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Biomedical subjects

Dieter Riemann

Publications and source records attributed to Dieter Riemann.

At least 19 recordsLinked to original sources
PubMed2007

Sleep electroencephalographic spectral power after withdrawal from alcohol in alcohol-dependent patients.

BACKGROUND: Dysfunctional hyperarousal is suspected to be a neurophysiological determinant of relapse in abstinent alcohol-dependent patients. In the present study, we used spectral power analysis of the sleep electroencephalographic (EEG) to quantify brain activity during sleep in patients during subacute withdrawal as well as in control subjects. Our hypothesis was that the subgroup of patients who relapsed within the 3 months to follow-up would exhibit-increased dysfunctional arousal manifested by higher-frequency (beta) EEG power during sleep. METHODS: Twenty-six alcohol-dependent in-patients were examined with polysomnography over 2 nights 2 to 3 weeks after withdrawal. At the 3-month clinical follow-up assessment, 12 of them had relapsed and 14 abstained. The control group consisted of 23 healthy subjects similar to the patients with alcohol dependence in age and gender distribution. Spectral sleep EEG analysis was performed on both nights (adaptation and baseline) of all subjects. Logarithmic artifact-controlled spectral band power of sleep stage 2 and rapid eye movement (REM) sleep was analyzed for Group, Gender, and Age effects using multiple analyses of covariance. Three groups were compared with the Group factor: relapsers, abstainers, and controls. RESULTS: Generally, both Group and Age effects were significant for the second, baseline night for the visually scored sleep parameters, while spectral EEG parameters showed significant differences in the adaptation night. In the adaptation night, a significant enhancement in the beta2 band (24-32 Hz) was seen in REM sleep in relapsers relative to both abstainers and controls. CONCLUSIONS: The beta2 increase could be interpreted as a sign of dysfunctional arousal during REM sleep "unmasked" by the additional stressor of sleep environment adaptation. Its determinants are likely to be both premorbid and drinking history related.

Adult↗
PubMed2006

Sleep in obsessive compulsive disorder: polysomnographic studies under baseline conditions and after experimentally induced serotonin deficiency.

Several lines of evidence suggest that brain serotonergic systems may be disturbed in obsessive compulsive disorder (OCD). The serotonergic system strongly affects sleep and characteristic abnormalities of sleep are documented in depression. This study, therefore, aimed to investigate sleep structure of OCD patients in order to evaluate whether similar changes as in depression are present. Up to now, this issue has been addressed only in few studies with small numbers of patients. Sleep patterns of 62 unmedicated patients with primary OCD and 62 age- and sex-matched healthy controls were investigated by polysomnography. Additionally, the impact of tryptophan depletion on sleep was studied in a subgroup of 12 OCD patients and 12 controls. The OCD patients exhibited moderate, but significant disturbances of sleep continuity measures but no abnormalities of slow wave sleep or REM sleep, except a significant elevation of 1st REM density. Tryptophan depletion induced a worsening of sleep continuity, but no changes of REM sleep or slow wave sleep. Assuming that changes of sleep architecture indicate underlying neurobiological abnormalities, this study indicates that neurobiological disturbances are different in primary OCD as compared with primary depression.

Adult↗
PubMed2006

Sleep and sleep disorders in adults with attention deficit/hyperactivity disorder.

Attention deficit/hyperactivity disorder (ADHD) is a frequent disorder that often persists in adulthood. Persistent ADHD is known to be a serious risk factor for other disorders in adulthood, and adults with ADHD often report on sleep disorders. Despite this, only few studies have investigated the subjective and objective quality of sleep in adults suffering from ADHD. Previous studies have revealed seriously impaired subjective sleep quality and increased nocturnal motor activity in spite of essentially normal standard polysomnographic parameters in this patient group. However, primary sleep disorders such as sleep apnea syndrome or restless legs syndrome (RLS) may be misdiagnosed as ADHD. Moreover, ADHD and primary sleep disorders may occur as comorbidities. In particular, RLS was suggested to be highly associated with ADHD, indicating a probable common central nervous dopaminergic dysfunction. To date, larger studies with adequate sample sizes that compare sleep in adult patients with ADHD, healthy control groups and patients with other primary sleep disorders are still lacking.

