Functional connectivity and topology in patients with restless legs syndrome: a case-control resting-state functional magnetic resonance imaging study.

BACKGROUND AND PURPOSE: Functional connectivity studies revealed alterations within thalamic, salience, and default mode networks in restless legs syndrome patients. METHODS: Eighty-two patients with restless legs syndrome (untreated, n = 30; on dopaminergic medication, n = 42; on alpha-2-delta ligands as mono- or polytherapy combined with dopaminergic medication, n = 10), and 82 individually age- and gender-matched healthy controls were studied with resting-state functional magnetic resonance imaging. Connectivity of 12 resting-state networks was investigated with independent component analysis, and network topology was studied with graph methods among 410 brain regions. RESULTS: Patients with restless legs syndrome showed significantly higher connectivity within salience (p = 0.029), executive (p = 0.001), and cerebellar (p = 0.041) networks, as well as significantly lower (p < 0.05) cerebello-frontal communication compared to controls. In addition, they had a significantly higher (p < 0.05) clustering coefficient and local efficiency in motor and frontal regions; lower clustering coefficient in the central sulcus; and lower local efficiency in the central opercular cortex, temporal, parieto-occipital, cuneus, and occipital regions compared to controls. Untreated patients had significantly lower (p < 0.05) cerebello-parietal communication compared to healthy controls. Connectivity between the thalamus and frontal regions was significantly increased (p < 0.05) in patients on dopaminergic medication compared to untreated patients and controls. CONCLUSIONS: Networks with higher intranetwork connectivity (i.e., salience, executive, cerebellar) and lower cerebello-frontal connectivity in the restless legs syndrome patients, as well as lower cerebello-parietal connectivity in untreated patients, correspond to regions associated with attention, response inhibitory control, and processing of sensory information. Intact cerebello-parietal communication and increased thalamic connectivity to the prefrontal regions in patients on dopaminergic medication suggests a treatment effect on thalamus.

Standard procedures for the diagnostic pathway of sleep-related epilepsies and comorbid sleep disorders: an EAN, ESRS and ILAE-Europe consensus review.

BACKGROUND AND PURPOSE: Some epilepsy syndromes (sleep-related epilepsies, SREs) have a strong link with sleep. Comorbid sleep disorders are common in patients with SRE and can exert a negative impact on seizure control and quality of life. Our purpose was to define the standard procedures for the diagnostic pathway of patients with possible SRE (scenario 1) and the general management of patients with SRE and comorbidity with sleep disorders (scenario 2). METHODS: The project was conducted under the auspices of the European Academy of Neurology, the European Sleep Research Society and the International League Against Epilepsy Europe. The framework entailed the following phases: conception of the clinical scenarios; literature review; statements regarding the standard procedures. For the literature search a stepwise approach starting from systematic reviews to primary studies was applied. Published studies were identified from the National Library of Medicine's MEDLINE database and Cochrane Library. RESULTS: Scenario 1: Despite a low quality of evidence, recommendations on anamnestic evaluation and tools for capturing the event at home or in the laboratory are provided for specific SREs. Scenario 2: Early diagnosis and treatment of sleep disorders (especially respiratory disorders) in patients with SRE are likely to be beneficial for seizure control. CONCLUSIONS: Definitive procedures for evaluating patients with SRE are lacking. Advice is provided that could be of help for standardizing and improving the diagnostic approach of specific SREs. The importance of identifying and treating specific sleep disorders for the management and outcome of patients with SRE is underlined.

Objective rest-activity cycle analysis by actigraphy identifies isolated rapid eye movement sleep behavior disorder.

