Procedural memory consolidation is associated with heart rate variability and sleep spindles.

Sleep and memory studies often focus on overnight rather than long-term memory changes, traditionally associating overnight memory change (OMC) with sleep architecture and sleep patterns such as spindles. In addition, (para-)sympathetic innervation has been associated with OMC after a daytime nap using heart rate variability (HRV). In this study we investigated overnight and long-term performance changes for procedural memory and evaluated associations with sleep architecture, spindle activity (SpA) and HRV measures (R-R interval [RRI], standard deviation of R-R intervals [SDNN], as well as spectral power for low [LF] and high frequencies [HF]). All participants (N = 20, Mage  = 23.40 ± 2.78 years) were trained on a mirror-tracing task and completed a control (normal vision) and learning (mirrored vision) condition. Performance was evaluated after training (R1), after a full-night sleep (R2) and 7 days thereafter (R3). Overnight changes (R2-R1) indicated significantly higher accuracy after sleep, whereas a significant long-term (R3-R2) improvement was only observed for tracing speed. Sleep architecture measures were not associated with OMC after correcting for multiple comparisons. However, individual SpA change from the control to the learning night indicated that only "SpA enhancers" exhibited overnight improvements for accuracy and long-term improvements for speed. HRV analyses revealed that lower SDNN and LF power was associated with better OMC for the procedural speed measure. Altogether, this study indicates that overnight improvement for procedural memory is specific for spindle enhancers, and is associated with HRV during sleep following procedural learning.

Guidelines for the recording and evaluation of pharmaco-sleep studies in man: the International Pharmaco-EEG Society (IPEG).

The International Pharmaco-EEG Society (IPEG) presents guidelines summarising the requirements for the recording and computerised evaluation of pharmaco-sleep data in man. Over the past years, technical and data-processing methods have advanced steadily, thus enhancing data quality and expanding the palette of sleep assessment tools that can be used to investigate the activity of drugs on the central nervous system (CNS), determine the time course of effects and pharmacodynamic properties of novel therapeutics, hence enabling the study of the pharmacokinetic/pharmacodynamic relationship, and evaluate the CNS penetration or toxicity of compounds. However, despite the presence of robust guidelines on the scoring of polysomnography -recordings, a review of the literature reveals inconsistent -aspects in the operating procedures from one study to another. While this fact does not invalidate results, the lack of standardisation constitutes a regrettable shortcoming, especially in the context of drug development programmes. The present guidelines are intended to assist investigators, who are using pharmaco-sleep measures in clinical research, in an effort to provide clear and concise recommendations and thereby to standardise methodology and facilitate comparability of data across laboratories.

Recent advances in sleep research.

The past two decades have witnessed substantial progress in methodology and knowledge in sleep research all over the world. The paper at hand will present some recent local contributions to this field. The first is a European project (SIESTA) focusing on the creation of an automatic sleep classification system and a normative database, including polysomnographic (PSG) and psychometric measures, in order to make it possible to diagnose sleep-disordered patients as compared with and age- and sex-matched healthy controls between 20 and 95 years of age. Subsequently, two trials on nonorganic sleep disorders in generalized anxiety disorder (GAD) and bruxism, as well as two trials on organic sleep disorders, i.e. snoring/sleep-disordered breathing treated with a mandibular advancement device (I.S.T.) and restless legs syndrome treated with ropinirole and gabapentin, will be discussed.

[Sleep disorders in psychiatry and their treatment]. / Schlafstörungen In Der Psychiatrieund Therapeutische Maßnahmen.

Sleep disturbances are frequent and multifaceted and have serious consequences. They play an important role within psychiatric symptoms and disorders. On the one hand they may appear as a symptom of a disorder, which may also be a diagnostic criterion, as for example in affective disorders, on the other hand they may be independent disorders or last but not least sequelae of psychiatric disorders or their pharmacological therapy, as with antidepressants or neuroleptics, which may cause or deteriorate nocturnal movement disorders. They may aggravate psychiatric disorders, perpetuate them or predict a disease onset, like in depressive or manic episodes. Also in organic sleep disorders, such as sleep-related breathing disorders or nocturnal movement disorders, increased anxiety or depression scores may be observed. Patients suffering from sleep disorders do not only experience impaired well-being, but also show deteriorations in cognition and performance, have a higher risk of accidents, are generally more prone to health problems, have a higher sickness absence rate, seek medical help more often and thus are also an important socioeconomic factor. This is why sleep disorders should be taken seriously and treated adequately.