Adult↗
PubMed2006

Periodic leg movements in sleep and periodic limb movement disorder: prevalence, clinical significance and treatment.

Periodic leg movements in sleep (PLMS) are a frequent finding in polysomnography. The prevalence of PLMS is estimated to be 4-11% in adults. In childhood, PLMS rarely occur although medical conditions like sleep apnea syndrome or neuropsychiatric disorders can lead to high rates of PLMS. In the elderly, PLMS are also common in subjects without sleep disturbances. In sleep studies, PLMS are found most frequently in restless legs syndrome (RLS) and often occur in narcolepsy, sleep apnea syndrome and REM sleep behavior disorder. Some patients with otherwise unexplained insomnia or hypersomnia reveal an elevated number of PLMS, a condition defined as periodic limb movement disorder (PLMD). PLMS were found also in various medical and neurological disorders that do not primarily affect sleep. A summary of these is presented. In sleep disorders related to dopaminergic dysfunction such as RLS, PLMS are considered to be a symptom of the disease. In other disorders like primary insomnia, the clinical relevance of PLMS is still being controversially discussed. Studies with findings both pro and contra are referred. To date, only a few studies have evaluated the efficacy of therapeutic substances in reducing PLMS in PLMD patients. Their results need to be confirmed in controlled randomized trials.

Aged↗
PubMed2006

Differential effects of the muscarinic M1 receptor agonist RS-86 and the acetylcholine-esterase inhibitor donepezil on REM sleep regulation in healthy volunteers.

Broad evidence from preclinical and clinical research indicates that cholinergic neurotransmission contributes significantly to the generation of rapid eye movement (REM) sleep. However, a potential role of different acetylcholine receptor (AChR) subtypes for the regulation of three main aspects of REM sleep, (1) REM onset, (2) REM maintenance, and (3) generation of REMs, are not clear. In the present double-blind, randomized and placebo-controlled study, we investigated the differential effects of the M1 muscarinic AChR (mAChR) agonist RS-86 and the ACh-esterase inhibitor donepezil to further specify the AChR subtype function on REM sleep regulation in n = 20 healthy volunteers. We found that RS-86 selectively shortened REM latency (multivariate analysis of variance post hoc contrast p = 0.024 compared to placebo, not significant for donepezil) and that donepezil specifically enhanced the duration of REM sleep (% sleep period time, p = 0.000 compared to placebo; p = 0.003 compared to RS-86) and the number of REMs (p = 0.000 compared to placebo; p = 0.000 compared to RS-86). These results provide evidence that the onset of REM sleep is, in part, mediated by M1 mAChR activity, whereas the maintenance of REM sleep and the number of REMs are mediated by non-M1, but presumably M2 mAChR activity. These findings are of interest for the understanding of sleep regulation and of neuropsychiatric disorders, such as Alzheimer's dementia and depressive disorders, whose etiopathology may involve alterations in cholinergic neurotransmission.

Adult↗
PubMed2006

Neuropsychological impairment in obsessive-compulsive disorder--improvement over the course of cognitive behavioral treatment.

A large body of studies demonstrates mild cognitive dysfunction in patients with Obsessive Compulsive Disorder (OCD). Few trials have investigated whether this dysfunction can be improved by treatment. Thirty unmedicated inpatients with OCD were administered a comprehensive neuropsychological test battery before and after 12 weeks of cognitive behavioral therapy (CBT). Thirty-nine carefully matched healthy controls were tested twice within the same interval. At baseline, patients exhibited significant impairments on several tests which normalized at follow-up. A significant group x time interaction was found for tests of nonverbal memory, set shifting and flexible, self guided behavior. Major responders improved significantly more than minor responders on the Rey-Osterrieth Figure immediate and delayed recall. Results suggest that cognitive dysfunction in OCD can improve in the course of treatment. We hypothesize that particularly cognitive behavioral treatment enables OCD patients to think and act in a more flexible way that helps them to develop more effective cognitive strategies.

Adult↗
PubMed2006

Impaired sleep-related memory consolidation in primary insomnia--a pilot study.

