Orexin receptor antagonism, a new sleep-enabling paradigm: a proof-of-concept clinical trial

The orexin system is a key regulator of sleep and wakefulness. In a multicenter, double-blind, randomized, placebo-controlled, two-way crossover study, 161 primary insomnia patients received either the dual orexin receptor antagonist almorexant, at 400, 200, 100, or 50 mg in consecutive stages, or placebo on treatment nights at 1-week intervals. The primary end point was sleep efficiency (SE) measured by polysomnography; secondary end points were objective latency to persistent sleep (LPS), wake after sleep onset (WASO), safety, and tolerability. Dose-dependent almorexant effects were observed on SE, LPS, and WASO. SE improved significantly after almorexant 400 mg vs. placebo (mean treatment effect 14.4%; P < 0.001). LPS (–18 min (P = 0.02)) and WASO (–54 min (P < 0.001)) decreased significantly at 400 mg vs. placebo. Adverse-event incidence was dose-related. Almorexant consistently and dose-dependently improved sleep variables. The orexin system may offer a new treatment approach for primary insomnia.

A longitudinal study on effects of a six-week course for energy conservation for multiple sclerosis patients

Objective Fatigue management and energy conservation are effective strategies to minimize fatigue in multiple sclerosis (MS). Sustained results have not yet been reported.

Methods A fatigue management course was provided for 32 MS patients. They were tested prior to, directly after participation in the course and in a 7—9 month follow-up with the Fatigue Severity Scale, the MS-specific Fatigue Scale, the Modified Fatigue Impact Scale (MFIS), the Pittsburgh Sleep Quality Index and a self-rating scale for depression. The Expanded Disability Status Score (EDSS) and the MS functional composite (MSFC) were evaluated before and after participation in the course.

Results The total score and the Cognitive and Physical subscores of the MFIS showed significant improvements on both points of time. Scores in the Fatigue Severity Scale, MS-specific Fatigue Scale and Psychosocial Fatigue Impact Scale did not improve significantly. MS functional composite and EDSS remained unchanged after six weeks of course participation. Subjective sleep quality improved directly after participation in the course and after 7—9 months. The depression score decreased significantly to a normal level at the end of training and in the 7—9 month follow-up.

Conclusion Fatigue management enables MS patients to cope with their fatigue and energy more effectively. Follow-up evaluations showed stable results after 7—9 months. Multiple Sclerosis 2008; 14: 500—505. http://msj.sagepub.com

Sleep spindle-related activity in the human EEG and its relation to general cognitive and learning abilities

Stage 2 sleep spindles have been previously viewed as useful markers for the development and integrity of the CNS and were more currently linked to 'offline re-processing' of implicit as well as explicit memory traces. Additionally, it had been discussed if spindles might be related to a more general learning or cognitive ability. In the present multicentre study we examined the relationship of automatically detected slow (< 13 Hz) and fast (> 13 Hz) stage 2 sleep spindles with: (i) the Raven's Advanced Progressive Matrices (testing 'general cognitive ability'); as well as (ii) the Wechsler Memory scale-revised (evaluating memory in various subdomains). Forty-eight healthy subjects slept three times (separated by 1 week) for a whole night in a sleep laboratory with complete polysomnographic montage. Whereas the first night only served adaptation and screening purposes, the two remaining nights were preceded either by an implicit mirror-tracing or an explicit word-pair association learning or (corresponding) control task. Robust relationships of slow and fast sleep spindles with both cognitive as well as memory abilities were found irrespectively of whether learning occurred before sleep. Based on the present findings we suggest that besides being involved in shaping neuronal networks after learning, sleep spindles do reflect important aspects of efficient cortical-subcortical connectivity, and are thereby linked to cognitive- and memory-related abilities alike.

Structural and serum surrogate markers of cerebrovascular disease in obstructive sleep apnea (OSA): association of mild OSA with early atherosclerosis