Dysfunctional pain modulation in somatoform pain disorder patients.

To date, pain perception is thought to be a creative process of modulation carried out by an interplay of pro- and anti-nociceptive mechanisms. Recent research demonstrates that pain experience constitutes the result of top-down processes represented in cortical descending pain modulation. Cortical, mainly medial and frontal areas, as well as subcortical structures such as the brain stem, medulla and thalamus seem to be key players in pain modulation. An imbalance of pro- and anti-nociceptive mechanisms are assumed to cause chronic pain disorders, which are associated with spontaneous pain perception without physiologic scaffolding or exaggerated cortical activation in response to pain exposure. In contrast to recent investigations, the aim of the present study was to elucidate cortical activation of somatoform pain disorder patients during baseline condition. Scalp EEG, quantitative Fourier-spectral analyses and LORETA were employed to compare patient group (N = 15) to age- and sex-matched controls (N = 15) at rest. SI, SII, ACC, SMA, PFC, PPC, insular, amygdale and hippocampus displayed significant spectral power reductions within the beta band range (12-30 Hz). These results suggest decreased cortical baseline arousal in somatoform pain disorder patients. We finally conclude that obtained results may point to an altered baseline activity, maybe characteristic for chronic somatoform pain disorder.

Comparative EEG mapping studies in Huntington's disease patients and controls.

Huntington's disease (HD) is a devastating neurodegenerative disorder with prominent motor and cognitive decline. Previous studies with small sample sizes and methodological limitations have described abnormal electroencephalograms (EEG) in this cohort. The aim of the present study was to investigate objectively and quantitatively the neurophysiological basis of the disease in HD patients as compared to normal controls, utilizing EEG mapping. In 55 HD patients and 55 healthy controls, a 3-min vigilance-controlled EEG (V-EEG) was recorded during midmorning hours. Evaluation of 36 EEG variables was carried out by spectral analysis and visualized by EEG mapping techniques. To elucidate drug interference, the analysis was performed for the total group, unmedicated patients only and between treated and untreated patients. Statistical overall analysis by the omnibus significance test demonstrated significant (p < 0.01 and p < 0.05) EEG differences between HD patients and controls. Subsequent univariate analysis revealed a general decrease in total power and absolute alpha and beta power, an increase in delta/theta power, and a slowing of the centroids of delta/theta, beta and total power. The slowing of the EEG in HD reflects a disturbed brain function in the sense of a vigilance decrement, electrophysiologically characterized by inhibited cortical areas (increased delta/theta power) and a lack of normal routine and excitatory activity (decreased alpha and beta power). The results are similar to those found in other dementing disorders. Medication did not affect the overall interpretation of the quantitative EEG analysis, but certain differences might be due to drug interaction, predominantly with antipsychotics. Spearman rank correlations revealed significant correlations between EEG mapping and cognitive and motor impairment in HD patients.

Comparative placebo-controlled polysomnographic and psychometric studies on the acute effects of gabapentin versus ropinirole in restless legs syndrome.

The aim of the present placebo-controlled sleep laboratory study was to compare the acute effects of gabapentin (GBT) and ropinirole (ROP) in restless legs syndrome (RLS). In a parallel-group design, 40 RLS patients received 300 mg GBT and another 40 patients 0.5 mg ROP as compared with placebo. Polysomnographic and psychometric measures were obtained in three sleep laboratory nights (screening/placebo/drug). Statistics included a Wilcoxon test for differences between drug and placebo and a U test for inter-group differences. Sleep efficiency and latency were found significantly improved after GBT, while they remained unchanged after ROP, with significant inter-drug differences. Sleep architecture showed oppositional changes after the two drugs: While GBT decreased S1, increased slow-wave sleep and SREM and shortened REM latency, ROP increased S2, decreased slow-wave sleep and SREM and increased REM latency. Periodic leg movements (PLM) showed a significantly greater decrease after ROP (-73%) than after GBT (-35%). Subjective sleep quality improved significantly only after GBT; mental performance improved after both drugs with no inter-drug differences. In conclusion, the dopamine agonist ROP showed acute therapeutic efficacy with regard to PLM measures only, whereas GBT had a less pronounced effect on these measures, but improved objective and subjective sleep and awakening quality as compared with both placebo and ROP. Differential acute drug effects may serve as prognostic indicators of therapeutic response of individual patients.