STUDY OBJECTIVES: To compare sleep-related consolidation of procedural memory in patients with primary insomnia and healthy controls. DESIGN: Controlled comparison pilot study. SETTING: Sleep Laboratory of the Department of Psychiatry and Psychotherapy, University of Freiburg, Germany. PATIENTS OR PARTICIPANTS: Seven patients with primary insomnia and 7 sex-, age-, and IQ-matched healthy controls. INTERVENTIONS: Subjects spent 1 night in the sleep laboratory with polysomnographic monitoring. Performance on a mirror tracing task was measured before and after sleep. MEASUREMENTS AND RESULTS: Polysomnography revealed a trend toward disturbed sleep in the patients, compared with the control group, without reaching significance. Performance in the mirror tracing task before sleep did not differ between the groups. Both groups performed significantly better in the retest condition after sleep. Healthy controls showed an improvement of 42.8% +/- 5.8% in the mirror tracing draw time, whereas patients with insomnia showed an improvement of 20.4% +/- 14.8% (multivariate analyses of variance test session x group interaction: F(3,10) = 10.9, p = .002). CONCLUSIONS: These preliminary findings support the view that sleep-associated consolidation of procedural memories may be impaired in patients with primary insomnia.

Adult↗
PubMed2006

Effects of alcohol on polysomnographically recorded sleep in healthy subjects.

BACKGROUND: After studying the sleep of alcohol-dependent patients at the beginning and over the course of abstinence in earlier studies, our interest in the current study focused on the direct effect of 2 doses of alcohol [0.03 and 0.1% blood alcohol level (BAL)] on healthy sleep. This is the first polysomnographic study testing the impact of 2 doses of alcohol ingestion (thus reflecting "normal" social drinking and alcohol abuse) in a single-blind randomized design in healthy volunteers. The study evaluated a short-term acute drinking period for 3 and 2 days of withdrawal from alcohol not only for polysomnographic variables but also for subjective estimates of sleep quality. METHODS: In a crossover design with a 1-week interval, healthy subjects received alcohol to raise their blood alcohol to either 0.03 or 0.1% BAL at bedtime for 3 consecutive nights after an alcohol-free baseline night. Objective (polysomnography) and subjective sleep (questionnaires) was recorded each night. During the following 2 days, alcohol was discontinued with simultaneous measurements of sleep to gauge withdrawal effects. RESULTS: At a dose of alcohol leading to BAL of 0.03%, no clear effects could be detected. Following an evening BAL of 0.1%, a hypnotic-like effect (shortened sleep latency, reduced number of wake periods, decreased stage 1 sleep) occurred primarily during the first half of the night with signs of rebound effects being already present during the second half of the night (increased stage 1 sleep). At this dose, alcohol significantly increased slow-wave sleep (SWS) in the first half of the night and reduced REM density in the beginning of the night. After discontinuation of the higher alcohol dose, REM sleep amount increased. No significant withdrawal or rebound effects could be observed for parameters of sleep continuity during the 2 nights after discontinuation from alcohol at a BAL of 0.1%. CONCLUSIONS: Owing to the small sample size, the results of this study need to be interpreted with caution. Short-term moderate alcohol consumption (BAL 0.03%) did not significantly alter objective or subjective parameters of sleep. Higher doses of alcohol resulting in a BAL level of 0.10% immediately before going to bed mainly influenced sleep in the first half of the night, resembling the effects of a short-acting hypnotic drug, including a suppression of phasic aspects of REM sleep (REM density). Interestingly, analysis of the latter part of these nights indicated the immediate presence of withdrawal effects (increased light sleep). No statistically significant effects on sleep parameters were observable during the 2 nights of withdrawal from alcohol at the higher BAL. Interpreted carefully, our data indicate that negative effects on sleep occur already with short-term use of alcohol at doses of BAL of 0.10%, despite hypnotic-like effects during the first hours of sleep, especially during the latter part of the night.

Adult↗
PubMed2006

M1 muscarinic acetylcholine receptor agonism alters sleep without affecting memory consolidation.

Preclinical studies have implicated cholinergic neurotransmission, specifically M1 muscarinic acetylcholine receptor (mAChR) activation, in sleep-associated memory consolidation. In the present study, we investigated the effects of administering the direct M1 mAChR agonist RS-86 on pre-post sleep memory consolidation. Twenty healthy human participants were tested in a declarative word-list task and a procedural mirror-tracing task. RS-86 significantly reduced rapid eye movement (REM) sleep latency and slow wave sleep (SWS) duration in comparison with placebo. Presleep acquisition and postsleep recall rates were within the expected ranges. However, recall rates in both tasks were almost identical for the RS-86 and placebo conditions. These results indicate that selective M1 mAChR activation in healthy humans has no clinically relevant effect on pre-post sleep consolidation of declarative or procedural memories at a dose that reduces REM sleep latency and SWS duration.

