Showing papers on "Polysomnography published in 1998"
TL;DR: SAGEA is frequently present in poorly performing first-grade students in whom it adversely affects learning performance and the data suggest that a subset of children with behavioral and learning disabilities could have SAGEA and may benefit from prospective medical evaluation and treatment.
Abstract: Objective. To assess the impact of sleep-associated gas exchange abnormalities (SAGEA) on school academic performance in children. Design. Prospective study. Setting. Urban public elementary schools. Participants. Two hundred ninety-seven first-grade children whose school performance was in the lowest 10th percentile of their class ranking. Methods. Children were screened for obstructive sleep apnea syndrome at home using a detailed parental questionnaire and a single night recording of pulse oximetry and transcutaneous partial pressure of carbon dioxide. If SAGEA was diagnosed, parents were encouraged to seek medical intervention for SAGEA. School grades of all participating children for the school year preceding and after the overnight study were obtained. Results. SAGEA was identified in 54 children (18.1%). Of these, 24 underwent surgical tonsillectomy and adenoidectomy (TR), whereas in the remaining 30 children, parents elected not to seek any therapeutic intervention (NT). Overall mean grades during the second grade increased from 2.43 ± 0.17 (SEM) to 2.87 ± 0.19 in TR, although no significant changes occurred in NT (2.44 ± 0.13 to 2.46 ± 0.15). Similarly, no academic improvements occurred in children without SAGEA. Conclusions. SAGEA is frequently present in poorly performing first-grade students in whom it adversely affects learning performance. The data suggest that a subset of children with behavioral and learning disabilities could have SAGEA and may benefit from prospective medical evaluation and treatment.
1,117 citations
TL;DR: Cardiovascular variability is altered in patients with OSA, evident even in the absence of hypertension, heart failure, or other disease states and may be linked to the severity of OSA.
Abstract: Background—Altered cardiovascular variability is a prognostic indicator for cardiovascular events. Patients with obstructive sleep apnea (OSA) are at an increased risk for cardiovascular disease. We tested the hypothesis that OSA is accompanied by alterations in cardiovascular variability, even in the absence of overt cardiovascular disease. Methods and Results—Spectral analysis of variability of muscle sympathetic nerve activity, RR interval, and blood pressure were obtained during undisturbed supine rest in 15 patients with moderate-to-severe OSA, 18 patients with mild OSA, and 16 healthy control subjects in whom sleep disordered breathing was excluded by complete overnight polysomnography. Patients with OSA were newly diagnosed, never treated for OSA, and free of any other known diseases. Patients with moderate-to-severe OSA had shorter RR intervals (793±27 ms) and increased sympathetic burst frequency (49±4 bursts/min) compared with control subjects (947±42 ms; 24±3 bursts/min; P=0.008 and P<0.001, re...
563 citations
TL;DR: The hypothesis that obesity, per se, in the absence of OSA, is not accompanied by increased sympathetic activity to muscle blood vessels is tested.
Abstract: Background—Obese humans are reported to have increased muscle sympathetic nerve activity (MSNA) Obstructive sleep apnea (OSA) may also be accompanied by increased MSNA Because there is a high prevalence of OSA in obese humans, it is possible that high MSNA reported in obese subjects may in fact reflect the presence of OSA in these subjects We tested the hypothesis that obesity, per se, in the absence of OSA, is not accompanied by increased MSNA Methods and Results—We measured MSNA in 25 healthy normal-weight subjects and 30 healthy sedentary obese subjects All subjects were screened by history and examination to exclude subjects with OSA or hypertension OSA was further excluded by overnight polysomnographic studies Despite careful screening, polysomnography revealed that 1 of 25 normal-weight subjects and 9 of 30 obese subjects had occult OSA (P=0015) MSNA was similar in normal-weight subjects (41±3 bursts per 100 heartbeats) and obese subjects without sleep apnea (42±3 bursts per 100 heartbeats,
516 citations
TL;DR: It is suggested that with rigorous training and clear protocols for data collection and processing, good-quality multichannel polysomnography data can be obtained for a majority of unattended studies performed in a research setting.
Abstract: Summary: This paper reviews the data collection, processing, and analysis approaches developed to obtain comprehensive unattended polysomnographic data for the Sleep Heart Health Study, a multicenter study of the cardiovascular consequences of sleep-disordered breathing. Protocols were developed and implemented to standardize in-home data collection procedures and to perform centralized sleep scoring. Of 7027 studies performed on 6 697 participants, 5 534 studies were determined to be technically acceptable (failure rate 5.3%). Quality grades varied over time, reflecting the influences of variable technician experience, and equipment aging and modifications. Eighty-seven percent of studies were judged to be of igoodi quality or better, and 75% were judged to be of sufficient quality to provide reliable sleep staging and arousal data. Poor submental EMG (electromyogram) accounted for the largest proportion of poor signal grades (9% of studies had <2 hours artifact free EMG signal). These data suggest that with rigorous training and clear protocols for data collection and processing, good-quality multichannel polysomnography data can be obtained for a majority of unattended studies performed in a research setting. Data most susceptible to poor signal quality are sleep staging and arousal data that require clear EEG (electroencephalograph) and EMG signals.
468 citations
TL;DR: These data are consistent with those from a prior unblinded study and suggest that RLS patients will have fewer symptoms if they have ferritin levels greater than 50 mcg/l.
