Lobar Dementia due to Extreme Widening of Virchow-Robin Spaces in One Hemisphere

Widened perivascular spaces known as Virchow-Robin spaces (VRS) are often seen on MRI and are usually incidental findings. It is unclear if enlarged VRS can be associated with neurological deficits. In this report, we describe a case of lobar dementia associated with unusual VRS widening in one cerebral hemisphere. A 77-year-old woman, seen at a memory clinic, presented with progressive cognitive decline, left hemianopsia, and mild pyramidal signs on the left side. On MRI, unusually wide VRS were visible, predominantly in the right centrum semiovale and the right temporo-occipital white matter. The clinical syndrome was consistent with the extent and location of the abnormally dilated VRS. The high MR signal in white matter bridges between the VRS suggested parenchymal damage, possibly representing gliotic white matter. No evidence for another etiology was found on cerebral MRI and rCBF SPECT. As a conclusion, enlarged VRS in one cerebral hemisphere may be associated with cognitive change and neurological deficits

Individual slow wave morphology is a marker of ageing

Contains fulltext : 206080.pdf (publisher's version ) (Open Access

Diminished nap effects on memory consolidation are seen under oral contraceptive use

Item does not contain fulltextMany young females take exogenous hormones as oral contraceptive (OC), a condition rarely controlled for in studies on sleep and memory consolidation even though sex hormones influence consolidation. This study investigated the effects of OCs on sleep-related consolidation of a motor and declarative task, utilizing a daytime nap protocol. Fifteen healthy, young females taking OCs came to the sleep lab for three different conditions: nap with previous learning, wake with previous learning and nap without learning. They underwent each condition twice, once during the "pill-active" weeks and once during the "pill-free" week, resulting in 6 visits. In all conditions, participants showed a significant off-line consolidation effect, independent of pill week or nap/wake condition. There were no significant differences in sleep stage duration, spindle activity or spectral EEG frequency bands between naps with or without the learning condition. The present data showed a significant off-line enhancement in memory irrespective of potential beneficial effects of a nap. In comparison to previous studies, this may suggest that the use of OCs may enhance off-line memory consolidation in motor and verbal tasks per se. These results stress the importance to control for the use of OCs in studies focusing on memory performance

Medial Prefrontal-Hippocampal Connectivity and Motor Memory Consolidation in Depression and Schizophrenia

Item does not contain fulltextBACKGROUND: Overnight memory consolidation is disturbed in both depression and schizophrenia, creating an ideal situation to investigate the mechanisms underlying sleep-related consolidation and to distinguish disease-specific processes from common elements in their pathophysiology. METHODS: We investigated patients with depression and schizophrenia, as well as healthy control subjects (each n = 16), under a motor memory consolidation protocol with functional magnetic resonance imaging and polysomnography. RESULTS: In a sequential finger-tapping task associated with the degree of hippocampal-prefrontal cortex functional connectivity during the task, significantly less overnight improvement was identified as a common deficit in both patient groups. A task-related overnight decrease in activation of the basal ganglia was observed in control subjects and schizophrenia patients; in contrast, patients with depression showed an increase. During the task, schizophrenia patients, in comparison with control subjects, additionally recruited adjacent cortical areas, which showed a decrease in functional magnetic resonance imaging activation overnight and were related to disease severity. Effective connectivity analyses revealed that the hippocampus was functionally connected to the motor task network, and the cerebellum decoupled from this network overnight. CONCLUSIONS: While both patient groups showed similar deficits in consolidation associated with hippocampal-prefrontal cortex connectivity, other activity patterns more specific for disease pathology differed.10 p

NISAS-2000 - die "Nationwide Insomnia Screening and Awareness Study": Insomnien und Schlafstörungen in der allgemeinärztlichen Versorgung

ZIEL: Ermittlung der Stichtagsprävalenz von Insomnie und anderen Schlafstörungen in deutschen Allgemeinarztpraxen sowie Bestimmung hausärztlicher Erkennensraten. METHODIK: Bundesweite Zufallsauswahl von 539 Arztpraxen. Charakterisierung der Arzt- und Praxismerkmale mittels initialer Vorstudie. Darauf folgend eine Stichtagsbefragung aller Hausarzt-Patienten mittels Schlaffragebogen (PSQI) und klinischen Fragen (N = 19155 Fälle) sowie klinisch-ärztliche Beurteilung durch den behandelnden Artz mittels CGI und Fragebogen. ERGEBNISSE: 1. Trotz nur moderater Kompetenzeinschätzungen hinsichtlich Diagnose und Therapie behandeln Hausärzte Insomnien und andere Schlafstörungen vorwiegend selbst, auch wenn diese einen hohen Behandlungsaufwand erfordern. 2. Die Stichprobe kann als typisch für die Hausarzt-Klientel angesehen werden. 3. Schlafstörungen sind der dritthäufigste Konsultationsanlass. Nahezu jeder zweite Patient berichtete, in den vergangenen 2 Wochen unter Schlafbeschwerden gelitten zu haben, 26,5% erfüllten aufgrund der subjektiven Angaben die Studienkriterien (DSM-IV) für Insomnie. 4. Auch die Ärzte beurteilten 46,4% aller ihrer Patienten mittels CGI zumindest als Grenzfälle einer Schlafstörung, 85,6% wurden als chronisch eingeordnet. Die ärtzlich beurteilte Insomnieprävalenz betrug 25,9%, die anderer Schlafstörungen 13,7%. 5. Nur 54,3% aller Insomniepatienten wurden auch als solche vom Hausarzt diagnostiziert. DISKUSSION: Die Studie liefert erstmals bundesrepräsentative, differenzierte epidemiologische Daten zu der Prävalenz, dem Schweregrad, den Einschränkungen und den Verlaufsmustern von Insomnien und Schlafstörungen. Die außerordentlich große Häufigkeit und die zum Teil markanten Defizite hinsichtlich Erkennen und Diagnostik in der primärärztlichen Versorgungen werden diskutiert.AIM: To estimate the point prevalence of insomnia, recognition and prescription behavior in primary care. METHODS: Nationwide sample of 539 primary care settings along with their characterization (stage 1). Standardized assessment of all attenders (N = 19.155 patients) on the NISAS target day using a sleep questionnaire (PSQI) and additional questions to cover psychosocial and additional clinical variables. All patients were evaluated by the primary care doctors using a standardized clinical appraisal questionnaire, including a CGI-rating. RESULTS: Prevalence insomnia according to DSM-IV was 26.5%. Recognition of presence of any clinically significant sleep disorder was 72%, recognition of insomnia was poor 54.3%. 85.6% of insomnia patients were rated as chronic. Close to 50% of all insomnia cases did not receive a specific insomnia therapy. Herbals, followed by hypnotics and sedatives and antidepressants were the three most frequent treatments applied, psychotherapy was only seldomly indicated. DISCUSSION: NISAS provides for the first time nationally representative estimates of interventions for insomnia in primary care. The relatively low treatment rates and the high proportion of chronic patients receiving longterm prescription of benzodiazepines seem to be critical. Priorities for future agenda to improve this situation are discussed