Adult↗
PubMed2005

Increased nocturnal interleukin-6 excretion in patients with primary insomnia: a pilot study.

The aim of the present study was to investigate whether there is a difference in evening/nocturnal interleukin-6 (IL-6) serum excretion in patients with primary insomnia compared to controls. We hypothesized that in insomniac patients, the excretion of evening/nocturnal IL-6 is enhanced, like observed in aged adults and after sleep deprivation in healthy subjects. We studied IL-6 serum concentrations in 11 patients (two males and nine females) with primary insomnia and 11 age and gender-matched healthy controls. Sleep was monitored polysomnographically for three consecutive nights. The measurement of IL-6 (from 19:00 h to 09:00 h) in 2-h intervals were performed prior to and during the last laboratory night. Polysomnographically determined sleep parameters and subjective ratings of sleep demonstrated clear-cut impairments of sleep in the insomniac group. Nocturnal IL-6 secretion was significantly increased (p<.05) in insomniac patients for the whole measurement period (mean area under the curve+/-SD: 27.94+/-14.15 pg/ml x 2h) compared to controls (16.70+/-7.64 pg/ml x 2h). Total IL-6 secretion correlated inversely with subjectively perceived sleep quality and amount of slow wave sleep in the insomniac patients. Amount of Wake Time correlated positively with IL-6 excretion in insomniacs. The results of the present study demonstrate significantly increased nocturnal IL-6 secretion in insomniacs. It might be speculated that chronic primary insomnia with polysomnographically documented sleep impairments activates the production of IL-6 analogous to sleep deprivation studies in healthy subjects. This might also implicate a higher risk for inflammatory and cardiovascular diseases in patients with chronic insomnia.

Adult↗
PubMed2005

The effects of clomethiazole on polysomnographically recorded sleep in healthy subjects.

Clomethiazole is widely used in European countries to treat alcohol withdrawal symptoms including delirium tremens. The current study aimed to explore the effects of clomethiazole on the sleep of healthy volunteers. We postulated both a hypnotic and a REM suppressive effect as well as the occurrence of a rebound phenomenon following three days of treatment with clomethiazole. The study group was composed of five men and five women. The probands were examined in the sleep laboratory throughout a course of seven nights. The first night was considered as the adaptation night and the second as the baseline night. Prior to nights 3 to 5, probands took 384 mg clomethiazole at 22 hours. The 6th and 7th nights served to record potential effects of medication discontinuation. The current study confirms the indication in the scientific literature with regard to hypnotic and REM-suppressive effects of clomethiazole, as well as a rebound phenomenon following discontinuation of the medication. The effect of clomethiazole on the sleep EEG was most obvious in the first half of the night. The analysis of the polysomnogram in terms of each half of the night gave no indication of a rebound phenomenon during the second half. The REM sleep-suppressing component of clomethiazole is of great interest in connection with its use in treating delirium tremens. The rebound phenomenon in healthy controls after only three days of medication at a relatively low dosage of clomethiazole underscores the need to administer it in doses individually tailored to the extent of the alcohol withdrawal syndrome in the individual patient.

Adult↗
PubMed2005

Spectral analysis of sleep EEG in patients with restless legs syndrome.