Abstract: STUDY OBJECTIVES Using blinded procedures, determine the relation between serum ferritin levels and severity of subjective and objective symptoms of the restless legs syndrome (RLS) for a representative patient sample covering the entire adult age range. DESIGN All patient records from the past 4 years were retrospectively reviewed to obtain data from all cases with RLS. All patients were included who had ferritin levels obtained at about the same time as a polysomnogram (PSG), met diagnostic criteria for RLS, and were not on iron or medications that would reduce the RLS symptoms at the time of the PSG. SETTING Sleep Disorders Center. PATIENTS 27 (18 females, 9 males), aged 29-81 years. INTERVENTIONS None. MEASUREMENTS AND RESULTS Measurements included clinical ratings of RLS severity and PSG measures of sleep efficiency and periodic limb movements (PLMS) in sleep with and without arousal. Lower ferritin correlated significantly to greater RLS severity and decreased sleep efficiency. All but one patient with severe RLS had ferritin levels < or = 50 mcg/l. Patients with lower ferritin (< or = 50 mcg/l) also showed significantly more PLMS with arousal than did those with higher ferritin, but the PLMS/hour was not significantly related to ferritin. This last finding may be due to inclusion of two 'outliers' or because of severely disturbed sleep of the more severe RLS patients. CONCLUSIONS These data are consistent with those from a prior unblinded study and suggest that RLS patients will have fewer symptoms if they have ferritin levels greater than 50 mcg/l.
451 citations
TL;DR: Higher cognitive functions in children, such as verbal creativity and abstract thinking, are impaired after a single night of restricted sleep, even when routine performance is relatively maintained.
Abstract: STUDY OBJECTIVES: Various aspects of human performance were assessed in children after sleep loss PARTICIPANTS: Sixteen children (7 males, 9 females) between the ages of 10 and 14 years DESIGN AND INTERVENTIONS: Children were randomly assigned to either a control (CTRL) group, with 11 hours in bed, or an experimental sleep restriction (SR) group, with 5 hours in bed, on a single night in the sleep laboratory MEASUREMENTS: Both groups were evaluated the following day with a battery of performance and sleepiness measures Psychomotor and cognitive performance tests were given during four 1-hour testing sessions at 2-hour intervals RESULTS: A multiple sleep latency test (MSLT) documented shorter latencies for SR children than controls Significant treatment differences were discovered in three of four variables of verbal creativity, including fluency, flexibility, and average indices There were also group differences found on the Wisconsin Card Sorting Test (WCST), which may be indicative of difficulty learning new abstract concepts Measures of rote performance and less-complex cognitive functions, including measures of memory and learning and figural creativity, did not show differences between groups, perhaps because motivation could overcome sleepiness-related impairment for these tasks CONCLUSIONS: Higher cognitive functions in children, such as verbal creativity and abstract thinking, are impaired after a single night of restricted sleep, even when routine performance is relatively maintained Language: en
439 citations
TL;DR: It is concluded that childhood OSAS is associated with systemic diastolic hypertension, and multiple linear regression showed that blood pressure could be predicted by apnea index, body mass index, and age.
Abstract: Hypertension is a common complication of obstructive sleep apnea in adults. However, hypertension has not been studied systematically in children with the obstructive sleep apnea syndrome (OSAS). We therefore measured blood pressure (BP) during polysomnography in 41 children with OSAS, compared to 26 children with primary snoring (PS). Systolic and diastolic BP were measured every 15 min via an appropriately sized arm cuff, using an automated system. This was tolerated by the children without inducing arousals from sleep. Children with OSAS had a significantly higher diastolic BP than those with PS (p < 0.001 for sleep and p < 0.005 for wakefulness). There was no significant difference in systolic BP between the two groups. Multiple linear regression showed that blood pressure could be predicted by apnea index, body mass index, and age. Blood pressure during sleep was lower than during wakefulness (p < 0.001 for diastole and p < 0.01 for systole), but did not differ significantly between rapid eye movement (REM) and non-REM sleep. We conclude that childhood OSAS is associated with systemic diastolic hypertension.
429 citations
TL;DR: It is concluded that, in chronic insomnia, the activity of both limbs of the stress system (i.e., the HPA axis and the sympathetic system) relates positively to the degree of objective sleep disturbance.
372 citations
TL;DR: A group of predominantly male patients with a characteristic association of RBD and degenerative dementia is reported, and it is hypothesized that the underlying pathology in these patients is DLB.
Abstract: Background: REM sleep behavior disorder (RBD) has been reported with various neurodegenerative disorders, most frequently in disorders with Lewy body pathology. RBD often precedes the onset of PD, and a recent prospective study showed that 38% of patients with RBD eventually developed PD. Methods: We identified 37 patients with degenerative dementia and a history of bursts of vigorous movement of the arms and legs with vocalization during sleep and associated with dream recall. Patients with and without two or more signs of parkinsonism were compared. Clinical, laboratory, and neuropsychometric features were analyzed, and criteria for the clinical diagnosis of dementia with Lewy bodies (DLB) were applied to all patients. Results: Thirty-four of the 37 patients were male with mean age at onset of 61.5 years for RBD and 68.1 years for cognitive decline. RBD commenced before or concurrently with dementia in all patients but two. Parkinsonism (two or more signs) occurred in 54% of the sample (20/37), with a mean age at onset of 69.1 years. Polysomnography (PSG) confirmed RBD in all patients studied. Neuropsychological testing demonstrated impaired perceptual-organizational skills, verbal fluency, and marked constructional dyspraxia in more than one-half the patients. There were no statistically significant differences in the frequency of clinical features or in neuropsychological performance between patients with and without parkinsonism. Thirty-four patients (92%) met criteria for clinically possible or probably DLB. Three patients were autopsied; all had limbic with or without neocortical Lewy bodies. Conclusions: We report a group of predominantly male patients with a characteristic association of RBD and degenerative dementia. The clinical and neuropsychometric features of the groups of patients with and without parkinsonism are similar. We hypothesize that the underlying pathology in these patients is DLB.
