Sleep-wake and melatonin pattern in craniopharyngioma patients

OBJECTIVE

To assess the influence of craniopharyngioma or consequent surgery on melatonin secretion, and the association with fatigue, sleepiness, sleep pattern and sleep quality.

DESIGN

Cross-sectional study.

METHODS

A total of 15 craniopharyngioma patients were individually matched to healthy controls. In this study, 24-h salivary melatonin and cortisol were measured. Sleep-wake patterns were characterised by actigraphy and sleep diaries recorded for 2 weeks. Sleepiness, fatigue, sleep quality and general health were assessed by Multidimensional Fatigue Inventory, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Short-Form 36.

RESULTS

Patients had increased mental fatigue, daytime dysfunction, sleep latency and lower general health (all, P≤0.05), and they tended to have increased daytime sleepiness, general fatigue and impaired sleep quality compared with controls. The degree of hypothalamic injury was associated with an increased BMI and lower mental health (P=0.01). High BMI was associated with increased daytime sleepiness, daytime dysfunction, mental fatigue and lower mental health (all, P≤0.01). Low midnight melatonin was associated with reduced sleep time and efficiency (P≤0.03) and a tendency for increased sleepiness, impaired sleep quality and physical health. Midnight melatonin remained independently related to sleep time after adjustment for cortisol. Three different patterns of melatonin profiles were observed; normal (n=6), absent midnight peak (n=6) and phase-shifted peak (n=2). Only patients with absent midnight peak had impaired sleep quality, increased daytime sleepiness and general and mental fatigue.

CONCLUSION

Craniopharyngioma patients present with changes in circadian pattern and daytime symptoms, which may be due to the influence of the craniopharyngioma or its treatment on the hypothalamic circadian and sleep regulatory nuclei.

[Obstructive sleep apnoea syndrome]

Obstructive sleep apnoea (OSA) and other sleep disordered breathing are common disorders causing significant morbidity, mortality and societal burden. A significant proportion of the patients are undiagnosed and consequently untreated. Due to the wide disease distribution we recommend increased disease awareness, especially among high-risk groups: patients with obesity, metabolic syndrome and cardio- and cerebrovascular diseases. Continuous positive airway pressure (CPAP) is the first-line of treatment together with weight reduction, whereas oral devices may be used for less severe OSA or in cases where CPAP cannot be used.

Morbidity in early Parkinson's disease and prior to diagnosis

BACKGROUND

Nonmotor symptoms are probably present prior to, early on, and following, a diagnosis of Parkinson's disease. Nonmotor symptoms may hold important information about the progression of Parkinson's disease.

OBJECTIVE

To evaluated the total early and prediagnostic morbidities in the 3 years before a hospital contact leading to a diagnosis of Parkinson's disease.

METHODS

Retrospective morbidity data from Danish National Patient Registry records (1997-2007) of 10,490 adult patients with a secondary care diagnosis of Parkinson's disease were compared with 42,505 control cases.

RESULTS

Parkinson's disease was associated with significantly higher morbidity rates associated with conditions in the following categories: mental and psychiatric, nervous system, gastrointestinal, musculoskeletal system and connective tissue, genitourinary, abnormal clinical and laboratory findings, injury, poisoning and certain other external causes, and other factors influencing health status and contact with health services. It was negatively associated with neoplasm, cardiovascular, and respiratory diseases.

CONCLUSIONS

Patients with a diagnosis of Parkinson's disease present significant differences in morbidities early on, following, and prior to, their diagnosis, compared with healthy controls.

Sleep impairment and prognosis of acute myocardial infarction: a prospective cohort study

STUDY OBJECTIVES

Impaired sleep is an established risk factor for the development of cardiovascular disease, whereas less is known about how impaired sleep affects cardiovascular prognosis. The aim of this study is to determine how different aspects of impaired sleep affect the risk of case fatality and subsequent cardiovascular events following first-time acute myocardial infarction (AMI).

DESIGN

Prospective cohort study.

SETTING

The Stockholm Heart Epidemiology Program, Sweden.

PARTICIPANTS

There were 2,246 first-time AMI cases.

MEASUREMENTS AND RESULTS

Sleep impairment was assessed by the Karolinska Sleep Questionnaire, which covers various indices of impaired sleep: disturbed sleep, impaired awakening, daytime sleepiness, and nightmares. Case fatality, defined as death within 28 days of initial AMI, and new cardiovascular events within up to 10 y of follow-up were identified through national registries. In women, disturbed sleep showed a consistently higher risk of long-term cardiovascular events: AMI (hazard ratio [HR] = 1.69; 95% confidence interval [CI] 0.95-3.00), stroke (HR = 2.61; 95% CI: 1.19-5.76), and heart failure (HR = 2.43; 95% CI: 1.18-4.97), whereas no clear effect of impaired sleep on case fatality was found in women. In men, a strong effect on case fatality (odds ratio = 3.27; 95% CI: 1.76-6.06) was observed in regard to impaired awakening; however, no consistent effect of impaired sleep was seen on long-term cardiovascular prognosis.

CONCLUSION

Results suggest sex-specific effects of impaired sleep that differ by short- and long-term prognosis. Sleep complaints are frequent, easily recognizable, and potentially manageable. Evaluation of sleep complaints may, even if they represent prognostic markers rather than risk factors, provide additional information in clinical risk assessment that could benefit secondary cardiovascular prevention.