There is increasing evidence of a causal interaction between obstructive sleep apnea (OSA) and cerebrovascular disease. The aim of the study was to elucidate the relationship between the polysomnographically (PSG) measured severity of OSA and carotid atherosclerosis determined by ultrasonography and serum surrogate markers. 147 patients (102 males, 45 females) referred to our sleep laboratory for evaluation of snoring and sleep-disordered breathing were investigated. Carotid atherosclerosis was evaluated by serum analysis of high-sensitivity C-reactive protein (hs-CRP) and fibrinogen and four sonographic indices: intima-media thickness (IMT) of the common carotid artery (CCA), IMT from bulb to internal carotid artery (Bulb-ICA), combined IMT measurements from all segments and a plaque score (PlaS). Pearson correlation analysis, intergroup comparison (ANOVA), covariance analysis and a multiple regression were performed to assess the association between surrogate markers and respiratory variables. 44 patients had no OSA (apnea-hypopnea index AHI < 5/h), 27 mild (AHI 5-15), 25 moderate (AHI 15-30) and 51 severe OSA (AHI > 30). After adjusting for potential confounders, significant differences between the controls and all three OSA groups were observed in the CCA-IMT (p = 0.032) and in the PlaS between the controls and the severe group (p = 0.034). Multiple regression revealed the AHI as an independent predictor of CCA-IMT (p = 0.001) and combined IMT (p = 0.001), whereas the percentage of total sleep time with an oxygen saturation below 90 % was associated with Bulb-ICA IMT (p = 0.018) and hs-CRP (p = 0.015). OSA is associated with higher surrogate levels of cerebrovascular disease. Even mild OSA seems to predispose to early atherosclerosis.

Loss of normal circadian profile of urine excretion in idiopathic restless legs syndrome

BACKGROUND

This study was performed to elucidate preliminary observations of excessive nighttime urine excretion in idiopathic restless legs syndrome (iRLS).

METHODS

Seventeen patients, with normal serum creatinine, blood urea nitrogen, and urate, and 11 healthy controls were examined. We measured excretory renal function parameters (urine volume, osmolarity, sodium, chloride, potassium, calcium, phosphate, microalbumin, aldosterone, creatinine) between 7:00 am and 10:00 pm and between 10:00 pm and 7:00 am.

RESULTS

During the nighttime, volume (P=0.006), sodium (P=0.009), and chloride excretion (P=0.001) were significantly higher, and osmolarity (P=0.025) was significantly lower in patients as compared to controls. In comparing daytime to nighttime, controls showed the physiological reduced nocturnal excretion of volume (P=0.009) and chloride (P=0.023), and an increased osmolarity (P=0.026), but patients showed similar excretion rates of these parameters (all differences ns).

CONCLUSIONS

These data indicate a loss of normal circadian profile of urine excretion in iRLS. The elevated nighttime excretion, with values similar to those in the daytime, hint at a possibly elevated fluid, sodium, and chloride intake during daytime.

Effects of socio-demographic variables on health-related quality of life determined by the quality of life index--German version

STUDY OBJECTIVE

The purpose of this study was to determine subjective health-related quality of life (HRQoL) in a sample of the Austrian population over 14 years of age in order to evaluate the effect of socio-demographic variables on HRQoL.

DESIGN/SETTING

HRQoL was determined by means of the quality of life index-German version (QLI-Ge). The influence of socio-demographic variables on HRQoL was assessed by statistical analysis using the Kruskal-Wallis test and an analysis of variance.

PARTICIPANTS

A random-quota procedure was used to get balanced representation from regions and demographic groups of the Austrian population. The sample consisted of 1049 participants, 493 men and 556 women.

MAIN RESULTS

Age was found to influence the QLI-Ge total score (index score) and most individual items, with increasing age resulting in a decrease in HRQoL. Differences between the sexes were observed in three dimensions: males scored higher in 'physical well-being', 'psychological well-being' and 'occupational functioning'. Marital status impacted most items with married persons showing better values than divorced persons or singles. Profession had only a minor effect on HRQoL, the level of education showed no influence at all.

CONCLUSIONS

The socio-demographic variables age, sex and objective living conditions had a major influence on subjectively rated HRQoL, whereas profession and education were found to play a minor role in this context. It is recommended that in the interpretation of studies assessing HRQoL the above-mentioned objective factors be considered. This will be of particular importance when determining the effect of a pharmacotherapy on HRQoL in patients.

Apomorphine in idiopathic restless legs syndrome: an exploratory study

BACKGROUND

Dopaminergic and opioidergic drugs have been found to be effective in patients with restless legs syndrome (RLS).

OBJECTIVES

To test the effect of apomorphine--a combined opioidergic and dopaminergic agonist--and subsequent selective antagonism by naloxone and metoclopramide on subjective and objective symptoms in patients with idiopathic RLS.

METHODS

Nine patients with RLS were pretreated with oral domperidone for three days. A modified suggested immobilisation test (SIT) was carried out between 8 pm and 1 am under the following conditions of intravenous drug administration: baseline-apomorphine-apomorphine plus naloxone-apomorphine plus metoclopramide. Outcome variables were a visual analogue scale (VAS) of subjective RLS symptoms and EMG documented periodic leg movements while awake (PLMW).

