P Anderer

Medical University of Vienna, Wien, Vienna, Austria

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Publications (245)500.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: 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.
    Psychiatria Danubina 12/2013; 25(4):447-452. · 0.63 Impact Factor
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    ABSTRACT: 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.
    Psychiatria Danubina 12/2013; 25(4):426-34. · 0.63 Impact Factor
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    ABSTRACT: 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.
    Neuropsychobiology 03/2013; 67(3):127-67. · 2.37 Impact Factor
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    ABSTRACT: There is growing evidence of the active involvement of sleep in memory consolidation. Besides hippocampal sharp wave-ripple complexes and sleep spindles, slow oscillations appear to play a key role in the process of sleep-associated memory consolidation. Furthermore, slow oscillation amplitude and spectral power increase during the night after learning declarative and procedural memory tasks. However, it is unresolved whether learning-induced changes specifically alter characteristics of individual slow oscillations, such as the slow oscillation up-state length and amplitude, which are believed to be important for neuronal replay. 24 subjects (12 men) aged between 20 and 30 years participated in a randomized, within-subject, multicenter study. Subjects slept on three occasions for a whole night in the sleep laboratory with full polysomnography. Whereas the first night only served for adaptation purposes, the two remaining nights were preceded by a declarative word-pair task or by a non-learning control task. Slow oscillations were detected in non-rapid eye movement sleep over electrode Fz. Results indicate positive correlations between the length of the up-state as well as the amplitude of both slow oscillation phases and changes in memory performance from pre to post sleep. We speculate that the prolonged slow oscillation up-state length might extend the timeframe for the transfer of initial hippocampal to long-term cortical memory representations, whereas the increase in slow oscillation amplitudes possibly reflects changes in the net synaptic strength of cortical networks.
    PLoS ONE 01/2013; 8(12):e82049. · 3.53 Impact Factor
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    ABSTRACT: Objective: Rapid eye movements (REMs) are a cardinal feature of REM sleep and their rate ("density" -REMD) is an indicator of the intensity of a hypothetical "REM process" (analogous to spectral power in the delta range in NREM sleep). The generation of REMs is assumed to be controlled by cholinergic and/or glutamatergic systems and REMD correlates with cognitive functions in elderly subjects. Thus, REMD might be a biomarker of successful aging. REMD was reduced in healthy elderly subjects as compared to young controls, while slow eye movements (SEMs) did not show any trend across REM periods. However, those studies were limited due to the small number of subjects and need confirmation in larger samples allowing establishing age curves for REMD. The aim of the present study was to confirm these findings in a larger database, using an automatic detection algorithm. Methods: REM density (time of REMs/ time in stage REM) and REM intensity (sum of eye movement amplitudes/min REM sleep) were evaluated automatically. Moreover, the Atonia Index (ATI, Ferri et al. 2008) was quantified as a measure of REM sleep atonia. 160 healthy subjects from the SIESTA database (86 females, 74 males aged between 20 to 95 years) participated in this study. REM periods were defined according to the standard criteria and visually checked for apparently missing periods. The effects of REM period and age on the obtained measures were investigated by means non parametric tests (Spearman rank correlations, Friedman test for dependent samples). Results: There are significant differences in REMD between REM periods 1 to 4 (p< 0.001), which was reduced in REM period 1 (no significant differences between periods 2 to 4 (p=.803)). Age did not correlate significantly with REMD (R = -.102, p= .199), but moderately with REM intensity (R = -.272, p< 0.001). Neither SEMD (p = .446), nor SEM intensity (p = .688) differed significantly between REM periods, or correlated significantly with age. There is a significant difference in ATI between REM periods (declining over the night), but no significant correlation with age (R = .081). Results: As expected, we could confirm a reduced REMD during the 1st REM period and a significant aging effect in REM intensity but not REMD. Likewise, REM ATI increases during the night, but was not significantly affected by aging. Discussion: Computerized analysis of rapid and slow eye movements is a sensitive marker of the intensity of the REM process.