369 citations
TL;DR: By alleviating OSA, CPAP reduces LV afterload and heart rate, unloads inspiratory muscles, and improves arterial oxygenation during stage 2 sleep in pharmacologically treated CHF patients with OSA.
Abstract: Background—The objectives of this study were to determine the effects of continuous positive airway pressure (CPAP) on blood pressure (BP) and systolic left ventricular transmural pressure (LVPtm) during sleep in congestive heart failure (CHF) patients with obstructive sleep apnea (OSA). In CHF patients with OSA, chronic nightly CPAP treatment abolishes OSA and improves left ventricular (LV) ejection fraction. We hypothesized that one mechanism whereby CPAP improves cardiac function in CHF patients with OSA is by lowering LV afterload during sleep. Methods and Results—Eight pharmacologically treated CHF patients with OSA were studied during overnight polysomnography. BP and esophageal pressure (Pes) (ie, intrathoracic pressure) were recorded before the onset of sleep and during stage 2 non–rapid eye movement sleep before, during, and after CPAP application. OSA was associated with an increase in systolic BP (from 120.4±7.8 to 131.8±10.6 mm Hg, P<0.05) and systolic LVPtm (from 124.4±7.7 to 137.2±10.8 mm Hg...
337 citations
TL;DR: The results of this investigation allowed the formulation of safety parameters for RF in this defined population with mild sleep-disordered breathing and there was a documented tissue reduction and improvement in symptoms in all subjects.
TL;DR: The SHHS achieved a high degree of intrascorer and interscorer reliability for the scoring of sleep stage and RDI in unattended in-home PSG studies.
Abstract: Study Objectives: Unattended, home-based polysomnography (PSG) is increasingly used in both research and clinical settings as an alternative to traditional laboratory-based studies, although the reliability of the scoring of these studies has not been described The purpose of this study is to describe the reliability of the PSG scoring in the Sleep Heart Health Study (SHHS), a multicenter study of the relation between sleep-disordered breathing measured by unattended, in-home PSG using a portable sleep monitor, and cardiovascular outcomes Design: The reliability of SHHS scorers was evaluated based on 20 randomly selected studies per scorer, assessing both interscorer and intrascorer reliability Results: Both inter- and intrascorer comparisons on epoch-by-epoch sleep staging showed excellent reliability (kappa statistics >080), with stage 1 having the greatest discrepancies in scoring and stage 3/4 being the most reliably discriminated The arousal index (number of arousals per hour of sleep) was moderately reliable, with an intraclass correlation (ICC) of 054 The scorers were highly reliable on various respiratory disturbance indices (RDls), which incorporate an associated oxygen desaturation in the definition of respiratory events (2% to 5%) with or without the additional use of associated EEG arousal in the definition of respiratory events (ICC>090) When RDI was defined without considering oxygen desaturation or arousals to define respiratory events, the RDI was moderately reliable (ICC=074) The additional use of associated EEG arousals, but not oxygen desaturation, in defining respiratory events did little to increase the reliability of the RDI measure (ICC=077) Conclusions: The SHHS achieved a high degree of intrascorer and interscorer reliability for the scoring of sleep stage and RDI in unattended in-home PSG studies
TL;DR: It is proposed that the sleep disruption associated with periodic limb movement disorder and restless Legs syndrome and the motor restlessness of restless legs syndrome while awake could contribute to the inattention and hyperactivity seen in a subgroup of ADHD-diagnosed children.
Abstract: Sleep disruption can lead to symptoms of attention-deficit hyperactivity disorder (ADHD) in children. Since periodic limb movement disorder and/or restless legs syndrome can cause sleep disruption, we assessed whether these two specific sleep disorders are likely to occur in children with ADHD. We asked a series of 69 consecutive parents of children with ADHD questions about the symptoms of periodic limb movement disorder. Based on a positive response to these periodic limb movement disorder queries, 27 children underwent all-night polysomnography. Eighteen children (aged 2 to 15 years) of the 27 (26% of the 69 children with ADHD) had 5 or more periodic leg movements in sleep per hour of sleep and had complaints of sleep disruption, thus fulfilling the criteria for periodic limb movement disorder. A comparably age- and sex-matched group of children referred to a sleep laboratory for sleep complaints but without ADHD showed only a 5% prevalence (2 of 38 subjects) of periodic leg movements in sleep (P=.017). Eight of the 18 children with ADHD and periodic limb movement disorder and one of the two control patients with periodic limb movement disorder had both a personal and parental history of restless legs syndrome symptomatology. This study further documents the occurrence of periodic limb movement disorder and restless legs syndrome in children and is the first large-scale study establishing a possible comorbidity between ADHD and periodic limb movement disorder. We propose that the sleep disruption associated with periodic limb movement disorder and restless legs syndrome and the motor restlessness of restless legs syndrome while awake could contribute to the inattention and hyperactivity seen in a subgroup of ADHD-diagnosed children.
TL;DR: The framework of the cyclic alternating pattern offers a unified interpretation for sleep bruxism and arousal-related phenomena.