BACKGROUND AND PURPOSE: Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is characterized by abnormal behaviours during REM sleep. Several studies showed that iRBD is a prodromal stage of synucleinopathies. Therefore, identifying iRBD in the general population is of utmost importance. In this study, we explore whether the assessment of rest-activity rhythm features can distinguish patients with iRBD from patients with disorders characterized by other pathological motor activity during sleep and healthy controls. METHODS: Nineteen patients with video-polysomnographic diagnosis of iRBD, 39 patients with other disorders with motor activity during sleep [19 with restless leg syndrome (RLS) and 20 with untreated sleep apnea syndrome (SAS)] and 16 healthy controls underwent 2-week actigraphy and video-polysomnography, and completed REM sleep behavior disorder screening questionnaires. Non-parametric analyses were applied to assess the rest-activity rhythm features. RESULTS: Patients with iRBD showed lower sleep efficiency, increased estimated wake after sleep onset and increased frequency of prolonged activity bouts compared to those with RLS and controls, while no difference emerged compared with SAS patients. Moreover, patients with iRBD presented increased occurrence of estimated nap in comparison to those with RLS, those with SAS and controls. The I < O, a 24-h measure that expresses the relationship between nocturnal and diurnal motor activity intensity, distinguished patients with iRBD from those with RLS, those with SAS and controls, with an area under the curve greater than that of REM sleep behavior disorder screening questionnaires. An I < O of 98.32 shows the best balance between sensitivity (63.2%) and specificity (89.1%). DISCUSSION: The I < O index distinguished iRBD patients from those with other pathological motor activity during sleep and controls, confirming its use as an objective measure suitable to screen large at-risk populations.

[Frequent neurological diseases associated with the restless legs syndrome]. / Häufige neurologische Erkrankungen assoziiert mit dem Restless-legs-Syndrom.

BACKGROUND: Restless legs syndrome (RLS) is a common neurological disease. Studies have shown that RLS is associated with a variety of medical and neurological disorders. OBJECTIVES: Using the example of three associated neurological diseases, the significance for everyday therapy decisions is assessed. MATERIAL AND METHODS: A systematic search was carried out in PubMed for all studies with the keyword "RLS" in combination with polyneuropathies (PNP), Parkinson's disease (PD) and multiple sclerosis (MS) and classified according to the methodology in high, medium or low study quality. RESULTS: Of 16 studies on RLS and MS, 10 were rated as "high". The high association frequency of RLS in MS between 13.3% and 65.1% (the variability possibly originates from different methods) prevents further statements about the prevalence. Within 30 studies on Parkinson's disease 17 were classified as having a high quality. In patients with Parkinson disease RLS occurs most frequently during therapy and is related to the duration of dopaminergic treatment. In patients with polyneuropathy, only 5 out of 24 studies were classified as being of high quality and an increased RLS prevalence was detected for acquired polyneuropathies with heterogeneous data for hereditary forms. CONCLUSION: There is an increased prevalence of association with RLS for the diseases discussed. This prevalence is possibly determined by the pathophysiology of these disorders. These diseases are possibly characterized by genetic predispositions as well, which can hopefully be classified more accurately in the future.

[Sleep disorders among physicians on shift work]. / Schlafstörungen bei Ärzten im Schichtdienst.

Sleep disorders in physicians who perform shift work can result in increased risks of health problems that negatively impact performance and patient safety. Even those who cope well with shift work are likely to suffer from sleep disorders. The aim of this manuscript is to discuss possible causes, contributing factors and consequences of sleep disorders in physicians and to identify measures that can improve adaptation to shift work and treatment strategies for shift work-associated sleep disorders. The risk factors that influence the development of sleep disorders in physicians are numerous and include genetic factors (15 % of the population), age (> 50 years), undiagnosed sleep apnea,, alcohol abuse as well as multiple stress factors inherent in clinical duties (including shift work), research, teaching and family obligations. Several studies have reported an increased risk for medical errors in sleep-deprived physicians. Shift workers have an increased risk for psychiatric and cardiovascular diseases and shift work may also be a contributing factor to cancer. A relationship has been reported not only with sleep deprivation and changes in food intake but also with diabetes mellitus, obesity, hypertension and coronary heart disease. Nicotine and alcohol consumption are more frequent among shift workers. Increased sickness and accident rates among physicians when commuting (especially after night shifts) have a socioeconomic impact. In order to reduce fatigue and to improve performance, short naps during shiftwork or naps plus caffeine, have been proposed as coping strategies; however, napping during adverse circadian phases is less effective, if not impossible when unable to fall asleep. Bright and blue light supports alertness during a night shift. After shiftwork, direct sunlight exposure to the retina can be avoided by using dark sunglasses or glasses with orange lenses for commuting home. The home environment for daytime sleeping after a night shift should be very dark to allow endogenous melatonin secretion, which is a night signal and supports continuous sleep. Sleep disorders can be treated with timed light exposure, as well as behavioral and environmental strategies to compensate for sleep deprivation. Fatigue due to sleep deprivation can only be systematically treated with sleep.

