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Dive into the research topics where Stefan Cohrs is active.

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Featured researches published by Stefan Cohrs.


CNS Drugs | 2008

Sleep disturbances in patients with schizophrenia : impact and effect of antipsychotics.

Stefan Cohrs

Difficulties initiating or maintaining sleep are frequently encountered in patients with schizophrenia. Disturbed sleep can be found in 30–80% of schizophrenic patients, depending on the degree of psychotic symptomatology. Measured by polysomnography, reduced sleep efficiency and total sleep time, as well as increased sleep latency, are found in most patients with schizophrenia and appear to be an important part of the pathophysiology of this disorder. Some studies also reported alterations of stage 2 sleep, slow-wave sleep (SWS) and rapid eye movement (REM) sleep variables, i.e. reduced REM latency and REM density. A number of sleep parameters, such as the amount of SWS and the REM latency, are significantly correlated to clinical variables, including severity of illness, positive symptoms, negative symptoms, outcome, neurocognitive impairment and brain structure.Concerning specific sleep disorders, there is some evidence that schizophrenic patients carry a higher risk of experiencing a sleep-related breathing disorder, especially those demonstrating the known risk factors, including being overweight but also long-term use of antipsychotics. However, it is still unclear whether periodic leg movements in sleep or restless legs syndrome (RLS) are found with a higher or lower prevalence in schizophrenic patients than in healthy controls.There are no consistent effects of first-generation antipsychotics on measuresof sleep continuity and sleep structure, including the percentage of sleep stages or sleep and REM latency in healthy controls. In contrast to first-generation antipsychotics, the studied atypical antipsychotics (clozapine, olanzapine, quetiapine, risperidone, ziprasidone and paliperidone) demonstrate a relatively consistent effect on measures of sleep continuity, with an increase in either total sleep time (TST) or sleep efficiency, and individually varying effects on other sleep parameters, such as an increase in REM latency observed for olanzapine, quetiapine and ziprasidone, and an increase in SWS documented for olanzapine and ziprasidone in healthy subjects.The treatment of schizophrenic patients with first-generation antipsychotics is consistently associated with an increase in TST and sleep efficiency, and mostly an increase in REM latency, whereas the influence on specific sleep stages is more variable. On the other hand, withdrawal of such treatment is followed by a change in sleep structure mainly in the opposite direction, indicating a deterioration of sleep quality. On the background of the rather inconsistent effects of first-generation antipsychotics observed in healthy subjects, it appears possible that the high-potency drugs exert their effects on sleep in schizophrenic patients, for the most part, in an indirect way by suppressing stressful psychotic symptomatology. In contrast, the available data concerning second-generation antipsychotics (clozapine, olanzapine, risperidone and paliperidone) demonstrate a relatively consistent effect on measures of sleep continuity in patients and healthy subjects, with an increase in TST and sleep efficiency or a decrease in wakefulness. Additionally, clozapine and olanzapine demonstrate comparable influences on other sleep variables, such as SWS or REM density, in controls and schizophrenic patients. Possibly, the effects of second-generation antipsychotics observed on sleep in healthy subjects and schizophrenic patients might involve the action of these drugs on symptomatology, such as depression, cognitive impairment, and negative and positive symptoms.Specific sleep disorders, such as RLS, sleep-related breathing disorders, night-eating syndrome, somnambulism and rhythm disorders have been described as possible adverse effects of antipsychotics and should be considered in the differential diagnosis of disturbed or unrestful sleep in this population.


Somnologie | 2011

S3-Leitlinie Nicht erholsamer Schlaf/Schlafstörungen

Dieter Riemann; E. Baum; Stefan Cohrs; T. Crönlein; Göran Hajak; Elisabeth Hertenstein; P. Klose; J. Langhorst; Geert Mayer; Christoph Nissen; Thomas Pollmächer; S. Rabstein; Angelika Schlarb; H. Sitter; Hans-Günther Weeß; T. Wetter; Kai Spiegelhalder

Somnologie 2017 · 21:2–44 DOI 10.1007/s11818-016-0097-x Online publiziert: 27. Februar 2017


Journal of Sleep Research | 2004

Is there a specific polysomnographic sleep pattern in children with attention deficit/hyperactivity disorder?

Roumen Kirov; Joerg Kinkelbur; Susanne Heipke; Tatiana Kostanecka-Endress; Moritz Westhoff; Stefan Cohrs; Eckart Rüther; Göran Hajak; Tobias Banaschewski; Aribert Rothenberger

The aim of the study was to characterize the sleep pattern in children with attention deficit/hyperactivity disorder (ADHD). By means of polysomnography (PSG), sleep patterns were studied in 17 unmedicated preadolescent boys rigorously diagnosed with ADHD and 17 control boys precisely matched for age and intelligence. Although ADHD children did not display a general sleep alteration, major PSG data showed a significant increase in the duration of the absolute rapid eye movement (REM) sleep and the number of sleep cycles in ADHD group when compared with controls. In addition, REM sleep latency tended to be shorter in ADHD children. These results suggest that in ADHD children, a forced REM sleep initiation may produce a higher incidence of sleep cycles and may also contribute to an increased duration of the absolute REM sleep. The overall pattern of the findings implies that a forced ultradian cycling appears characteristic for the sleep in ADHD children, which may be related to alterations of brain monoamines and cortical inhibitory control accompanying the ADHD psychopathology.