Abstract: There is evidence that sleep bruxism is an arousal-related phenomenon. In non-REM sleep, transient arousals recur at 20- to 40-second intervals and are organized according to a cyclic alternating pattern. Polysomnographic recordings from six subjects (two females and four males) affected by sleep bruxism (patients) and six healthy age-and gender-matched volunteers without complaints about sleep (controls) were analyzed to: (1) compare the sleep structure of bruxers with that of non-complaining subjects; and (2) investigate the relations between bruxism episodes and transient arousals. Patients and controls showed no significant differences in conventional sleep variables, but bruxers showed a significantly higher number of the transient arousals characterized by EEG desynchronization. Bruxism episodes were equally distributed between non-REM and REM sleep, but were more frequent in stages 1 and 2 (p < 0.0001) than in slow-wave sleep. The great majority of bruxism episodes detected in non-REM sleep (88%) were associated with the cyclic alternating pattern and always occurred during a transient arousal. Heart rate during the bruxism episodes (69.3+/-18.2) was significantly higher (p < 0.0001) than that during the pre-bruxing period (58.1+/-15.9). Almost 80% of all bruxism episodes were associated with jerks at the anterior tibial muscles. The framework of the cyclic alternating pattern offers a unified interpretation for sleep bruxism and arousal-related phenomena.
TL;DR: The studies assembled in the review do not provide evidence to support the use of surgery in sleep apnoea/hypopnoeA syndrome, as overall significant benefit has not been demonstrated.
Abstract: BACKGROUND Obstructive sleep apnoea/hypopnoea syndrome(OSAHS) is the periodic reduction or cessation of airflow during sleep. The syndrome is associated with loud snoring, disrupted sleep and observed apnoeas. Surgery for obstructive sleep apnoea/hypopnoea syndrome aims to alleviate symptoms of daytime sleepiness, improve quality of life, and reduce the signs of sleep apnoea recorded by polysomnography. OBJECTIVES The objective of this review was to assess the effects of any type of surgery for the treatment of the symptoms of obstructive sleep apnoea/hypopnoea syndrome in adults. SEARCH STRATEGY We searched the Cochrane Airways Group Specialised Register and reference lists of articles. We contacted experts in the field, research dissemination bodies and other Cochrane Review Groups. Searches were current as of July 2005. SELECTION CRITERIA Randomised trials comparing any surgical intervention for obstructive sleep apnoea/hypopnoea syndrome with other surgical or non-surgical interventions or no intervention. DATA COLLECTION AND ANALYSIS Two reviewers assessed electronic literature search results for possibly relevant studies. Characteristics and data from studies meeting the inclusion criteria were extracted and entered into RevMan 4.2. MAIN RESULTS In the 2005 update for this review eight studies (412 participants) of mixed quality met the inclusion criteria. Data from seven studies were eligible for assessment in the review. No data could be pooled. Uvulopalatopharyngoplasty (UPPP) versus conservative management (one trial): An un validated symptom score showed intermittent significant differences over a 12-month follow-up period. No differences in Polysomnography (PSG) outcomes were reported. Laser-assisted uvulopalatoplasty (LAUP) versus conservative management/placebo (two trials): One study recruited mixed a population, and separate data could not be obtained for this trial. In the other study no significant differences in Epworth scores or quality of life reported. A significant difference in favour of LAUP was reported in terms of apnoea hypopnoea index (AHI) and frequency and intensity of snoring. UPPP versus oral appliance (OA) (one trial): AHI was significantly lower with OA therapy than with UPPP. No significant differences were observed in quality of life. UPPP versus lateral pharyngoplasty (lateral PP) (one trial): No significant difference in Epworth scores, but a greater reduction in AHI with lateral PP was reported. Tongue advancement (mandibular osteotomy) + PPP versus tongue suspension + PPP (one trial): There was a significant reduction in symptoms in both groups, but no significant difference between the two surgery types. Complications reported with all surgical techniques included nasal regurgitation, pain and bleeding. These did not persist in the long term. An additional study assessed the effects of four different techniques. No data were available on between group comparisons. Multilevel temperature-controlled radiofrequency tissue ablation (TCRFTA) versus sham placebo and CPAP (one trial): There was an improvement in primary and secondary outcomes of TCRFTA over sham placebo and but no difference in symptomatic improvement when compared with CPAP. AUTHORS' CONCLUSIONS There are now a small number of trials assessing different surgical techniques with inactive and active control treatments. The studies assembled in the review do not provide evidence to support the use of surgery in sleep apnoea/hypopnoea syndrome, as overall significant benefit has not been demonstrated. The participants recruited to the studies had mixed levels of AHI, but tended to suffer from moderate daytime sleepiness where this was measured. Short-term outcomes are unlikely to consistently identify suitable candidates for surgery. Long-term follow-up of patients who undergo surgical correction of upper airway obstruction is required. This would help to determine whether surgery is a curative intervention, or whether there is a tendency for the signs and symptoms of sleep apnoea to re-assert themselves, prompting patients to seek further treatment for sleep apnoea.
TL;DR: Sleep impairs counterregulatory-hormone responses to hypoglycemia in patients with type I diabetes and normal subjects.
Abstract: Background In patients with type I diabetes mellitus, hypoglycemia occurs commonly during sleep and is frequently asymptomatic. This raises the question of whether sleep is associated with reduced counterregulatory-hormone responses to hypoglycemia. Methods We studied the counterregulatory-hormone responses to insulin-induced hypoglycemia in eight adolescent patients with type I diabetes and six age-matched normal subjects when they were awake during the day, asleep at night, and awake at night. In each study, the plasma glucose concentration was stabilized for 60 minutes at approximately 100 mg per deciliter (5.6 mmol per liter) and then reduced to 50 mg per deciliter (2.8 mmol per liter) and maintained at that concentration for 40 minutes. Plasma free insulin, epinephrine, norepinephrine, cortisol, and growth hormone were measured frequently during each study. Sleep was monitored by polysomnography. Results The plasma glucose and free insulin concentrations were similar in both groups during all studies...