Autonomic symptoms in idiopathic REM behavior disorder: a multicentre case-control study

Patients with idiopathic REM sleep behavior disorder (iRBD) are at very high risk of developing neurodegenerative synucleinopathies, which are disorders with prominent autonomic dysfunction. Several studies have documented autonomic dysfunction in iRBD, but large-scale assessment of autonomic symptoms has never been systematically performed. Patients with polysomnography-confirmed iRBD (318 cases) and controls (137 healthy volunteers and 181 sleep center controls with sleep diagnoses other than RBD) were recruited from 13 neurological centers in 10 countries from 2008 to 2011. A validated scale to study the disorders of the autonomic nervous system in Parkinson's disease (PD) patients, the SCOPA-AUT, was administered to all the patients and controls. The SCOPA-AUT consists of 25 items assessing the following domains: gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor, and sexual dysfunction. Our results show that compared to control subjects with a similar overall age and sex distribution, patients with iRBD experience significantly more problems with gastrointestinal, urinary, and cardiovascular functioning. The most prominent differences in severity of autonomic symptoms between our iRBD patients and controls emerged in the gastrointestinal domain. Interestingly, it has been reported that an altered gastrointestinal motility can predate the motor phase of PD. The cardiovascular domain SCOPA-AUT score in our study in iRBD patients was intermediate with respect to the scores reported in PD patients by other authors. Our findings underline the importance of collecting data on autonomic symptoms in iRBD. These data may be used in prospective studies for evaluating the risk of developing neurodegenerative disorders.

Health, social and economic consequences of hypersomnia: a controlled national study from a national registry evaluating the societal effect on patients and their partners

Hypersomnia causes significant socioeconomic burden, but there is insufficient information about the time course and the effect on the partner. The aim of this study was to estimate the factual direct and productivity costs of hypersomnia in a controlled study including all national patients and their partners. Using records from the Danish National Patient Registry (1997-2009), we identified all patients with a diagnosis of hypersomnia and compared these patients and their partners with randomly chosen controls matched for age, gender, geographic area and marital status. Direct and productivity costs, including frequencies of primary and sector contacts and procedures, medication, labour supply and social transfer payments were extracted from the national databases. A total of 2,855 national patients was compared to 11,382 controls. About 70 % of patients and controls were married or cohabiting. Patients with hypersomnia had significantly higher rates of health-related contact, medication use and socioeconomic cost. Furthermore, they had slightly lower employment rates, and those in employment had a lower income level than control subjects. The annual mean excess health-related cost including social transfers was <euro>3,498 for patients with hypersomnia and <euro>3,851 for their partners. The social and health-related consequences could be identified up to 11 years before the first diagnosis among both the patients and their partners and became more pronounced as the disease advanced. The health effects were present in all age groups and in both genders. On the basis of this retrospective controlled study in the Danish population, symptoms and findings of hypersomnia are associated with major socioeconomic consequences for patients, their partners and society.

Postoperative sleep disturbances after zolpidem treatment in fast-track hip and knee replacement

STUDY OBJECTIVES

Previous studies have demonstrated pronounced reduction of REM sleep on the first nights following major surgery which may influence pain, analgesic use, and recovery. This placebo-controlled, randomized, double-blind study set out to evaluate the effect of zolpidem on sleep architecture in an elderly population undergoing fast-track total hip and knee arthroplasty (THA/TKA) with length of stay < 3 days.

METHODS

Twenty patients (≥ 60 years) undergoing THA or TKA in a standardized setup with spinal anesthesia and multimodal opioid-sparing postoperative analgesia were included. Polysomnography measures were performed for 2 nights, 1 night at home prior to surgery and on the first night after surgery, when the patient received placebo or zolpidem 10 mg. Analgesic use, pain levels, and subjective measures of fatigue and sleep quality were recorded. Analysis of sleep data was performed according to the American Academy of Sleep Medicine manual.

RESULTS

Objective sleep data did not show a significant difference between groups in any of the sleep stages. However, subjective data on sleep quality and fatigue showed significantly less fatigue and better sleep quality in the zolpidem group (p < 0.05), and reduced objectively recorded number of arousals (p = 0.004). Levels of pain and opioid use were similar in the 2 groups.

CONCLUSIONS

Our objective data did not support the primary hypothesis that one night's treatment with zolpidem would significantly improve sleep architecture following major surgery, although there was improved feeling of sleep quality and fatigue associated with fewer postoperative arousals.

CITATION

Krenk L; Jennum P; Kehlet H. Postoperative sleep disturbances after zolpidem treatment in fast-track hip and knee replacement.

Effect of intermittent aerobic exercise on sleep quality and sleep disturbances in patients with rheumatoid arthritis - design of a randomized controlled trial

BACKGROUND

Poor sleep is prevalent in patients with systemic inflammatory disorders, including rheumatoid arthritis, and, in addition to fatigue, pain, depression and inflammation, is associated with an increased risk of co-morbidity and all-cause mortality. Whereas non-pharmacological interventions in patients with rheumatoid arthritis have been shown to reduce pain and fatigue, no randomized controlled trials have examined the effect of non-pharmacological interventions on improvement of sleep in patients with rheumatoid arthritis. The aim of this trial was to evaluate the efficacy of an intermittent aerobic exercise intervention on sleep, assessed both objectively and subjectively in patients with rheumatoid arthritis.

METHODS/DESIGN

A randomized controlled trial including 44 patients with rheumatoid arthritis randomly assigned to an exercise training intervention or to a control group. The intervention consists of 18 session intermittent aerobic exercise training on a bicycle ergometer three times a week. Patients are evaluated according to objective changes in sleep as measured by polysomnography (primary outcome). Secondary outcomes include changes in subjective sleep quality and sleep disturbances, fatigue, pain, depressive symptoms, physical function, health-related quality of life and cardiorespiratory fitness.