    21st Congress of the European Sleep Research Society; 09/2012
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    ABSTRACT: Parkinson’s disease (PD) is often accompanied by dysfunctions of the autonomous nervous system (ANS). Heart rate variability (HRV) may impact on sleep regulation with regard to sympatho-vagal balance and sleep stages. This study analyzed possible differences in ANS activity between PD patients medicated with levodopa and a healthy control group in context with sleep. Methods: In PD patients (N = 8) and controls (N = 11) polysomnographic (PSG) recordings were registered for two nights. To minimize a possible first night effect, only the second night was used. Electrocardiography (ECG) recordings were inspected by an automatic algorithm to detect R-R interval lengths, which were then analyzed via fast Fourier transformation. For use as a marker for sympatho-vagal balance, the resultant frequency ranges were subdivided into low frequency (LF, 0.04-0.15 Hz) and high frequency (HF, 0.15-0.4 Hz) sub-bands. In addition, ratio of LF and HF (LF/HF ratio) was calculated. Results: LF was higher in controls compared to PD patients. Both groups showed significant variation, with peaks during wake and REM and troughs during NonREM sleep. Similarly, LF/HF ratio was lower in PD patients compared to controls, significantly so during Wake, Stage 1, Stage 2, and REM. On a group level, LF/HF ratio never exceeded the HRV of controls, but the difference was not significant. For HF, no significant changes were found in either group. Conclusion: We conclude that PD reduces sympatho-vagal balance. The decrease in LF and LF/HF was especially distinctive during REM. This could be an effect of sympathetic degeneration in cardiac cells. Keywords: Parkinson’s disease, autonomous nervous system, sleep, heart rate variability, levodopa
    Movement Disorders 01/2012; 27(3):454. · 5.63 Impact Factor
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    ABSTRACT: Scalp electric potentials (electroencephalogram; EEG) are contingent to the impressed current density unleashed by cortical pyramidal neurons undergoing post-synaptic processes. EEG neuroimaging consists of estimating the cortical current density from scalp recordings. We report a solution to this inverse problem that attains exact localization: exact low-resolution brain electromagnetic tomography (eLORETA). This non-invasive method yields high time-resolution intracranial signals that can be used for assessing functional dynamic connectivity in the brain, quantified by coherence and phase synchronization. However, these measures are non-physiologically high because of volume conduction and low spatial resolution. We present a new method to solve this problem by decomposing them into instantaneous and lagged components, with the lagged part having almost pure physiological origin.
    Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences 10/2011; 369(1952):3768-84. · 2.89 Impact Factor
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    ABSTRACT: In the present double-blind, randomized, sham-controlled cross-over study, possible effects of electromagnetic fields emitted by Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA)/Universal Mobile Telecommunications System (UMTS) cell-phones on the macrostructure of sleep were investigated in a laboratory environment. An adaptation night, which served as screening night for sleep disorders and as an adjustment night to the laboratory environment, was followed by 9 study nights (separated by a 2-week interval) in which subjects were exposed to three exposure conditions (sham, GSM 900 and WCDMA/UMTS). The sample comprised 30 healthy male subjects within the age range 18-30 years (mean ± standard deviation: 25.3 ± 2.6 years). A cell-phone usage at maximum radio frequency (RF) output power was simulated and the transmitted power was adjusted in order to approach, but not to exceed, the specific absorption rate (SAR) limits of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for general public exposure (SAR(10g) = 2.0 W kg(-1)). In this study, possible effects of long-term (8 h) continuous RF exposure on the central nervous system were analysed during sleep, because sleep is a state in which many confounding intrinsic and extrinsic factors (e.g. motivation, personality, attitude) are eliminated or controlled. Thirteen of 177 variables characterizing the initiation and maintenance of sleep in the GSM 900 and three in the WCDMA exposure condition differed from the sham condition. The few significant results are not indicative of a negative impact on sleep architecture. From the present results there is no evidence for a sleep-disturbing effect of GSM 900 and WCDMA exposure.