Book•
14 Oct 1998
TL;DR: Part I Basic aspects of sleep: an overview of sleep neurophysiology of sleep biochemical pharmacology of sleep physiological changes during sleep and clinical aspects: an approach to a patient with sleep complaints classification of sleep disorders sleep apnea syndromes insomnia narcolepsy.
Abstract: Part I Basic aspects of sleep: an overview of sleep neurophysiology of sleep biochemical pharmacology of sleep physiological changes during sleep. Part 2 Technical considerations: polysomnographic technique EEG, EMG and EOG EKG recognition of cardiac arrhythmias respiration and respiratory function - technique of recording and evaluation measurement of sleepiness/alertness - MSLT ambulatory cassette polysomnography sleep scoring technique techniques for the evaluation of sleep-related erections. Part 3 Clinical aspects: an approach to a patient with sleep complaints classification of sleep disorders sleep apnea syndromes insomnia narcolepsy motor functions and dysfunctions of sleep sleep, breathing, and neurological disorders sleep disorders in psychiatric illness sleep and other medical disorders circadian rhythm disorders parasomnias sleep disorders in the elderly sleep disorders in childhood sleep and epilepsy positive airway pressure in the treatment of sleep related breathing disorders.
TL;DR: The results show that analysis of DLMO of patients suffering from DSPS is important both for diagnosis and therapy, and actigraphy showed a significant advance of sleep onset and polysomnography, a significant decreased sleep latency.
Abstract: In a double-blind placebo-controlled cross-over study, 30 patients with Delayed Sleep Phase Syndrome (DSPS) were included, of whom 25 finished the study. Melatonin 5 mg was administered during two weeks in a double-blind setting and two weeks in an open setting successively or interrupted by two weeks of placebo. The study's impact was assessed by measurements of the 24-h curves of endogenous melatonin production and rectal temperature (n=14), polysomnography (n=22), actigraphy (n=13), sleep log (n=22), and subjective sleep quality (n=25). Mean dim light melatonin onset (DLMO) (±SD), before treatment, occurred at 23.17 hours (±138 min). Melatonin was administered five hours before the individual DLMO. After treatment, the onset of the nocturnal melatonin profile was significantly advanced by approximately 1.5 hour. Body temperature trough did not advance significantly. During melatonin use, actigraphy showed a significant advance of sleep onset and polysomnography, a significant decreased sleep latency. Sleep architecture was not influenced. During melatonin treatment patients felt significantly more refreshed in the morning. These results show that analysis of DLMO of patients suffering from DSPS is important both for diagnosis and therapy. These results are discussed in terms of the biochemistry of the pineal.
TL;DR: It is concluded that there is a relationship between sleep apnea and hypertension that, although partially explained by the confounding variables body mass index, age, and sex, persists when these are allowed for.
Abstract: This study was designed to measure the prevalence of obstructive sleep apnea in untreated and treated hypertensive patients by comparing them with normotensive subjects, taking into account the possible confounding variables body mass index, age, sex, and alcohol consumption Subjects with no known sleep disorders were recruited, had full polysomnography, and had their blood pressure assessed with a 24-h ambulatory monitor Subjects with a mean 24-h blood pressure greater than 140/90, and receiving no treatment for, or with no history of, hypertension were classified as untreated hypertensives; those receiving antihypertension medication were classified as treated hypertensives; those with a mean 24-h blood pressure less than 140/90 and no history of hypertension were classified as normotensives Thirty-eight percent of the 34 untreated and 38% of the 34 treated hypertensives, and 4% of the 25 normotensives had apnea-hypopnea indexes greater than 5 Logistic regression analysis showed that body mass index (p = 0001), age (p = 007), sex (p = 007), treated hypertension (p = 005), and untreated hypertension (p = 006) were associated with the presence of sleep apnea, but that alcohol consumption (p = 082) was not It is concluded that there is a relationship between sleep apnea and hypertension that, although partially explained by the confounding variables body mass index, age, and sex, persists when these are allowed for
TL;DR: It is concluded that subjective and objective measures of baseline sleep are predictors of relapse in treated alcoholic patients and neurophysiological dysfunction contributes strongly to the etiology of relapse, and sleep disturbance warrants clinical attention as a target of alcoholism treatment.
Abstract: Previous studies indicate that subjectively reported and objectively measured sleep abnormalities at baseline can increase the risk of relapse in treated alcoholics. However, previous studies did not include both subjective and objective sleep measures in the same group of patients. We utilized polysomnography and the Sleep Disorders Questionnaire to determine if baseline polysomnography increased the ability to predict relapse beyond the prediction with subjective measures alone, after controlling for nonsleep variables that were associated with relapse. We followed 74 patients with a DSM-III-R diagnosis of alcohol dependence, of whom 36 relapsed to at least some drinking during an average follow-up interval of 5 months. Univariate analyses revealed that relapsed patients did not differ from abstinent patients at baseline in demographics or psychiatric co-morbidity, but they had more prior treatment episodes for alcoholism, more difficulty falling asleep, more complaints of abnormal sleep, and, on polysomnography, longer sleep latencies, shorter rapid eye movement sleep latencies, and less stage 4 sleep percentage than abstinent patients. With a series of logistic regression analyses, which controlled for age and gender, we demonstrated that sleep measures improved the prediction model compared with nonsleep variables alone, and that polysomnography-measured sleep latency was the most significant predictor variable. We conclude that subjective and objective measures of baseline sleep are predictors of relapse in treated alcoholic patients. These data also suggest that neurophysiological dysfunction contributes strongly to the etiology of relapse. Finally, sleep disturbance warrants clinical attention as a target of alcoholism treatment.