Prevalence of restless legs syndrome in a Georgian primary healthcare setting: a pilot study.

BACKGROUND: The prevalence of restless legs syndrome (RLS) is approximately 10% in Western Europe, but unknown in Georgia. This pilot study aimed to assess RLS prevalence in a focused Georgian population. METHODS: An RLS epidemiological questionnaire [Allen et al.: Sleep Med 2003;4:101-119] was filled out by patients in five primary healthcare centers in two Georgian cities between March and September 2006. Additionally, questions related to RLS symptom onset, family history, treatment, sleep disturbance and history of iron deficiency were included. RLS diagnosis was based on an expert interview and an epidemiological questionnaire for RLS. RESULTS: The total number of respondents was 115 (75% women/25% men); mean age was 47 years (range 18-85). Thirteen subjects (11.3%) reported RLS symptoms (9 women/4 men); mean age was 52 years (range 32-83). Eleven (85%) had a positive family history of RLS. All subjects had sleep disturbance and none had a history of known iron deficiency. CONCLUSION: The prevalence of RLS in a focused Georgian population is in line with other RLS epidemiologic studies performed in clinical settings. However, the prevalence rate of RLS in a studied group might not be representative for the general Georgian population. Further population-based epidemiological studies are required.

Sleep habits and sleep complaints in Austria: current self-reported data on sleep behaviour, sleep disturbances and their treatment.

OBJECTIVES: To acquire current information on sleep habits, disturbances and treatment options in the adult population of Austria and compare results with previously collected data. MATERIALS AND METHODS: A representative sample of the Austrian population (women: n = 522, men: n = 478). RESULTS: Seventy-five percent reported daily sleep-duration between 6 and 8 h. In 76%, sleep latency was <30 min, 15% described difficulties in sleep maintenance. Longer sleep on weekends was prevalent in 54%, 23% took a nap. Concerning sleep environment, 31% reported sleeping alone; the rest had a constant or occasional bed partner. Sleep disturbances such as sleep disruption or prolonged sleep latency were reported by 18%. Predominant symptoms included snoring/apneas (22%), nightmares (22%) and restless legs (21%). Daytime tiredness was reported by 17% and sleepiness by 20%. Twenty-four percent did not take treatment. Only 7% asked for medical help: 96% consulted their physician; 47% tried to change their way of living. Sleep promoting drugs were taken by 7%. Sleep improving measures were: sleep promoters (45%), general measures (20%), consultation of general practitioner (20%), psychotherapy (6%), and technical tools (3%). Comparison with a dataset of 1993 revealed only a slight increase in short sleepers and a slight decrease in long sleepers. CONCLUSIONS: Subjectively reported sleep disorders proved to be relatively stable between 1993 and 2007.

Replication of restless legs syndrome loci in three European populations.

BACKGROUND: Restless legs syndrome (RLS) is associated with common variants in three intronic and intergenic regions in MEIS1, BTBD9, and MAP2K5/LBXCOR1 on chromosomes 2p, 6p and 15q. METHODS: Our study investigated these variants in 649 RLS patients and 1230 controls from the Czech Republic (290 cases and 450 controls), Austria (269 cases and 611 controls) and Finland (90 cases and 169 controls). Ten single nucleotide polymorphisms (SNPs) within the three genomic regions were selected according to the results of previous genome-wide scans. Samples were genotyped using Sequenom platforms. RESULTS: We replicated associations for all loci in the combined samples set (rs2300478 in MEIS1, p = 1.26 x 10(-5), odds ratio (OR) = 1.47, rs3923809 in BTBD9, p = 4.11 x 10(-5), OR = 1.58 and rs6494696 in MAP2K5/LBXCOR1, p = 0.04764, OR = 1.27). Analysing only familial cases against all controls, all three loci were significantly associated. Using sporadic cases only, we could confirm the association only with BTBD9. CONCLUSION: Our study shows that variants in these three loci confer consistent disease risks in patients of European descent. Among the known loci, BTBD9 seems to be the most consistent in its effect on RLS across populations and is also most independent of familial clustering.