Computer-assisted sleep classification according to the standard of the American Academy of Sleep Medicine: validation study of the AASM version of the Somnolyzer 24 × 7.

BACKGROUND: In 2007, the AASM Manual for the Scoring of Sleep and Associated Events was published by the American Academy of Sleep Medicine (AASM). Concerning the visual classification of sleep stages, these new rules are intended to replace the rules by Rechtschaffen and Kales (R&K). METHODS: We adapted the automatic R&K sleep scoring system Somnolyzer 24 × 7 to comply with the AASM rules and subsequently performed a validation study based on 72 polysomnographies from the Siesta database (56 healthy subjects, 16 patients, 38 females, 34 males, aged 21-86 years). Scorings according to the AASM rules were performed manually by experienced sleep scorers and semi-automatically by the AASM version of the Somnolyzer. Manual scorings and Somnolyzer reviews were performed independently by at least 2 out of 8 experts from 4 sleep centers. RESULTS: In the quality control process, sleep experts corrected 4.8 and 3.7% of the automatically assigned epochs, resulting in a reliability between 2 Somnolyzer-assisted scorings of 99% (Cohen's kappa: 0.99). In contrast, the reliability between the 2 manual scorings was 82% (kappa: 0.76). The agreement between the 2 Somnolyzer-assisted and the 2 visual scorings was between 81% (kappa: 0.75) and 82% (kappa: 0.76). CONCLUSION: The AASM version of the Somnolyzer revealed an agreement between semi-automated and human expert scoring comparable to that published for the R&K version with a validity comparable to that of human experts, but with a reliability close to 1, thereby reducing interrater variability as well as scoring time to a minimum.

Controlled clinical, polysomnographic and psychometric studies on differences between sleep bruxers and controls and acute effects of clonazepam as compared with placebo.

The pathogenesis, pathophysiology, and pharmacotherapy of sleep bruxism (SB) are still not fully understood. We investigated symptomatology, objective and subjective sleep and awakening quality of middle-aged bruxers compared with controls and acute effects of clonazepam 1 mg compared with placebo by polysomnography and psychometry. Twenty-one drug-free bruxers spent 3 nights in the sleep lab, 21 age- and sex-matched controls 2 nights. Clinically, bruxers exhibited deteriorated PSQI, SAS, SDS and IRLSSG measures, polysomnographically impaired sleep maintenance, increased movement time, stage shift index, periodic leg movements (PLM) and arousals and psychometrically deteriorated subjective sleep and awakening quality, evening/morning well-being, drive, mood, drowsiness, attention variability, memory, and fine motor activity. As compared with placebo, clonazepam significantly decreased the SB index in all patients (mean: -42 +/- 15%). Sleep efficiency, maintenance, latency, awakenings and nocturnal wake time, the stage shift index, S1, PLM, the arousal index, subjective sleep and awakening quality, and fine motor activity improved.

Cognitions in Sleep: Lucid Dreaming as an Intervention for Nightmares in Patients With Posttraumatic Stress Disorder.

About 80% of posttraumatic stress disorder (PTSD) patients suffer from nightmares or dysphoric dreams that cause major distress and impact nighttime or daytime functioning. Lucid dreaming (LD) is a learnable and effective strategy to cope with nightmares and has positive effects on other sleep variables. In LDs, the dreamer is aware of the dreaming state and able to control the dream content. The aim of this study is to evaluate the effectiveness of lucid dreaming therapy (LDT) in patients suffering from PTSD. We suggest that learning a technique that enables the affected subjects to regulate the occurrence and content of nightmares autonomously increases the chance of coping with the complex symptoms of PTSD and can reduce suffering. Sleep quality (PSQI, Pittsburgh Sleep Quality Index), daytime sleepiness (ESS, Epworth Sleepiness Scale), quality of life (MQLI, Multicultural Quality of Life Index), psychological distress (SCL-90-R, Symptom Checklist 90-Revised), distress caused by traumatic events (IE-S, Impact of Events Scale), anxiety (SAS, Self-Rating Anxiety Scale), depression (SDS, Self-Rating Depression Scale), and nightmare severity were assessed in a self-rating questionnaire before and after the intervention. LDT had no effect on the investigated sleep variables. No correlation between reduction of nightmare severity and changes in PTSD-profile (IE-S) was found. Nevertheless, levels of anxiety and depression decreased significantly in the course of therapy. LDT could provide an alternate or complementary treatment option for nightmares in PTSD, specifically for symptoms of anxiety and depression.