TL;DR: Oxygen stabilized sleep disordered breathing and reduced sympathetic activity in patients with heart failure and Cheyne-Stokes respiration was unable to demonstrate an effect on either patient symptoms or cognitive function.
Abstract: Background Cheyne-Stokes respiration disrupts sleep, leading to daytime somnolence and cognitive impairment. It is also an independent marker of increased mortality in heart failure. This study evaluated the effectiveness of oxygen therapy for Cheyne-Stokes respiration in heart failure.
Methods Eleven patients with stable heart failure and Cheyne-Stokes breathing were studied. Oxygen and air were administered for 4 weeks in a double-blind, cross-over study. Sleep and disordered breathing was assessed by polysomnography. Symptoms were assessed using the Epworth Sleepiness Scale, visual analogue and quality of life scores. Cognitive function was assessed by neuropsychometric testing. Overnight urinary catecholamine excretion was used as a measure of sympathetic nerve activity.
Results Ninety-seven percent of apnoeas were central in origin. Oxygen therapy reduced the central apnoea rate (18.4 ± 4.1 vs 3.8 ± 2.1 per hour; P =0.05) and periodic breathing time (33.6 ± 7.4 vs 10.7 ± 3.9% of actual sleep time; P =0.003). Oxygen did not improve sleep quality, patient symptoms or cognitive failure. Oxygen reduced urinary noradrenaline excretion (8.3 ± 1.5 vs 4.1 ± 0.6 nmol . mmol‒1 urinary creatinine; P =0.03).
Conclusion Oxygen stabilized sleep disordered breathing and reduced sympathetic activity in patients with heart failure and Cheyne-Stokes respiration. We were unable to demonstrate an effect on either patient symptoms or cognitive function.
TL;DR: All three melatonin treatments shortened latencies to persistent sleep, demonstrating that high physiological doses of melatonin can promote sleep in this population of patients with age-related sleep-maintenance insomnia, however, melatonin was not effective in sustaining sleep.
Abstract: The present investigation used a placebo-controlled, double-blind, crossover design to assess the sleep-promoting effect of three melatonin replacement delivery strategies in a group of patients with age-related sleep-maintenance insomnia. Subjects alternated between treatment and "washout" conditions in 2-week trials. The specific treatment strategies for a high physiological dose (0.5 mg) of melatonin were: (1) EARLY: An immediate-release dose taken 30 minutes before bedtime; (2) CONTINUOUS: A controlled-release dose taken 30 minutes before bedtime; (3) LATE: An immediate-release dose taken 4 hours after bedtime. The EARLY and LATE treatments yielded significant and unambiguous reductions in core body temperature. All three melatonin treatments shortened latencies to persistent sleep, demonstrating that high physiological doses of melatonin can promote sleep in this population. Despite this effect on sleep latency, however, melatonin was not effective in sustaining sleep. No treatment improved total sleep time, sleep efficiency, or wake after sleep onset. Likewise, melatonin did not improve subjective self-reports of nighttime sleep and daytime alertness. Correlational analyses comparing sleep in the placebo condition with melatonin production revealed that melatonin levels were not correlated with sleep. Furthermore, low melatonin producers were not preferentially responsive to melatonin replacement. Total sleep time and sleep efficiency were correlated with the timing of the endogenous melatonin rhythm, and particularly with the phase-relationship between habitual bedtime and the phase of the circadian timing system.
TL;DR: The results suggest that sleep fragmentation indices are useful for identifying OSA patients with sleepiness likely to respond to nCPAP.
Abstract: Sleep fragmentation and respiratory disturbance measures are used in the assessment of obstructive sleep apnea (OSA) but have proved to be disappointingly poor correlates of daytime sleepiness. This study investigates the ability of electroencephalograph (EEG) and non-EEG sleep fragmentation indices to predict both presenting sleepiness and the improvement in sleepiness with subsequent nasal continuous positive airway pressure (nCPAP) therapy (nCPAP responsive sleepiness). Forty-one patients (36 men, 5 women), ranging from nonsnorers to severe OSA (> 4% O2 dip rate, median 11.1, range 0.4 to 76.5), had polysomnography with microarousal scoring, computerized EEG analysis, autonomic arousal detection, and body movement analysis. All patients received a trial of nCPAP regardless of sleep study outcome. Spearman's correlation analysis showed significant and similar associations between all sleep fragmentation indices with both pretreatment and nCPAP responsive sleepiness. There was no deterioration in sleepiness on nCPAP in the nonsnorers. Using stepwise multiple regression analysis, the best predictor of nCPAP responsive subjective and objective sleepiness was body movement index, explaining 38% and 43% of the variance, respectively. Variability in EEG sleep depth, quantified from computerized EEG analysis, was the only other index to contribute to these models. Together these indices explained 44% and 51% of the subjective and objective response to nCPAP, respectively. These results suggest that sleep fragmentation indices are useful for identifying OSA patients with sleepiness likely to respond to nCPAP.
TL;DR: The influence of sleep on the incidence of seizures and the reciprocal effects of epilepsy on sleep were analyzed in 30 patients with intractable partial seizures, all candidates for surgery.
Abstract: Summary: Purpose: The influence of sleep on the incidence of seizures and the reciprocal effects of epilepsy on sleep were analyzed in 30 patients with intractable partial seizures, all candidates for surgery.
Methods: The patients were classified into two groups of 15 patients according to the documented site of the epileptogenic zone: frontal lobe epilepsy (FLE) and medial temporal lobe epilepsy (TLE). Frequency and waking-sleep distribution of seizures were evaluated by continuous video-EEG monitoring for 5 days, under defined antiepileptic drug (AED), sleep, and sleep deprivation regimens. Sleep organization was analyzed by polysomnography prior to the presurgical protocol.