RESULTS

Compared with baseline, apomorphine resulted in a rapid and significant improvement in subjective RLS symptoms as measured by VAS (54.5% improvement; p = 0.011), and an almost immediate cessation of PLMW, measured by PLMW index (98.0% improvement; p = 0.012). Neither additional naloxone nor metoclopramide blocked this effect significantly. While given apomorphine with metoclopramide, there was a trend to reappearance of PLMW.

CONCLUSIONS

Apomorphine may be an effective treatment for idiopathic RLS. Its effectiveness may reflect both to its dopaminergic and its opioidergic activity, and is not diminished significantly by blocking only one of these pathways. The trend to a worsening of the PLMW index with metoclopramide hints at a primarily dopaminergic effect of apomorphine in idiopathic RLS.

EEG-tomographic studies with LORETA on vigilance differences between narcolepsy patients and controls and subsequent double-blind, placebo-controlled studies with modafinil

The aim of the present study was to identify brain regions associated with vigilance in untreated and modafinil-treated narcoleptic patients by means of low-resolution brain electromagnetic tomography (LORETA). 16 drug-free narcoleptics and 16 normal controls were included in the baseline investigation. Subsequently patients participated in a double-blind, placebo-controlled crossover study receiving a three-week fixed titration of modafinil (200, 300, 400 mg) and placebo. Measurements comprised LORETA, the Multiple Sleep Latency Test (MSLT) and the Epworth Sleepiness Scale (ESS) obtained before and after three weeks' therapy. Statistical overall analysis by means of the omnibus significance test demonstrated significant inter-group differences in the resting (R-EEG), but not in the vigilance-controlled recordings (V-EEG). Subsequent univariate analysis revealed a decrease in alpha-2 and beta 1-3 power in prefrontal, temporal and parietal cortices, with the right hemisphere slightly more involved in this vigilance decrement. Modafinil 400 mg/d as compared with placebo induced changes opposite to the aforementioned baseline differences (key-lock principle) with a preponderance in the left hemisphere. This increase in vigilance resulted in an improvement in the MSLT and the ESS. LORETA provided evidence of a functional deterioration of the fronto-temporo-parietal network of the right-hemispheric vigilance system in narcolepsy and a therapeutic effect of modafinil on the left hemisphere, which is less affected by the disease.

Factors influencing quality of life in multiple sclerosis patients: disability, depressive mood, fatigue and sleep quality

OBJECTIVES

In a series of 504 patients with multiple sclerosis (MS), quality of life (QOL) and its main clinical and demographic determinants were assessed in comparison with healthy individuals.

MATERIALS AND METHODS

A postal questionnaire with self-completed measures of disability (Expanded Disability Status Scale, EDSS), QOL (Quality of Life Index, QLI), depressive mood (Self-rating Depression Scale, SDS), fatigue severity (Fatigue Severity Scale, FSS) and sleep quality (Pittsburgh Sleep Quality Index, PSQI) was sent to this sample of MS patients.

RESULTS

Most patients were severely disabled; almost half were mildly to severely depressed, suffering from reduced sleep quality and/or fatigue. The multiple sclerosis patients had significantly lower QLI scores than healthy controls. EDSS and SDS scores were found to be predictors of global QLI score. Regarding the different QLI domains, mean SDS scores remained predictive for all QLI items, while mean EDSS, PSQI and FSS scores were only predictive for physical domains.

CONCLUSION

Our study clearly demonstrates that depressive mood is the main factor influencing QOL. The disability status, fatigue and reduced sleep quality have an impact mainly on physical domains of life quality.

Normal striatal D2 receptor binding in idiopathic restless legs syndrome with periodic leg movements in sleep

Dopaminergic treatment is very effective in restless legs syndrome (RLS) and periodic leg movements in sleep (PLMS). However, neuroreceptor imaging studies that addressed altered striatal dopaminergic function have given controversial results. In this present study, 14 patients with idiopathic RLS (iRLS) and PLMS with a good response to dopaminergic and non-dopaminergic treatment and ten healthy sex- and age-matched controls were investigated off-medication by using 123I-IBZM and SPECT. RLS symptoms and sleep disturbances were evaluated using three nights of polysomnography, the Pittsburgh Sleep Quality Index, and the International RLS Study Group (IRLSSG) rating scale. The patients presented with sleep disturbances, a high PLMS index (56.2 +/- 33.1 per h), and severe RLS symptoms during SPECT (IRLSSG rating scale 23.1 +/- 8.0), and showed no significant differences in striatal to frontal IBZM binding to D2 receptors compared to controls (ratio striatum/frontal cortex, right side 1.60 +/- 0.10 vs 1.63 +/- 0.08, P = 0.35, NS; left side 1.61 +/- 0.11 vs 1.63 +/- 0.08, P = 0.51, NS). These findings show normal function of striatal D2 receptors in successfully treated patients with iRLS and PLMS. Dopaminergic and non-dopaminergic pretreatment does not appear to change striatal D2 receptor binding as compared to healthy controls. Structures other than striatal D2 receptors are discussed as possible causes of the treatment effects in RLS.