DISCUSSION

This trial will provide evidence of the effect of intermittent aerobic exercise on the improvement of sleep in patients with rheumatoid arthritis, which is considered important in promotion of health and well-being. As such, the trial meets a currently unmet need for the provision of non-pharmacological treatment initiatives of poor sleep in patients with rheumatoid arthritis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01966835.

Comorbidity and medication in REM sleep behavior disorder: a multicenter case-control study

OBJECTIVE

This controlled study investigated associations between comorbidity and medication in patients with polysomnographically confirmed idiopathic REM sleep behavior disorder (iRBD), using a large multicenter clinic-based cohort.

METHODS

Data of a self-administered questionnaire on comorbidity and medication use of 318 patients with iRBD and 318 matched controls were analyzed. Comparisons between cases and controls were made using logistic regression analysis.

RESULTS

Patients with iRBD were more likely to report depression (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.3-2.9) and concomitant antidepressant use (OR 2.2, 95% CI 1.4-3.6). Subanalysis of antidepressant agents revealed that the increased use of antidepressants in iRBD was due to selective serotoninergic reuptake inhibitors (OR 3.6, 95% CI 1.8-7.0) and not due to other antidepressant classes. Patients with iRBD reported more lifetime antidepressant use than comorbid depression (antidepressant use: OR 1.9, 95% CI 1.1-3.3; depression: OR 1.6, 95% CI 1.0-2.5). Patients with iRBD reported more ischemic heart disease (OR 1.9, 95% CI 1.1-3.1). This association did not change substantially when adjusting for cardiovascular risk factors (OR 2.3, 95% CI 1.3-3.9). The use of inhaled glucocorticoids was higher in patients with iRBD compared to controls (OR 5.3, 95% CI 1.8-15.8), likely reflecting the higher smoking rate in iRBD (smoking: OR 15.3, 95% CI 2.0-118.8; nonsmoking: OR 2.4, 95% CI 0.4-13.2) and consequent pulmonary disease.

CONCLUSIONS

This large study confirms the association between comorbid depression and antidepressant use in iRBD. In addition, there was an unexpected association of iRBD with ischemic heart disease that was not explained by cardiovascular risk factors.

The sensory construction of dreams and nightmare frequency in congenitally blind and late blind individuals

OBJECTIVES

We aimed to assess dream content in groups of congenitally blind (CB), late blind (LB), and age- and sex-matched sighted control (SC) participants.

METHODS

We conducted an observational study of 11 CB, 14 LB, and 25 SC participants and collected dream reports over a 4-week period. Every morning participants filled in a questionnaire related to the sensory construction of the dream, its emotional and thematic content, and the possible occurrence of nightmares. We also assessed participants' ability of visual imagery during waking cognition, sleep quality, and depression and anxiety levels.

RESULTS

All blind participants had fewer visual dream impressions compared to SC participants. In LB participants, duration of blindness was negatively correlated with duration, clarity, and color content of visual dream impressions. CB participants reported more auditory, tactile, gustatory, and olfactory dream components compared to SC participants. In contrast, LB participants only reported more tactile dream impressions. Blind and SC participants did not differ with respect to emotional and thematic dream content. However, CB participants reported more aggressive interactions and more nightmares compared to the other two groups.

CONCLUSIONS

Our data show that blindness considerably alters the sensory composition of dreams and that onset and duration of blindness plays an important role. The increased occurrence of nightmares in CB participants may be related to a higher number of threatening experiences in daily life in this group.

Direct and indirect economic and health consequences of COPD in Denmark: a national register-based study: 1998-2010

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is among the leading causes of morbidity and mortality worldwide, but longitudinal studies of the economic consequences of COPD are scarce. This Danish study evaluated for the first time ever the economic consequences of COPD of an entire nation before and after the diagnosis.

SETTING

Records from the Danish National Patient Registry (1998-2010), direct and indirect costs, including frequency of primary and secondary sector contacts and procedures, medication, unemployment benefits and social transfer payments were extracted from national databases.

PARTICIPANTS

131 811 patients with COPD were identified and compared with 131 811 randomly selected controls matched for age, gender, educational level, residence and marital status.

PRIMARY AND SECONDARY OUTCOME MEASURES

Direct and indirect economic and health consequences of COPD in Denmark in the time period 1998-2010.

RESULTS

Patients with COPD had a poor survival. The average (95% CI) 12-year survival rate was 0.364 (0.364 to 0.368) compared with 0.686 among controls (0.682 to 0.690). COPD was associated with significantly higher rates of health-related contacts, medication use and higher socioeconomic costs. The employment and the income rates of employed patients with COPD were significantly lower compared with controls. The annual net costs, including social transfers were €8572 for patients with COPD. These consequences were present up to 11 years before first-time diagnosis in the secondary healthcare sector and became more pronounced with disease advancement.

CONCLUSIONS

This study provides unique national data on direct and indirect costs before and after initial diagnosis with COPD in Denmark as well as mortality, health and economic consequences for the individual and for society. It could be speculated that early identification and intervention might contribute to the solution.