    Journal of Sleep Research 03/2011; 20(1 Pt 1):73-81. · 3.04 Impact Factor
  • European Psychiatry 01/2011; 26:1564-1564. · 3.29 Impact Factor
  • European Psychiatry 01/2011; 26:1881-1881. · 3.29 Impact Factor
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    ABSTRACT: ELECTROPHYSIOLOGICAL NEUROIMAGING REVEALS RE-SET, RE-ACTIVATION AND REPROCESSING OF PROCEDURAL AND DECLARATIVE MEMORY TRACES DURING POSTTRAINING SLEEP P. Anderer (1,2), G. Gruber (2), S. Parapatics (2), C. Sauter (3), G. Kloesch (3), M. Schabus (4), W. Klimesch (4), G.M.Saletu-Zyhlarz (1), B. Saletu (1), J. Zeitlhofer (3) 1) Department of Psychiatry and Psychotherapy, Medical University of Vienna, 2) The Siesta Group Schlafanalyse GmbH, 3) Department of Neurology, Medical Universitiy of Vienna, Vienna, 4) Department of Physiological Psychology, University of Salzburg, Salzburg, Austria Objectives: Experience-dependent cortical plasticity observed during post-training sleep has been hypothesized to be part of the global process of memory consolidation. Combining the temporal resolution of microstructure detectors and the spatial resolution of low-resolution brain electromagnetic tomography (LORETA) makes it possible to investigate when and where the experience-dependent reactivation occurs under normal (undisturbed) sleeping conditions. Methods: After an adaptation night, in the 2nd and 3rd night 48 young healthy volunteers were randomly assigned either to a control condition or to an experimental condition (declarative Memory task: paired-associate word list or procedural memory task: mirror tracing). Sleep stages and sleep microstructures (slow waves, spindles and theta bursts) were detected automatically by means of the Somnolyzer 24x7. Changes in LORETA sources (experimental minus control night) were correlated with changes in memory performance (morning minus evening recall). Results: Overnight improvements in the mirror tracing task were correlated with increased slow-wave sources in the right posterior parietal cortex (r=.70,p< 0.01) during NREM sleep and with desynchronized (r=-.76,p< 0.01) and synchronized (r=.62,p< 0.01) rolandic mu rhythm sources during periods with theta bursts in REM sleep. Overnight improvements in the declarative memory task were significantly correlated with increased spindle sources (r= .52, p< .01) in frontal, temporal and cingulate brain regions. Conclusions: The present study supports the hypotheses of (1) a use-dependent reset of synaptic plasticity during slow-wave sleep (restorative function), (2) an experience-dependent reactivation during spindle episodes (stabilizing function) and (3) an off-line neuronal reprocessing during REM sleep (improvement without further training for novel tasks)
    European Psychiatry - EUR PSYCHIAT. 01/2011; 26:1849-1849.
  • Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2011; 122.
  • European Psychiatry - EUR PSYCHIAT. 01/2011; 26:1776-1776.
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    ABSTRACT: Previous studies have shown abnormal electroencephalography (EEG) in Huntington's disease (HD). The aim of the present investigation was to compare quantitatively analyzed EEGs of HD patients and controls by means of low-resolution brain electromagnetic tomography (LORETA). Further aims were to delineate the sensitivity and utility of EEG LORETA in the progression of HD, and to correlate parameters of cognitive and motor impairment with neurophysiological variables. In 55 HD patients and 55 controls a 3-min vigilance-controlled EEG (V-EEG) was recorded during midmorning hours. Power spectra and intracortical tomography were computed by LORETA in seven frequency bands and compared between groups. Spearman rank correlations were based on V-EEG and psychometric data. Statistical overall analysis by means of the omnibus significance test demonstrated significant (p < 0.01) differences between HD patients and controls. LORETA theta, alpha and beta power were decreased from early to late stages of the disease. Only advanced disease stages showed a significant increase in delta power, mainly in the right orbitofrontal cortex. Correlation analyses revealed that a decrease of alpha and theta power correlated significantly with increasing cognitive and motor decline. LORETA proved to be a sensitive instrument for detecting progressive electrophysiological changes in HD. Reduced alpha power seems to be a trait marker of HD, whereas increased prefrontal delta power seems to reflect worsening of the disease. Motor function and cognitive function deteriorate together with a decrease in alpha and theta power. This data set, so far the largest in HD research, helps to elucidate remaining uncertainties about electrophysiological abnormalities in HD.