Neuroethological approach to frontolimbic epileptic seizures and parasomnias: The same central pattern generators for the same behaviours.

The aim of this report is not to make a differential diagnosis between epileptic nocturnal seizures and non-epileptic sleep-related movement disorders, or parasomnias. On the contrary, our goal is to emphasize the commonly shared semiological features of some epileptic seizures and parasomnias. Such similar features might be explained by the activation of the same neuronal networks (so-called 'central pattern generators' or CPG). These produce the stereotypical rhythmic motor sequences - in other words, behaviours - that are adaptive and species-specific (such as eating/alimentary, attractive/aversive, locomotor and nesting habits). CPG are located at the subcortical level (mainly in the brain stem and spinal cord) and, in humans, are under the control of the phylogenetically more recent neomammalian neocortical structures, according to a simplified Jacksonian model. Based on video-polygraphic recordings of sleep-related epileptic seizures and non-epileptic events (parasomnias), we have documented how a transient "neomammalian brain" dysfunction - whether epileptic or not - can 'release' (disinhibition?) the CPG responsible for involuntary motor behaviours. Thus, in both epileptic seizures and parasomnias, we can observe: (a) oroalimentary automatisms, bruxism and biting; (b) ambulatory behaviours, ranging from the classical bimanual-bipedal activity of 'frontal' hypermotor seizures, epileptic and non-epileptic wanderings, and somnambulism to periodic leg movements (PLM), alternating leg muscle activation (ALMA) and restless legs syndrome (RLS); and (c) various sleep-related events such as ictal fear, sleep terrors, nightmares and violent behaviour.

Sleep and sleep disorders in Franz Kafka's narrative works.

OBJECTIVE: As Franz Kafka, one of the most important writers of the 20th century, suffered from severe chronic insomnia disorder and inadequate sleep hygiene that impaired his quality of life, we speculated that sleep disorders would be found in his narrative works. METHODS: We read Kafka's complete literary works looking for references to sleep and sleep disorders, excluding insomnia. RESULTS: In Kafka's works, sleeping well and for a long time was used as an allegory of having a pleasant life. We found that some of his characters were disturbed by excessive daytime sleepiness and sleep attacks, circadian rhythm sleep-wake disorders, sleep-related hallucinations, sleep symptoms in the context of heart failure and abnormal sleep behaviors (eg, sleep-talking, sleep-crying, sleep-laughing and dream-enacting motor manifestations). Kafka also recalled a dream where bruxism occurred. CONCLUSION: Kafka's narrative works contain characters suffering from a wide variety of sleep disorders which in some cases represent autobiographical elements but not in others indicating that he was an astute observer of people, sleep and its disorders. The inclusion of characters suffering from sleep disorders was used by Kafka as a literary resource to enrich his texts.

Basic clinical features do not predict dopamine transporter binding in idiopathic REM behavior disorder.

REM sleep behavior disorder (RBD) is strongly associated with development of Parkinson's Disease and other α-synuclein-related disorders. Dopamine transporter (DAT) binding deficit predicts conversion to α-synuclein-related disorders in individuals with RBD. In turn, identifying which individuals with RBD have the highest likelihood of having abnormal DAT binding would be useful. The objective of this analysis was to examine if there are basic clinical predictors of DAT deficit in RBD. Participants referred for inclusion in the RBD cohort of the Parkinson Progression Markers Initiative were included. Assessments at the screening visit including DAT SPECT imaging, physical examination, cognitive function screen, and questionnaire-based non-motor assessment. The group with DAT binding deficit (n = 49) was compared to those without (n = 26). There were no significant differences in demographic or clinical features between the two groups. When recruiting RBD cohorts enriched for high risk of neurodegenerative disorders, our data support the need for objective biomarker assessments.

The insomnia of Franz Kafka.