OBJECTIVE: Conventional analyses of sleep EEG recordings according to standard criteria indicate severe sleep disturbances in patients with restless legs syndrome (RLS). Spectral analysis of sleep EEG may be a sensitive tool to detect functional alterations of sleep mechanisms beyond the visual scoring of polysomnographic records. We analysed sleep EEG spectral power differences between RLS patients and healthy subjects. Furthermore, we studied the relationship of sleep EEG spectral power to the occurrence of periodic leg movements in sleep (PLMS) and arousal events. METHODS: Sleep EEGs from 20 patients with idiopathic RLS and of 20 age and sex matched healthy subjects were investigated. The spectral analysis was carried out on the same 30s epochs for which sleep stages had been determined. As a first step, whole-night spectral power excluding epochs with an arousal or with a PLMS was compared separately for REM and NREM sleep between RLS and healthy subjects. In a second step, we evaluated the spectral effects of PLMS, PLMS with associated arousals and isolated arousals relative to epochs of sleep without such events in both groups. In this part of the analysis, we only included the epochs of sleep stage 2 (the main and most stable non-REM sleep stage) and of REM sleep. RESULTS: Spectral power of all sleep epochs (excluding arousals and PLMS) did not differ between patients with RLS and healthy subjects. As expected, arousals and PLMS-associated arousals resulted in a significant increase in higher-frequency activity (alpha, beta1, beta2 and gamma bands) in both groups. Spectral power in epochs with PLMS alone did not significantly differ from spectral power in epochs without PLMS and without arousal in any of the groups. CONCLUSIONS: We found no evidence for an altered cortical activity in sleep stage 2 and REM sleep epochs in RLS patients compared to that in healthy controls if epochs with arousals were not considered. Furthermore, while PLMS associated with an arousal have a high impact on EEG spectra, the effect of a PLMS without arousal seems to be minor and transient. SIGNIFICANCE: Our data suggest that RLS related symptoms may intermittently disrupt sleep but do not appear to involve a persistent disturbance of the basic sleep generating patterns.

Adult↗
PubMed2005

Increased delta power and discrepancies in objective and subjective sleep measurements in borderline personality disorder.

BACKGROUND: Previous studies have shown depression-like sleep abnormalities in borderline personality disorder (BPD). However, findings in BPD are not unequivocal for REM dysregulation, as well as for a decrement of slow wave sleep and sleep continuity disturbances. Earlier findings in sleep EEG abnormalities in BPD may have been confounded by concomitant depressive symptoms. METHODS: Twenty unmedicated female BPD patients without current comorbid major depression and 20 sex- and age-matched control subjects entered the study. Conventional polysomnographic parameters and for the first time sleep EEG spectral power analysis was performed on two sleep laboratory nights. Subjective sleep parameters were collected by sleep questionnaires in order to assess the relationship between objective and subjective sleep measurements. RESULTS: BPD patients showed a tendency for shortened REM latency and significantly decreased NonREM sleep (stage 2). Spectral EEG analysis showed increased delta power in total NREM sleep as well as in REM sleep in BPD patients. Subjective ratings documented drastically impaired sleep quality in BPD patients for the two weeks before the study and during the two laboratory nights. CONCLUSION: Not-depressed BPD patients only showed tendencies for depression-like REM sleep abnormalities. Surprisingly, BPD patients displayed higher levels of delta power in the sleep EEG in NREM sleep than healthy control subjects. There was a marked discrepancy between objective and subjective sleep measurements, which indicates an altered perception of sleep in BPD. The underlying psychological and neurobiological mechanisms of these alterations are still unclear and need to be clarified in future studies including interventions on a pharmacological and cognitive-behavioral level.

Adolescent↗
PubMed2005

Sleep in adults with attention-deficit/hyperactivity disorder: a controlled polysomnographic study including spectral analysis of the sleep EEG.

STUDY OBJECTIVES: Previous studies in children with attention-deficit/hyperactivity disorder and attention deficit disorder (ADHD/ADD) have shown impaired sleep quality with increased nocturnal motor activity. However, polysomnographic findings are not unequivocal. Up to now, in adults with ADHD, only 1 case-control polysomnographic study with small sample size has been performed. We investigated objective and subjective sleep quality in adultADHD, including an electroencephalogram spectral power analysis. DESIGN: Single-blind comparative study. SETTING: University medical center. PARTICIPANTS: Twenty adult unmedicated ADHD patients without current comorbid major depression, drug abuse, or comorbid axis-II disorder and 20 sex- and age-matched control subjects. INTERVENTIONS: N/A. MEASUREMENTS: Conventional polysomnographic parameters and sleep electroencephalogram spectral power analysis was calculated for the 2 laboratory nights. Subjective sleep parameters were estimated by sleep questionnaires to assess the relationship between objective and subjective sleep measurements. RESULTS: Adult ADHD patients showed increased nocturnal motor activity (as indicated by heightened indexes of periodic leg movements in sleep), which was significantly inversely correlated with subjective total sleep time. Although ADHD patients displayed significantly increased objective total sleep time, the subjective ratings documented impaired sleep quality in those with ADHD. Other polysomnographic sleep patterns and spectral electroencephalogram parameters did not differ between ADHD patients and normal controls. CONCLUSIONS: Similar to children, adults with ADHD show increased nocturnal motor activity. Otherwise, sleep does not seem to be impaired in ADHD patients. However, the dissociation between objective and subjective sleep parameters points to a misinterpretation of sleep quality in patients with ADHD.