Reduced Brain Electric Activity and Functional Connectivity in Bipolar Euthymia: An sLORETA Source Localization Study.

Bipolar disorder (BD) is a chronic illness with a relapsing and remitting time course. Relapses are manic or depressive in nature and intermitted by euthymic states. During euthymic states, patients lack the criteria for a manic or depressive diagnosis, but still suffer from impaired cognitive functioning as indicated by difficulties in executive and language-related processing. The present study investigated whether these deficits are reflected by altered intracortical activity in or functional connectivity between brain regions involved in these processes such as the prefrontal and the temporal cortices. Vigilance-controlled resting state EEG of 13 euthymic BD patients and 13 healthy age- and sex-matched controls was analyzed. Head-surface EEG was recomputed into intracortical current density values in 8 frequency bands using standardized low-resolution electromagnetic tomography. Intracortical current densities were averaged in 19 evenly distributed regions of interest (ROIs). Lagged coherences were computed between each pair of ROIs. Source activity and coherence measures between patients and controls were compared (paired t tests). Reductions in temporal cortex activity and in large-scale functional connectivity in patients compared to controls were observed. Activity reductions affected all 8 EEG frequency bands. Functional connectivity reductions affected the delta, theta, alpha-2, beta-2, and gamma band and involved but were not limited to prefrontal and temporal ROIs. The findings show reduced activation of the temporal cortex and reduced coordination between many brain regions in BD euthymia. These activation and connectivity changes may disturb the continuous frontotemporal information flow required for executive and language-related processing, which is impaired in euthymic BD patients.

Sleep classification according to AASM and Rechtschaffen & Kales: effects on sleep scoring parameters.

STUDY OBJECTIVE: To investigate differences between visual sleep scoring according to the classification developed by Rechtschaffen and Kales (R&K, 1968) and scoring based on the new guidelines of the American Academy of Sleep Medicine (AASM, 2007). DESIGN: All-night polysomnographic recordings were scored visually according to the R&K and AASM rules by experienced sleep scorers. Descriptive data analysis was used to compare the resulting sleep parameters. PARTICIPANTS: Healthy subjects and patients (38 females and 34 males) aged between 21 and 86 years. INTERVENTIONS: N/A. MEASUREMENT AND RESULTS: While sleep latency and REM latency, total sleep time, and sleep efficiency were not affected by the classification standard, the time (in minutes and in percent of total sleep time) spent in sleep stage 1 (S1/N1), stage 2 (S2/N2) and slow wave sleep (S3+S4/N3) differed significantly between the R&K and the AASM classification. While light and deep sleep increased (S1 vs. N1 [+10.6 min, (+2.8%)]: P<0.01; S3+S4 vs. N3 [+9.1 min (+2.4%)]: P<0.01), stage 2 sleep decreased significantly according to AASM rules (S2 vs. N2 [-20.5 min, (-4.9%)]: P<0.01). Moreover, wake after sleep onset was significantly prolonged by approximately 4 minutes (P<0.01) according to the AASM standard. Interestingly, the effects on stage REM were age-dependent (intercept at 20 years: -7.5 min; slope: 1.6 min for 10-year age increase). No effects of sex and diagnosis were observed. CONCLUSION: The study shows significant and age-dependent differences between sleep parameters derived from conventional visual sleep scorings on the basis of R&K rules and those based on the new AASM rules. Thus, new normative data have to be established for the AASM standard.

Interrater reliability for sleep scoring according to the Rechtschaffen & Kales and the new AASM standard.