Sequential MRI in a case of Creutzfeldt-Jakob disease

A 48-year-old man suddenly developed clinically and electroencephalographically nonspecific dementia. On MRI sequences, only diffusion-weighted images (DWI) of the cortex were unequivocally pathological. Obvious atrophy and basal ganglia signal changes appeared only 9 months after the onset. Brain biopsy confirmed Creutzfeldt-Jakob disease (CJD). In rapidly progressive dementia, we recommend DWI for early diagnosis of CJD.

Sleeping habits in the Austrian population

OBJECTIVES

To gain reliable data on sleeping habits and sleep disturbances of the Austrian population.

BACKGROUND

Exact data on sleeping habits are of interest in relation to assessment of sleep disturbance-related illnesses and general social processes.

METHODS

A prospective, cross-sectional study was performed with recruitment of a representative sample of 1049 Austrians (aged 15-82 years), according to the Federal Statistics population characteristics. Interviews were conducted in the households of the participants by specially trained interviewers of an institute for empirical research.

RESULTS

Men consider their quality of sleep to be significantly better than women (P=0.00234), and younger persons consider their quality of sleep to be significantly better than older persons (P=0.00001). In comparison, women and people over the age of 50 report worse subjective sleep quality, worse sleep efficiency, more difficulty in falling asleep and sleep maintenance, more apneic events, more pathologic limb movements, more daytime dysfunction, and more intake of sleeping medication. Other sociodemographic factors influence sleep reports to a lesser extent.

CONCLUSIONS

Subjectively disturbed sleep (prevalence in the total population 24.9%), excessive hypnotic drug intake (prevalence 13.0%), and daytime dysfunction (prevalence 17.4%) are a widespread problem, especially in women and older people. With increasing life expectancy in Western societies, the prevalence of sleep disturbances will increase.

Treatment of idiopathic restless legs syndrome (RLS) with gabapentin

Nine patients with idiopathic restless legs syndrome (RLS) were treated with 300 mg of gabapentin as an initial dose and an up-titration until relief of symptoms for 4 weeks. Subjective symptoms improved significantly. Polysomnographic data showed a reduction of periodic leg movements during sleep (PLMS) (p = 0.003) and PLMS index (p = 0.001). The authors conclude that gabapentin provides a well-tolerated and effective treatment of idiopathic RLS.

Sleep disorders and depression in patients with Parkinson's disease

OBJECTIVES

Sleep disorders and depression are frequent in patients with Parkinson's disease (PD). However, the exact prevalence and the causality are still unknown.

PATIENTS AND METHODS

We interviewed 56 consecutive PD patients and 59 age-matched healthy controls concerning sleep disorders and depression. Sleep Disorders Questionnaire (SDQ) and Zung Depression Scale (ZDS) were used as standardized valid and reliable psychometric tests.

RESULTS

Patients with PD had significantly higher values in the clinical-diagnostic scale narcolepsy (P=0.01), correlating with the L-dopa dose (P=0.007). Concerning sleep apnea (P=0.49), psychiatric sleep disorder (P=1.00) and periodic limb movement disorder (P=0.12), no significant difference could be identified. PD patients showed significantly higher depression scores than healthy control subjects (P=0.01), increasing with the duration of PD (P=0.04).

CONCLUSION

The significant higher narcolepsy score in PD patients must be seen due to dopaminergic medication and PD-specific neurodegeneration and immobility rather than due to narcolepsy. This leads to the conclusion that extreme caution is advised when carrying out the SDQ and interpreting the results in various persons and patient groups with motor problems. The strong association of depression, disease severity and sleep disorders in PD patients underlines the importance of identifying and treating both conditions in these patients.