OBJECTIVE: To characterize the insomnia suffered by Franz Kafka (1883-1924), one of the most important literary figures of the 20th century. METHODS: We read Kafka's diaries and private correspondence to his fiancée, friends, editors and relatives looking for references to his insomnia. RESULTS: We found 292 references to insomnia indicating that Kafka suffered from chronic insomnia disorder that originated from and was maintained by the following predisposing and precipitating factors: (1) a complex personality predisposing to an increased arousal level, (2) intrusive thoughts and ruminations at bedtime, (3) excessive worrying about sleep loss and its daytime consequences, and (4) an extraordinary intolerance to noise. Since he could not sleep at night and felt the necessity to compose his literary works in an absolutely quiet environment, Kafka deliberately changed his sleep-wake schedule so he could write at night and nap in the afternoon. These maladaptive sleep habits perpetuated his insomnia and led to chronic sleep deprivation resulting in fatigue, lack of concentration and sleep-related auditory, tactile and visual hallucinations. Kafka sought help in alternative medicine however this was ineffective in improving his insomnia. CONCLUSIONS: Kafka suffered from chronic insomnia disorder and had inadequate sleep hygiene resulting in chronic sleep deprivation. These sleep problems impaired Kafka's quality of life.

World Association of Sleep Medicine (WASM) 2016 standards for recording and scoring leg movements in polysomnograms developed by a joint task force from the International and the European Restless Legs Syndrome Study Groups (IRLSSG and EURLSSG).

This report presents the results of the work by a joint task force of the International and European Restless Legs Syndrome Study Groups and World Association of Sleep Medicine that revised and updated the current standards for recording and scoring leg movements (LM) in polysomnographic recordings (PSG). First, the background of the decisions made and the explanations of the new rules are reported and then specific standard rules are presented for recording, detecting, scoring and reporting LM activity in PSG. Each standard rule has been classified with a level of evidence. At the end of the paper, Appendix 1 provides algorithms to aid implementation of these new standards in software tools. There are two main changes introduced by these new rules: 1) Candidate LM (CLM), are any monolateral LM 0.5-10 s long or bilateral LM 0.5-15 s long; 2) periodic LM (PLM) are now defined by runs of at least four consecutive CLM with an intermovement interval ≥10 and ≤ 90 s without any CLM preceded by an interval <10 s interrupting the PLM series. There are also new options defining CLM associated with respiratory events. The PLM rate may now first be determined for all CLM not excluding any related to respiration (providing a consistent number across studies regardless of the rules used to define association with respiration) and, subsequently, the PLM rate should also be calculated without considering the respiratory related events. Finally, special considerations for pediatric studies are provided. The expert visual scoringof LM has only been altered by the new standards to require accepting all LM > 0.5 s regardless of duration, otherwise the technician scores the LM as for the old standards. There is a new criterion for the morphology of LM that applies only to computerized LM detection to better match expert visual detection. Available automatic scoring programs will incorporate all the new rules so that the new standards should reduce technician burden for scoring PLMS.

Parkinson's Disease Genetic Loci in Rapid Eye Movement Sleep Behavior Disorder.

Rapid eye movement (REM) sleep behavior disorder (RBD) is a prodromal condition for Parkinson's disease (PD) and other synucleinopathies, which often occurs many years before the onset of PD. We analyzed 261 RBD patients and 379 controls for nine PD-associated SNPs and examined their effects, first upon on RBD risk and second, on eventual progression to synucleinopathies in a prospective follow-up in a subset of patients. The SCARB2 rs6812193 (OR = 0.67, 95 % CI = 0.51-0.88, p = 0.004) and the MAPT rs12185268 (OR-0.43, 95 % CI-0.26-0.72, p = 0.001) were associated with RBD in different models. Kaplan-Meier survival analysis in a subset of RBD patients (n = 56), demonstrated that homozygous carriers of the USP25 rs2823357 SNP had progressed to synucleinopathies faster than others (log-rank p = 0.003, Breslow p = 0.005, Tarone-Ware p = 0.004). As a proof-of-concept study, these results suggest that RBD may be associated with at least a subset of PD-associated genes, and demonstrate that combining genetic and prodromal clinical data may help identifying individuals that are either more or less susceptible to develop synucleinopathies. More studies are necessary to replicate these results, and identify more genetic factors affecting progression from RBD to synucleinopathies.

Transient restless legs syndrome after spinal anesthesia: a prospective study.