Adult↗
PubMed2005

Impact of sleep-related complaints on depressive symptoms in patients with restless legs syndrome.

OBJECTIVE: Restless legs syndrome (RLS) is a distressing sensorimotor disorder with a 5% to 10% prevalence in the United States and Western Europe. The nocturnal occurrence of symptoms often leads to severe sleep disturbances. RLS has been reported to be associated with depression and anxiety. The aim of the present study was to investigate the relationship between RLS symptom severity, sleep disturbances, and depressive symptoms. METHOD: Questionnaire data from 100 consecutive patients with idiopathic RLS who had been investigated in our Sleep Disorders Unit from April 1999 to December 2004 were evaluated. Patients were untreated regarding RLS, depression, or sleep disturbances. Severity of RLS was assessed with the International RLS Study Group rating scale (IRLS). Depressive symptoms and subjective sleep quality were determined using the Beck Depression Inventory (BDI) and the Pittsburgh Sleep Quality Index (PSQI), respectively. RESULTS: IRLS scores indicated moderate-to-severe RLS symptoms in the population studied (mean +/- SD IRLS score = 23.6 +/- 6.7). The mean +/- SD BDI score was 9.3 +/- 5.6, with highest values on the "reduced sleep," "loss of energy," and "work difficulties" items, indicating predominating somatic symptoms of depression. Fourteen patients had a BDI score of 15 to 20 ("mild depression"), and 3 patients had a BDI score of 20 to 30 ("mild to moderate depression"). Overall, patients estimated their sleep quality as moderately impaired (mean +/- SD PSQI score = 10.9 +/- 3.7). Severity of RLS correlated with the impairment of subjective sleep quality (r = 0.281, p = .007) but not with self-rated depressive symptoms (r = 0.119, p = .237). CONCLUSION: RLS patients scored high on the somatic items of the BDI, particularly on those related to sleep disturbance, but not on the other items that mostly address cognitive symptoms. Our results indicate that RLS might be associated with some features of depression but not with the full spectrum of a depressive disorder. The relationship between the 2 disorders should be investigated in further studies.

Comorbidity↗
PubMed2005

Variability of periodic leg movements in various sleep disorders: implications for clinical and pathophysiologic studies.

STUDY OBJECTIVES: Periodic leg movements in sleep (PLMS) are a frequent phenomenon in various sleep disorders. The pathophysiology of PLMS is still not understood, but recent studies indicate a hypoactivity of the dopaminergic system in subjects with PLMS. In the present study, we investigated the intrasubject variance of PLMS from one night to the other because a fluctuation in the number of PLMS may influence the outcome of pharmacologic and pathophysiologic studies. DESIGN: Retrospective observational study. SETTING: Data collection occurred in the sleep disorders unit. PATIENTS: Sleep electroencephalogram and PLMS data of 115 patients with PLMS monitoring over 2 consecutive nights were evaluated retrospectively. Patients were grouped into the following diagnostic categories: restless legs syndrome, insomnia secondary to a psychiatric disorder, primary insomnia, sleep apnea syndrome, and narcolepsy or idiopathic hypersomnia. INTERVENTIONS: N/A. RESULTS: In 27% of the entire patient population, we found a considerable variability of the PLMS index (difference between nights > 10/hour) and, in 19% of patients, variability of the PLMS arousal index (difference between nights > 5/hour) across the 2 investigated nights. The intraindividual variance occurred most frequently and to the highest extent in patients with RLS. CONCLUSIONS: The variability of PLMS indexes should considered if the PLMS recording is performed in support of the clinical diagnosis or in the interpretation of studies investigating drug efficacy. Furthermore, the variability of PLMS may be an indicator of an instability of the dopaminergic system that should be taken into account in studies investigating central nervous system dopaminergic activity.

Circadian Rhythm↗