Low-resolution brain electromagnetic tomography revealed simultaneously active frontal and parietal sleep spindle sources in the human cortex

Analyses of scalp-recorded sleep spindles have demonstrated topographically distinct slow and fast spindle waves. In the present paper, the electrical activity in the brain corresponding to different types of sleep spindles was estimated by means of low-resolution electromagnetic tomography. In its new implementation, this method is based on realistic head geometry and solution space is restricted to the cortical gray matter and hippocampus. In multichannel all-night electroencephalographic recordings, 10-20 artifact-free 1.25-s epochs with frontally, parietally and approximately equally distributed spindles were marked visually in 10 normal healthy subjects aged 20-35years. As a control condition, artifact-free non-spindle epochs 1-3s before or after the corresponding spindle episodes were marked. Low-resolution electromagnetic tomography demonstrated, independent of the scalp distribution, a distributed spindle source in the prefrontal cortex (Brodmann areas 9 and 10), oscillating with a frequency below 13Hz, and in the precuneus (Brodmann area 7), oscillating with a frequency above 13Hz. In extremely rare cases only the prefrontal or the parietal source was active. Brodmann areas 9 and 10 have principal connections to the dorsomedial thalamic nucleus; Brodmann area 7 is connected to the lateroposterior, laterodorsal and rostral intralaminar centrolateral thalamic nuclei. Thus, the localized cortical brain regions are directly connected with adjacent parts of the dorsal thalamus, where sleep spindles are generated. The results demonstrated simultaneously active cortical spindle sources which differed in frequency by approximately 2Hz and were located in brain regions known to be critically involved in the processing of sensory input, which is in line with the assumed functional role of sleep spindles.

[Sleep-related headaches]

Headaches and sleep disorders are frequent and can be associated with each other. Some headache syndromes are related to certain sleep phases or circadian rhythms. These so-called sleep-related headache syndromes include specific types of migraine, cluster headache, chronic paroxysmal hemicrania, and the hypnic headache syndrome. Except for the latter, they were included in the International Classification of Sleep Disorders and are described in this article.

[Myasthenia gravis and sleep]

In myasthenia gravis respiratory function is often disturbed in the night, especially during REM sleep, despite of normal daytime respiratory function. Nevertheless, nocturnal respiratory problems are rarely diagnosed. Sleepiness, concentration and memory problems can be symptoms of a sleep related breathing disorder. Reports of reduction of REM sleep, memory dysfunction, and detection of acetylcholine receptor (AchR)-antibodies in the cerebrospinal fluid have lead to the hypothesis of a central nervous system involvement in myasthenia gravis. Possible mechanisms are centrally acting AchR-antibodies, unspecifically acting cytokines and hypoxia, possibly the most important influence upon REM sleep reduction and impaired cognitive function. In a patient presenting possible CNS-involvement (cephalea, fatigue, concentration and memory problems), a polysomnographic investigation should therefore be performed to detect a sleep related breathing disorder.

An autosomal dominant early adult-onset distal muscular dystrophy

In this study we describe an autosomal dominant distal muscular dystrophy in a small Austrian family. The myopathy started in early adulthood with a slowly progressive weakness of the muscles of the anterior tibial compartment, followed by the long finger extensors and sternocleidomastoids in some family members. Other muscles were spared. Histopathology showed fiber size variation and autophagic vacuoles. This disease pattern is similar to Laing distal myopathy, which has been described previously in only one other family.

Sleep and quality of life in the Austrian population

PURPOSE

To compare the self-reported estimation of sleep quality evaluated by the Pittsburgh Sleep Quality Index (PSQI) and life quality assessed by the Quality of Life Index (QLI).

BACKGROUND

The PSQI comprised 19 questions and assessed a wide variety of factors relating to sleep quality. The QLI consisted of 10 items for self assessment of different dimensions of life quality.

SUBJECTS

A representative Austrian sample (n = 1049) aged above 15 years.

PROCEDURE

Interviews in the homes of the participants.

RESULTS

32.1% could be classified as poor sleepers (37% females, 26.5% males). Sleep quality decreased with increasing age, especially in women. Overall quality of life was highest in younger (15-29 years) and lowest in elderly subjects (over 50 years). Life quality decreased with increasing age. Between subjective sleep quality and quality of life a moderate, significant correlation was found (r2= 0.6721).

CONCLUSIONS

Complaints about a bad quality of sleep could be used as a screening method in the exploration of patients' quality of life (QoL).

[Electromagnetic fields--effects on health]

This literature review shows the current knowledge of health effects on humans concerning static, low frequency electric and magnetic fields and high frequency electromagnetic fields up to 300 GHz. Basic physical knowledge and the current thresholds are demonstrated. Different frequency ranges of electromagnetic fields, their natural and technical origins and the different biological effects, especially possible hazards such as cancerogenity or risks for the brain, are discussed. Open questions and future research aspects are demonstrated. Finally electrosensibility and psychological aspects are shown.