OBJECTIVE: To assess the incidence and time course of new-onset restless legs syndrome (RLS) after spinal anesthesia. METHODS: A total of 202 consecutive patients undergoing spinal anesthesia for various types of surgery were prospectively evaluated regarding the presence and severity of RLS symptoms 48 to 72 hours post surgery and after 1 week, 1 month, 3 months, and 6 months. A diagnosis of RLS was made according to the criteria of the International RLS Study Group (IRLSSG), and severity was assessed by the IRLSSG severity scale. RESULTS: Of 161 patients without any history of RLS, 8.7% developed first-onset RLS after spinal anesthesia. Symptoms were transient, with a mean duration of 33 +/- 30 days. Low mean corpuscular volume and mean corpuscular hemoglobin were associated with the occurrence of new-onset RLS after spinal anesthesia. CONCLUSIONS: Transient RLS can be induced by spinal anesthesia. The mechanisms by which spinal anesthesia can trigger RLS are unclear but may include deficits in spinal sensorimotor integration in susceptible individuals.

A clinical, pharmacologic, and polysomnographic study of sleep benefit in Parkinson's disease.

We assessed the effect of sleep benefit on motor performance in Parkinson's disease (PD) and analyzed its relation to pharmacologic and sleep measures. The sleep benefit phenomenon-motor improvement after sleep before drug intake-in patients with PD has been addressed by questionnaire studies, but objective data are scarce. Ten PD patients with sleep benefit were pairwisely matched to 10 PD patients without sleep benefit for gender, age, PD symptom duration, and medications. We examined motor performance at night before sleep, during morning baseline state immediately after spontaneous awakening, and continuously after intake of the usual levodopa dose. Plasma levodopa concentrations were measured serially and all-night polysomnography was performed. Between night and morning evaluations, motor state improved slightly in patients with sleep benefit and deteriorated slightly in patients without sleep benefit. The difference between both groups proved to be significant. After levodopa induced "on" state, patients with sleep benefit had more severe interdose "off" than those without. Levodopa concentrations and polysomnographic findings were similar in both conditions, although there was a trend toward more abnormal sleep measures in sleep benefit patients. Sleep benefit is a small but significant phenomenon. It does not clearly relate to a specific sleep variable; however, patients with sleep benefit showed a different response profile to levodopa. Subjective perception or possibly sensory mechanisms could play an additional role in sleep benefit in PD.

Modafinil for the treatment of daytime sleepiness in Parkinson's disease: a double-blind, randomized, crossover, placebo-controlled polygraphic trial.

OBJECTIVES: To assess the therapeutic efficacy of modafinil in the treatment of increased daytime sleepiness in patients with Parkinson's disease (PD). DESIGN: Double-blind, randomized, placebo-controlled crossover study with two 2-week treatment blocks, separated by a 2-week washout phase. SETTING: Tertiary Parkinson's disease care center and sleep laboratory at university hospital neurology department. PATIENTS: Fifteen patients with idiopathic PD and daytime sleepiness (Epworth sleepiness score (ESS) 10 or more). INTERVENTIONS: Administration of placebo or modafinil as a single morning dose in a randomized crossover order. The modafinil dose was 100 mg in the first, and 200 mg in the second treatment week. MEASUREMENTS AND RESULTS: At baseline and at the end of each treatment block, sleepiness was evaluated using subjective (perceived sleepiness with the ESS) and objective measures (maintenance of wakefulness test). Twelve patients completed the study (9 male, 3 female; mean age 65.0 +/- 7.6 years, mean disease duration 6.8 +/- 4.1 years). Epworth scores were significantly improved with modafinil (3.42 +/- 3.90) compared to placebo (0.83 +/- 1.99; p = 0.011). Latency to sleep in the maintenance of wakefulness test was not significantly altered by modafinil treatment: 10.9 (3-40)/15.1 (2.5-40) minutes before/after placebo and 12 (2.6-40)/17.8 (4.2-40) minutes before/after modafinil (p = 0.139) [data given as mean +/- standard deviation or median (range)]. CONCLUSIONS: The results of this study suggest that modafinil improves daytime sleepiness in PD patients, at least on a subjective or behavioral level. Modafinil treatment may be considered for EDS in PD patients, in whom otherwise treatable causes of Excessive Daytime Sleepiness (EDS) are absent.