    Journal of Neurology 12/2010; 258(5):840-54. · 3.58 Impact Factor
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    ABSTRACT: 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.
    European Archives of Psychiatry and Clinical Neuroscience 11/2010; · 3.36 Impact Factor
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    ABSTRACT: The aim of this paper was to assess the prevalence of morning headaches in the Austrian general population and to analyse their relationship to daytime functioning and quality of sleep. In a nationwide survey, we recruited 1000 adults (478 men, 522 women, age over 14 years). For this study, we selected all subjects with self-reported morning headaches as well as controls matched for age, sex, size of hometown, level of education and marital status. Forty-eight persons reported morning headaches making a prevalence of 5% in the Austrian general population. Compared to controls, subjects with morning headaches reported more often daytime sleepiness (50% vs. 18.8%, p = 0.003), difficulties in staying awake (47.9% vs. 18.8%, p = 0.005) and falling asleep involuntarily (29.2% vs. 8.3%, p = 0.019). Moreover, they reported a longer sleep onset latency (26.5 ± 27.5 vs. 13.5 ± 13.5 min, p = 0.005), and more often sleep disturbances (58.3% vs. 14.6%, p < 0.001), tossing and turning around during the night (50.0% vs. 8.0%, p < 0.001), problems with sleep maintenance (64.6% vs. 22.9%, p < 0.001) and the symptom of restless legs (20.8% vs. 2.1%, p = 0.01). In addition, subjects with morning headaches felt less often refreshed in the morning (18% vs. 51%, p < 0.001) and reported regular use of medication more often (64.6% vs. 29.2%, p = 0.001) than controls. After correction for multiple testing, the differences in sleep maintenance, sleep disturbances and regular use of medication remained statistically significant. In conclusion, this is the first Austrian population-based controlled study to show that morning headaches afflict one out of 20 persons and are related to self-reported sleep problems.
    Wiener klinische Wochenschrift 10/2010; 122(19-20):579-83. · 0.81 Impact Factor
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    ABSTRACT: 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.
    Journal of Neural Transmission 10/2010; 117(11):1307-18. · 3.05 Impact Factor
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    ABSTRACT: 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.
    European Archives of Psychiatry and Clinical Neuroscience 10/2010; 261(4):267-75. · 3.36 Impact Factor
  • Clinical Neurophysiology 10/2010; 121. · 3.14 Impact Factor

Publication Stats

4k Citations
500.95 Total Impact Points

Institutions

  • 1970–2013
    • Medical University of Vienna
      • • Department of Psychiatry and Psychotherapy
      • • Universitätsklinik für Neurologie
      Wien, Vienna, Austria
  • 2009
    • Charité Universitätsmedizin Berlin
      • Department of Psychiatry and Psychotherapy
      Berlin, Land Berlin, Germany
  • 2008
    • Université de Caen Basse-Normandie
      Caen, Lower Normandy, France
  • 2005–2008
    • University of Salzburg
      • Division of Physiological Psychology
      Salzburg, Salzburg, Austria
  • 1987–2006
    • University of Vienna
      • Department of Neurobiology
      Vienna, Vienna, Austria
  • 2004
    • Hospital de la Santa Creu i Sant Pau
      Barcino, Catalonia, Spain
  • 2003
    • University of Innsbruck
      Innsbruck, Tyrol, Austria
  • 2002
    • Alexandria University
      Al Iskandarīyah, Alexandria, Egypt
    • Austrian Research Institute for Artificial Intelligence
      Wien, Vienna, Austria
    • Autonomous University of Barcelona
      • Departamento de Farmacología, Terapéutica y Toxicología
      Cerdanyola del Vallès, Catalonia, Spain
  • 1991
    • Psychiatrische Universitätsklinik Zürich
      Zürich, Zurich, Switzerland
  • 1990
    • Western Psychiatric Institute and Clinic
      Pittsburgh, Pennsylvania, United States