Neuroreport | 1998

High-frequency repetitive transcranial magnetic stimulation delays rapid eye movement sleep.

Stefan Cohrs; Frithjof Tergau; Sebastian Riech; Sabine Kastner; Walter Paulus; Ulf Ziemann; Eckart Rüther; Göran Hajak

REPETITIVE transcranial magnetic stimulation (rTMS) is a promising new treatment for patients with major depression. However, the mechanisms underlying the antidepressive action of rTMS are widely unclear. Rapid eye movement (REM) sleep has been shown to play an important role in the pathophysiology of depression. In the present study we demonstrate that rTMS delays the first REM sleep epoch on average by 17 min (102.6 ± 22.5 min vs 85.7 ± 18.8 min; p <0.02) and prolongs the nonREM-REM cycle length (109.1 ± 11.4 min vs 101.8 ± 13.2 min, p <0.012). These rTMS-induced changes in REM sleep variables correspond to findings observed after pharmacological and electroconvulsive treatment of depression. Therefore, it is likely that the capability of rTMS to affect circadian and ultradian biological rhythms contributes to its antidepressive action.


Journal of Psychosomatic Research | 2003

Disturbed sleep in children with Tourette syndrome: A polysomnographic study

Tatiana Kostanecka-Endress; Tobias Banaschewski; Jörg Kinkelbur; Ina Wüllner; Sigrid Lichtblau; Stefan Cohrs; Eckart Rüther; Wolfgang Woerner; G. Hajak; Aribert Rothenberger

OBJECTIVE To evaluate objective data on sleep quantity/quality and motor activity during night sleep in children with Tourette syndrome (TS). METHOD Polysomnography of 17 unmedicated TS children (ages: 7;11-15;5, mean: 11;10 years) without comorbid attention-deficit hyperactivity disorder (ADHD) was compared with 16 age-, sex- and IQ-matched healthy controls. Sleep analyses according to the procedure of Rechtschaffen and Kales were supplemented by counting epochs with short arousal-related movements (<or=15 s), thus allowing to calculate correlations between motor activity and sleep parameters. RESULTS Children with TS demonstrated changes in sleep parameters, including longer sleep period time, longer sleep latency, reduced sleep efficiency, and prolonged wakefulness after sleep onset. Their sleep profiles showed significantly more time awake and less sleep stage II. However, REM sleep variables, slow-wave sleep, and number of sleep stage changes were unaffected. Movement time was similar in both groups, but epochs with short arousal-related movements were increased in TS. Further analyses showed no significant correlations between sleep parameters and nighttime nontic movements, level of psychopathology or tic severity during daytime. Periodic limb movements during sleep (PLMS) were only seen in one TS patient (low PLMS index of 7.8/h). CONCLUSIONS Children with TS have disturbed sleep quality with increased arousal phenomena, which both may be intrinsic to the disorder and might trigger tics and other behavioral problems during daytime. This indicates the need for sleep evaluation in patients with TS.


Peptides | 2005

Obstructive sleep apnea: Plasma endothelin-1 precursor but not endothelin-1 levels are elevated and decline with nasal continuous positive airway pressure.

Wolfgang Jordan; Alexander Reinbacher; Stefan Cohrs; Rolf W. Grunewald; Geert Mayer; Eckart Rüther; Andrea Rodenbeck

Assessment of plasma endothelin-1 (ET-1) reveals conflicting results in cerebral and noncerebral conditions. Obstructive sleep apnea (OSA) syndrome has been used as a definite challenge for the investigation of endothelin measurements. Despite marked sleep-related breathing disturbances in untreated patients peripherally measurable ET-1 concentrations remained within the normal range and did not change after an appropriate therapy with continuous positive airway pressure (CPAP). In contrast, its precursor, big ET-1, was considerably elevated in untreated patients and dropped to normal values after long-term CPAP depending on compliance. Relatively stable big ET-1 elevations in untreated patients, during sleep and wakefulness, suggest that a general endothelial alteration beyond that explained by a direct impact of nocturnal breathing disturbances on the vascular system occurs. CPAP-therapy effectively lowered plasma big ET-1 in compliant patients and thus possibly their related risk for vascular diseases. Big ET-1 has been demonstrated to be a more appropriate marker of endothelial alteration than ET-1 because of its longer half-life. Simultaneous measurements are to be recommended.