Detection of K-complexes based on the wavelet transform

Sleep scoring needs computational assistance to reduce execution time and to assure high quality. In this pilot study a semi-automatic K-Complex detection algorithm was developed using wavelet transformation to identify pseudo-K-Complexes and various feature thresholds to reject false positives. The algorithm was trained and tested on sleep EEG from two databases to enhance its general applicability. When testing on data from subjects from the DREAMS© database, a mean true positive rate of 74 % and a positive predictive value of 65 % were achieved. After adjusting a few thresholds to adapt to the second database, the Danish Center for Sleep Medicine, a similar performance was achieved. The algorithm performs at the level of the State of the Art and surpasses the inter-rater agreement rate.

Novel method for detection of Sleep Apnoea using respiration signals

Polysomnography (PSG) studies are considered the "gold standard" for the diagnosis of Sleep Apnoea (SA). Identifying cessations of breathing from long-lasting PSG recordings manually is a labour-intensive and time-consuming task for sleep specialist, associated with inter-scorer variability. In this study a simplified, semi-automatic, three-channel method for detection of SA patients is proposed in order to increase analysis reliability and diagnostic accuracy in the clinic. The method is based on characteristic features, such as respiration stoppages pr. hour and the total number of oxygen desaturations > 3%, extracted from the thorax and abdomen respiration effort belts, and the oxyhemoglobin saturation (SaO2), fed to an Elastic Net classifier and validated according to American Academy of Sleep Medicine (AASM) using the patients' AHI value. The method was applied to 109 patient recordings and resulted in a very high SA classification with accuracy of 97.9%. The proposed method reduce the time spent on manual analysis of respiration stoppages and the inter- and intra-scorer variability, and may serve as an alternative screening method for SA.

Economic and health consequences of COPD patients and their spouses in Denmark--1998-2010

OBJECTIVE

Chronic Obstructive Pulmonary Disease (COPD) is among the leading causes of morbidity and mortality worldwide, but longitudinal studies of the economic consequences of COPD are scarce. This study evaluated the economic consequences of COPD patients in Denmark and their spouses at a national level before and after initial diagnosis.

METHODS

Using records from the Danish National Patient Registry (1998-2010), 171,557 patients with COPD and 86,260 spouses were identified; patients were compared with 664,821, and the spouses with 346,524, all controls were randomly selected and matched for age, gender and residence. Direct and indirect costs, including frequency of primary and secondary sector contacts and procedures, medication, unemployment benefits and social transfer payments were extracted from national databases for patients, spouses and controls.

RESULTS

COPD patients are earning approximately half of that of controls before diagnosis. After diagnosis this effect diminishes due to people getting older and retiring from work (65 years). Total health expenses are more than twice as high in the COPD group regardless of age and gender compared to controls. Spouses of COPD patients had significantly higher rates of health-related contacts, medication use and higher socioeconomic costs compared to controls. The employment and income rates of employed spouses of COPD patients were significantly lower compared to controls.

CONCLUSION

This study provides unique data on the economic consequences of COPD patients in Denmark and their spouses as well as displaying the serious health consequences for the individual spouse and society. Second, data shows substantial impact of COPD on income level and health expenses regardless of age and gender. It could be speculated that early identification and intervention might contribute to more health and economic equality between patients and controls.

Sleep phenomena as an early biomarker for Parkinsonism

Idiopathic Rapid-Eye-Movement (REM) sleep Behavior Disorder (iRBD) is one of the most potential biomarkers for Parkinson's Disease (PD) and some atypical PD (AP). It is characterized by REM sleep with abnormal high surface EMG (sEMG) activity. Some twitching during REM sleep is normal, but no one has defined what normal is, and no well-defined methodology for measuring muscle activity in REM sleep exists. The purpose of this study is to investigate the possibility of detecting abnormal high muscle activity during REM sleep in subjects diagnosed with iRBD. This has been achieved by considering the abnormal high muscle activity during REM sleep in iRBD subjects as an outlier detection problem, while exploiting that iRBD muscle activity is more grouped. It was possible to correctly discriminate all iRBD subjects from healthy elderly control subjects and subjects diagnosed with periodic limb movement (PLM) disorder. However, not all PD subjects were classified as having abnormal muscle activity, which is assumed to support the fact that not all PD subjects develop RBD.

Classification of iRBD and Parkinson's disease patients based on eye movements during sleep

Patients suffering from the sleep disorder idiopathic rapid-eye-movement sleep behavior disorder (iRBD) have been observed to be in high risk of developing Parkinson's disease (PD). This makes it essential to analyze them in the search for PD biomarkers. This study aims at classifying patients suffering from iRBD or PD based on features reflecting eye movements (EMs) during sleep. A Latent Dirichlet Allocation (LDA) topic model was developed based on features extracted from two electrooculographic (EOG) signals measured as parts in full night polysomnographic (PSG) recordings from ten control subjects. The trained model was tested on ten other control subjects, ten iRBD patients and ten PD patients, obtaining a EM topic mixture diagram for each subject in the test dataset. Three features were extracted from the topic mixture diagrams, reflecting "certainty", "fragmentation" and "stability" in the timely distribution of the EM topics. Using a Naive Bayes (NB) classifier and the features "certainty" and "stability" yielded the best classification result and the subjects were classified with a sensitivity of 95 %, a specificity of 80% and an accuracy of 90 %. This study demonstrates in a data-driven approach, that iRBD and PD patients may exhibit abnorm form and/or timely distribution of EMs during sleep.

Physical activity maintenance in patients with rheumatoid arthritis: a qualitative study

Objective:

To describe the experience of physical activity maintenance in patients with rheumatoid arthritis.

Design:

A qualitative salutogenic-oriented interview study.

Setting:

A rheumatology outpatient clinic.