Divergent Associations of Slow‐Wave Sleep versus Rapid Eye Movement Sleep with Plasma Amyloid‐Beta

Objective: Recent evidence shows that during slow-wave sleep (SWS), the brain is cleared from potentially toxic metabolites, such as the amyloid-beta protein. Poor sleep or elevated cortisol levels can worsen amyloid-beta clearance, potentially leading to the formation of amyloid plaques, a neuropathological hallmark of Alzheimer disease. Here, we explored how nocturnal neural and endocrine activity affects amyloid-beta fluctuations in the peripheral blood. Methods: We acquired simultaneous polysomnography and all-night blood sampling in 60 healthy volunteers aged 20–68 years. Nocturnal plasma concentrations of amyloid-beta-40, amyloid-beta-42, cortisol, and growth hormone were assessed every 20 minutes. Amyloid-beta fluctuations were modeled with sleep stages, (non)oscillatory power, and hormones as predictors while controlling for age and participant-specific random effects. Results: Amyloid-beta-40 and amyloid-beta-42 levels correlated positively with growth hormone concentrations, SWS proportion, and slow-wave (0.3–4Hz) oscillatory and high-band (30–48Hz) nonoscillatory power, but negatively with cortisol concentrations and rapid eye movement sleep (REM) proportion measured 40–100 minutes previously (all t values > j3j, p values < 0.003). Older participants showed higher amyloid-beta-40 levels. Interpretation: Slow-wave oscillations are associated with higher plasma amyloid-beta levels, whereas REM sleep is related to decreased amyloid-beta plasma levels, possibly representing changes in central amyloid-beta production or clearance. Strong associations between cortisol, growth hormone, and amyloid-beta presumably reflect the sleepregulating role of the corresponding releasing hormones. A positive association between age and amyloid-beta-40 may indicate that peripheral clearance becomes less efficient with age

Sleep spindles and intelligence:evidence for a sexual dimorphism

Contains fulltext : 136083.pdf (publisher's version ) (Open Access)Sleep spindles are thalamocortical oscillations in nonrapid eye movement sleep, which play an important role in sleep-related neuroplasticity and offline information processing. Sleep spindle features are stable within and vary between individuals, with, for example, females having a higher number of spindles and higher spindle density than males. Sleep spindles have been associated with learning potential and intelligence; however, the details of this relationship have not been fully clarified yet. In a sample of 160 adult human subjects with a broad IQ range, we investigated the relationship between sleep spindle parameters and intelligence. In females, we found a positive age-corrected association between intelligence and fast sleep spindle amplitude in central and frontal derivations and a positive association between intelligence and slow sleep spindle duration in all except one derivation. In males, a negative association between intelligence and fast spindle density in posterior regions was found. Effects were continuous over the entire IQ range. Our results demonstrate that, although there is an association between sleep spindle parameters and intellectual performance, these effects are more modest than previously reported and mainly present in females. This supports the view that intelligence does not rely on a single neural framework, and stronger neural connectivity manifesting in increased thalamocortical oscillations in sleep is one particular mechanism typical for females but not males.11 p

A New Way of Identifying Biomarkers in Biomedical Basic-Research Studies

A simple, nonparametric and distribution free method was developed for quick identification of the most meaningful biomarkers among a number of candidates in complex biological phenomena, especially in relatively small samples. This method is independent of rigid model forms or other link functions. It may be applied both to metric and non-metric data as well as to independent or matched parallel samples. With this method identification of the most relevant biomarkers is not based on inferential methods; therefore, its application does not require corrections of the level of significance, even in cases of thousands of variables. Hence, the introduced method is appropriate to analyze and evaluate data of complex investigations in clinical and pre-clinical basic research, such as gene or protein expressions, phenotype-genotype associations in case-control studies on the basis of thousands of genes and SNPs (single nucleotide polymorphism), search of prevalence in sleep EEG-Data, functional magnetic resonance imaging (fMRI) or others