Results: Significant differences were found between the two groups in sleeping-waking distribution of seizures under varied conditions, and in the quality of sleep organization. In FLE patients, seizures most often occurred during sleep, although sleep organization was normal. In TLE patients, most seizures occurred while patients were awake, and sleep organization was characterized by a low efficiency index. The difference in seizure distribution between FLE and TLE persisted under all conditions investigated, i.e., after AED discontinuation and sleep deprivation.
Conclusions: Sleep recording may be useful for diagnosis of FLE, and monitoring after sleep deprivation for that of TLE. We speculate that sleep-related seizures in FLE may depend on interaction between frontal lobe areas with the thalamus cortical synchronization system and the acetylcholine regulatory system of waking.
TL;DR: 87.9% of apnoea-associated bradyarrhythmias occur during rapid eye movement sleep; the vast majority of heart block episodes occur during a desaturation of at least 4% without a previously described threshold value of 72; and nasal continuous positive airway pressure or nasal bi-level positiveAirway pressure is the therapy of choice in patients with apnOEa- associated bradyARRhythmia.
Abstract: Heart block during sleep has been described in up to 10% of patients with obstructive sleep apnoea. The aim of this study was to determine the relationship between sleep stage, oxygen desaturation and apnoea-associated bradyarrhythmias as well as the effect of nasal continuous positive airway pressure (nCPAP)/nasal bi-level positive airway pressure (nBiPAP) therapy on these arrhythmias in patients without electrophysiological abnormalities. Sixteen patients (14 males and two females, mean age 49.6+/-10.4 yrs) with sleep apnoea and nocturnal heart block underwent polysomnography after exclusion of electrophysiological abnormalities of the sinus node function and atrioventricular (AV) conduction system by invasive electrophysiological evaluation. During sleep, 651 episodes of heart block were recorded, 572 (87.9%) occurred during rapid eye movement (REM) sleep and 79 (12.1%) during nonrapid eye movement (NREM) sleep stages 1 and 2. During REM sleep, the frequency of heart block was significantly higher than during NREM sleep: 0.69+/-0.99 versus 0.02+/-0.04 episodes of heart block x min(-1) of the respective sleep stage (p<0.001). During apnoeas or hypopnoeas, 609 bradyarrhythmias (93.5%) occurred with a desaturation of at least 4%. With nCPAP/ nBiPAP therapy, apnoea/hypopnoea index (AHI) decreased from 75.5+/-39.6 x h(-1) to 3.0+/-6.6 x h(-1) (p<0.01) and the number of arrhythmias from 651 to 72 (p<0.01). We conclude that: 1) 87.9% of apnoea-associated bradyarrhythmias occur during rapid eye movement sleep; 2) the vast majority of heart block episodes occur during a desaturation of at least 4% without a previously described threshold value of 72%; and 3) nasal continuous positive airway pressure or nasal bi-level positive airway pressure is the therapy of choice in patients with apnoea-associated bradyarrhythmias.
TL;DR: It is concluded that the hypotonic upper airway becomes most collapsible by the third breath after an abrupt decrease in PN, regardless of sleep stage and despite an increase in genioglossus-muscle activity.
Abstract: The structural properties of the upper airway determine its collapsibility during periods of muscle hypotonia. Both rapid-eye-movement (REM) sleep and increases in nasal pressure (PN) produce hypotonia, which persists even after nasal pressure is abruptly reduced. To determine the factors that influence the collapsibility of the hypotonic airway, the critical pressure (Pcrit) and nasal resistance upstream to the site of pharyngeal collapse (RN) were measured in the first three breaths after abrupt reductions in PN during non-REM and REM sleep. PN was reduced abruptly from 15.2+/-3.2 cm H2O (mean +/- SD) for three breaths in 19 apneic patients. Upper-airway pressure-flow relationships were analyzed to determine Pcrit for each breath in non-REM and REM sleep. We found that Pcrit rose (collapsibility increased, p < 0.001) and RN fell (p = 0.02) between the first and third breath after the decrease in PN, whereas no difference in Pcrit was detected between sleep stages. In six patients, genioglossus-muscle electromyograms (EMGs) were recorded. Peak phasic activity rose between the first and third breath (p = 0.03), but tonic and peak phasic EMG activity fell in REM as compared with non-REM sleep (p < 0.001). We conclude that the hypotonic upper airway becomes most collapsible by the third breath after an abrupt decrease in PN, regardless of sleep stage and despite an increase in genioglossus-muscle activity. Our findings suggest that predominantly mechanical rather than neuromuscular factors modulate the properties of the pharynx after abrupt reductions in nasal pressure.
TL;DR: Arousals implied from blood pressure rises (using pulse transit time) can be measured easily, are objective, and appear no worse at predicting subjective sleepiness than either EEG micro arousals or AHI, and may provide a useful alternative to manual scoring ofmicro arousals from the EEG as an index of sleep fragmentation in sleep clinic patients undergoing investigation for possible OSA.