Subjects:

A purposive sample of 16 physically active patients (mean age 50, range 37–67) diagnosed with rheumatoid arthritis on average 21 years previously (range 4–46 years).

Methods:

In-depth interviews were conducted using a semi-structured interview guide to illuminate how the phenomenon ‘physical activity maintenance’ was experienced by patients with rheumatoid arthritis. The interviews were analysed using systematic text condensation, inspired by Giorgi’s descriptive phenomenological methodology.

Results:

The analysis revealed three categories: (1) knowing and enjoying the body; (2) responsibility and challenges; (3) autonomy and social belonging. On the basis of these categories, the essential meaning of the phenomenon of physical activity maintenance for patients with rheumatoid arthritis was summarized into ‘striving for a transparent body and participation’, pointing to experiences of sensations of wellbeing, liberation from restrictions and social participation on equal terms with non-arthritis populations.

Conclusion:

This study demonstrates that physical activity in patients with rheumatoid arthritis may be understood as a resource to resist disability and to feel and stay healthy while creating and sustaining meaningfulness in life.

Activity, sleep and cognition after fast-track hip or knee arthroplasty

Optimized perioperative care after total hip and knee arthroplasty (THA/TKA) has decreased length of stay (LOS) but data on activity, sleep and cognition after discharge are limited. We included 20 patients ≥ 60 years undergoing THA/TKA, monitoring them for 3 days preoperatively and 9 days postoperatively with actigraphs for sleep and activity assessment. Pain scores were recorded daily. Cognition was evaluated by 2 cognitive tests. Results showed a mean age was 70.5 years and mean LOS was 2.6 days. Actigraphs showed increased daytime sleep and decreased motor activity postoperatively. Early postoperatively cognitive decline and increased pain returned to preoperative levels by postoperative day (POD) 5-9. Despite the small sample size the study illustrated that post-discharge activity is decreased and daytime sleep is increased after fast-track THA/TKA, while cognition and pain return to preoperative levels by POD 9. Objective assessment of these recovery parameters may be valuable in future interventional studies to enhance recovery after THA/TKA.

Reduced sympathetic activity in idiopathic rapid-eye-movement sleep behavior disorder and Parkinson's disease

BACKGROUND

More than 50% of patients with idiopathic REM sleep behavior disorder (iRBD) will develop Parkinson's disease or Lewy body dementia. In a previous study, we found attenuated heart rate responses in iRBD and Parkinson's disease patients during sleep. The current study aimed to evaluate heart rate variability further in order to identify possible changes in these components during wakefulness and sleep in patients with iRBD and Parkinson's disease.

METHODS

We evaluated heart rate variability in 5-minute electrocardiography segments from wakefulness, and non-REM and REM sleep in 11 iRBD patients and 23 Parkinson's disease patients, and compared these with 10 control subjects.

RESULTS AND CONCLUSIONS

Patients with iRBD had attenuated sympathetic nervous system activity compared with controls and this was more pronounced in patients with Parkinson's disease. The cardiac parasympathetic nervous system seems to be relatively well preserved in patients with iRBD and Parkinson's disease. The progressive reduction of sympathetic nervous activity is in line with the postganglionic sympathetic nervous dysfunction seen in early Parkinson's disease.

Validation of a novel automatic sleep spindle detector with high performance during sleep in middle aged subjects

Many of the automatic sleep spindle detectors currently used to analyze sleep EEG are either validated on young subjects or not validated thoroughly. The purpose of this study is to develop and validate a fast and reliable sleep spindle detector with high performance in middle aged subjects. An automatic sleep spindle detector using a bandpass filtering approach and a time varying threshold was developed. The validation was done on sleep epochs from EEG recordings with manually scored sleep spindles from 13 healthy subjects with a mean age of 57.9 ± 9.7 years. The sleep spindle detector reached a mean sensitivity of 84.6 % and a mean specificity of 95.3 %. The sleep spindle detector can be used to obtain measures of spindle count and density together with quantitative measures such as the mean spindle frequency, mean spindle amplitude, and mean spindle duration.

Sleep transitions in hypocretin-deficient narcolepsy

STUDY OBJECTIVES

Narcolepsy is characterized by instability of sleep-wake, tonus, and rapid eye movement (REM) sleep regulation. It is associated with severe hypothalamic hypocretin deficiency, especially in patients with cataplexy (loss of tonus). As the hypocretin neurons coordinate and stabilize the brain's sleep-wake pattern, tonus, and REM flip-flop neuronal centers in animal models, we set out to determine whether hypocretin deficiency and/or cataplexy predicts the unstable sleep-wake and REM sleep pattern of the human phenotype.

DESIGN

We measured the frequency of transitions in patients with narcolepsy between sleep-wake states and to/from REM and NREM sleep stages. Patients were subdivided by the presence of +/- cataplexy and +/- hypocretin-1 deficiency.

SETTING

Sleep laboratory studies conducted from 2001-2011.

PATIENTS

In total 63 narcolepsy patients were included in the study. Cataplexy was present in 43 of 63 patients and hypocretin-1 deficiency was present in 37 of 57 patients.

MEASUREMENTS AND RESULTS

Hypocretin-deficient patients with narcolepsy had a significantly higher frequency of sleep-wake transitions (P = 0.014) and of transitions to/from REM sleep (P = 0.044) than patients with normal levels of hypocretin-1. Patients with cataplexy had a significantly higher frequency of sleep-wake transitions (P = 0.002) than those without cataplexy. A multivariate analysis showed that transitions to/from REM sleep were predicted mainly by hypocretin-1 deficiency (P = 0.011), whereas sleep-wake transitions were predicted mainly by cataplexy (P = 0.001).

