measured in five rats lacking circadian rhythms owing to lesions of the suprachiasmatic nuclei. Total sleep (TS) episode lengths and the amount of NREM sleep and paradoxical sleep (PS) within each episode were examined in relationship to the lengths of the immediately preceding and the immediately following wake episodes. As putative measures of sleep intensity, average and maximum delta wave (1-4 Hz) incidence and amplitude within NREM were also examined in relation to adjacent wake episode lengths. For sleep episodes longer than 50 min (78% of daily sleep), TS episode lengths and amount of NREM within these episodes showed significant positive correlations with both prior and subsequent wake episode lengths. PS durations within sleep episodes also showed significant positive correlations with subsequent wake episode lengths, but little correlation with prior wake episode lengths. The results suggest that in the absence of sleep-wake circadian rhythms, sleep time is subject to short-term homeostatic regulation. Amounts of PS within sleep episodes were highly correlated (r = 0.84) with amounts of NREM. NREM delta wave incidence and amplitude showed no significant relationships with the lengths of prior or subsequent wake episodes, suggesting that variations in sleep intensity may not play a prominent role in the short-term homeostatic regulation of ad lib sleep. Delta wave incidence and amplitude were also not correlated with the duration of NREM episodes, but incidence during wake was positively correlated with wake episode duration, suggesting that delta density during wake may be an electrophysiological indicator of the propensity to sleep.

Journal ArticleDOI
TL;DR: When the heart rate changes associated with sleep movements were studied it was found that the para‐sympathetic deceleration component in the parkinsonian patients was absent and the motor dysfunction associated with Parkinson's disease is reflected in many ways in the sleep movement activity.
Abstract: Nine parkinsonian patients were studied during one night using the static charge sensitive bed (SCSB) method for the monitoring of respiration, ballistocardiogram (BCG) and body movements. The parkinsonian sleep was more restless than that of the controls. As the SCSB-defined levels of autonomic nervous activity were concerned, the amount of motor active wakefulness (MAW) was significantly (P less than 0.05) increased in parkinsonian patients, who also had less quiet sleep (P less than 0.05) than the controls. Parkinsonian tremor was present during 29.8 +/- 15.8% of the time in bed. Usually it was observed during wakefulness; it disappeared when the patient fell asleep. The frequency of turning-over events in bed was smaller in the parkinsonian patients than in the controls (P less than 0.05). When the heart rate changes associated with sleep movements were studied it was found that the parasympathetic deceleration component in the parkinsonian patients was absent. The motor dysfunction associated with Parkinson's disease is reflected in many ways in the sleep movement activity. Sleep disturbances in PD seem to be secondary in character; i.e. they can be due to impaired motor functions like turning around in the bed, or due to impaired arousal mechanisms during sleep.

Journal ArticleDOI
TL;DR: This hypothesis was tested by imposing a 6-hour phase delay of sleep in 10 young male subjects and there were reliable changes in observers' ratings of mood and in some self-report measures.
Abstract: A phase advance of some circadian rhythms (e.g., body temperature and rapid eye movement [REM] sleep propensity) relative to the sleep-wake cycle is thought to be implicated in the pathophysiology and pathogenesis of some affective disorders. Since this phase disturbance can be induced in normal subjects by acutely delaying their sleep onset, it follows that the outcome of this experimental procedure should resemble the symptoms of depressive illness. This hypothesis was tested by imposing a 6-hour phase delay of sleep in 10 young male subjects. There were reliable changes in observer's ratings of mood and in some self-report measures. For the most part, the effect was modest, being largely confined to variations within normal limits. Two of the subjects, however, were noticeably depressed when interviewed after either the first or the second night of phase shift.