A comparison of the prognostic value of neuron-specific enolase serum levels and somatosensory evoked potentials in 13 reanimated patients.

Thirteen patients resuscitated after circulatory arrest due to cardiopulmonary aetiologies were studied with regard to survival and outcome. Exclusion criteria were known central nervous system disorders or death secondary to cerebrovascular accident. The serum level of neuron-specific enolase (NSE), presumably a reliable marker of neuronal death, was measured by enzyme immunoassay in peripheral blood samples over the course of 4 days at 12 h intervals. On the first and third day post-resuscitation, median nerve somatosensory evoked potentials (SSEPs) were recorded and evaluated for the absence of the cortical potential--presently the standard approach for assessing prognosis in terms of post-resuscitation hypoxaemic brain damage. Absent cortical potentials were found in six patients with NSE levels above 140 micrograms l-1. Five of these patients died; one patient survived with loss of cortical functioning. Five patients had normal SSEP findings, and their NSE maximum levels were below 25 micrograms l-1. All five patients survived without neurological deficits. One patient with a peak NSE level of 36 micrograms l-1 on the second day developed a prolonged delirium (according to DSM III-R criteria) and one patient with a peak level of 76 micrograms l-1 on the fourth day developed an acute respiratory distress syndrome; both patients had preserved cortical potentials. In conclusion, pathological SSEPs and increased NSE levels are of comparable prognostic value. They may well be complementary investigations. The neuron-bound enzyme NSE is a biochemical marker which varies with the extent of neuronal damage, while absence of the cortical potentials may indicate neurophysiological loss of function.

[Excessive daytime sleepiness: etiology, differential diagnosis and diagnostic procedures]. / Exzessive Tagesschläfrigkeit: Ursachen, Differentialdiagnosen und Untersuchungsmethoden.

This article gives an overview on frequent causes of excessive daytime sleepiness in clinical practice. Specifically, the insufficient sleep syndrome, sleep disordered breathing, narcolepsy, restless legs syndrome/periodic limb movements in sleep, and circadian disorders causing daytime sleepiness are discussed. Other possible causes including symptomatic daytime sleepiness associated with various medical conditions are mentioned. Different methods to determine daytime sleepiness are discussed in the final section.

Polysomnographic measures in Parkinson's disease: a comparison between patients with and without REM sleep disturbances.

STUDY OBJECTIVE: To assess the frequency of rapid eye movement (REM) sleep abnormalities in Parkinson's disease (PD) patients and compare polygraphic sleep measures in those with and without REM sleep disturbances. DESIGN: Polysomnographic recordings of 2 consecutive nights were performed in 45 patients with PD (mean age 65 years, mean Hoehn and Yahr stage 2.2). Twenty patients were treated with dopaminergic drugs, 10 were drug-free for two weeks and 15 had never been treated with L-dopa or dopamine agonists. According to the polysomnographic findings, the patients were divided into those with and without REM sleep abnormalities. Abnormal REM sleep features were defined as REM sleep without atonia (RWA) and REM sleep behavior disorder (RBD). RESULTS: Eighteen (40%) of the PD patients showed either RWA (24%; 6 men, 5 women) or RBD (16%; 6 men, 1 woman). Patients with REM sleep disturbances had a significantly longer duration of the disease (8.3 vs. 3.9 years), a more severe stage of the disease (2.6 vs. 2.0 Hoehn and Yahr stage) and were treated with a higher dosage of dopaminergic drugs (L-dopa, pergolide and bromocriptin). 67% of the patients with normal REM sleep were untreated at the time of the sleep study, but only 39% of those with REM sleep abnormalities. Sleep EEG measures (sleep efficiency, sleep onset latency, sleep period time, relative amounts of sleep stages) for the second night showed no significant differences between both groups apart from a significantly lower sleep period time in PD patients with RWA/RBD. CONCLUSIONS: Abnormal REM sleep features are a frequent finding in patients with PD. The prevalence seems to increase with a longer disease duration. Therefore, a careful follow-up is necessary. A sleep architecture not different from PD patients without RWA/RBD suggests that the underlying abnormality is confined to REM sleep.