CONCLUSIONS

In human narcolepsy, hypocretin deficiency and cataplexy are both associated with signs of destabilized sleep-wake and REM sleep control, indicating that the disorder may serve as a human model for the sleep-wake and REM sleep flip-flop switches.

Evaluation of novel algorithm embedded in a wearable sEMG device for seizure detection

We implemented a modified version of a previously published algorithm for detection of generalized tonic-clonic seizures into a prototype wireless surface electromyography (sEMG) recording device. The method was modified to require minimum computational load, and two parameters were trained on prior sEMG data recorded with the device. Along with the normal sEMG recording, the device is able to set an alarm whenever the implemented algorithm detects a seizure. These alarms are annotated in the data file along with the signal. The device was tested at the Epilepsy Monitoring Unit (EMU) at the Danish Epilepsy Center. Five patients were included in the study and two of them had generalized tonic-clonic seizures. All patients were monitored for 2-5 days. A double-blind study was made on the five patients. The overall result showed that the device detected four of seven seizures and had a false detection rate of 0.003/h or one in twelve days.

Rapid eye movement sleep behavior disorder: devising controlled active treatment studies for symptomatic and neuroprotective therapy--a consensus statement from the International Rapid Eye Movement Sleep Behavior Disorder Study Group

OBJECTIVES

We aimed to provide a consensus statement by the International Rapid Eye Movement Sleep Behavior Disorder Study Group (IRBD-SG) on devising controlled active treatment studies in rapid eye movement sleep behavior disorder (RBD) and devising studies of neuroprotection against Parkinson disease (PD) and related neurodegeneration in RBD.

METHODS

The consensus statement was generated during the fourth IRBD-SG symposium in Marburg, Germany in 2011. The IRBD-SG identified essential methodologic components for a randomized trial in RBD, including potential screening and diagnostic criteria, inclusion and exclusion criteria, primary and secondary outcomes for symptomatic therapy trials (particularly for melatonin and clonazepam), and potential primary and secondary outcomes for eventual trials with disease-modifying and neuroprotective agents. The latter trials are considered urgent, given the high conversion rate from idiopathic RBD (iRBD) to Parkinsonian disorders (i.e., PD, dementia with Lewy bodies [DLB], multiple system atrophy [MSA]).

RESULTS

Six inclusion criteria were identified for symptomatic therapy and neuroprotective trials: (1) diagnosis of RBD needs to satisfy the International Classification of Sleep Disorders, second edition, (ICSD-2) criteria; (2) minimum frequency of RBD episodes should preferably be ⩾2 times weekly to allow for assessment of change; (3) if the PD-RBD target population is included, it should be in the early stages of PD defined as Hoehn and Yahr stages 1-3 in Off (untreated); (4) iRBD patients with soft neurologic dysfunction and with operational criteria established by the consensus of study investigators; (5) patients with mild cognitive impairment (MCI); and (6) optimally treated comorbid OSA. Twenty-four exclusion criteria were identified. The primary outcome measure for RBD treatment trials was determined to be the Clinical Global Impression (CGI) efficacy index, consisting of a four-point scale with a four-point side-effect scale. Assessment of video-polysomnographic (vPSG) changes holds promise but is costly and needs further elaboration. Secondary outcome measures include sleep diaries; sleepiness scales; PD sleep scale 2 (PDSS-2); serial motor examinations; cognitive indices; mood and anxiety indices; assessment of frequency of falls, gait impairment, and apathy; fatigue severity scale; and actigraphy and customized bed alarm systems. Consensus also was established for evaluating the clinical and vPSG aspects of RBD. End points for neuroprotective trials in RBD, taking lessons from research in PD, should be focused on the ultimate goal of determining the performance of disease-modifying agents. To date no compound with convincing evidence of disease-modifying or neuroprotective efficacy has been identified in PD. Nevertheless, iRBD patients are considered ideal candidates for neuroprotective studies.

CONCLUSIONS

The IRBD-SG provides an important platform for developing multinational collaborative studies on RBD such as on environmental risk factors for iRBD, as recently reported in a peer-reviewed journal article, and on controlled active treatment studies for symptomatic and neuroprotective therapy that emerged during the 2011 consensus conference in Marburg, Germany, as described in our report.

Acute Sleep Restriction Reduces Insulin Sensitivity in Adolescent Boys

BACKGROUND

Short sleep duration has been linked to impaired glucose metabolism in many experimental studies. Moreover, studies have reported indications of an increased metabolic stress following sleep restriction.

OBJECTIVE

We aimed to investigate the effects of partial sleep deprivation on markers of glucose metabolism. Additionally, we aimed to investigate if short sleep duration induces a state of endocrine stress.

DESIGN

A randomized crossover design, with 2 experimental conditions: 3 consecutive nights of short sleep (SS, 4 h/night) and long sleep (LS, 9 h/night) duration.

SUBJECTS AND MEASUREMENTS

In 21 healthy, normal-weight male adolescents (mean ± SD age: 16.8 ± 1.3 y) we measured pre- and post-prandial glucose, insulin, C-peptide, and glucagon concentrations. Furthermore, we measured fasting cortisol, 24-h catecholamines, and sympathovagal balance.