Addiction Biology | 2014

Impaired sleep quality and sleep duration in smokers-results from the German Multicenter Study on Nicotine Dependence

Stefan Cohrs; Andrea Rodenbeck; Dieter Riemann; Bertram Szagun; Andreas Jaehne; Jürgen Brinkmeyer; Gerhard Gründer; Thomas F. Wienker; Amalia Diaz-Lacava; Arian Mobascher; Norbert Dahmen; Norbert Thuerauf; Johannes Kornhuber; Falk Kiefer; Jürgen Gallinat; Michael Wagner; Dieter Kunz; Ulrike Grittner; Georg Winterer

Cigarette smoking is a severe health burden being related to a number of chronic diseases. Frequently, smokers report about sleep problems. Sleep disturbance, in turn, has been demonstrated to be involved in the pathophysiology of several disorders related to smoking and may be relevant for the pathophysiology of nicotine dependence. Therefore, determining the frequency of sleep disturbance in otherwise healthy smokers and its association with degree of nicotine dependence is highly relevant. In a population‐based case‐control study, 1071 smokers and 1243 non‐smokers without lifetime Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Axis I disorder were investigated. Sleep quality (SQ) of participants was determined by the Pittsburgh Sleep Quality Index. As possible confounders, age, sex and level of education and income, as well as depressiveness, anxiety, attention deficit hyperactivity, alcohol drinking behaviour and perceived stress, were included into multiple regression analyses. Significantly more smokers than non‐smokers (28.1% versus 19.1%; P < 0.0001) demonstrated a disturbed global SQ. After controlling for the confounders, impaired scores in the component scores of sleep latency, sleep duration and global SQ were found significantly more often in smokers than non‐smokers. Consistently, higher degrees of nicotine dependence and intensity of smoking were associated with shorter sleep duration. This study demonstrates for the first time an elevated prevalence of sleep disturbance in smokers compared with non‐smokers in a population without lifetime history of psychiatric disorders even after controlling for potentially relevant risk factors. It appears likely that smoking is a behaviourally modifiable risk factor for the occurrence of impaired SQ and short sleep duration.


Journal of Neural Transmission | 2004

CPAP-therapy effectively lowers serum homocysteine in obstructive sleep apnea syndrome

W. Jordan; C. Berger; Stefan Cohrs; Andrea Rodenbeck; G. Mayer; P. Niedmann; N. von Ahsen; E. Rüther; Johannes Kornhuber; Stefan Bleich

Summary.Assessment of serum total homocysteine (tHcy) in patients with obstructive sleep apnea (OSA) syndrome is highly relevant since both are strongly associated with stroke and cognitive dysfunction. Seven of 16 untreated OSA patients showed tHcy levels exceeding 11.7 µmol/l. The circadian pattern of serum tHcy in untreated and treated patients (p < 0.001) implied a diagnostic impact of blood sampling time. Treatment with continuous positive airway pressure (CPAP) effectively lowered tHcy levels in patients by about 30% (p < 0.005) and thus probably the (hyper)homocysteinemia-related cognitive dysfunction and the risk for cardio-/cerebrovascular diseases.


Brain Research | 2005

Normal hypocretin-1 (orexin-A) levels in the cerebrospinal fluid of patients with Huntington's disease

Andreas Meier; Brit Mollenhauer; Stefan Cohrs; Andrea Rodenbeck; Wolfgang Jordan; Johannes Meller; Markus Otto

A significant atrophy and loss of hypocretin neurons in the brains of human patients with Huntingtons disease (HD) and in R6/2 mice have been reported. We included 10 patients with HD and 12 patients with chorea-like hyperkinetic movement disorders (non-HD). All patients of the HD group and eleven patients of the non-HD group showed normal hypocretin-1 levels. Thus, hypocretin-1 may not serve as an additional diagnostic marker for HD.


Drugs & Aging | 2002

Tolerability of hypnosedatives in older patients.

Udo Wortelboer; Stefan Cohrs; Andrea Rodenbeck; Eckart Rüther

Sleep disturbances are common and prevalence rates increase with age. Especially in the elderly, somatic diseases and medications with adverse effects relating to sleep are frequent reasons for disturbed and nonrefreshing sleep. It should be emphasised that these reasons must be excluded before symptomatic therapy is started. In some cases the use of hypnosedatives may be included as part of the treatment of a somatic disease and may cause sleep disturbances. Pharmacotherapy is one of the main approaches in the management of primary insomnia and should be part of a broader treatment strategy including nonpharmacological methods.This article focuses on the tolerability of frequently prescribed hypnosedatives in the elderly with primary insomnia and addresses the primary care physician. In general, recommendations for the pharmacotherapy of insomnia in elderly patients include using a reduced dosage. For some substances (e.g. Zolpidem, zopiclone, zaleplon, temazepam and triazolam) the recommended dosage is half that recommended for younger patients. The properties of the selected hypnosedative should be taken into consideration and matched with the type of sleep disturbance experienced by the patient. Ultrashort-acting drugs may be useful when initiating sleep is the main problem, whereas shortand intermediate-acting substances are recommended for maintaining sleep. Possible interactions with pre-existing medication must also be taken into consideration.Some agents such as antipsychotics, antidepressants, melatonin and herbal agents may be used in specific indications. However, only a few of these substances have proven tolerability in the elderly and further investigations are recommended.

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Eckart Rüther

University of Göttingen

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E. Rüther

University of Göttingen

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G. Hajak

University of Göttingen

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Göran Hajak

University of Regensburg

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A. Meier

University of Göttingen

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Andreas Meier

University of Göttingen

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