Interrater variability of sleep stage scorings has an essential impact not only on the reading of polysomnographic sleep studies (PSGs) for clinical trials but also on the evaluation of patients' sleep. With the introduction of a new standard for sleep stage scorings (AASM standard) there is a need for studies on interrater reliability (IRR). The SIESTA database resulting from an EU-funded project provides a large number of studies (n = 72; 56 healthy controls and 16 subjects with different sleep disorders, mean age +/- SD: 57.7 +/- 18.7, 34 females) for which scorings according to both standards (AASM and R&K) were done. Differences in IRR were analysed at two levels: (1) based on quantitative sleep parameter by means of intraclass correlations; and (2) based on an epoch-by-epoch comparison by means of Cohen's kappa and Fleiss' kappa. The overall agreement was for the AASM standard 82.0% (Cohen's kappa = 0.76) and for the R&K standard 80.6% (Cohen's kappa = 0.68). Agreements increased from R&K to AASM for all sleep stages, except N2. The results of this study underline that the modification of the scoring rules improve IRR as a result of the integration of occipital, central and frontal leads on the one hand, but decline IRR on the other hand specifically for N2, due to the new rule that cortical arousals with or without concurrent increase in submental electromyogram are critical events for the end of N2.

Double-blind, placebo-controlled, multiple-ascending-dose study on the pharmacodynamics of ABIO-08/01, a new CNS drug with potential anxiolytic activity. 2. EEG-tomography findings based on LORETA (low-resolution brain electromagnetic tomography).

Effects of ABIO-08/01, a new potentially anxiolytic isoxazoline, on regional electrical brain generators were investigated by 3-dimensional EEG tomography. In a double- blind, placebo-controlled, multiple-ascending-dose study, 16 healthy males (30.2 +/- 5.7 years) received 3 oral drug doses (10, 20, 40 mg) and placebo for 7 days (8-day wash-out) in a randomized non-balanced design for phase-1 studies. A 3-min vigilance-controlled (V) EEG, a 4-min resting (R) EEG with eyes closed, a 1-min eyes-open (EO) EEG and psychometric tests were performed 0, 1 and 6 h after taking the drug on days 1 and 5. Low-resolution brain electromagnetic tomography (LORETA) was computed from the spectrally analyzed EEG data, and differences between drug and placebo were displayed as statistical parametric maps. Data were registered to the Talairach-Tournoux Human Brain Atlas available as a digitized MRI. An overall omnibus significance test followed by a voxel-by-voxel t test demonstrated significant regional EEG changes after ABIO-08/01 versus placebo, dependent on recording condition, dose and time. While in the EO-EEG specifically the lowest dose of ABIO-08/01 induced pronounced sedative effects (delta/theta and beta increase) 1 h after acute and slightly less so after superimposed administration, in the 6th hour a decrease in alpha and beta activity signaled less sedative and more relaxant action. In the V-EEG these changes were less pronounced, in the R-EEG partly opposite. Hemisphere-specific changes were observed, suggesting increases in LORETA power over the left temporal, parietal, superior frontal regions and decreases over the right prefrontal, temporal pole and occipital regions. These LORETA changes are discussed in the light of neuroimaging findings on anxiety and anxiolytics.

Double-blind, placebo-controlled, multiple-ascending-dose study on the pharmacodynamics of ABIO-08/01, a new CNS drug with potential anxiolytic activity. 1. EEG mapping, psychometric and tolerability findings.

In a double-blind, placebo-controlled, multiple-ascending-dose study, the encephalotropic and psychotropic properties of ABIO-08/01, a new potentially anxiolytic and nootropic isoxazoline, were studied in 16 young healthy males. In a randomized nonbalanced phase 1 study, they received 3 oral drug doses (10, 20, 40 mg) and placebo for 7 days (washout period 8 days). EEG mapping and psychometry were carried out at hours 0, 1, 6 of day 1 (acute effect) and day 5 (subacute and superimposed effects). MANOVA/ Hotelling T(2) test demonstrated significant central effects of ABIO-08/01 versus placebo after acute, subacute and superimposed administration of all doses in the resting, vigilance-controlled and eyes-open EEG. Univariate analysis revealed activating patterns in the resting EEG (40 mg > 20 mg > 10 mg), and sedative patterns in the eyes-open EEG (10 mg > 20 mg > 40 mg). In the vigilance-controlled EEG, 40 mg of ABIO-08/01 induced activating patterns, whereas 10 mg induced sedative patterns. Concerning psychometry, ABIO-08/01 improved concentration (40 mg > 20 mg > 10 mg; activating effect) and deteriorated well-being (10 mg > 20 mg > 40 mg; sedative effect). Ten milligrams also improved reaction time performance and psychomotor activity. ABIO-08/01 is well-tolerated and is of interest in anxiety disorders.