RESULTS

Fasting insulin was 59% higher (P = 0.001) in the SS than the LS condition as was both fasting (24%, P < 0.001) and post-prandial (11%, P = 0.018) C-peptide. Pre- and post-prandial glucose and glucagon were unchanged between conditions. The homeostasis model assessment of insulin resistance (HOMA-IR) index was 65% higher (P = 0.002) and the Matsuda index was 28% lower (P = 0.007) in the SS condition compared to the LS condition. The awakening cortisol response and 24-h norepinephrine were not affected by sleep duration, whereas 24-h epinephrine was 24% lower (P = 0.013) in the SS condition. Neither daytime nor 24-h sympathovagal balance differed between sleep conditions. Short wave sleep was preserved in the SS condition.

CONCLUSION

Short-term sleep restriction is associated with decreased insulin sensitivity in healthy normal-weight adolescent boys. There were no indications of endocrine stress beyond this.

CITATION

Klingenberg L; Chaput JP; Holmbäck U; Visby T; Jennum P; Nikolic M; Astrup A; Sjödin A. Acute Sleep Restriction Reduces Insulin Sensitivity in Adolescent Boys. SLEEP 2013;36(7):1085-1090.

Comorbidity and mortality of narcolepsy: a controlled retro- and prospective national study

STUDY OBJECTIVES

To identify the factual morbidity and mortality of narcolepsy in a controlled design.

SETTING

National Patient Registry.

PATIENTS

All national diagnosed patients (757) with health information at least 3 years prior to and after diagnose of narcolepsy.

CONTROLS

Randomly selected four citizens (3,013) matched for age, sex, and socioeconomic status from the Danish Civil Registration System Statistics.

RESULTS

Increased morbidity prior to narcolepsy diagnosis included (odds ratio, 95% confidence interval):- diseases of the endocrine, nutritional, and metabolic systems (2.10, 1.32-3.33); nervous system (5.27, 3.65-7.60); musculoskeletal system (1.59, 1.23-2.05); and other abnormal symptoms and laboratory findings (1.66, 1.25-2.22). After the diagnosis, narcolepsy patients experienced diseases of the endocrine, nutritional, and metabolic (2.31, 1.51-3.54), nervous (9.19, 6.80-12.41), musculoskeletal (1.70, 1.28-2.26), eye (1.67, 1.03-2.71), and respiratory systems (1.84, 1.21-2.81). Specific diagnoses were diabetes (2.4, 1,2-4.7, P < 0.01), obesity (13.4, 3.1-57.6, P < 0.001), sleep apnea (19.2, 7.7-48.3, P < 0.001), other sleep disorders (78.5, 11.8-523.3, P < 0.001), chronic obstructive pulmonary disease (2.8, 1.4-5.8, P < 0.01), lower back pain (2.5, 1.4-4.2, P < 0.001), arthrosis/arthritis (2.5, 1.3-4.8, P < 0.01), observation of neurological diseases (3.5, 1.9-6.5, P < 0.001), observation of other diseases (1.7, 1.2-2.5, P < 0.01), and rehabilitation (5.0, 1.5-16.5, P < 0.005). There was a trend towards greater mortality in narcolepsy (P = 0.07).

CONCLUSIONS

Patients with narcolepsy present higher morbidity several years prior to diagnose and even higher thereafter. The mortality rate due to narcolepsy was slightly but not significantly higher.

Family history of idiopathic REM behavior disorder: a multicenter case-control study

OBJECTIVE

To compare the frequency of proxy-reported REM sleep behavior disorder (RBD) among relatives of patients with polysomnogram-diagnosed idiopathic RBD (iRBD) in comparison to controls using a large multicenter clinic-based cohort.

METHODS

A total of 316 patients with polysomnography-confirmed iRBD were recruited from 12 RBD study group centers, along with 316 controls matched on sex and age group. All subjects completed a self-administered questionnaire that collected proxy-reported information on family history of tremor, gait trouble, balance trouble, Parkinson disease, memory loss, and Alzheimer disease. The questionnaire also included a single question that asked about possible symptoms of RBD among first-degree relatives (siblings, parents, and children).

RESULTS

A positive family history of dream enactment was reported in 13.8% of iRBD cases compared to 4.8% of controls (odds ratio [OR] = 3.9, 95% confidence interval [CI] 2.0-7.7). ORs were increased for both siblings (OR = 6.1, 95% CI 2.1-18.1) and parents (OR = 3.2, 95% CI 1.4-7.8). We found no significant difference in sex, current age (65.3 ± 10.2 vs 66.9 ± 10.2 years), or age at self-reported RBD onset (55.2 ± 11.7 vs 56.6 ± 15.1 years) in possible familial vs sporadic iRBD. No differences were found in family history of tremor, walking and balance troubles, Parkinson disease, memory loss, or Alzheimer disease.

CONCLUSION

We found increased odds of proxy-reported family history of presumed RBD among individuals with confirmed iRBD. This suggests the possibility of a genetic contribution to RBD.

The socioeconomic consequences of optic neuritis with and without multiple sclerosis: a controlled national study

OBJECTIVES

Optic neuritis (ON) often precedes multiple sclerosis (MS). MS is associated with a significant socioeconomic burden. However, the burden of ON with and without MS before and after its diagnosis has never been calculated.

METHODS

Using complete national records from the Danish National Patient Registry (1998-2006), we identified 1677 patients with ON and compared them with 6708 randomly selected citizens matched for age, sex and geography. A societal perspective is taken towards the cost analyses. Costs included in the analysis are those of the health sector, including all contacts with primary and secondary sectors, and the use and costs of drugs. Productivity losses included labour supply and income. All social transfer payments were also calculated.