Abstract: Estimating the degree of sleep fragmentation is an important part of a respiratory sleep study and is conventionally measured using EEG micro arousals or is inferred indirectly from respiratory abnormalities such as apnoeas and desaturations. There is a need for less labour-intensive measures of sleep fragmentation, and transient rises in blood pressure and heart rate may fulfil this role. Forty unselected sleep clinic referrals undergoing investigation for possible obstructive sleep apnoea (OSA) were studied with one night of polysomnography. Three conventional indices of sleep fragmentation (EEG micro arousals, apnoea/hypopnoea index (AHI) and oxygen saturation dip rate (SaO2 dips)) and two autonomic indices (heart rate and blood pressure rises) have been compared. Correlations between these five indices ranged from r=0.38 to r=0.73. Of the two autonomic indices, the correlations for blood pressure rises with SaO2 dips and EEG micro arousals were stronger (r=0.71 and r=0.65, respectively) than those for heart rate rises (0.55 and 0.51). All indices of sleep fragmentation, apart from heart rate rises, were similar in their correlation with subjective sleepiness (r-values 0.21-0.36). Arousals implied from blood pressure rises (using pulse transit time) can be measured easily, are objective, and appear no worse at predicting subjective sleepiness than either EEG micro arousals or AHI. They may therefore provide a useful alternative to manual scoring of micro arousals from the EEG as an index of sleep fragmentation in sleep clinic patients undergoing investigation for possible OSA.
TL;DR: In this paper, the authors performed EEG-polysomnography in 21 subjects with medically refractory temporal lobe epilepsy to test the hypothesis that deepening sleep activates focal interictal epileptiform discharges (IEDs).
Abstract: Summary: Purpose: To test the hypothesis that deepening sleep activates focal interictal epileptiform discharges (IEDs), we performed EEG-polysomnography in 21 subjects with medically refractory temporal lobe epilepsy. Methods: At the time of study, subjects were seizure-free for 224 h and were taking stable doses of antiepileptic medications (AEDs). Sleep depth was measured by log delta power (LDP). Visual sleep scoring and visual detection of IEDs also were performed. Logistic-regression analyses of IED occurrence in relation to LDP were carried out for two groups of subjects, nine with frequent IEDs (group 1) and 12 with rare IEDs (group 2). Results: The LDP differentiated visually scored non-rapid eye movement (NREM) sleep stages (p = 0.QOOl). The IEDs were most frequent in NREM stages 3/4 and least frequent in REM sleep. Within NREM sleep, in both groups, IEDs were more frequent at higher levels of LDP (p < 0.05). In group 1, after accounting for the level of LDP, IEDs were more frequent (a) on the ascending limb of LDP and with more rapid increases in LDP (p = 0.007), (b) in NREM than in REM sleep (p = 0.002), and (c) closer to sleep onset (p < 0.0001). Fewer than 1% of IEDs occurred within 10 s of an EEG arousal. Conclusions: Processes underlying the deepening of NREM sleep, including progressive hyperpolarization in thalamocortical projection neurons, may contribute to IED activation in partial epilepsy. Time from sleep onset and NREM versus REM sleep also influence IED occurrence. Key Words: Sleep-Epilepsy-Electroencephalography-Quantitative EEG-Interictal epileptiform discharges.
TL;DR: Delta sleep deficits that occur in schizophrenia may be related to the primary pathophysiological characteristics of the illness and may not be secondary to previous neuroleptic use.
Abstract: Background Several, though not all, polysomnographic studies that use conventional visual scoring techniques show delta sleep deficits in schizophrenia. Delta sleep (in particular, ≥1- to 2-Hz frequency range), mediated by thalamocortical circuits, is postulated to be abnormal in schizophrenia. We investigated whether deficits in delta sleep occur in schizophrenia and whether these are primarily related to the illness or are epiphenomena of previous medication use or illness chronicity. Methods We compared 30 unmedicated schizophrenic patients and 30 age- and sex-matched controls for sleep data evaluated by visual scoring as well as automated period amplitude analyses and power spectral analyses. Results Schizophrenic patients had reduced visually scored delta sleep. Period amplitude analyses showed significant reductions in delta wave counts but not rapid eye movement counts; power spectral analyses showed reductions in delta as well as theta power. Delta spectral power was also reduced in the subset of 19 neuroleptic-naive, first-episode schizophrenic patients compared with matched controls. Delta deficits were more pronounced in the greater than 1- to 2-Hz frequency range. Conclusions Delta sleep deficits that occur in schizophrenia may be related to the primary pathophysiological characteristics of the illness and may not be secondary to previous neuroleptic use. Automated sleep quantification by means of period amplitude and power spectral analyses can complement the use of conventional visual scoring for understanding electrophysiological abnormalities in psychiatric disorders.
TL;DR: Preliminary data suggest that RME may be a useful treatment alternative for selected patients with OSA, and improvements in snoring and hypersomnolence are reported.
Abstract: The precise role of maxillary constriction in the pathophysiology of obstructive sleep apnea (OSA) is unclear However, it is known that subjects with maxillary constriction have increased nasal resistance and resultant mouth-breathing, features typically seen in OSA patients Maxillary constriction is also associated with alterations in tongue posture which could result in retroglossal airway narrowing, another feature of OSA Rapid maxillary expansion (RME) is an orthodontic treatment for maxillary constriction which increases the width of the maxilla and reduces nasal resistance The aim of this pilot study was to investigate the effect of rapid maxillary expansion in OSA We studied 10 young adults (8 male, 2 female, mean age 27 +/- 2 [sem] years) with mild to moderate OSA (apnea/hypopnea index-AHI 19 +/- 4 and minimum SaO2 89 +/- 1%), and evidence of maxillary constriction on orthodontic evaluation All patients underwent treatment with RME, six cases requiring elective surgical assistance Polysomnography was repeated at the completion of treatment Nine of the 10 patients reported improvements in snoring and hypersomnolence There was a significant reduction in AHI (19 +/- 4 vs 7 +/- 4, p < 005) in the entire group In seven patients, the AHI returned to normal (ie, = < 5); only one patient showed no improvement These preliminary data suggest that RME may be a useful treatment alternative for selected patients with OSA