[The pupillary response test as a method to differentiate various types of dementia]. / Der Rezeptortest bei der Pupillometrie als Methode zur Differenzierung des dementiellen Syndroms.

AIM: Pupillometry is a non-invasive measurement technique based on the pupillary response to specific sensoric, mental and emotional variables. After topical application of a cholinergic antagonist (tropicamide) an increased pupillary dilatation response in Alzheimers s disease patients was described ("receptor test"). The aim of the present study was to evaluate the usefulness of the 0.01% tropicamide receptor test in differentiating types of dementia. METHOD: 425 patients (159 men, 266 women, mean age 75 years) of the Memory Clinic of the SMZ Ost Vienna, Austria were included in the study. 195 patients suffered from a dementia in Alzheimer's disease with late onset (ICD-10: F00.1), 42 from dementia in Alzheimer's disease with early onset (F00.0), 71 from vascular dementia (F01), 34 from Lewy-Body dementia (F03) and 83 from mixed dementia (F00.2). All patients were investigated by means of a computer-assisted pupillometer. The pupillary diameter of the left eye was measured 4 times (baseline=0 minutes, after 20, 40 and 60 minutes). 4 minutes after baseline one drop of 0.01% tropicamide solution was installed onto the left eye of the patients. RESULTS: At baseline the pupillary diameter was largest in Lewy-Body dementia, smallest in vascular dementia. Significant differences were observed between vascular dementia and early-onset dementia in Alzheimer's disease as well as between Lewy-Body dementia and all other dementia syndromes (except dementia in Alzheimer's disease with early onset). The 0.01% tropicamide receptor test made it possible to differentiate early-onset dementia in Alzheimer's disease from vascular and mixed dementia. CONCLUSION: Utilizing pupillometry in combination with the 0.01% tropicamide receptor test allows to discriminate between different dementia types of, as demonstrated in our study.

Proactive telemedicine monitoring of sleep apnea treatment improves adherence in people with stroke- a randomized controlled trial (HOPES study).

OBJECTIVE: Obstructive sleep apnea (OSA) impacts stroke recovery and outcome negatively. Although its identification and treatment are part of the current stroke guidelines, standard management with positive airway pressure (PAP) therapy is not routinely performed and adherence rates are very low. The purpose of this study was to determine whether PAP adherence can be improved by a PAP training strategy during in-hospital rehabilitation combined with a telemedicine monitoring system after discharge. METHODS: In this study, we performed a controlled trial (RCT) on standard PAP treatment (SG) as compared with proactive telemonitored PAP treatment (TG). After three months and one year, PAP adherence (min of use per day) and clinical outcome variables were compared. RESULTS: In 33 (47.1%) out of 70 patients diagnosed with therapy-relevant OSA [70% male, 62 (5) years, body mass index (BMI) 30 (4) kg/m2, Barthel Index 90 (20), NIHSS 3 (3)] in-hospital PAP titration was performed. Subsequently, they were randomized to SG or TG. Drop-out rates after three months and after one year were 12% and 30%, respectively, with no differences between the groups. After three months, telemonitored patients used the PAP device 76 min longer per night (SG: 299 (76), TG: 375 (86) minutes per night; p = 0.017), after one year there was no significant difference. CONCLUSION: People with stroke and therapy-relevant OSA who accept PAP therapy should receive additional telemedicine monitoring at least for three months. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov; Unique identifier: NCT02748681.

Interindividual sleep spindle differences and their relation to learning-related enhancements.