RESULTS

Patients with ON had higher rates of contact with healthcare services, medication use and income from employment, all of which incurred a higher socioeconomic cost. Employed patients had lower income than control subjects. The total annual excess costs relative to matched controls were €3501 for ON patients and €9215 for patients with a dual diagnosis of ON and MS. The ON and ON+MS patients received an annual mean excess social transfer income of €1175 and €4619. ON/ON+MS patients presented social and economic consequences up to 8 years before diagnosis, and these increased after the diagnosis was established.

CONCLUSIONS

ON, especially if combined with a diagnosis of MS, has a significant socioeconomic consequence for the individual patient and for society. Productivity losses are a far more important economic factor than health sector costs.

Low-frequency oscillations and vasoreactivity of cortical vessels in obstructive sleep apnea during wakefulness: a near infrared spectroscopy study

OBJECTIVES

Effective nasal continuous positive airway pressure (CPAP) therapy reduces the cardiovascular outcomes associated with obstructive sleep apnea (OSA), but the mechanism behind this effect is unclear. We investigated if OSA patients during wakefulness showed signs of increased sympathetic activity and decreased vasoreactivity in cerebral cortical vessels as measured with near-infrared spectroscopy (NIRS), and if this may be reversed by CPAP treatment.

SUBJECTS AND METHODS

23 OSA patients (mean age, 55y) naive to CPAP were included in a prospective interventional study. The OSA patients received CPAP therapy for at least two months. Cortical low-frequency oscillation (LFO) amplitudes and vasoreactivity during a breath hold test were measured with NIRS and were compared between baseline and after CPAP treatment. Baseline values also were compared to 13 healthy controls (mean age, 52y).

RESULTS

We found a decrease in LFO amplitudes after CPAP therapy (P=0.022) in OSA patients. We found no differences in LFO amplitudes between OSA patients and healthy controls (P=0.934). There were no differences in peak vascular response following breath hold tests in OSA patients before and after CPAP therapy (P=0.158) or compared to healthy controls (P=0.740).

CONCLUSION

Our NIRS study revealed a decrease in LFO amplitude following two months of CPAP treatment in OSA patients, which may reflect a decrease in sympathetic activity affecting cortical vessels.

ImmunoChip study implicates antigen presentation to T cells in narcolepsy

Recent advances in the identification of susceptibility genes and environmental exposures provide broad support for a post-infectious autoimmune basis for narcolepsy/hypocretin (orexin) deficiency. We genotyped loci associated with other autoimmune and inflammatory diseases in 1,886 individuals with hypocretin-deficient narcolepsy and 10,421 controls, all of European ancestry, using a custom genotyping array (ImmunoChip). Three loci located outside the Human Leukocyte Antigen (HLA) region on chromosome 6 were significantly associated with disease risk. In addition to a strong signal in the T cell receptor alpha (TRA@), variants in two additional narcolepsy loci, Cathepsin H (CTSH) and Tumor necrosis factor (ligand) superfamily member 4 (TNFSF4, also called OX40L), attained genome-wide significance. These findings underline the importance of antigen presentation by HLA Class II to T cells in the pathophysiology of this autoimmune disease.

While there is now broad consensus that narcolepsy-hypocretin deficiency results from a highly specific autoimmune attack on hypocretin cells, little is understood regarding the initiation and progression of the underlying autoimmune process. We have taken advantage of a unique high-density genotyping platform (the ImmunoChip) designed to study variants in genes known to be important to autoimmune and inflammatory diseases. Our study of nearly 2000 narcolepsy cases compared to 10,000 controls underscored important roles for HLA DQB1*06:02 and the T cell receptor alpha genes and implicated two additional genes, Cathepsin H and TNFSF4/OX40L, in disease pathogenesis. These findings are particularly important, as these encoded proteins have key roles in antigen processing, presentation, and T cell response, and they suggest that specific interactions at the immunological synapse constitute the pathway to the disease. Further studies of these genes and encoded proteins may therefore reveal the mechanism leading to this highly selective and unique autoimmune disease.

Separation of Parkinson's patients in early and mature stages from control subjects using one EOG channel

In this study, polysomnographic left side EOG signals from ten control subjects, ten iRBD patients and ten Parkinson's patients were decomposed in time and frequency using wavelet transformation. A total of 28 features were computed as the means and standard deviations in energy measures from different reconstructed detail subbands across all sleep epochs during a whole night of sleep. A subset of features was chosen based on a cross validated Shrunken Centroids Regularized Discriminant Analysis, where the controls were treated as one group and the patients as another. Classification of the subjects was done by a leave-one-out validation approach using same method, and reached a sensitivity of 95%, a specificity of 70% and an accuracy of 86.7%. It was found that in the optimal subset of features, two hold lower frequencies reflecting the rapid eye movements and two hold higher frequencies reflecting EMG activity. This study demonstrates that both analysis of eye movements during sleep as well as EMG activity measured at the EOG channel hold potential of being biomarkers for Parkinson's disease.

Automatic detection of REM sleep in subjects without atonia

Idiopathic Rapid-Rye-Movement (REM) sleep Behavior Disorder (iRBD) is a strong early marker of Parkinson's Disease and is characterized by REM sleep without atonia (RSWA) and increased phasic muscle activity. Current proposed methods for detecting RSWA assume the presence of a manually scored hypnogram. In this study a full automatic REM sleep detector, using the EOG and EEG channels, is proposed. Based on statistical features, combined with subject specific feature scaling and post-processing of the classifier output, it was possible to obtain an mean accuracy of 0.96 with a mean sensitivity and specificity of 0.94 and 0.96 respectively.