We reported earlier that overnight change in explicit memory is positively related to the change in sleep spindle activity (between a control and a learning night). However, it remained unclear whether this effect was restricted to good memory performers and whether a general association of sleep spindles and a "sleep-related learning trait" may not account for this effect. Here we now present a secondary and more detailed analysis of our randomized multicenter study. Subjects were studied over a 4-week study period (including actigraphy and daily sleep diaries), including three overnight stays in the sleep laboratory. In the course of the study, subjects completed test-batteries of memory (Wechsler-Memory-Scale-revised; WMS) and other cognitive abilities (Raven's Advanced-Progressive-Matrices; APM) and were asked to study 160 word pairs in the evening before being tested by cued-recall. Afterwards, subjects went to bed in the laboratory with full polysomnographic montages. Additionally, subjects participated on another occasion in a non-learning control (perceptual priming) task that was counterbalanced either before or after the learning condition. Slow as well as fast spindle activities were analyzed at frontopolar and central topographies. Although it was found that spindle activity is generally (in learning as well as control nights) elevated in highly gifted subjects, spindle analyses revealed that spindle increase (control to learning night) is specifically related to explicit memory improvement overnight, independent of individual learning traits. Together these findings suggest that the spindle increase after learning is related to elaborate encoding before sleep, whereas an individual's general learning ability is well reflected in interindividual (and trait-like) differences of absolute sleep spindle activity.

Efficacy of rotigotine transdermal system in severe restless legs syndrome: a randomized, double-blind, placebo-controlled, six-week dose-finding trial in Europe.

BACKGROUND: In a pilot placebo-controlled study, low dosages of 0.5-2mg/24h rotigotine showed a dose-dependent beneficial effect in restless legs syndrome (RLS) patients. METHODS: Efficacy and safety of the dopamine agonist rotigotine, formulated as a once-daily transdermal system (patch), was investigated for five fixed dosages and compared to placebo in patients with idiopathic RLS in a double-blind, randomized, parallel-group, multicenter, six-week dose-finding trial. Primary efficacy measure was the total score of the International RLS Severity Scale (IRLS); in addition, the RLS-6 scales and the Clinical Global Impressions (CGI) were administered. RESULTS: Of 371 enrolled patients, 341 patients (mean age 58+/-10years, 67% females) were randomized. The IRLS total score improved between baseline and end of the six-week treatment period by -10.6 (0.5mg/24h rotigotine; patch area 2.5cm2), -15.1 (1mg/24h; 5cm2), -15.7 (2mg/24h; 10cm2), -17.5 (3mg/24h; 15cm2), and -14.8 (4mg/24h, 20cm2) as compared to placebo (-9.2). The hierarchical statistical test procedure demonstrated superiority of rotigotine over placebo for 4mg/24h, 3mg/24h, 2mg/24h, and 1mg/24h, with p-values of 0.0013, <0.0001, 0.0003, and 0.0004, respectively. Only the 0.5mg/24h dose was not different compared to placebo (p=0.2338). The CGI and the RLS-6 severity items supported the efficacy of the rotigotine doses beyond 0.5mg/24h. The most frequent side effects were application site reactions and nausea and tended to be more frequent with higher doses. CONCLUSIONS: This dose-finding trial identified the range for a maintenance dose of rotigotine from 1mg/24h to 3mg/24h. The lowest dose was ineffective and, with the highest dose, no additional benefit was observed.

Event-related-potential low-resolution brain electromagnetic tomography (ERP-LORETA) suggests decreased energetic resources for cognitive processing in narcolepsy.

OBJECTIVE: Event-related potentials (ERPs) are sensitive measures of both perceptual and cognitive processes. The aim of the present study was to identify brain regions involved in the processes of cognitive dysfunction in narcolepsy by means of ERP tomography. METHODS: In 17 drug-free patients with narcolepsy and 17 controls, ERPs were recorded (auditory odd-ball paradigm). Latencies, amplitudes and LORETA sources were determined for standard (N1 and P2) and target (N2 and P300) ERP components. Psychometry included measures of mental performance, affect and critical flicker fusion frequency (CFF). RESULTS: In the ERPs patients demonstrated delayed cognitive N2 and P300 components and reduced amplitudes in midline regions, while N1 and P2 components did not differ from controls. LORETA suggested reduced P300 sources bilaterally in the precuneus, the anterior and posterior cingulate gyri, the ventrolateral prefrontal cortex and the parahippocampal gyrus. In psychometry, patients demonstrated deteriorated mood, increased trait anxiety, decreased CFF and a trend toward reduced general verbal memory and psychomotor activity. CONCLUSIONS: Narcoleptic patients showed prolonged information processing, as indexed by N2 and P300 latencies and decreased energetic resources for cognitive processing. SIGNIFICANCE: Electrophysiological aberrations in brain areas related to the 'executive attention network' and the 'limbic system' may contribute to a deterioration in mental performance and mood at the behavioral level.